Disclosure of Invention
The invention mainly aims to provide a rigid-flexible coupling gripper, which solves the technical problems that the rigid gripper unit of the existing rigid-flexible coupling gripper is difficult to control accurately, the stability is poor and the gripping precision is not high.
In order to solve the technical problems, the invention provides the following technical scheme:
A rigid-flexible coupled grip, comprising: a supporting unit; the rigid gripper unit is connected with the support unit in parallel and comprises a sector gear connected with the support unit and a rigid gripper connected with the sector gear and capable of moving under the drive of the sector gear; the motor drive unit, connect in the rigidity tongs unit, including motor and incomplete gear, the incomplete gear includes toothed portion and toothless portion, wherein: the motor is connected to the incomplete gear and used for driving the incomplete gear to rotate; the sector gear is arranged to be capable of meshing with the toothed portion of the incomplete gear; and the pneumatic driving unit is connected with the flexible gripper unit and used for driving the flexible gripper unit to generate bending deformation.
Further, the flexible gripper unit comprises at least two flexible grippers, the rigid gripper unit comprises at least two groups of rigid grippers, each group of rigid grippers comprises two rigid grippers, each group of rigid grippers is connected with one flexible gripper in parallel, and the parallel connection is that: the rigid gripper can drive the flexible gripper to generate bending deformation when being driven by the motor driving unit to move; and when the flexible gripper is driven by the pneumatic driving unit to generate bending deformation, the flexible gripper can be driven to move.
Further, two rigid grippers of each group of rigid grippers are positioned at two sides of the flexible grippers connected in parallel with the two rigid grippers, and the finger root of each rigid gripper is respectively connected with one sector gear.
Further, the motors are double-shaft motors, each group of rigid handles is driven by a double-shaft motor, two sides of each double-shaft motor are respectively provided with one incomplete gear, and the double-shaft motors are respectively connected with the incomplete gears on the sides of the double-shaft motors through keys on the two sides.
Further, the ratio of the circumferential ratio of the toothed portion to the non-toothed portion of the incomplete gear is 15:12-19:12.
Further, the fan-shaped central angle of the fan-shaped gear is 60-80 degrees.
Further, the motor can drive the rigid gripper to generate 5-58 degrees of angle change.
Further, the flexible grip of the flexible grip unit comprises a flexible finger inner layer, fibers, a flexible finger surface layer and a strain limiting layer; the flexible finger inner layer is provided with an inflatable hollow structure connected with the air pump of the pneumatic driving unit, and the flexible finger inner layer is inflated to generate expansion deformation; the fiber is wound around the periphery of the flexible finger inner layer and is used for limiting the transverse expansion of the flexible finger inner layer; the flexible finger surface layer is sleeved outside the flexible finger inner layer and can extend along the length direction under the drive of the flexible finger inner layer; the strain limiting layer is connected with the flexible finger inner layer, and deformation of the strain limiting layer is smaller than that of the flexible finger inner layer, so that the flexible finger inner layer and the flexible finger surface layer bend towards the side where the strain limiting layer is located when the flexible finger inner layer is inflated, and bending deformation of the flexible gripper unit is achieved.
Further, the rigid grip includes a fingertip plate, a first strut, a first link, an intermediate plate, a second strut, and a second link; the fingertip plate is provided with a finger tip, a first connecting part and a second connecting part which are positioned on the opposite sides of the fingertip end, and the middle plate is provided with a third connecting part, a fourth connecting part and a fifth connecting part; the first end of the first supporting rod is movably connected with the first connecting part, the first end of the first connecting rod is movably connected with the second connecting part, the second end of the first supporting rod is movably connected with the third connecting part, the second end of the first connecting rod is movably connected with the fourth connecting part, the first end of the second supporting rod is movably connected with the third connecting part, the first end of the second connecting rod is movably connected with the fifth connecting part, the second end of the second supporting rod is movably connected with the sector gear, and the second end of the second connecting rod is movably connected with the sector gear; one side of the fingertip plate, the first support rod and the second support rod are all connected with the strain limiting layer of the flexible gripper and are located in the same plane with the bottom surface of the strain limiting layer so as to realize the parallel connection.
Further, a tail part is formed at the central angle of the sector gear in an extending way, and is provided with a first mounting hole for mounting the second end of the second connecting rod; a second mounting hole is formed in the circle center of the sector gear and used for mounting the second end of the second supporting rod; and the sector gear is mounted to the supporting unit through the second mounting hole.
The technical scheme of the invention has the beneficial effects that: according to the invention, the motor is used as a driving source of the rigid gripper unit, and the problem of low movement precision of the pneumatic driven rigid gripper due to difficult accurate control of the inflation amount and the air inlet speed is solved by matching the incomplete gear with the sector gear, and the precise control of the rotation angle can be realized by adopting a motor driving gear meshing mode, so that the grabbing precision of the rigid gripper is improved, and the rigid-flexible coupling gripper can grab with high weight and high precision. On the other hand, the motor drives the incomplete gear to be meshed with/not meshed with the sector gear, and the rigid gripper can be directly driven by the motor in the meshed state to realize high-stability, heavy-weight and high-precision gripping; in the engaged but motor stop working state, or in the non-engaged state, even if the motor still runs, the motor only idles and does not drive the rigid gripper to move, in this case, the flexible gripper can be pneumatically driven, and the gripping with high adaptability and high safety on fragile and fragile objects can be implemented; when the rigid main grabbing is required to be switched, the response speed of the motor drive is faster than that of the pneumatic drive, so that the rigid-flexible coupling grabbing hand is improved in the mode switching response speed. Moreover, in the prior art, under the pneumatic driving mode, the air charging amount and the air charging speed are difficult to accurately control, even an air pressure controller is additionally arranged, and the pneumatic driving unit is reduced, the two air pumps are not required to perform cross switching of air charging and air charging, and the structure and the control are simplified. Finally, in the prior art, the clamping force of the rigid gripper is required to be improved by increasing the pressure in the air cylinder, which puts higher requirements on the tightness of the air cylinder.
Detailed Description
The invention will be further described with reference to the drawings and the detailed description.
The driving speed of the air cylinder is limited by factors such as the flowing speed of air and the structural size of the air cylinder, and is generally slower than the response speed of motor driving, so that the double-pneumatic-driving rigid-flexible coupling hand grip is obviously unsuitable for application scenes needing quick response, such as high-speed production lines or mechanical arms needing quick positioning and scenes needing quick switching of grabbing modes; secondly, the force output by the air cylinder is limited by the air pressure and the area of the piston, so that accurate control is not easy to realize, and therefore, the movement precision of the rigid gripper is difficult to control, and the gripping precision is not high; moreover, the gas in the cylinder may leak, which results in insufficient or unstable gas pressure, which affects the normal operation of the cylinder, and severely reduces the working stability of the rigid gripper for gripping a large weight; finally, as most of the energy of the cylinder drive is consumed in compressing the gas and overcoming the friction, it severely reduces the energy efficiency of a rigid gripper that grips a large weight.
In conclusion, the existing rigid coupling gripper still has the problems of low gripping precision, poor stability caused by accurate control of output force energy, low energy efficiency, limited driving response speed, low mode switching response speed and the like. In view of this, the embodiments of the present invention provide a novel rigid-flexible coupling gripper, which solves the above-mentioned problems by changing the driving manner of the rigid gripper and the connection manner between the rigid gripper and the driving unit thereof. The rigid-flexible coupling gripper provided by the embodiment of the invention can inherit the large-range grabbing capacity of the rigid gripper and the good adaptability of the flexible gripper, can accurately control the movement precision of the rigid gripper, improves the grabbing precision of the rigid gripper, and is more stable when controlling the rigid gripper to grab a heavy object; moreover, the hand grip can also respond faster during mode switching, can better cope with various complex and changeable working environments, and improves the overall working efficiency and the grabbing accuracy of the hand grip.
The following describes the structure and working principle of the rigid-flexible coupling hand grip according to the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the examples are provided for illustrative purposes only and are not intended to limit the structure of the rigid-flexible coupling fingers of the present invention. In addition, with respect to the spatial orientation terms such as "upper", "lower", "left" and "right" used in the present specification, it is convenient to describe the relative positional relationship between the constituent components of the rigid-flexible coupling hand grip, and not to represent the direction of the product shown in the drawings, and in actual use, the spatial related descriptions describing the direction of the product should be interpreted in a similar manner as the direction of the product is different (e.g. rotated 90 degrees or other orientations). Furthermore, the terms first, second, and the like, herein, are used solely for distinguishing between components and should not be limited by such terms, nor should they necessarily be used to indicate any such order of components or method of manufacture.
Referring to fig. 1 and 1A, a rigid-flexible coupling handle according to an embodiment of the present invention includes: the pneumatic gripper comprises a support unit, a rigid gripper unit and a flexible gripper unit, wherein the rigid gripper unit and the flexible gripper unit are connected to the support unit, a motor driving unit is connected to the rigid gripper unit, and a pneumatic driving unit is connected to the flexible gripper unit. The rigid gripper unit is connected in parallel with the flexible gripper unit. The rigid gripper unit comprises a sector gear 7 connected to the support unit and a rigid gripper connected to the sector gear 7. The motor drive unit includes a motor 13 and an incomplete gear 10, the incomplete gear 10 including a toothed portion and a non-toothed portion. Wherein, the motor 13 is connected to the incomplete gear 10 for driving the incomplete gear 10 to rotate; the sector gear 7 is arranged to mesh with the toothed portion of the incomplete gear 10, such that, when the sector gear meshes with the toothed portion, the sector gear rotates with the rotation of the incomplete gear to move the rigid gripper, suitable for performing a gripping action, which is mainly rigid gripping. The pneumatic driving unit is used for driving the flexible gripper unit to generate bending deformation and carrying out flexible gripping with high adaptability and no damage.
In the scene that high precision and high stability are needed for grabbing such as assembly and carrying, the rigid-flexible coupling gripper provided by the embodiment of the invention drives the rigid gripper unit through the motor to realize accurate clamping and moving, and the motor drive can provide strong power and accurate and stable control to ensure that the rigid gripper has high stability, reliability and precision when executing the tasks. When objects with irregular shapes and size changes, such as fruits, vegetables and the like, are required to be grabbed, the rigid-flexible coupling gripper provided by the embodiment of the invention drives the flexible gripper unit through the pneumatic driving unit, so that self-adaptive and damage-free grabbing is realized. The flexible gripper unit has the characteristic of self-adaptive grabbing, can be automatically adjusted according to the shape and the size of an object, and improves the adaptability and the success rate of grabbing. The person skilled in the art can determine the grabbing mode to be adopted according to the shape, size, weight, material and other article information of the object to be grabbed, and then control the rigid-flexible coupling grab to grab and switch the modes through the control system.
It should be understood that the rigid-flexible coupling gripper in the embodiment of the invention can also be used for simultaneously driving the rigid gripper by a motor and the flexible gripper by pneumatic driving so as to fully exert respective advantages and realize more efficient and stable gripping effect. In this case, however, the direction of movement of the rigid grip and the direction of movement of the flexible grip should coincide. The flexible combination mode enables the rigid-flexible coupling handle to have excellent adaptability and high efficiency when dealing with various complex grabbing tasks.
In addition, when the rigid-flexible coupling handle provided by the embodiment of the invention works, the motor can generate larger torque by increasing the input voltage or current of the motor, so that the driving duty ratio of the motor driving unit is improved; the drive duty cycle of the pneumatic drive unit may also be increased by increasing the pressure of the air supply. According to different grabbing requirements and scenes, the driving proportion of the motor driving unit and the pneumatic driving unit can be flexibly allocated, and the grabbing range and the grabbing close fitting degree of the rigid-flexible coupling grab can be regulated and controlled. For example, fragile articles or precise parts can be grabbed, and a softer grabbing action can be realized by increasing the driving proportion of the pneumatic driving unit, so that the damage to the articles is avoided; in the application scenes of heavy transportation, hoisting and the like, the driving proportion of the motor driving unit can be increased to overcome the gravity and the friction force.
The flexible gripper unit of the embodiment of the invention comprises at least two flexible grippers, the rigid gripper unit comprises at least two groups of rigid grippers, each group of rigid grippers comprises two rigid grippers, each group of rigid grippers is respectively connected with one flexible gripper in parallel, and the parallel connection is that: when the rigid gripper moves under the drive of the motor driving unit, the flexible gripper can be driven to generate bending deformation, and under the condition, the rigid gripper is active, the flexible gripper is driven, and the rigid gripping is the main; and when the flexible gripper generates bending deformation under the drive of the pneumatic driving unit, the flexible gripper can be driven to move, the flexible gripper is driven under the condition, the flexible gripper is mainly used for flexible gripping, and the rigid gripper can provide certain gripping force for flexible gripping. The two rigid grippers of each group of rigid grippers are positioned on both sides of the flexible grippers connected in parallel with the two rigid grippers, and the root of each rigid gripper is respectively connected with a sector gear 7.
Referring to fig. 1, 1A, and 2, in this embodiment, the flexible gripper unit includes two flexible grippers symmetrically connected to both sides of the support unit, each flexible gripper including a flexible finger inner layer 21, a fiber 22, a flexible finger skin layer 8, and a strain limiting layer 9; the flexible finger inner layer 21 is provided with an inflatable hollow structure connected with an air pump of the pneumatic driving unit, and the flexible finger inner layer 21 is inflated to deform for grabbing when the gripper works during the flexible operation; the fiber 22 is wound around the periphery of the flexible finger inner layer 21 and is used for limiting the transverse expansion of the flexible finger inner layer 21; the flexible finger surface layer 8 is sleeved outside the flexible finger inner layer 21 and can extend along the length direction under the drive of the flexible finger inner layer 21; the strain limiting layer 9 is connected with the flexible finger inner layer 21, and the deformation of the strain limiting layer is smaller than that of the flexible finger inner layer 21, so that the flexible finger inner layer 21 and the flexible finger surface layer 8 bend towards the side where the strain limiting layer 9 is located when the flexible finger inner layer is inflated, and the flexible gripper unit can grasp the bending deformation of an object. In the manufacturing process of the flexible gripper, a wire slot is cast on the outer surface of the inner layer 21 of the flexible finger and used for fixing the fiber 22, the fiber 22 is wound from one end of the inner layer 21 of the flexible finger to the other end and knotted and fixed, then the inner layer 21 of the flexible finger is combined with the surface layer 8 of the flexible finger, the fiber 22 is fixed, then the fiber 22 is taken out from a die and then is adhered and fixed with the strain limiting layer 9 through silica gel, and then the root end of the inner layer 21 of the flexible finger and the connecting block 20 of the flexible gripper are sealed to form the hollow structure. The trachea inserts this hollow structure through the connecting block, and when gas fills flexible finger inlayer 21, it extends in length direction, makes whole flexible tongs have the extension trend, and simultaneously because the deformation of strain limiting layer 9 is less than the deformation of flexible finger inlayer 21, finally, flexible finger inlayer 21, flexible finger top layer 8 and strain limiting layer 9 are crooked to the side that strain limiting layer 9 is located simultaneously, inwards draws in.
It should be understood that the number of flexible grippers of the flexible gripper unit is not limited to 2, preferably at least 2, but may be three, four or other numbers; the plurality of flexible grippers are preferably evenly distributed circumferentially around the support unit. Preferably, the rigid gripper unit comprises the same number of sets of rigid grippers as the number of flexible grippers, e.g. in embodiments with two flexible grippers, two sets of 4 rigid grippers are included. The number of grippers does not limit the scope of the present invention, and a person skilled in the art can design different numbers of grippers according to actual requirements.
Referring to fig. 1, 1A and 3A, in this embodiment, the rigid gripper unit includes two sets of rigid grippers, each set of rigid grippers includes two rigid grippers disposed at left and right sides of a flexible gripper connected in parallel thereto, and each rigid gripper includes a fingertip plate 1, a first strut 2, a first link 3, a middle plate 4, a second strut 5, and a second link 6. Wherein the fingertip plate 1 has a finger tip (lower end as shown in fig. 3) and first and second connection parts located at opposite sides of the fingertip end, and the intermediate plate 4 has third, fourth and fifth connection parts. In some preferred embodiments, the first end (lower end as shown in fig. 3) of the first strut 2 is movably connected to the first connection portion of the fingertip plate 1, the first end (lower end as shown in fig. 3) of the first link 3 is movably connected to the second connection portion of the fingertip plate 1, the second end (upper end as shown in fig. 3) of the first strut 2 is movably connected to the third connection portion of the intermediate plate 4, the second end (upper end as shown in fig. 3) of the first link 3 is movably connected to the fourth connection portion of the intermediate plate 4, the first end (lower end as shown in fig. 3) of the second strut 5 is movably connected to the third connection portion of the intermediate plate 4, the first end (lower end as shown in fig. 3) of the second link 6 is movably connected to the fifth connection portion of the intermediate plate 4, the second end (upper end as shown in fig. 3) of the second link 5 is movably connected to the sector gear 7, and the second end (upper end as shown in fig. 3) of the second link 6 is movably connected to the sector gear 7. Furthermore, one side of the fingertip plate 1, the first strut 2 and the second strut 5 are all connected with the strain limiting layer 9 of the flexible grip and are in the same plane with the bottom surface of the strain limiting layer 9, thereby realizing the parallel connection of the rigid grip and the flexible grip.
Referring to fig. 3 and 3A, a tail portion is formed at the central angle of the sector gear 7 in an extending manner, and is provided with a first mounting hole 25 for mounting the second end of the second link 6; a second mounting hole 24 is formed in the center of the sector gear 7 and used for mounting the second end of the second supporting rod 5; meanwhile, the sector gear 7 is mounted to the supporting unit through the second mounting hole 24. Referring to fig. 7 and 2, the supporting unit 23 includes a connection frame 15, rib plates 16 and an inner fixing plate 19, and a groove is formed at the inner side of the inner fixing plate 19 for accommodating the outer inflation tube 14 and the three-way air tube connector 17 of the pneumatic driving unit, and the pneumatic driving unit is fixed by the two inner fixing plates 19 in a matched manner. In order to ensure the stability of the rigid gripper unit and to prevent it from shaking, the outer surface of the inner fixing plate 19 is designed to mate with the inner surface of the rib on the same side, forming two mutually gripping surfaces, which effectively limits the free movement of the rigid gripper unit in multiple directions, thus improving the rigidity and stability of the overall gripper structure. The rib plates 16 are symmetrically arranged on the outer sides of the two inner fixing plates 19; the rib plate 16 and the inner fixing plate 19 are connected with the connecting frame 15, and the top of the connecting frame 15 is used for being connected with a mechanical arm. The sector gear 7, the second end of the second strut 5 and the rib plate 16 are fixed by bolts through the second mounting holes 24.
It should be understood that the present invention is not limited to the shape of the fingertip and intermediate plates. In some embodiments, the fingertip plate 1 and the middle plate 4 may be triangular plates, with continued reference to fig. 1, 3 and 3A, wherein the shortest side and two corners of the fingertip plate 1 are located at the upper end, the corner located at the lower end is said fingertip end, connected to the strain limiting layer of the flexible grip, two holes are respectively opened at the two corners of the upper end, the hole located at the inner corner is used for mounting the first end of the first strut 2, and the hole located at the outer corner is used for mounting the first end of the first link 3. The inner side and the outer side are relative to the grabbing action, the grippers move inwards to close during grabbing, and release outwards during releasing. The middle plate 4 is preferably an obtuse triangle, the shorter side is used as a power arm, the longest side is used as a resistance arm, and a larger rotation effect can be generated or maintained by smaller force; and three holes are respectively formed at three corners, wherein the mounting hole at the largest corner is used for mounting the first end of the second connecting rod 6, and the mounting holes at the other two corners are respectively used for mounting the second end of the first supporting rod 2 and the second end of the first connecting rod 3, wherein the hole for mounting the second end of the first supporting rod 2 is also used for mounting the first end of the second supporting rod 5. Referring to fig. 3A, in order to facilitate the assembly and movement of the rigid grip, both ends of the first link 3, the second link 6 and the second strut 5 are respectively provided with square grooves in the thickness direction of the bar, and the larger end of the first strut 2 (the end connected to the fingertip plate, i.e. the first end of the first strut) is also provided with square grooves. The biggest angle end of the fingertip plate 1 is placed in the square groove at the larger end of the first supporting rod 2, and the hole at the biggest angle end of the inter-digital plate 1 is matched with the hole at the larger end of the first supporting rod 2 coaxially, so that the first supporting rod 2 and the fingertip plate 1 can rotate relatively. The second large angle end of the inter-digital plate 1 is placed in the square groove at the first end of the first connecting rod 3 and is coaxially matched with the hole at the first end of the first connecting rod 3, so that the first connecting rod 3 and the fingertip plate 1 can also rotate relatively. The second large angle end 41 of the intermediate plate 4 is provided with a groove in a direction perpendicular to the plate thickness for easy assembly and movement, and the smaller end of the first strut 2 (the end connected to the intermediate plate 4, i.e. the second end of the first strut) is placed in this groove of the intermediate plate 4, while the hole of the second end of the first strut 2 is co-axially aligned with the hole of the second large angle end 41 of the intermediate plate 4. The smallest angular end 42 of the intermediate plate 4 is then connected to the square groove of the second end of the first link 3, while the largest angular end 43 of the intermediate plate 4 is connected to the square groove of the first end of the second link 6. In addition, the hole of the second most angular end of the intermediate plate 4 is co-axially matched with the second end of the first strut 2. At the same time, the first mounting hole 25 is coaxially fitted with the hole of the second end of the second link 6.
In the embodiment of the present invention, since each group of rigid grippers includes two rigid grippers having the same structure, the motor for driving each group of rigid grippers is a dual-shaft motor, and referring to fig. 1 and 1A, the dual-shaft motor is connected and fixed with the supporting unit through the L-shaped fixing plate 12, two sides of the dual-shaft motor are respectively provided with the keys 11, two sides of one motor are respectively provided with one incomplete gear 10, and one incomplete gear 10 is correspondingly connected with one key 11. In some embodiments, the ratio of the circumferential ratio of the toothed portion to the non-toothed portion of the incomplete gear 10 is 15:12-19:12 to ensure proper operation and performance optimization of the gear, and in one embodiment of the present invention, a ratio of 17:12 is used. In some embodiments, the central angle of the sector gear is set in the range of 60 ° to 80 °, preferably 70 ° as the central angle of the sector gear, this choice ensuring a moderate volume of the sector gear, while its movement stroke is sufficient to meet the actual requirements. In the cooperation of the sector gear and the incomplete gear, the two must meet the basic conditions of meshing, including equal modulus, consistent pressure angle, identical tooth form and accurate center distance. The satisfaction of these conditions ensures that the toothed portions of the sector gear and the incomplete gear mesh smoothly and remain stable and reliable during transmission. In addition, in some embodiments of the invention, the motor can drive the rigid grip to produce an angular change of 5-58 °.
In addition, it should be noted that, the rigid-flexible coupling gripper according to the embodiment of the invention realizes mode switching by using the cooperation of the incomplete gear and the sector gear on the basis of adopting the motor to drive the rigid gripper unit. When the toothed part of the incomplete gear of the double-shaft motor is meshed with the sector gear, the rigid gripper can be driven to retract inwards or expand outwards by adjusting the rotation direction of the motor, so that grabbing or releasing is correspondingly realized; in addition, due to the design of the parallel connection of the rigid gripper and the flexible gripper, the rigid gripper can also drive the flexible gripper to generate bending deformation in the same direction when moving to grasp, so that the holding capacity of the rigid gripper on an object is further enhanced, and a stable and reliable grasping effect is ensured. When the sector gear corresponds to the toothless portion of the incomplete gear (no longer meshes with the toothed portion), such as the state shown in fig. 4, this state is called a non-meshing state, or when the motor stops driving although in the meshing state, the flexible grip is driven pneumatically to perform flexible gripping, and at this time, the flexible grip can drive the rigid grip to rotate to a certain extent, so as to increase a certain gripping force for flexible gripping, also due to the parallel connection. Based on this unique rigid-flexible coupling design, and the interaction of the sector gear and the incomplete gear, the rigid-flexible coupling grip of the embodiments of the present invention may have the following states:
① In the initialized state before the rigid-flexible coupling gripper starts working, the incomplete gear 10 and the sector gear 7 are in a non-meshed state, and no force transmission and transmission relation exists between the incomplete gear 10 and the sector gear.
② After starting to work, if the control system selects a mode mainly comprising rigid grabbing, the toothed part of the incomplete gear is meshed with the sector gear along with the driving of the motor, at the moment, the rigid grab starts to move under the driving action to grab an object, and meanwhile, a certain bending moment is applied to the flexible grab, the moment causes the flexible grab unit to bend and deform, at the moment, if the rigid grab stops moving, the flexible grab still keeps a certain bending state, because the flexible grab and the rigid grab are connected in parallel, and at the moment, better wrapping performance can be added for rigid grabbing by inflating the flexible grab. Or after starting to work, if the control system selects a grabbing mode mainly based on flexibility, the flexible grippers are driven pneumatically instead of being driven by the motor, at the moment, the flexible grippers start to bend and deform under the driving action to prepare for grabbing objects, and meanwhile, the bending deformation can drive the rigid grippers to move in the same direction to generate certain activities, so that grabbing force is increased for flexible grabbing.
③ In the working process, when the grabbing mode is switched from the grabbing mode with the rigidity being the main mode to the grabbing mode with the flexibility being the main mode, the motor driving can be directly stopped, and the pneumatic driving unit can be started. Even if the toothed part of the incomplete gear and the sector gear are still in a meshed state at the moment, the partial joint (such as a joint close to a fingertip) of the rigid gripper can be driven to move by the flexible gripper due to the fact that the incomplete gear and the sector gear are basically clamped due to the fact that the motor stops driving in the process of driving the flexible gripper to bend and deform by the pneumatic driving unit. On the contrary, when the grabbing mode of the main body is needed to be switched from the grabbing mode of the main body of the flexible body, the pneumatic driving unit is stopped, the motor driving unit is started, the motor drives the incomplete gear to rotate, and the rigid grippers move in the meshed state of the toothed part and the sector gear to provide larger holding force. In the embodiment of the invention, the ratio of the circumference ratio of the toothed part to the non-toothed part of the incomplete gear is 15:12-19:12, and the ratio of the toothed part to the non-toothed part is more.
The flexible handle provided by the embodiment of the invention has enough flexibility and adaptability, and can be tightly attached to the shape of paper. Referring to fig. 2 and 4, when the flexible grip is pressurized, it will bend inward, creating a certain clamping force. When the flexible gripper is bent to a certain angle, the flexible gripper can just clamp paper, no pressurization is performed, and clamping action is completed. The specific operation steps are as follows: the air is inflated from the outer inflation tube 14, and flows to the two inner air guide tubes 18 respectively after passing through the three-way air tube connector 17, each inner air guide tube 18 is directly inserted into the small opening end of the flexible gripper connecting block 20, and finally the air is inflated into the hollow structure of the flexible finger inner layer 21 of the flexible gripper, so that the flexible gripper bends until the fingertip part is attached to the paper, and the paper is clamped in a nondestructive way.
As shown in fig. 5, when a larger cuboid object is grabbed, the rigid-flexible coupling handle of the embodiment of the invention can be well attached to the surface of the object, and a stable grabbing effect is ensured. In particular embodiments, the rigid-flexible coupled grip exhibits excellent adaptability to different shapes and sizes of objects, with different modes of operation being adjusted for gripping by mode switching. First, the rigid grip unit of the rigid-flexible coupled grip may be bent and extended according to the shape and size of the object to accommodate the shape of the object. The incomplete gear toothed part is meshed with the sector gear by controlling the rotation of the double-shaft motor, and the rigid handle is provided with a plurality of joints, so that the bending in different directions can be realized, and the rigid handle is tightly attached to each surface of the cuboid. Secondly, the flexible gripper unit also plays a key role: when the rigid gripper unit is fully extended, the flexible gripper unit is pressurized, so that the flexible gripper unit has enough elasticity and resilience, can be adaptively adjusted according to the shape and hardness of an object, and can be tightly attached to the surface of the object when the flexible gripper unit is contacted with a cuboid, friction is increased, vibration is reduced, and the grabbing stability and accuracy are ensured.
In addition, in order to demonstrate the grabbing effect of the rigid-flexible coupling grab in grabbing objects with different weights, another embodiment of the invention also selects a heavier weight as a grabbing object. The embodiment adopts the motor driving unit and the pneumatic driving unit to realize stable grabbing through combined driving. Firstly, when a weight is required to be grabbed, a control system controls a motor to rotate so as to drive an incomplete gear 10 to rotate, so that a toothed part of the incomplete gear is meshed with a sector gear 7, and a rigid gripper is driven to bend or stretch, so that the weight is primarily grabbed; secondly, the pneumatic driving unit is controlled by the control system to inflate the flexible gripper according to the requirement, and the grabbing force is further enhanced by air pressure. The pneumatic driving device has the advantages that the pneumatic pressure can be flexibly adjusted according to the weight of the object and the grabbing requirement, so that the objects with different weights can be stably grabbed. Meanwhile, the strain limiting layer can be tightly attached to the surface of the weight under the action of air pressure, friction is increased, vibration is reduced, and grabbing stability and accuracy are improved.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several equivalent substitutions and obvious modifications can be made without departing from the spirit of the invention, and the same should be considered to be within the scope of the invention.