Detailed Description
Further advantages and effects of the present application will become apparent to those skilled in the art from the disclosure of the present application, which is described by the following specific examples.
In the following description, reference is sometimes made to the accompanying drawings, which depict several embodiments of the application. It is to be understood that other embodiments may be utilized and that structural, electrical, and operational changes may be made without departing from the spirit and scope of the present application. The following detailed description is not to be taken in a limiting sense, and the scope of embodiments of the present application is defined only by the appended claims. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements or parameters in some examples, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another element or parameter. For example, a first robotic arm may be referred to as a second robotic arm, and similarly, a second robotic arm may be referred to as a first robotic arm, without departing from the scope of the various described embodiments. The first and second robotic arms are each described as one robotic arm, but they are not the same unless the context clearly indicates otherwise. The terms "or" and/or "as used herein are to be construed as inclusive, or meaning any one or any combination. Accordingly, "A, B or C" or "A, B and/or C" means any of A, B, C, A and B, A and C, B and C, A, B and C. An exception to this definition will occur only when a combination of elements, functions, steps or operations are in some way inherently mutually exclusive.
It will be understood that when a component or element is referred to as being "on" or extending "onto" another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or extending "directly onto" another element, there are no intervening elements present. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.
Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe one element, layer or region's relationship to another element, layer or region as illustrated in the figures. It will be understood that these terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. In the present application, the terms "vertical", "horizontal", "parallel" are defined to include the case of 10% of soil on the basis of the standard definition. For example, perpendicular generally refers to an included angle of 90 ° with respect to the reference line, but in the present application, perpendicular refers to a case including within 80 ° to 100 °.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Unless explicitly stated otherwise, comparative quantitative terms such as "above" and "below" are intended to encompass equivalent concepts. As an example, "above" may mean not only "greater than" in a mathematical sense, but also "equal to".
In view of the technical problems mentioned in the background art, the application discloses a 3D printing robot and 3D printing equipment, wherein a feeding system with a storage device and a melt extrusion device is arranged on a mechanical arm of the 3D printing robot, so that the buffering of particles and the melting of the particles are realized, and the conveying path of molten fluid is shortened to a certain extent; furthermore, the feeding pipeline used for communicating the melt extrusion device and the printing head is arranged between the mechanical arm and the printing head, so that the short-path supply of the fluid material from the melt extrusion device to the nozzle of the printing head is realized, the feeding pipeline with the rigidity smaller than that of the mechanical arm is designed, and the feeding pipeline is arranged between the fourth shaft joint of the robot body and the printing head, so that the flexibility of the movement of each mechanical arm in the printing process of the robot is ensured, the instantaneous pressure change caused by the fluid material can be reduced, the uniform supply of the fluid material is ensured, and the temperature control device is arranged on the pipeline body of the feeding pipeline, so that the viscosity increase and even the stagnation caused by the cooling of the fluid material due to the heat loss in the long-distance conveying process can be avoided, the blockage of the fluid material in the pipeline body and the printing head is avoided, the continuous supply of the fluid material is ensured, and the 3D printing efficiency and the printing quality of objects are further improved.
In any of the embodiments provided herein, the 3D object may be a 3D model obtained by stacking 3D printing materials layer by layer using a 3D printing technique, which may be, for example, a cartoon or animal sculpture, a building such as a corporate foreground, an outdoor artistic modeling, or the like. The 3D printing technique may be, for example, a fused deposition modeling technique based on fusible particulate material, and in this example, the 3D printing material from which the 3D object is constructed may be, for example, a thermoplastic material. The thermoplastic material may comprise, for example, a polymeric composite printing material of nylon, paraffin, cast wax, elastomer, metal, ceramic, etc., which may be heated to a flowable or semi-flowable state in powder or pellet form, and then deposited and cooled layer by layer to form a 3D object.
In some embodiments, referring to fig. 1 and 2, a schematic structural diagram of a 3D printing apparatus according to the present application is shown, and as shown in the drawings, the 3D printing apparatus includes a forming chamber 1, a printing platform 2, a 3D printing robot 3, and a log reduction robot 4.
The 3D printing apparatus of the present application is described in detail below.
The forming chamber 1 is used for providing a closed forming space for a 3D printing job. It will be appreciated that fused deposition modeling printing techniques are relatively temperature sensitive, and when a 3D printing material needs to be fused and extruded, it needs to be heated to a melting point to form a semi-fluid state, and when a fused 3D printing material is extruded onto a printing platform, it needs to be cooled to a temperature below the melting point to cause the printed layers to be solidified and shaped, and therefore, the shaping chamber 1 needs to be arranged in a closed form to build a closed internal environment to reduce the effect of air flow outside the shaping chamber on the 3D printing job, and to make the temperature of the internal environment constant to facilitate temperature control.
To construct a constant temperature environment within the forming chamber, in one embodiment, the forming chamber 1 may be configured as a composite structure having multiple layers of materials, for example, its outer layer contacting the external environment may be configured as metal or high strength plastic to provide rigid support to the forming chamber. The inner layer that contacts the internal environment of the 3D print job may be configured as a thermal insulation material, such as polyurethane foam, polycarbonate sheets, aluminum silicate fibers, or mineral wool, to reduce heat loss from the internal environment.
In an embodiment, please refer to fig. 3 in combination with fig. 1 and 2, wherein fig. 3 is a schematic structural diagram of a forming chamber according to an embodiment of the present application, and a cross section of the forming chamber 1 in a horizontal direction is a symmetrical hexagonal structure with four obtuse angles and two right angles as shown in the drawing. Specifically, the six corners located within the hexagonal structure are angle a, angle b, angle c, angle d, angle e, angle f, respectively, in the clockwise direction. The four obtuse angles are an angle b, an angle c, an angle d, and an angle e, respectively, and for convenience of distinction, the angle b, the angle c, the angle d, and the angle e may be described as a first obtuse angle b, a second obtuse angle c, a third obtuse angle d, and a fourth obtuse angle e, respectively. The two right angles are an angle a and an angle f, respectively, which are also described as a first right angle a and a second right angle f, respectively, for ease of distinction. In the example shown in fig. 3, the six corners are all angular, and in other examples, to avoid colliding with an operator, the six corners may be configured as rounded corners.
In one embodiment, as shown in fig. 3, an inlet 13 of the forming chamber 1 is provided on one side of the forming chamber 1, and the width of the inlet 13 is larger than the rotation diameter of the printing platform 2. The rotation diameter may be described in the following embodiments, and will not be described here. The access opening 13 may be used for operator access, and loading and unloading of various devices, structures, components, 3D objects, etc. within the 3D printing apparatus. In order to ensure that the forming chamber 1 is able to provide a closed internal environment during 3D printing, in one implementation the access opening 13 may be configured as a revolving door which is hinged to the forming chamber 1 such that the revolving door is able to effect opening and closing of the forming chamber 1 by a rotational movement. Of course, in other certain implementations, sliding doors, automatic doors, and the like may also be configured.
In an embodiment, as shown in fig. 2, the 3D printing robot 3 is disposed between a first right angle a and a first obtuse angle b in the forming chamber 1, and the log reduction robot 4 is disposed between a second right angle f and a fourth obtuse angle e in the forming chamber 1. In another embodiment, as shown in fig. 1, the 3D printing robot 3 is disposed between a first right angle a and a first obtuse angle b in the forming chamber 1, and the log reduction robot 4 is disposed between a second obtuse angle c and a third obtuse angle D in the forming chamber 1. However, the present application is not limited thereto, and the 3D printing robot 3 and the material reduction robot 4 may be further disposed at other positions in the forming chamber 1, and may be specifically determined according to actual production requirements. It should be noted here that the configuration of the forming chamber 1 is shown in fig. 1 to 3 by way of a schematic representation only, and in this example, in order to reduce the area of the forming chamber 1 as much as possible, to reduce the heating range, thereby increasing the heat transfer speed, and thus facilitating the control of the temperature in the forming chamber, the side length of the hexagonal structure is set according to the widths of the 3D printing robot 3 and the log reduction robot 4, and in some other examples, the forming chamber 1 may be set in other shapes than rectangular and hexagonal, such as pentagonal, circular, etc., which is determined according to the actual production requirements, and the present application is not limited thereto.
In one embodiment, as shown in fig. 3, a first accessory device arrangement area 11 is disposed outside a side formed between a first obtuse angle b and a second obtuse angle c in the forming chamber 1, and a second accessory device arrangement area 12 is disposed outside a side formed between a third obtuse angle d and a fourth obtuse angle e in the forming chamber 1. The outer side of the side refers to an outer area of the forming chamber corresponding to one side of the hexagonal structure formed by the forming chamber 1, for example, the outer side of the side formed between the first obtuse angle b and the second obtuse angle c refers to an area located outside the forming chamber 1 corresponding to a side m shared by the first obtuse angle b and the second obtuse angle c. The first accessory device configuration area 11 is used for configuring a first accessory device, and the second accessory device configuration area 12 is used for configuring a second accessory device. It should be noted that, the first accessory device configuration area 11 or the second accessory device configuration area 12 may be configured separately or may be configured together, and of course, the first accessory device configuration area 11 or the second accessory device configuration area 12 may not be provided, and the present application is not limited thereto, specifically determined according to the needs of actually configuring the first accessory device and the second accessory device.
In an embodiment, the first accessory device or the second accessory device may be configured as a power device, e.g. as a generator, providing a stable power supply for the 3D printing device. In another embodiment, the device may be configured as an imaging device for observing the 3D printing process in real time outside the molding chamber, so as to ensure the normal operation of the 3D printing robot and the subtractive robot, but not limited thereto, and the specific configuration thereof is determined according to the actual production requirements.
In some embodiments, the 3D object may have a large size, so that it is difficult to ensure constant internal temperature and external atmosphere temperature between stacked layers, which makes the formed stacked layers receive different thermal stresses, resulting in internal stress aggregation of the 3D object and uneven shrinkage, so that the 3D object may warp, deform, and the like. In view of this, an atmosphere temperature control system is disposed in the forming chamber 1, and the temperature control system may be configured to include a cold-hot air circulation convection device, where the cold-hot air circulation convection device is used to make the temperature of the stacked layers of the 3D object constant, so as to avoid the problems of warpage, deformation, and the like of the 3D object.
Of course, in some other embodiments, an air conditioner and a fan may be configured in the forming chamber 1, so as to control the temperature of the internal environment in a suitable range, or a dehumidifier may be configured to adjust the humidity of the internal environment, so as to ensure that each device, structure and component in the 3D printing apparatus can work normally, and ensure that the 3D printing material can be in an ideal state, so as to ensure that the 3D printing job can be performed smoothly. In addition, an air purifying system can be arranged in the forming chamber 1 to remove gas and particles generated in the printing process in time, so that the cleaning of the internal environment is ensured. Those skilled in the art may select a particular configuration based on an actual design within the scope of the present application.
In one embodiment, the printing platform 2 is rotatably disposed in the forming chamber 1 for carrying the formed 3D object. In the example shown in fig. 3, the printing table 2 is configured as a circular table having a diameter ranging from 2800mm to 3600mm, for example, about 2800mm, 2900mm, 3000mm, 3100mm, 3200mm, 3300mm, 3400mm, 3500mm, 3600mm, or the like. In some other examples, the printing platform 2 may be configured in other shapes than a circle, such as a rectangle or a hexagon, where the printing platform 2 has a rotation diameter and a rotation center, the rotation diameter refers to a diameter of a circle range occupied by the printing platform 2 when rotated, and the rotation center refers to a center of a circle range occupied by the printing platform 2 when rotated. It should be understood that, when the printing platform is configured as a circular platform, the rotation diameter and the rotation center are the diameter and the center of the printing platform, and in the following embodiments, the description will not be repeated when referring to the rotation diameter and the rotation center.
In one embodiment, to achieve rotation of the printing platform 2, a rotating shaft (not shown) is provided on the printing platform 2, and a grating encoder and a servo motor are provided on the rotating shaft. The grating encoder is used to provide a measurement of the rotation angle of the printing platform 2 and feedback the servo motor is used to provide rotational power to the shaft, which in some examples may be rotated clockwise and counterclockwise. In certain embodiments, the servo motor may also be replaced by a hydraulic motor.
In one embodiment, a grating encoder includes a grating encoder housing, a grating encoder disk, and a read head. The grating encoder housing is disposed about the rotational axis and houses the grating encoder disk and the read head. The grating encoder disk is provided with grating strips, when the rotating shaft rotates, the grating strips on the grating encoder disk are shielded along with the grating strips and generate corresponding optical signals, the reading head can comprise an optical measuring device such as a camera, rotation information of the rotating shaft is obtained through interpretation of the generated optical signals, and the information is fed back to a control device, so that real-time control on the rotation of the printing platform is realized.
In an embodiment, the printing platform 2 is provided with a brake positioner, and the brake positioner is used for stopping the rotary motion of the printing platform 2, and meanwhile, the printing platform 2 can be prevented from rotating due to external acting force when stopping the motion, so that the printing precision is further ensured. In one implementation, the brake positioner may be configured to include a brake actuator and a locking pin, the brake actuator locking the locking pin to the print platform by controlling movement of the locking pin such that rotational movement of the print platform is stopped. The brake actuator may be, for example, a motor.
In one embodiment, the printing platform 2 is provided with a temperature control assembly for controlling the temperature of the molding surface. The molding surface is the surface of the printing platform, which is contacted with the printing layer of the 3D object. In one example, the temperature control assembly includes a temperature sensor for monitoring the temperature of the molding surface in real time, a temperature controller for providing thermal energy to increase the temperature of the molding surface, which may be, for example, a resistive heater, a heating winding, a heating cable, etc., and a heating element for providing a cooling effect to decrease the temperature of the molding surface, which may be, for example, a fan, a cooling water circulation system, a refrigerant circulation system, etc. Specifically, when the temperature sensor monitors that the temperature of the molding surface is lower than a threshold value, the temperature controller controls the heating element to operate until the temperature of the molding surface reaches the threshold value, and when the temperature sensor monitors that the temperature of the molding surface is higher than the threshold value, the temperature controller controls the cooling element to operate until the temperature of the molding surface reaches the threshold value. The threshold value is a temperature value or a temperature range which is preset by an operator and is lower than the melting point of the 3D printing material, so that the printing layer can be solidified and molded when being deposited on the molding surface.
In one embodiment, the printing platform 2 may perform zone temperature control on the molding surface, and in particular, please refer to fig. 4, which illustrates a schematic diagram of the printing platform performing zone temperature control according to an embodiment of the present application. As shown in fig. 4, the printing platform 2 may be divided into eight temperature areas, one of which is indicated by the letter t in fig. 4, and each temperature area has an independent temperature control component, so as to implement independent temperature control of each temperature area. Further, a heat insulating layer or a heat insulating material can be arranged between each two temperature areas, so that heat transmission between the temperature areas is reduced, and the temperature control precision is improved. Of course, any number of temperature zones may be provided on the printing platform 2, and those skilled in the art may select an appropriate number of temperature zones according to the actual design in light of the present disclosure. It should be noted that the temperature control assembly on the printing platform 2 may cooperate with the atmosphere temperature control system in the forming chamber 1 described in the foregoing embodiment, so as to ensure that the 3D printing material for forming the 3D object has a temperature that is favorable for forming when contacting the printing platform 2, and avoid warpage or deformation of the 3D object caused by temperature difference.
Referring to fig. 5 in combination with fig. 1, fig. 5 is a schematic structural diagram of a 3D printing robot according to an embodiment of the application. As shown in fig. 1 and 5, the 3D printing robot 3 is disposed on a first side of the printing platform 2, and is configured to deposit powder or granular material onto the printing platform 2 according to a first printing path after melting to form the 3D object layer by layer, and includes a robot body 30, a feeding system 32, a printhead 33, and a feeding pipeline 34.
Wherein the first side of the printing platform 2 is the position where the 3D printing robot 3 is located as shown in fig. 1, that is, as described in the foregoing embodiment, the 3D printing robot 3 is disposed between the first right angle and the first obtuse angle in the forming chamber 1. In an implementation, the 3D printing robot 3 may be fixedly disposed at a first side of the printing platform 2, and in order to achieve the fixation of the 3D printing robot 3, it may further include a first base 35. The first base 35 is used as a base component of the 3D printing robot 3 for carrying the robot body 30, and in an example, the first base 35 has a relatively large weight to provide a firm overall stability, so as to reduce mechanical vibration and ensure that the 3D printing robot remains balanced. The material of the first base 35 includes, but is not limited to, cast iron, alloy, carbon structural steel, so that the first base 35 has sufficient rigidity and strength to impart sufficient durability and load-bearing capacity to the first base 35. It should be appreciated that the first base 35 may serve as a seat for the robot body 30 in the 3D printing robot 3, and the specific structure thereof may be changed based on different functional requirements or structural requirements.
The robot body 30 includes a first mechanical arm 31 and a plurality of shaft joints, and the end of the first mechanical arm 31 is configured with a printable head 33 to provide a degree of freedom of movement of the print head 33 in space, thereby improving the accuracy of the print head 33. In the present embodiment, the first robot arm 31 is pivotally connected to the shaft joint, which enables the print head 33 to generate a rotational rotation about the axis of the first robot arm 31 or a hinged rotation perpendicular to the axis of the first robot arm 31. For example, the 3D printing robot 3 may be configured as a six-axis industrial robot provided with six axis joints to provide six-axis rotation, which may be configured on the print head 33 and the first robotic arm 31, respectively, alone or in combination.
In one embodiment, as shown in fig. 5, the first robot arm 31 has opposite proximal and distal ends, the proximal end of which is connected to the first base 35, and the distal end of which is configured with a printhead 33. It should be noted that, in the following embodiments, in order to clearly describe the relative positions of the components, structures, assemblies, mechanisms, components, or devices in the 3D printing robot, the components, structures, assemblies, mechanisms, components, or devices are distinguished based on the proximal end and the distal end of the first mechanical arm, where a side relatively close to the proximal end of the first mechanical arm is referred to as a proximal end (may also be referred to as a proximal end), and a side relatively close to the distal end of the first mechanical arm is referred to as a distal end (may also be referred to as a distal end).
It should be understood that the first mechanical arm 31 refers to a robotic arm including a plurality of mechanical joint arms in the present application, for example, in an embodiment in which the 3D printing robot is a six-axis industrial robot, the first mechanical arm 31 includes a first mechanical joint arm 310 and a second mechanical joint arm 311.
The six shaft joints in fig. 5 are a first shaft joint 312, a second shaft joint 313, a third shaft joint 314, a fourth shaft joint 315, a fifth shaft joint 316, and a sixth shaft joint 317, respectively. Wherein a first shaft joint 312 is coupled to the first base 35, which provides rotational rotation about an axis of the first base 35, a second shaft joint 313 is coupled to a proximal end of the first mechanical arm 310 and is proximate to the first shaft joint 312, and the second shaft joint 313 provides hinged rotation about an axis perpendicular to the first mechanical arm 310 (which may correspond to the axis of the second shaft joint 313). The third shaft joint 314 is connected to the proximal end of the second mechanical joint arm 311, providing a hinged rotation about an axis perpendicular to the second mechanical joint arm 311 (which may correspond to the axis of the third shaft joint 314). A fourth shaft joint 315 is connected to the distal end of the second mechanical arm 311, and provides rotational rotation about the axis of the second mechanical arm 311, and a fifth shaft joint 316 and a sixth shaft joint 317 are cooperatively provided to the print head 33 to provide hinged rotation and rotational rotation of the print head 33, respectively.
In some other examples, the 3D printing robot may also be configured as a five-axis industrial robot provided with five axis joints to provide five-axis rotation. It should be noted here that the shaft joints may be configured in any number to meet the actual production needs, and the present application is not limited thereto, and for convenience of description and illustration, the following embodiment is described by taking the 3D printing robot 3 as a six-axis industrial robot as an example, and should not be construed as limiting the present application.
In an embodiment, the first mechanical arm 31 may be configured to be elongated or thick and short approximately cylindrical, and may be made of a suitable rigid material, such as a lightweight high-strength metal alloy such as an aluminum alloy, a magnesium alloy, or a carbon composite material.
In one embodiment, each of the shaft joints includes an angular encoder that provides information about the relative rotation of the first robotic arm 31, and the encoders of all of the shaft joints provide information that determines where the printhead is accumulating 3D printing material. Further, control of the 3D print job may be achieved by a control device based on the rotation information provided by the encoders.
In an embodiment in which the 3D printing robot is configured as a six-axis industrial robot, the control device is configured to control the six axis joints to rotate, thereby controlling the first mechanical arm 31 to move along the first motion path, and further controlling the print head 33 to move along the first print path, so as to implement layer-by-layer deposition of the 3D printing material. The first movement path refers to a movement path of the first mechanical arm 31 during the whole printing process, the movement path is different in space on each mechanical joint arm, the first printing path refers to a movement path when the printing head 33 deposits the 3D printing material during the movement of the first mechanical arm 31 along the first movement path, and further, the first printing path may be a movement path of the printing head. In order to form a distinction with the second control device included in the subtractive robot in the subsequent embodiments, the control device included in the 3D printing robot is referred to as a first control device, and the first control device and the second control device are not described in detail later.
In an embodiment, the first control device includes a processing unit, a storage unit, and a plurality of interface units. Each interface unit is respectively connected with a device or a component or a mechanism which is independently packaged in the 3D printing robot such as the first mechanical arm, the printing head and the like and transmits data through an interface. The first control device also comprises at least one of a prompt device, a man-machine interaction device and the like. The interface unit determines its interface type according to the connected device or component or mechanism, including but not limited to a universal serial interface, a video interface, an industrial control interface, a wireless communication port, etc. The storage unit is used for storing a printing program, and the processing unit is connected with the storage unit and is used for controlling each part or assembly or structure coordination in the 3D printing robot 3 to realize 3D printing operation on the printing head 33 when the printing program is executed.
As shown in fig. 5, the feeding system 32 is disposed on the first robot arm between the third axis joint 314 and the fourth axis joint 315 of the robot body 30, that is, on the second robot arm 311. Specifically, to maximize the ease of loading of the second robotic arm 311 and avoid interfering with the flexibility of the second robotic arm 311 in moving, the feed system 32 may be positioned proximate to the third axis joint 314. Of course, in other embodiments, the feeding system 32 may be disposed on the first mechanical arm 310 and the second mechanical arm 311 at the same time, and be carried by the first mechanical arm 310 and the second mechanical arm 311 at the same time. The material of the feeding system 32 includes, but is not limited to, metal, and the connection manner of the feeding system and the mechanical arm includes, but is not limited to, welding and integrally forming connection, and the specific configuration manner and the configuration position are determined according to the actual production requirements, which is not limited in the application.
In one embodiment, as shown in fig. 5, the feed system 32 includes a hopper 321 and a melt extrusion device 322, wherein the hopper 321 is used for buffering 3D printing material such as powder or granule, and the melt extrusion device 322 is used for melting the 3D printing material into fluid material and pressurizing out.
In an embodiment, the stocker 321 is connected to the external silo through a gas path pipe, and a portion of the gas path pipe is disposed in the first mechanical arm between the second shaft joint 313 and the third shaft joint 314 of the robot body 30 in a penetrating manner. That is, the air path pipe penetrates the first mechanical joint arm 310. In this embodiment, the external silo is used for long-term and large-scale storage of the particles to ensure sufficient raw material supply, which delivers the particles to the hopper 321 through the gas path pipeline, and the hopper 321 is used for temporarily storing the particles, and at the same time, the flow rate of the particles can be adjusted to ensure that the subsequent delivery of the particles can be smoothly performed. In one example, the air path conduit may have a negative pressure air flow generated therein by an air source device, such as a blower or compressor, to push the particulate material into the air path conduit.
In one embodiment, the pellets buffered in the hopper 321 are fed to the melt extrusion device 322 by a feed screw disposed at the bottom of the hopper 321. In one example, the feed screw may uniformly and continuously convey the pellets from hopper 321 to melt extrusion device 322 by a rotational motion. The feed screw may be configured to include a screw body, a helical blade, a helical flight, and a screw drive, for example. The screw body can be made of metal, and the surface of the screw body is smooth, so that the granular materials can be smoothly conveyed. The helical blades and the helical threads are arranged in a helical manner along the axis of the screw body so as to push the particles to move in the rotating process, and the pitch between the helical blades and the helical threads can be determined according to the properties of the particles, so that the application is not limited. The screw drive may be configured, for example, as a drive motor for powering the rotation of the screw body.
In one embodiment, referring to fig. 6 in combination with fig. 5, fig. 6 is a schematic structural diagram of a melt extrusion apparatus according to an embodiment of the present application, as shown in fig. 5 and 6, the melt extrusion apparatus 322 includes a melt cylinder 3221, a plurality of heaters, and a screw mechanism (not shown), wherein the melt cylinder 3221 is in communication with a hopper 321, the plurality of heaters are sleeved on a circumferential side of the melt cylinder 3221, and the screw mechanism is disposed inside the melt cylinder 3221 and along an axial direction of the melt cylinder 3221, and is used to drive molten fluid material to be pressurized and extruded toward an outlet direction of the melt cylinder 3221 when rotated. In the embodiment shown in fig. 5 and 6, the melt barrel 3221 is configured to receive particulate material conveyed by a feed screw disposed at the bottom of the hopper 321, the plurality of heaters are configured to heat and melt the particulate material into a fluid material, the screw mechanism is rotatable to agitate and mix the unmelted particulate material and the melted fluid material to achieve sufficient melting of the particulate material, and to pressurize and extrude the melted fluid material toward the outlet of the melt barrel 3221.
To power the rotational movement of the screw mechanism, in one embodiment, melt extrusion device 322 includes a drive motor 3225 disposed at the proximal end of melt barrel 3221 and in communication with the screw mechanism. In one example, the drive motor 3225 may further include a speed regulator that may control the rotational speed of the drive motor, and thus the rotational speed of the screw mechanism, to control the speed at which the fluid material is extruded. In an embodiment, the driving motor 3225 is, for example, a servo motor, and the speed regulator is, for example, a speed reducer for linking the servo motor, and of course, in other embodiments, the speed regulator is, for example, a control circuit of the servo motor to control the rotation speed of the servo motor.
In other certain embodiments, the screw mechanism may further include a screw body and a screw blade on the basis of the driving motor 3225, and the specific structure and function of the screw body and the screw blade may be referred to the description in the foregoing embodiments, which is not repeated herein.
Considering that the melting barrel of the main body part of the 3D printing robot melt extrusion device cannot be designed to be longer along with the movement of the mechanical arm of the robot in the printing process, namely, the melting barrel serving as the main body of the melt extrusion device cannot be arranged on two mechanical joint arms at the same time (otherwise, the movement freedom of the mechanical arm is influenced), the melting barrel can only be arranged on one mechanical joint arm, namely, the second mechanical joint arm, so as to avoid the influence on the plasticizing uniformity of the granular material due to the shortening of the heating path from the granular material to the extruded fluid material.
In this embodiment, as shown in fig. 5 and 6, the heater includes a pre-heater 3222 and a main heater, wherein the pre-heater 3222 is sleeved on a middle area of the melting barrel 3221, and the main heater is sleeved on a distal end of the melting barrel 3221. It will be appreciated that the pre-heater 3222 is used to initially heat the particulate material entering the melt barrel 3221 over a temperature range to raise the temperature of the particulate material to near a molten state, and the main heater is used to further raise the temperature of the material over a temperature range to substantially melt the material. The pre-heater 3222 cooperates with the main heater to gradually increase the temperature of the material, thereby reducing thermal shock and temperature fluctuations to ensure uniform heating of the material.
In one example, the heating temperature of the preheater 3222 is in the range of 80-120 ℃, such as may be approximately 80℃、81℃、82℃、83℃、84℃、85℃、86℃、87℃、88℃、89℃、90℃、91℃、92℃、93℃、94℃、95℃、96℃、97℃、98℃、99℃、100℃、101℃、102℃、103℃、104℃、105℃、106℃、107℃、108℃、109℃、110℃、111℃、112℃、113℃、114℃、115℃、116℃、117℃、118℃、119℃、 or 120 ℃, etc.
In one embodiment, as shown in FIG. 6, the primary heaters include a first primary heater 3223 and a second primary heater 3224, the first primary heater 3223 is sleeved on the distal end of the melt barrel 3221, and the second primary heater 3224 is positioned between the pre-heater 3222 and the first primary heater 3223. Specifically, the second main heater 3224 is used to further heat the material heated by the preheater 3222 so as to completely melt the material into a fluid material. In one example, the heating temperature of the second main heater 3224 is in the range of 120-220 ℃, such as may be about 120℃、125℃、130℃、135℃、140℃、145℃、150℃、155℃、160℃、165℃、170℃、175℃、180℃、185℃、190℃、195℃、200℃、205℃、210℃、215℃、 or 220 ℃, etc.
The first main heater 3223 is used to maintain the material heated by the second main heater 3224 in a molten fluid state so that the temperature of the fluid material is constant. In one example, the heating temperature of the first main heater 3223 is in the range of 220 ℃ to 240 ℃, such as may be about 220℃、221℃、222℃、223℃、224℃、225℃、226℃、227℃、228℃、290℃、230℃、231℃、232℃、2330℃、234℃、235℃、236℃、237℃、238℃、239℃、 or 240 ℃, or the like. It should be noted that the pre-heater 3222, the second main heater 3224, and the first main heater 3223 may be adjusted according to the properties of the granular materials to be melted in the technical teaching of the present application.
In order to maintain the heating temperatures of the preheater 3222 and the main heater within the respective heating temperature ranges, in one embodiment, one or more temperature sensors corresponding to the heating regions of the preheater 3222 and the main heater, respectively, are provided on the melt extrusion apparatus 322. The temperature sensors are used to monitor the material temperatures in the heating areas of the pre-heater 3222 and the main heater, respectively, in real time. Suitably, the melt extrusion apparatus 322 may be further configured with a temperature controller and cooling means for providing cooling to the melt barrel section between the preheater 3222 and the accumulator 321, preventing the feed inlet pellets from softening the throat upon heat, which may be, for example, a cooling water circulation means, a refrigerant circulation means, etc. Specifically, when the temperature sensor detects that the material temperature in each heating area is lower than the corresponding heating temperature range, the temperature controller controls the preheater 3222 and the main heater to operate until the material temperature in each heating area is within the corresponding heating temperature range, and maintains the set temperature in a thermal compensation manner. When the temperature sensor detects that the material temperature is higher than the corresponding heating temperature range, the temperature controller controls the heater to stop working or the auxiliary cooling device to operate until the material temperature in each heating area is located in the corresponding heating temperature range again.
In some embodiments, the one or more temperature sensors are connected to a computer system of a 3D printing robot that controls the one or more heaters according to the temperatures reported by the one or more temperature sensors. For example, the computer system may control one or more heaters to adjust the temperature of the material within each of the heaters, feed lines, and/or nozzles. In some embodiments, the system operates as a closed loop feedback system to maintain an approximately constant temperature of the device or device components (i.e., cartridge, nozzle, or feed line). The temperature of the materials within the different components of the device may be the same or different. In some embodiments, the feedback system is controlled using a proportional-integral-derivative (PID) controller, a Bang-Bang controller, a predictive controller, a fuzzy control system, or any other suitable algorithm.
In one embodiment, feed system 32 includes a pressure sensor for detecting the pressure of fluid material within the extrusion channel of printhead 33. Wherein the structure and function of the extrusion channel can be found in the description of the following embodiments. Types of pressure sensors include, but are not limited to, piezoelectric sensors, strain gauge sensors, and capacitive sensors. According to the real-time monitoring of the pressure fluctuation in the whole feeding process by the pressure sensor, the speed of the extruded molten fluid material can be controlled, and the speed of the material deposited on the printing platform is further controlled. In this embodiment, the pressure sensor is also configured with a computer feedback system that may use a proportional-integral-derivative (PID) controller, a Bang-Bang controller, a predictive controller, a fuzzy control system, an expert system controller, or any other suitable control algorithm. In some embodiments, the sampling rate of the pressure sensor is about 20ms or more, such as about 10ms or more, about 5ms or more, or about 2ms or more. In some embodiments, the pressure of the fluid material within the extrusion channel is controlled to be within a preset target pressure.
As described above, the granular materials are conveyed to the accumulator 321 through the air channel pipeline from the external bunker, and then conveyed to the melt extrusion device 322 through the feeding screw arranged at the bottom of the accumulator 321, the melt extrusion device 322 heats and melts the granular materials into fluid materials through the preheater 3222 and the main heater, and the screw mechanism positioned inside the melt extrusion device 322 extrudes the fluid materials under pressure. The fluid material is then output to the printhead 33 via the feed line 34.
As shown in fig. 5, the feeding line 34 is disposed between the end of the melt barrel 3221 and the print head 33, and the feeding line 34 has no physical connection with other parts of the robot body 30 except that both ends of the feeding line 34 are physically connected with the melt barrel 3221 and the print head 33, so that the feeding line 34 does not limit the degrees of freedom of the robot joint arm/mechanical arm. In this embodiment, the axis of the start end of the feeding pipe 34 extends transversely to be almost perpendicular to the axis of the melt barrel 3221, as shown in fig. 6, so that the feeding pipe 34 extends in a direction away from the second mechanical arm so as not to affect the movement track or movement route of the second mechanical arm 311 and the fourth shaft joint 315 and the print head 33.
In the present embodiment, the length of the feeding line 34 is greater than the maximum movement distance between the fourth axis joint 315 of the robot body 30 and the print head 33. It should be understood that in the example in which the 3D printing robot is configured as a six-axis industrial robot, the print head 33 located at the end of the first mechanical arm has a plurality of degrees of freedom in directions in space by means of the movement of the plurality of joints and the joint arms. In the present embodiment, the length of the feeding pipeline 34 is greater than the maximum distance between the fourth shaft joint 315 and the print head 33, so that the movement of the print head 33 in space can be prevented from being limited, and the print head 33 can not generate additional resistance in the printing process, thereby ensuring the printing precision.
In one embodiment, the feed line 34 includes a line body and a temperature control device. The pipe body has a second stiffness and, correspondingly, the first arm 31 has a first stiffness. The rigidity refers to the capability of the first mechanical arm 31 or the pipeline body to resist elastic deformation when being stressed, and is used for representing the difficulty of deformation of the first mechanical arm 31 or the pipeline body, the rigidity is determined by the material and the structure of the rigidity body, the larger the rigidity is, the stronger the capability of the rigidity body to resist deformation is, and the smaller the rigidity is, the weaker the capability of the rigidity body to resist deformation is. In an example, the second stiffness is less than the first stiffness. It should be understood that the pipe body having the second stiffness smaller than the first stiffness of the first mechanical arm 31 means that the first mechanical arm 31 cannot be deformed by the force applied to the first mechanical arm 31 when the pipe body is deformed. That is, the pipe body may be configured as a hose structure. It should be noted that, when the melt extrusion device 322 and the print head 33 are connected, the pipe body needs to be adjusted in direction, so that the pipe body is convenient to install due to the smaller rigidity, in addition, the transient pressure change caused by the fluid material melted inside can be reduced due to the smaller rigidity, so that the smooth flow of the fluid material can be ensured, and the uniform extrusion of the fluid material by the print head can be ensured, furthermore, the pipe body with smaller rigidity is smaller than the first rigidity, so that the joint arm between the four-axis joint 315 of the first mechanical arm 31 and the print head 33 does not generate reaction force or traction force against the above movement when the joint arm rotates, stretches, contracts, and the like, so that the degree of freedom of the robot joint arm/mechanical arm is limited.
In one embodiment, the body of the feeding pipe 34 is a high temperature resistant rubber pipe, plastic pipe or metal bellows.
In another embodiment, the feed line 34 has a threaded support structure that is a high temperature hose. When the threaded support structure is a continuous support body with a preset length, namely the hose body is a threaded pipe, or a certain section of the high-temperature-resistant hose body is a threaded pipe, and when the threaded support structure is a spacing support body with a preset length, namely at least two partial pipe sections of the hose body are threaded pipes. Here, the threaded pipe is made of rubber or metal, and the threaded pipe can be easily bent under the action of external force, but cannot be shrunken under the action of negative pressure generated in the hose body, or shrunken at a bending position in large-amplitude bending, so that the fluxion of the fluid material is ensured in the process of conveying the molten fluid material.
In some embodiments, to better ensure the support of the threaded pipe, the threaded pipe may further be a steel wire threaded pipe, which is a three-layer structure. The inner and outer layers of the three-layer structure are made of plastic materials, such as PTFE (Polytetrafluoroethylene), and the middle layer is made of steel wire reinforced structures, such as spiral steel wires. Therefore, the steel wire reinforcing structure can ensure that the threaded pipe cannot collapse under the action of negative pressure to a greater extent, the supporting force is enhanced, and the fluxion of fluid is ensured.
In an embodiment, the temperature control device is disposed on the pipeline body. It will be appreciated that the distance between the melt extrusion apparatus and the printhead is relatively large, and that heat loss may occur in the fluid material during long distance transport, leading to gradual cooling and stagnation of the fluid material or increased viscosity of the fluid material due to heat loss, which in turn leads to clogging of the material in the pipe body. Therefore, in order to ensure that the fluid material can be stably conveyed into the printing head, the pipeline body is provided with the temperature control device.
In one implementation, the temperature control device is configured as a computer system or a temperature controller, a temperature sensor embedded in the pipeline body, and a heating wire wound on the pipeline body. Further, an auxiliary cooling element may be provided for rapidly reducing the temperature of the fluid material at which it is too high. Of course, the temperature control device may be configured in other ways as long as it is capable of heating and thermostating the fluid material in the body of the pipe. In some other implementations, the temperature control device may further be configured with a cooling element on the basis of the configuration of the heating wire, so as to prevent the fluid material from being heated to an excessive temperature.
In order to control the fluid material in the line body at a suitable temperature, the distal end of the feed line 34 is provided with a temperature control sensor in one embodiment. The temperature control sensor can be matched with the temperature control device, and particularly, when the temperature control sensor monitors that the temperature of the material in the pipeline body is lower than a threshold value, the temperature controller controls the heating wire to operate until the temperature of the material reaches the threshold value. And when the temperature sensor detects that the material temperature is higher than the threshold value, the temperature controller controls the heating wire to stop running until the material temperature reaches the threshold value again. The threshold value is a temperature value or a temperature range preset by an operator and capable of enabling the material to be in a molten state.
In general, when the delivery of the molten material to the printing head needs to be stopped, the printing head is controlled to deliver or stop delivering the molten material by controlling the opening and closing of the valve mechanism of the printing head, however, the valve mechanism of the nozzle of the common printing head is difficult to realize the complete closing of the printing head, which can cause leakage of the molten material to influence the printing precision, and if the valve mechanism is completely closed, the fluid material in the valve mechanism can press the closed valve mechanism to the inner wall of the valve cavity due to the pressure generated by thermal expansion so as to generate direct mechanical contact with the printing head, so that the printing head cannot be re-opened in the next use, or a more force forced switch is needed, which can cause mechanical abrasion of the valve mechanism, the valve mechanism is easy to loosen after multiple uses, the service life of the printing head is influenced, and the printing head is damaged after long-term use, thereby influencing the smooth operation of the 3D printing operation.
Accordingly, the printhead according to the present application in the embodiments shown in fig. 7 to 16 below is designed to solve the technical problems that it is difficult to achieve the complete closing of the printhead, the leakage of the molten material causes the printing accuracy to be low, and the forced closing of the valve mechanism causes the damage of the printhead.
In an embodiment, referring to fig. 7, which is a schematic diagram of a printhead according to an embodiment of the present application, a broken line is only schematically shown in the internal structure of the printhead 33, and as shown in fig. 7, the printhead 33 includes a printhead body 331, a valve cavity 332 disposed in the printhead body 331, a valve core 333 disposed in the valve cavity 332, an extrusion channel 334 communicating with the feed line 34, and a nozzle 335 communicating with the extrusion channel 334, and the nozzle 335 includes a tapered extrusion port 3351 for printing fluid materials.
In the present embodiment, the valve spool 333 is rotatable within the valve chamber 332 by an angle to effect switching of the passage between the extrusion passage 334 and the nozzle 335 between an open state and a closed state. In other words, after the granular 3D printing material is heated to the molten fluid material by the heater of the feeding system 32, the fluid material is output to the printhead 33 through the feeding line 34, specifically, is output to the extrusion channel 334 through the feeding line 34 connected to the printhead body 331, and is output to the valve element 333. When the valve element 333 is in the open state, the fluid material may be output to the nozzle 335 through the extrusion channel 334, and finally extruded through the tapered extrusion port 3351 and deposited on the printing platform. When the valve element 333 is in the closed state, the fluid material is output only to the valve element 333 to stop the flow into the subsequent structure.
In an embodiment, the upper side of the print head 33 is provided with an access device 324, refer to fig. 8 in combination with fig. 7, wherein fig. 8 is a schematic structural diagram of the print head with the access device according to the present application. As shown in fig. 8, the connector 324 is disposed in a first direction for communicating with the feed line 34 and the extrusion passage 334. In the embodiment shown in fig. 7 and 8, the access 324 is arranged laterally in communication with the feed line 34 to accommodate the tendency of the feed line 34 to bend, i.e., to allow the feed line 34 to be accessed laterally from a direction away from the printhead 33, thereby avoiding having a relatively large curvature at the end of the feed line 34 to affect the smoothness of the internal passageway thereof, and the access 324 is arranged vertically in communication with the extrusion passageway 334, i.e., the access 324 is connected to the feed line 34 and is spatially perpendicular to the extrusion passageway 334.
In order to define the direction and the operation mode between different structures, in the embodiment of the present application, a three-dimensional space defined by a first direction, a second direction and a third direction is defined, where the first direction, the second direction and the third direction are all straight line directions and are perpendicular to each other. For example, the longitudinal extension direction of the access is defined as a first direction or lateral direction (e.g., the direction of X in fig. 7), the longitudinal extension direction of the spool is defined as a second direction (e.g., the direction of Y in fig. 7), and the vertical direction is also referred to as a vertical, plumb, or up-down direction is defined as a third direction or vertical direction (e.g., the direction of Z in fig. 7). In the following embodiments, the description is omitted when referring to the first direction, the second direction, and the third direction.
In one embodiment, both ends of the access 324 are provided with compensation heaters for heating the fluid material passing through the access 324, the types of compensation heaters including, but not limited to, resistive heaters, heating windings, heating cables, and the like. It will be appreciated that after the 3D printing material, for example powder or granule, has been heated to molten fluid material by the heater of the feed system, the fluid material needs to be output from the feed system 32 to the printhead 33 via the feed line 34, during which time the fluid material may be lost to avoid heat, in order to ensure that the fluid material meets the viscosity requirements for smooth extrusion, and in particular, the passageway of the connector 324 is spatially perpendicular to the extrusion passageway 334 to avoid fluid flow in large turns, so that the fluid material needs to be heated in compensation before being output to the extrusion passageway 334 to further control the viscosity of the fluid material to be maintained at a relatively low level to ensure that it is in a fluid state that meets the extrusion requirements.
In one embodiment, as shown in fig. 8, the two sides of the print head 33 are symmetrically provided with end heaters 336 for heating the fluid material in the print head 33. It should be understood that when the valve core 333 rotates in the valve cavity 332 to switch between the open state and the closed state, the fluid material should be ensured to be in an optimal flow state, so that the friction force exerted by the valve core 333 when rotating in the valve cavity 332 is minimized, and therefore, an end heater 336 needs to be disposed on the print head 33 at a position corresponding to the valve core 333 to avoid an increase in viscosity of the fluid material, so that the obstruction of the rotation of the valve core 333 can be reduced to the greatest extent.
In one embodiment, to avoid viscosity increase of the fluid material due to insufficient temperature and carbonization due to excessive heating, and thus avoid impeding the switching of the valve element 333 within the valve cavity 332, the print head 33 is provided with an end temperature sensor for detecting the temperature of the fluid material in the print head 33, which is capable of monitoring the temperature of the fluid material at the valve element 333 in real time. The temperature controller and the cooling device can also be configured to control the temperature of the fluid material. The specific functions of the temperature controller and the cooling device may be referred to the description in the foregoing embodiments, and will not be described herein.
In an embodiment, before the valve element 333 is switched from the closed state to the open state, for example, before a new print job is started or before the 3D printing robot is started, the end heater 336 preheats the material reserved in the print head 33 and melts it into a fluid material because the material left in the valve cavity 332 in the previous print job is solidified into a solid state due to long-time cooling and is embedded in the valve cavity 332. It should be noted that, when the 3D print job is finished, the valve element 333 is switched from the open state to the closed state, and the fluid material is reserved in the valve element 333 and the valve cavity 332, and the reserved fluid material is resolidified and locks the valve element 333 and the valve cavity 332 together with cooling at the temperature. At this time, if the valve element 333 needs to be switched to the open state, the solidified material reserved in the valve element 333 and the valve cavity 332 needs to be melted again to be fluid material, so that the valve element 333 can be unlocked.
As described above, the end heater 336 heats and melts the material reserved in the printhead 33 to the fluid material, the valve element 333 is switched from the closed state to the open state, at the same time, the fluid material is output from the feeding system 32 to the printhead via the feeding pipeline 34, after which the fluid material reserved in the printhead 33 and the fluid material output from the feeding system 32 are jointly output to the nozzle 335 via the open valve element 333, and finally extruded through the tapered extrusion port 3351.
Furthermore, before a new print job is started or before the 3D printing robot starts to start, it takes a period of time for the fluid material melted by the particulate material newly entering the melt barrel 3221 to be output to the printhead through the feeding pipeline 34, if the 3D printing robot is already moving to execute the printing command, the fluid material melted by the material left in the valve cavity 332 in the previous print job will be timely delivered to the nozzle to avoid the empty coating condition of the nozzle of the printhead, in other words, the sink slot formed on the shaft body of the printhead also has the function of pre-storing part of the printing material to realize the seamless connection with the newly flowing fluid material.
In one embodiment, to smoothly guide the fluid material to the tapered extrusion port 3351, reduce resistance and turbulence of the fluid material as it flows, ensure that the fluid material flows more stably and accurately within the nozzle 335 and the actual temperature within the nozzle is detected by the sensor, the nozzle 335 includes a tapered inner cavity surrounded by a tapered inner surface. It will be appreciated that with the cooperation of the tapered inner cavity and the tapered extrusion port 3351, the cross-sectional area of the fluid material gradually decreases as it passes through the nozzle 335, enabling the fluid material to be extruded and deposited on the printing platform more uniformly at a higher flow rate.
In an embodiment, please refer to fig. 9 to 11, wherein fig. 9 and 10 are schematic views of a valve core according to an embodiment of the present application under different viewing angles, and fig. 11 is a cross-sectional view of the valve core according to an embodiment of the present application. As shown in fig. 9 to 11, the valve element 333 includes a shaft body 3331, a flow passage 3332 radially penetrating the shaft body 3331, and a sink 3333 formed around the shaft body 3331. Wherein, the partial surrounding means that the area of the sinking groove 3333 surrounding the shaft body 3331 is an open arc structure.
In an embodiment, the flow channel 3332 has an inlet 33321 and an outlet 33322, as shown in fig. 10, the inlet 33321 of the flow channel 3332 is located in the sink 3333 to be filled with the fluid material from the extrusion channel 334, and when the valve core 333 is in the open state shown in fig. 10, the flow channel 3332 connects the extrusion channel 334 with the tapered extrusion outlet 3351 to flow the fluid material through the nozzle 335.
In one embodiment, as shown in fig. 9, the outlet 33322 of the flow channel 3332 is partially positioned in the sink 3333. That is, in an embodiment in which the sink 3333 is configured in an open arc structure, a part of the outlet 33322 is positioned inside the arc structure and another part is positioned outside the arc structure. Referring to fig. 12, a schematic diagram of a valve element in a closed state according to an embodiment of the application is shown. As shown in fig. 12, when the valve body 333 is in the closed state, the outlet hole 33322 of the flow passage 3332 is offset from the tapered extrusion port 3351 to prevent the fluid material from flowing through the nozzle 335 and to hold the fluid material filled in the sink 3333 between the valve body 333 and the valve cavity 332.
In an embodiment, referring to fig. 7 to 10, the shaft body 3331 is disposed in the valve cavity 332 along the second direction. To achieve the rotary movement of the valve core 333 in the valve cavity 332, the valve core 333 is pivotally connected to the valve cavity 332, as shown in fig. 9, the shaft body 3331 includes a rotating shaft section 33311 and a suspending section 33312, the rotating shaft section 33311 is pivotally connected to two sides of the valve cavity 332, the suspending section 33312 is located between the rotating shaft sections 33311 on two sides, and in this example, the flow channel 3332 and the sinking groove 3333 are formed in the suspending section 33312 corresponding to the extrusion channel 334.
In one embodiment, to further effect rotation of the valve spool within the valve cavity, the valve spool 333 may be engaged with an actuator. Referring to fig. 13 in combination with fig. 7, fig. 13 is a schematic diagram of the valve core and the actuator according to an embodiment of the application, as shown in fig. 7 and fig. 13, a first end of the shaft body 3331 is connected to the actuator 337, and the actuator 337 is used for driving the valve core 333 to rotate, so as to realize the switching of the valve core 333 between the open state shown in fig. 10 and the closed state shown in fig. 12. It should be understood that the first end corresponds to the right side of the shaft body 3331, and the second end in the following embodiments is a side far away from the first end, that is, the left side of the shaft body 3331, and the description of the first end and the second end will not be repeated. In the example shown in fig. 7 and 13, the actuator 337 is disposed in the printhead 33 in a first direction perpendicular to a second direction and is movably coupled to a first end of the shaft body 3331. In other words, the shaft body 3331 and the actuator 337 are perpendicular to each other in space, and the actuator 337 is movably connected to the first end of the shaft body 3331.
In an embodiment, the actuator 337 is configured as a pneumatic actuator, and in this embodiment, the actuator 337 may be configured as an air cylinder, and includes a sliding block 3371, and a first piston 3372 and a second piston 3373 fixedly disposed at two ends of the sliding block 3371, where a body of the sliding block 3371 is movably connected to a first end of the shaft body 3331, and the first piston 3372 and the second piston 3373 are respectively configured to move linearly in the sliding block 3371 to drive the shaft body 3331 to rotate when driven by air pressure generated by the air cylinder 3371.
In one implementation, the shaft body 3331 is movably coupled to the body of the slider 3371 by a spline 338 around the first end. Specifically, a rack is disposed at a position where the slider 3371 contacts the spline 338, and the rack can be meshed with the spline 338 to rotate the shaft body 3331. For example, in the example shown in fig. 13, the valve element 333 is in an open state, at this time, the first piston 3372 is driven by air pressure in the first air pressure tube 339, and the linear motion in the slider 3371 along the arrow direction indicated by the dashed line in the figure drives the shaft body 3331 to rotate counterclockwise, so that the outlet hole of the flow channel is dislocated from the tapered extrusion port, and the valve element 333 is switched to a closed state. If the valve core 333 is required to be switched to the open state again, the gas in the second pneumatic tube 340 is required to drive the second piston 3373, so that the second piston 3373 moves linearly in the direction opposite to the arrow in the slide block 3371, and the shaft body 3331 is driven to rotate clockwise until the outlet hole of the flow channel is communicated with the tapered extrusion port.
In this embodiment, the selection of the alternative air paths formed by the first air pressure pipe 339 and the second air pressure pipe 340 may be configured such that the computer control system drives the end electromagnetic air valve according to the instruction of the printing program, and the action time may be 0.1s-0.5s, for example, about 0.1s, 0.2s, 0.3s, 0.4s, or 0.5s, etc., which is specific to the practical situation.
In one embodiment, the actuator 337 is configured as a mechanical actuator. In this embodiment, the first piston 3372 and the second piston 3373 may be configured to be driven by a mechanical force such as a motor, for example, a driving source such as a servo motor, and the specific driving process thereof may be described in the foregoing, which is not repeated herein.
In an embodiment, to achieve the switching of the valve core 333 between the open state and the closed state, the rotation angle of the shaft body 3331 is 15-45 °, preferably the rotation angle is 20 °. For example, the rotation angle may be configured to 15°、16°、17°、18°、19°、20°、21°、22°、23°、24°、25°、26°、27°、28°、29°、30°、31°、32°、33°、34°、35°、36°、37°、38°、39°、40°、41°、42°、43°、44°、 or 45 °, or the like. It should be understood that the rotation angle can be adjusted accordingly according to the arrangement positions of the inlet hole and the outlet hole of the runner.
Referring to fig. 14 and 15, fig. 14 is a schematic cross-sectional view of the valve core in an open state in the valve cavity according to an embodiment of the application, fig. 15 is a schematic cross-sectional view of the valve core in a closed state in the valve cavity according to an embodiment of the application, and the valve core 333 shown in fig. 14 is in an open state in the valve cavity 332. In this state, when the extrusion channel 334 and the inlet 33321, the flow channel 3332, the outlet 33322, and the flow channel of the nozzle of the valve plug 333 are in a communication state and the feeding system 322 outputs the fluid material to the printhead 321 through the extrusion channel 334 of the access 324 via the feeding line 34, the fluid material is output to the valve plug 333 through the extrusion channel 334 perpendicular to the feeding line 34 and is output to the nozzle through the outlet 33322 by the flow channel 3332 thereof while being filled in the sink 3333, so as to realize a subsequent printing operation. When closing is required, the valve spool 333 shown in fig. 15 is in a closed state in the valve chamber 332. In the closed state, the valve spool 333 rotates within the valve chamber 332 by a predetermined angle, such as 20 ° as described above.
As shown in fig. 15, in the closed state, the outlet hole 33322 of the flow channel 3332 of the valve core 333 is dislocated with the tapered extrusion port 3351, so that the outlet hole 33322 of the flow channel 3332 is blocked by the inner wall of the valve cavity 332 to prevent the fluid material in the flow channel 3332 from flowing through the nozzle 335, in this state, the fluid material from the extrusion channel 334 keeps the fluid material filled in the sink 3333 between the valve core 333 and the valve cavity 332, so that the valve core 333 is wrapped by the fluid material and is in a "suspended" state, and is kept between the valve core 333 and the valve cavity 332, so that the valve core 333 is almost wrapped by the fluid material, thereby avoiding the direct mechanical contact of the valve core with the printhead, and before the valve core 333 needs to be switched to the open state next time, the material reserved in the sink 3333 is preheated by the end heater 336 and melted into the fluid material, and when the re-melted fluid material acts as a smooth agent to a certain extent so that the valve core 333 is re-rotated, the valve core 333 will be smoothly adjusted to the inlet holes 33321, the flow channel 334 and the valve core 333, the flow channel 33322, the outlet hole 33322 and the tapered extrusion port are in communication state.
To facilitate indicating the operator, in an embodiment, the second end of the shaft body 3331 is provided with a marking structure to indicate the open state and the closed state of the valve element 333. The marking structure may be configured as at least one of a structural marking, a text marking, and a symbol marking, and may be configured at the second end of the shaft body 3331 by, but not limited to, overlaying, engraving, labeling, laser engraving, and a digital display. For example, the marking structure may be configured as "ζ", which indicates upright "ζ" when the valve element 333 is in the open state, and indicates inclined "ζ" when the valve element 333 is in the closed state. In this way, the operator can determine whether the valve element 333 is in the open state or the closed state only according to the direction of the identification structure, so as to perform the next operation. It should be noted herein that the above examples are only exemplary, and should not be construed as limiting the application, and the identification structure may be configured in any form as long as it provides an indication to the operator.
As previously described, the sink 3333 is formed in the suspension section 33312 of the shaft body 3331 corresponding to the extrusion channel 334. In one embodiment, as shown in FIG. 10, the width d1 of the sink 3333 is greater than or equal to the aperture d2 of the extrusion channel 334. It should be appreciated that in the embodiment shown in fig. 10, the aperture d2 of the extrusion channel 334 is equal to the aperture of the flow channel 3332, so that the molten fluid material can be rapidly output from the extrusion channel 334 to the flow channel 3332 and then flow from the tapered inner cavity of the nozzle 335 to the tapered extrusion port 3351, since the inlet 33321 of the flow channel 3332 is located entirely in the sink 3333, the width d1 of the sink 3333 needs to be greater than or equal to the aperture d2 of the extrusion channel 334.
In one embodiment, the length of the sidewall top edge of the countersink 3333 is less than the surface circumference of the shaft body 3331. The sidewall top edge is the upper edge of the sidewall where the sinking groove 3333 is connected with the shaft body 3331, and as illustrated in fig. 9, the sidewall top edge of the sinking groove 3333 is partially overlapped with the surface of the shaft body 3331. As described above, the countersink 3333 only partially surrounds the shaft body 3331, and thus, the top edge of the sidewall of the countersink 3333 has a length smaller than the surface circumference of the shaft body 3331.
In an embodiment, as shown in fig. 11, the angle β corresponding to the arc of the top edge of the sidewall of the sinking groove 3333 is between 270 ° and 330 °, for example, may be about 270 °, 280 °, 290 °, 300 °, 310 °, 320 °, or 330 °, etc., which is determined according to practical production requirements, and the application is not limited thereto.
In one embodiment, the inlet 33321 of the flow channel 3332 is positioned at the region with the greatest groove depth of the sink 3333. When the melted fluid material is output from the extrusion channel 334 to the flow channel 3332, the fluid material fills the sink 3333 at the junction of the extrusion channel 334 and the inlet hole 33321, specifically, the fluid material is deposited at the inlet hole 33321 and gradually diffuses into other areas of the sink 3333, so that when the inlet hole 33321 is positioned at the area with the greatest groove depth of the sink 3333, the fluid material can uniformly diffuse into the whole sink.
In one embodiment, the maximum groove depth d3 of the sink 3333 is less than or equal to the diameter d4 of the flow channel 3332. In one embodiment, the volume of the sink 3333 is greater than or equal to the volume of the flow channel 3332, such that the fluid material filled in the sink 3333 is greater than or equal to the fluid material filled in the flow channel 3332.
In an embodiment, as shown in fig. 11, the sink 3333 has a trend of increasing depth from one end of the outlet 33322 of the flow channel 3332 toward one end of the inlet 33321 of the flow channel 3332, and a trend of decreasing depth after passing through the inlet 33321 of the flow channel 3332. That is, when the fluid material is diffused from both sides of the inlet hole 33321 of the flow channel 3332 to the entire sink 3333, the fluid material can be filled in the sink 3333 at a faster speed due to the gradually reduced sectional area of the sink 3333.
In another embodiment, referring to fig. 16, a cross-sectional view of a valve core according to another embodiment of the present application is shown, as shown in fig. 16, in which the depth of the sink 3333 increases from one end of the outlet 33322 of the flow channel 3332 toward the other end. Of course, the sink 3333 may be provided in other shapes, which are determined according to actual production requirements, and the present application is not limited thereto.
In an embodiment, the length of the intersection of the sink 3333 and the flow channel 3332 is less than 1/2 of the aperture of the outlet 33322, for example, as shown in fig. 16, the aperture of the outlet 33322 is equal to the diameter d4 of the flow channel 3332, the length of the intersection of the sink 3333 and the flow channel 3332 is denoted as d5, and d5 is less than 1/2 of d4 as shown in fig. 16.
The following describes the operation of the 3D printing robot according to the present application in detail with reference to fig. 5 to 16.
First, the end heaters 336 provided at both sides of the print head 33 preheat the material reserved in the print head 33 to be melted into fluid material, so that the valve core 333 is wrapped with the fluid material and is in a "floating" like state. The computer control system acts on the actuator 337 by the opening power source according to the instruction of the printing program, so that the first piston 3372 of the actuator 337 moves linearly, drives the shaft body 3331 to rotate a certain angle, and enables the flow passage 3332 to be communicated with the extrusion channel 334 and the conical extrusion port 3351, and to be in an open state as shown in fig. 10 or 14. In this process, the granular materials are conveyed to the accumulator 321 through the gas path pipeline from the external bunker, and then conveyed to the melt extrusion device 322 through the feeding screw arranged at the bottom of the accumulator 321, and the melt extrusion device 322 heats and melts the granular materials into fluid materials through the pre-heater 3222, the second main heater 3224 and the first main heater 3223 respectively, and the screw mechanism positioned inside the melt extrusion device 322 extrudes the fluid materials under pressure. The fluid material is then output to the printhead 33 via the feed line 34. Then, the fluid material is output to the valve core 333 through the extrusion passage 334 perpendicular to the feeding pipe 34, and is output to the nozzle 335 through the flow passage 3332 while being filled in the sink 3333, so as to realize the subsequent printing operation.
When the fluid material is required to be stopped, the computer control system acts the closing power source on the actuator according to the instruction of the printing program, so that the second piston 3373 of the actuator 337 moves linearly in the opposite direction, and drives the shaft body 3331 to rotate by a certain angle in the opposite direction, so that the outlet hole 33322 of the flow channel 3332 is dislocated from the tapered extrusion port 3351, and the closed state shown in fig. 12 or 15 is presented, and the fluid material can be prevented from flowing through the nozzle 335.
In one embodiment, the 3D object constructed by the 3D printing robot needs further processing, such as cutting it to obtain a smooth surface, or grinding, lapping, carving, drilling, etc. to meet the user's needs. In another embodiment, the support associated with the 3D object may need to be removed. In view of this, the 3D printing apparatus of the present application includes a subtractive robot 4 for further fine processing and high quality surface treatment of the 3D object.
With continued reference to fig. 1, as shown in fig. 1, the material reducing robot 4 is disposed on a second side of the printing platform 2 and forms a first preset angle with the 3D printing robot 3, and includes a second mechanical arm 41 and a cutting assembly 42, where the second mechanical arm 41 can move on the upper side of the printing platform 2 according to a second movement path, and the cutting assembly 42 is disposed on the second mechanical arm 41 and is configured to perform material reducing processing on a 3D object deposited on the printing platform 2 according to the material reducing path.
The cutting assembly 42 is used for subtractive processing of 3D objects, and may be configured as a milling cutter or grinding wheel, for example.
The second mechanical arm 41 and the first mechanical arm 31 may be configured identically, and will not be described herein. In an example, the material reduction robot 4 is configured as a six-axis industrial robot, and the following embodiment is described by taking the material reduction robot 4 as a six-axis industrial robot as an example, and should not be construed as limiting the present application. It should be understood that the second arm 41 is a robotic arm including a plurality of mechanical joint arms.
In an embodiment, the material reducing robot 4 further includes a second control device, where the second control device is configured to control six axis joints in the material reducing robot 4 to perform rotational rotation, so as to control the material reducing robot 4 to move along a second motion path, and further control the cutting assembly to move along the material reducing path, so as to implement material reducing processing on the 3D object. The second motion path refers to a motion path of the second mechanical arm 41 during the whole printing process, and the material reduction path refers to a motion path when the cutting assembly performs material reduction processing on the 3D object during the movement of the second mechanical arm 41 along the second motion path. The second control device and the first control device are configured in the same manner, and are not described in detail herein.
In an embodiment, the second mechanical arm 41 of the subtractive robot 4 has a third stiffness, and the third stiffness is greater than the first stiffness of the first mechanical arm 31 of the 3D printing robot 3. Wherein, the stiffness refers to the capability of the first mechanical arm 31 or the second mechanical arm 41 to resist elastic deformation when being stressed, which is used for representing the difficulty of deformation of the first mechanical arm 31, and it should be understood that the third stiffness of the second mechanical arm 41 is greater than the first stiffness of the first mechanical arm 31 means that the force born by the first mechanical arm 31 when being deformed is applied to the second mechanical arm 41 and cannot deform the second mechanical arm 41. It should be noted that, a larger cutting force is generated during the process of performing the material reduction treatment on the 3D object, and a larger impact and vibration are generated on the second mechanical arm 41, at this time, if the rigidity of the second mechanical arm 41 is insufficient, the second mechanical arm 41 is deformed or an error is generated in the movement path of the second mechanical arm 41, so as to affect the processing precision and the surface quality of the 3D object. In contrast, in depositing the melted 3D printing material layer by layer, the first mechanical arm 31 receives a smaller force of melt extrusion, and the rigidity requirement of the first mechanical arm 31 is relatively low. Therefore, in the present embodiment, the third stiffness of the second mechanical arm 41 needs to be greater than the first stiffness of the first mechanical arm 31.
In an embodiment, the second side of the printing platform 2 is at the position of the log reduction robot 4 shown in fig. 1, that is, the log reduction robot 4 is disposed between the second obtuse angle and the third obtuse angle in the forming chamber 1 as in the previous embodiment. In order to realize the arrangement of the log reduction robot 4 on the second side of the printing platform 2, the log reduction robot 4 may further include a second base 43, where the second base 43 may be configured identically to the first base 35, and will not be described herein. In the present embodiment, the 3D printing robot 3 and the subtractive robot 4 have a first preset angle, which is an angle α between the 3D printing robot 3, the center of rotation of the printing platform 2, and a line connecting the subtractive robots 4, and in the example shown in fig. 1, the first preset angle α is 90 °.
In another embodiment, the second side of the printing platform 2 is in the position of the log reduction robot 4 shown in fig. 2, i.e. the log reduction robot 4 is arranged between the second right angle and the fourth obtuse angle in the forming chamber 1 as described in the previous embodiment. In the example shown in fig. 2, the first preset angle α is 180 °.
In an embodiment, the second mechanical arm 41 of the subtractive robot 4 performs the subtractive process on the upper side of the printing platform 2 according to the second movement path, and the area of the molding surface on the printing platform 2 is 75% -100%, where the molding surface refers to the area of the printing platform 2 for depositing the 3D printing material for building the 3D object, and the range of the area may be less than or equal to the range of the printing platform 2. For example, the working area of the second movement path on the upper side of the printing platform 2 may occupy approximately 75%, 80%, 85%, 90%, 95%, or 100% of the molding surface area, for example.
In an embodiment, in an example where the working area of the second motion path occupies 75% of the area of the molding surface, referring to fig. 17, a schematic diagram of the working area of the second motion path occupying the molding surface on the printing platform is shown in the embodiment of the present application, the log reduction robot 4 is illustrated with a small circle in fig. 17, the printing platform 2 is illustrated with a large circle, and the range of the working area on the molding surface 21 occupied by the log reduction robot 4 is illustrated with a hatched portion, in this example, the length of the second mechanical arm 41 is set in a suitable range to ensure that the working area of the second motion path occupies at least 75% of the area of the molding surface 21, so that the log reduction robot 4 can realize the cutting operation of the whole 3D object without changing the position in cooperation with the rotation of the six axes of the log reduction robot 4 and the rotation of the printing platform 2.
It should be noted here that fig. 17 only schematically shows the working area occupied on the molding surface 21 when the log reduction robot 4 is disposed between the second obtuse angle and the third obtuse angle in the molding chamber 1, and should not be construed as limiting the present application, for example, in another example, the log reduction robot 4 is disposed between the second right angle and the fourth obtuse angle, and at this time, the working area of the second movement path on the upper side of the printing platform 2 may still occupy 75% -100% of the molding surface area.
In an embodiment, please refer to fig. 18, which is a schematic diagram of the present application in which the first motion path and the second motion path occupy the printing area and the working area of the printing platform respectively, in an embodiment, the 3D printing robot 3 and the subtractive robot 4 are illustrated with two small circles, the printing platform 2 is illustrated with a large circle, and the first motion path and the second motion path are illustrated with the shadow areas corresponding to the 3D printing robot 3 and the subtractive robot 4 respectively. As shown in the figure, the first mechanical arm 31 of the 3D printing robot 3 is connected to the center of rotation of the printing platform 2 in accordance with the first movement path in the printing area on the upper side of the printing platform 2 and the second mechanical arm 41 of the material reducing robot 4 is connected to the second movement path in the working area on the upper side of the printing platform 2 in accordance with the material reducing process. In this way, the 3D printing robot 3 and the material reduction robot 4 can print and cut 3D objects at the same time, the printing area and the operation area are maximized, and meanwhile, the printing operation and the cutting operation are not interfered with each other, so that the manufacturing efficiency of the 3D objects is improved, and 100% coverage of the full-platform molding area can be realized by means of rotation of the printing platform in a time-sharing operation.
In another embodiment, the area of the forming surface of the printing platform is 75% -100% by the first mechanical arm of the 3D printing robot and the area of the single area of the printing area and the single area of the single area by the second mechanical arm of the material reduction robot, which are located on the upper side of the printing platform according to the first movement path, respectively, and the description of any one embodiment in fig. 17 can be referred to, and the description is omitted here. For example, the print area and the work area may occupy approximately 75%, 80%, 85%, 90%, 95%, or 100%, respectively, of the land area, for example. Of course, the second mechanical arm of the material reduction robot may also be configured to print 3D objects, and may be specifically determined according to actual production requirements.
In summary, in order to solve the technical problems that the 3D printing robot has limited movement freedom degree due to larger size and is difficult to realize continuous and smooth supply of molten materials and the like in the related art, the 3D printing robot and the 3D printing equipment provided by the application have the advantages that the feeding system with the material storage device and the melting extrusion device is arranged on the mechanical arm of the 3D printing robot, so that buffering of the particle materials and melting of the particle materials are realized, the conveying path of molten fluid is shortened to a certain extent, the feeding pipeline for communicating the melting extrusion device and the printing head is arranged between the mechanical arm and the printing head, the short-path supply of fluid materials from the melting extrusion device to the nozzle of the printing head is realized, the feeding pipeline with rigidity smaller than that of the mechanical arm is designed, the feeding pipeline is arranged between the fourth shaft joint of the robot body and the printing head, the flexibility of the movement of each mechanical arm in the printing process of the robot is guaranteed, the instantaneous pressure change caused by the fluid materials can be reduced, the uniform supply of the fluid materials is guaranteed, the temperature control device is arranged on the pipeline body of the feeding pipeline, the long-distance device is capable of controlling the feeding pipeline is prevented from being used for conveying the fluid materials in the long distance, the material is prevented from being blocked by the material in the printing process, and the continuous material is prevented from being caused by the viscosity loss of the material in the printing process, and the printing material is prevented from being caused by the continuous material.
In addition, through setting up the valve pocket that is used for holding the case in the print head, set up the runner that radially runs through the axle body of case and dock with extrusion channel in the case for the runner can realize the open condition of case when switch-on extrusion channel and toper extrusion mouth, can realize the closed condition of case when the play hole of runner and the toper extrusion mouth on the print head nozzle dislocation, with the nozzle that controls fluid material and can flow through on the print head, thereby realize the normal opening and the complete closure of print head, avoid fluid material's leakage, and then guaranteed the printing precision. The valve core is arranged on the shaft body of the valve core, the valve core can be filled in the sinking groove when in a closed state and is kept between the valve core and the valve cavity, so that the valve core is wrapped by the fluid material, and then the valve core is in a similar suspension state, the valve core can be prevented from being pressed on the inner wall of the valve cavity due to thermal expansion of the fluid material when being closed, the direct mechanical contact between the valve core and the printing head is avoided, the damage of the printing head is avoided, and the smooth printing operation is ensured.
Further, through setting up the 3D printing robot that is used for printing the 3D article in the shaping room and being used for carrying out the material reduction robot that subtracts the material was handled to the 3D article, realized the integration that prints the operation and subtract the material was handled, and then avoided the clamping location again of 3D article, machining efficiency has been improved, through setting up 3D printing robot and subtracting the material robot in rotatable printing platform's first side and second side, when realizing 3D printing robot and subtracting the material robot in the reasonable layout of shaping room, make 3D printing robot and subtract the material robot need not to shift and can realize respectively the printing and subtracting the material handling to the 3D article, thereby further improved machining efficiency.
The above embodiments are merely illustrative of the principles of the present application and its effectiveness, and are not intended to limit the application. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the application. Accordingly, it is intended that all equivalent modifications and variations of the application be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.