CN110961633A

Movatterモバイル変換

Info

Publication number: CN110961633A
Application number: CN201811142489.0A
Authority: CN
Inventors: 俞红祥; 应华; 杨以杰
Original assignee: Pera Global Technology Co ltd
Current assignee: Pera Global Technology Co ltd
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-04-07

Abstract

The invention discloses a three-dimensional printing method, which adopts a distance measuring head to scan and measure the landform data of the surface of a printing substrate; calculating three-dimensional printing parameters such as a follow-up path, deposition thickness distribution data and the like of a forming action head on each printing layer along with the landform of the printing substrate to implement deposition operation through a three-dimensional printing controller, and controlling the forming action head to implement deposition operation along with the landform on the surface of the printing substrate; in the printing process, the following movement of the Z-axis positioning mechanism ensures that the forming action head continuously adjusts the deposition thickness at each XY coordinate position, and the deposition thickness is accumulated layer by layer, so that the accurate three-dimensional body is directly printed on the surface of the printing substrate. The method disclosed by the invention can be used for directly implementing material increase operation on an inclined plane, a curved surface and a non-regular plane without accurately pre-positioning the printing base material, preparing a three-dimensional numerical model of the printing base material in advance and pre-matching the three-dimensional shape of the target to be printed and the printing base material, and can be realized in a real-time control system.

Description

Three-dimensional printing method and device

Technical Field

The invention belongs to the electromechanical method class, and particularly relates to a non-planar printing method and a non-planar printing device.

Background

The printing of three-dimensional objects using fused deposition methods, such as FDM (fused deposition modeling) processes, LMD (laser fused deposition) processes, typically needs to be performed on a planar printed substrate. The main reason is that the designed three-dimensional printed object usually includes a bottom surface with an ideal plane, so it is better to print the three-dimensional object on a printing substrate close to the ideal plane to meet the printing requirement. However, in practice, when the deviation of the flatness of the printed substrate is large, the initially deposited layer may warp, which may result in a printing failure. Furthermore, in practice, the printing substrate needs to be in an absolute horizontal position during operation. Under the traditional mode, can control the plane degree that prints the substrate usually and accord with at comparatively strict plane degree level to set up manual adjusting bolt in printing base plate or three-dimensional printing device four corners, rely on measuring tools such as feeler gauge and artifical the repetition adjustment, be in higher levelness with the realization printing base plate, but its operation is comparatively loaded down with trivial details.

At present, the requirement of three-dimensional printing on the flatness and levelness of a printing substrate improves the cost of three-dimensional printing equipment, and also limits the application scene of the application field of three-dimensional printing. Therefore, once the requirements on the flatness and levelness of the printed substrate are broken through, the limitation of the printed substrate can be broken, and even the three-dimensional printing can be carried out on the surface of any three-dimensional object or the surface of any base material.

In order to rapidly and conveniently perform three-dimensional printing on the surface of any three-dimensional object, it is necessary to develop a three-dimensional printing method which does not need to accurately pre-position a printing substrate, prepare a three-dimensional numerical model of the substrate in advance and pre-match a three-dimensional printing part with the surface shape of the substrate.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a three-dimensional printing method which is simple in scheme and feasible in technology, so that three-dimensional printing is carried out on a three-dimensional object at least one side of which is an inclined plane, a curved surface or other irregular planes.

The technical scheme of the invention is as follows:

a method of three-dimensional printing, the method comprising the steps of:

s01, moving a Z-axis positioning mechanism to move the printing substrate to a measurement coordinate position;

s02, the distance measuring head scans the landform of the printing area of the printing substrate and records landform data according to a set sampling interval;

s03, the three-dimensional printing controller superposes the landform data and the three-dimensional data of the target to be printed, and calculates the number of printing layers of each scanning point in the area to be printed and the deposition thickness of each printing layer;

and S04, controlling the forming action head and the Z-axis positioning mechanism by the three-dimensional printing controller to print the three-dimensional object.

Preferably, the step S04 specifically includes:

s41, calculating a follow-up path of a Z-axis coordinate corresponding to the current printing layer by the three-dimensional printing controller according to the XY instantaneous coordinate position of the forming action head, and controlling the Z-axis positioning mechanism to output Z-axis motion;

s42, the three-dimensional printing controller calls the deposition thickness of the current printing layer calculated in the step S03 corresponding to the XY instantaneous coordinate position;

s43, driving a forming action head by a three-dimensional printing controller, and depositing a printing material with a deposition thickness corresponding to the XY instantaneous coordinate position;

s44, the three-dimensional printing controller drives the XY axis positioning mechanism to move the forming action head to the next XY instantaneous coordinate position of the printing sequence layer;

s45, repeating S41 to S44 until the printing of the printing sequence layer is finished;

and S46, driving the Z-axis positioning mechanism to move to the next printing sequence layer position, and repeating the steps from S41 to S45 until all the three-dimensional object printing layers are printed.

Preferably, the printing substrate is a three-dimensional article with at least one side of the three-dimensional article being an inclined plane, a curved plane or other irregular plane.

Preferably, the print substrate is non-permanently affixed to the Z-axis positioning mechanism.

Preferably, the geomorphic data is a two-dimensional array storage structure, wherein the row index of the two-dimensional array element corresponds to the X-axis coordinate value of the scanning point, the column index corresponds to the Y-axis coordinate value of the scanning point, and the value of the array element is the geomorphic variable corresponding to the scanning point.

Preferably, the topographic data is superposed with the three-dimensional data of the target to be printed, and the plane where the highest point of the printing area is located, or the plane where the lowest point is located, or the median height, or any height is taken as a base plane, the relative value of the topographic variable is added to the coordinate position lower than the base plane, and the relative value of the topographic variable is subtracted from the coordinate position higher than the base plane.

Preferably, the number of printing layers in the actual state can be calculated by a direct calculation method or an iterative method.

Preferably, the deposition thickness in the actual state can be calculated according to the number of printing layers or an iterative method.

Preferably, the print-order layers are obtained by performing a lateral planning on the number of print layers calculated in step S03 and the deposition thickness of each layer by a print layer numbering method or a contour method.

Preferably, the printing device comprises a rigid support, an XY axis positioning mechanism, a Z axis positioning mechanism, a first moving platform, a second moving platform, a forming head, a distance measuring head, a printing substrate, and a three-dimensional printing controller, wherein:

the XY axis positioning mechanism is positioned at the top of the rigid support, and a first moving platform is arranged on the XY axis positioning mechanism; the first moving platform is provided with a forming action head and a distance measuring head, wherein the forming action head and the distance measuring head perform plane motion by utilizing an XY axis positioning mechanism; the Z-axis positioning mechanism is positioned on the side surface of the rigid support, and a second moving platform is arranged on the Z-axis positioning mechanism; the second moving platform is basically parallel to the first moving platform and can be close to or far away from the forming action head and the distance measuring head under the drive of the Z-axis positioning mechanism; a printing substrate is arranged on the second moving platform; the three-dimensional printing controller is respectively and electrically connected with the XY axis positioning mechanism, the Z axis positioning mechanism, the forming action head and the distance measuring head. The method has the advantages that the additive operation can be directly carried out on the surface of the three-dimensional object with at least one surface of an inclined plane, a curved surface and other irregular planes, the precise pre-positioning of the base material is not needed, the three-dimensional numerical model of the base material is not needed to be prepared in advance, and the pre-matching of the three-dimensional shape of the target to be printed and the printing base material is not needed to be carried out, so that the method can be realized in a real-time control system.

Drawings

FIG. 1 is a schematic structural diagram of a three-dimensional printing apparatus for implementing a three-dimensional printing method according to the present invention;

FIG. 2 illustrates steps of a three-dimensional printing method according to the present invention;

FIG. 3 illustrates a specific implementation of a portion of the three-dimensional printing method of the present invention;

FIGS. 4A to 4D are schematic diagrams of an ideal state and an actual state of a three-dimensional object according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an ideal state and an actual state of a three-dimensional object according to one embodiment of the invention;

FIG. 6 is a diagram of control signal connections according to an embodiment of the present invention.

Reference numerals: the device comprises a high-rigidity support 1, an XYaxis positioning mechanism 2, a first moving platform 3, a forming action head 4, a distance measuring head 5, a Z axis positioning mechanism 6, a second moving platform 7, aprinting substrate 8, a target to be printed 10 and a three-dimensional printing controller 11.

Detailed Description

The following describes embodiments of the present invention in detail with reference to the accompanying drawings.

In order to implement the method for compensating the plane distortion of the printing substrate, a corresponding printing device is shown in fig. 1, and the printing device comprises a rigid support 1, an XYaxis positioning mechanism 2, a Z axis positioning mechanism 6, a first moving platform 3, a second moving platform 7, a forming action head 4, a distance measuring head 5, aprinting substrate 8 and a three-dimensional printing controller 11, wherein:

the XYaxis positioning mechanism 2 is positioned on the top of the rigid support 1, and a first moving platform 3 is arranged on the XYaxis positioning mechanism 2; the first moving platform 3 is provided with a forming action head 4 and a distance measuring head 5, wherein the forming action head 4 and the distance measuring head 5 perform plane motion by utilizing an XYaxis positioning mechanism 2; the Z-axis positioning mechanism 6 is arranged on the side surface of the rigid support 1, and a second moving platform 7 is arranged on the Z-axis positioning mechanism 6; the second moving platform 7 is basically parallel to the first moving platform 3 and can be driven by the Z-axis positioning mechanism 6 to approach or depart from the forming action head 4 and the distance measuring head 5; aprinting substrate 8 is fixed on the second moving platform 7; the three-dimensional printing controller 11 is respectively and electrically connected with the XY-axis positioning mechanism 2, the Z-axis positioning mechanism 6, the forming action head 4 and the distance measuring head 5.

The printing device is suitable for three-dimensional printing of FDM (fused deposition modeling) process and LMD (laser fused deposition) process. When the printing device is an FDM process, the forming head 4 includes a wire feeder, a heater, and a nozzle. When the wire feeding device works, the printing wire is sent to the heater by the wire feeding device, and the printing wire is in a melting state after being heated, so that the printing wire flows out of the nozzle and is deposited on the surface of a printing substrate. The outer diameter of the nozzle is 0.1-0.8 mm. When the printing device is an LMD process, the forming action head 4 comprises a powder feeding device, a laser head and a nozzle. When the laser printer works, laser is emitted from a laser head and irradiates and covers the powder spot sprayed from the nozzle, so that the powder is quickly melted and continuously flies and deposits on the surface of a printing base material under the action of jet kinetic energy. The printing precision of the LMD process can reach 0.5-2 mm.

In the method for printing a three-dimensional object disclosed by the present invention, theprinting substrate 8 can be selected from three-dimensional objects with at least one surface being an inclined surface, a curved surface and other irregular planes, including but not limited to plates, wooden products, fabrics, plastic products and rubber products. Preferably, theprinting substrate 8 can be an artificially synthesized metal or non-metal plate, a wood board, an artificial handicraft, a cloth and textile, a plastic block, a plastic table, a plastic disc, a plastic base, a rubber pad.

Theprinting substrate 8 is fixed on the second moving platform 7 in a non-permanent manner and can move along the Z axis along with the Z axis positioning mechanism 6. Preferably, the non-permanent modes comprise modes of clamping, riveting, inserting, screw connection, pasting, pressing and the like,

through the three-dimensional printing method provided by the invention, deposition material increase operation on theprinting substrate 8 is realized.

In one or more embodiments, the present invention provides a method for compensating for planar distortion of a printed substrate, which comprises the following steps:

s01, moving the Z-axis positioning mechanism 6 to move theprinting substrate 8 to a measurement coordinate position;

s02, the distance measuring head 5 scans the landform of the printing area of theprinting substrate 8 and records landform data according to a set sampling interval;

s03, the three-dimensional printing controller 11 superposes the landform data and the three-dimensional data of the target to be printed, and calculates the number of printing layers of each scanning point in the area to be printed and the deposition thickness of each printing layer;

s04, the three-dimensional printing controller 11 controls the forming action head 4 and the Z-axis positioning mechanism 6 to print the three-dimensional object.

Specifically, in one or more embodiments, after theprinting substrate 8 moves to the measurement coordinate position, the three-dimensional printing controller 11 drives the distance measuring head 5 to scan the terrain of the printing area of theprinting substrate 8 through the XYaxis positioning mechanism 2 according to the set scanning path and the set scanning speed, and records the terrain data according to the set adoption interval. The recorded data adopts a two-dimensional array storage structure; wherein, the row index of the array element corresponds to the X-axis coordinate value of the scanning point, the column index corresponds to the Y-axis coordinate value of the scanning point, and the value of the array element is the landform variable of the corresponding scanning point; further, the three-dimensional printing controller 11 calculates a peak-to-peak value Dp-n of the topography of theprinting substrate 8 based on the complete scan data stored in the two-dimensional array. And superposing the landform data and the three-dimensional data of thetarget 10 to be printed to obtain the three-dimensional data of thetarget 10 to be printed at each coordinate in the actual printing area of thetarget 10 to be printed.

In one or more embodiments, when the printed substrate topographic data is overlaid with the three-dimensional data of the target to be printed, one or a combination of the following overlay modes may be selected:

(1) taking a plane where the highest point of the printing area is as a base plane, adding a relative value of a landform variable to an XY coordinate position corresponding to the bottom of the target to be printed;

(2) taking the plane of the lowest point of the printing area as a base plane, and subtracting the relative value of the landform variable from the XY coordinate position corresponding to the bottom of the target to be printed;

(3) selecting the median height of the printing area or any height as a base plane, and adding the relative value of the landform variable if the XY coordinate position of the bottom of the target to be printed is lower than the base plane, and subtracting the relative value of the landform variable if the XY coordinate position of the bottom of the target to be printed is higher than the base plane;

in one or more embodiments, after obtaining the three-dimensional data of the object to be printed within the actual printing area, the three-dimensional printer controller may determine, in a direct calculation method, the total number of printing layer layers for each XY coordinate position, that is, the deposition thickness of the preferred interval of the deposition amount per layer of the action head 4 divided by the actual height per XY coordinate position, according to a usual setting. Specifically, the height of the three-dimensional object at the n-th row and m-column coordinates of the actual three-dimensional object printing data is represented by h' { n, m }, divided by the preferred deposition thickness Δ D of the action head 4_preRange, the total number of printing layers j' { n, m } at the nth row, m column coordinates is obtained.

In other embodiments, the three-dimensional printer controller may determine the total number of printing layers j' { n, m } in the actual state by an iterative method with reference to the number of printing layers j { n, m } at the n-th row and m-column coordinates in the ideal state. Specifically, h' { n, m } is divided by the number of printing layers j { n, m } of the XY coordinate in the ideal state to obtain an estimated printing layer deposition amount D in the n-th row and m-th column_e' { n, m }; comparison D_eWhether or not the value of' { n, m } meets the range of the maximum adjustment value Δ Dmax of the deposition thickness of each layer of the action head 4; if the result is yes, D is added_e' { n, m } is set so that the deposition amount D ' { n, m }, j ' { n, m } of each print layer in the actual state coincides with j { n, m }; if not, then divide h' { n, m } by (j { n, m } +1) or (j { n, m } -1); repeating the above steps until D_e'{ n, m } is satisfied, and the total number of printing layer layers j' { n, m } -, j { n, m } + -q, q is an integer in an actual state.

In one or more embodiments, thetarget 10 to be printed, which is shown in fig. 4A in a side view, ideally, has a planar lower surface of thetarget 10 to be printed. On the same m-coordinate, the three-dimensional printing controller 11 divides it into 6 n-coordinate positions, and prints 6 layers in total.

In one embodiment, theprinting substrate 81 is shown in fig. 4B, and thehighest plane 91 of the printing area is taken as a base plane, and the relative values of the topographic variables of the corresponding positions are added to the other n-coordinate points. Thus, the three-dimensional data of the obtained target to be printed in the actual printing state is as shown in 101.

In one embodiment, theprint substrate 82 is shown in FIG. 4C with the lowest plane 92 of the print area as the base plane and the relative values of the topographical variables at the corresponding locations subtracted from the other n-coordinate points. Thus, the three-dimensional data of the obtained target to be printed in the actual printing state is as shown at 102.

In one embodiment, theprinting substrate 83 is shown in fig. 4D, and acertain plane 93 of the printing area is taken as a base plane, and for n coordinate points lower than the base plane, the relative values of the landform variables at corresponding positions are subtracted; for n coordinate points above the base, the relative values of the geomorphic variables for the corresponding locations are added. Thus, the three-dimensional data of the obtained target to be printed in the actual printing state is shown as 103.

In the above-described embodiment, the total number of printing layers j' { n, m } of the target to be printed 10 in the ideal state is the same as the total number of printing layers j { n, m } in the ideal state, and is 6 layers. In other embodiments, the total number of layers j' { n, m } of printed layers in the actual state may be different from the number of layers printed in the ideal state.

In the above embodiment, the upper surface of the target to be printed 10 is a plane both in the ideal state and in the actual state, and the design concept of three-dimensional printing is conformed from the appearance of the three-dimensional object.

In other embodiments, as shown in fig. 5, the upper surface of the three-dimensional object 104 is a non-planar design concept, and the three-dimensional data 104' in the actual state can still ensure that the printing result meets the design concept by the three-dimensional printing method disclosed in the present invention. In the above embodiment, 104' leftmost column, since the plane compensation value is large, is printed in accordance with j { n, m }Then D is_e' { n, m } would be outside the Δ Dmax range; therefore, a process of adding one print layer, i.e., j' { n, m } ═ j { n, m } +1 is performed. D' { n, m } at this time meets the range requirement of Δ Dmax.

Preferably, as shown in fig. 3, in one or more embodiments, the step S04 specifically includes:

s41, the three-dimensional printing controller 11 calculates a follow-up path of a Z-axis coordinate corresponding to the current printing layer according to the XY instantaneous coordinate position of the forming action head 4, and controls the Z-axis positioning mechanism 6 to output Z-axis motion;

s42, the three-dimensional printing controller 11 calls the deposition thickness of the current printing layer calculated in the step S03 corresponding to the XY instantaneous coordinate position;

s43, the three-dimensional printing controller 11 drives the forming action head 4 to deposit the printing material with the deposition thickness corresponding to the XY instantaneous coordinate position;

s44, the three-dimensional printing controller 11 drives the XYaxis positioning mechanism 2 to move the forming action head 4 to the next XY instantaneous coordinate position of the printing sequence layer;

and S46, driving the Z-axis positioning mechanism 6 to move to the next printing sequence layer position, and repeating S41-S45 until all three-dimensional object printing layers are printed.

Specifically, in one or more embodiments, during printing of the three-dimensional object, the three-dimensional printing controller 11 calculates, based on the XY instantaneous coordinate position at which the forming head 4 is located, and based on the formula: h' { n, m }. multidot (i)_p-i₀) The current position i is calculated from the XY instantaneous coordinate position₀To the ith_pThe following path of the Z-axis coordinate of the printing layer outputs the Z-axis motion of the Z-axis positioning mechanism 6, theprinting substrate 8 is driven to move to the corresponding Z-axis position, and the printing material can be deposited to the corresponding printing layer when the forming action head 4 works.

In one or more embodiments, the three-dimensional print controller 11 stores the deposition amount of each print layer calculated in step S03, or on another storage medium; in step S43, the three-dimensional printing controller 11 directly retrieves the XY instantaneous coordinate position and the deposition amount data corresponding to the printing layer, and further drives the forming head 4 to complete printing at the instantaneous position.

In one or more embodiments, to save printing time, reduce the repetitive motion of the Z-axis positioning mechanism, and improve printing efficiency, the forming head typically selects the three-dimensional object to be printed layer-by-layer, i.e., according to the print order layers, first prints each dot on the print order layer, and then prints each print order layer one-by-one.

The printing order layer is a layer in which the number of printing layers calculated in step S03 and the deposition thickness of each layer are planned in the transverse direction. Wherein the planning comprises two methods:

the first is a printing layer numbering method, namely, printing layers with the same numbering sequence are planned to be the same printing sequence layer from the bottom layer;

the second method is a contour method, namely, printing layers with the same or similar horizontal heights at all XY coordinate positions are planned to be the same printing sequence layer.

In one or more embodiments, the profiling head 4 controls the instantaneous deposition amount only at the set actual print layer deposition amount D' { n, m }, and the Z-axis positioning mechanism no longer superimposes the compensation motion.

Preferably, as shown in fig. 6, the three-dimensional printing controller 11 is electrically connected to the XY-axis positioning mechanism 2, the Z-axis positioning mechanism 6, the forming action head 4, and the distance measuring head 5, respectively, for controlling the movement of the XY-axis positioning mechanism 2, the Z-axis positioning mechanism 6, and for controlling the action head 4 to deposit the corresponding printing material.

Preferably, the distance measuring head solution in this embodiment includes not only a common infrared distance measuring detecting element, but also other plane distortion detecting elements such as a depth camera, and these distance measuring solutions should fall within the scope of the present invention.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the printing substrate does not need high-precision plane processing, does not need a complex leveling mechanism, is not limited by materials, can be subjected to additive operation only by adopting a single distance measuring head and matching with an original movement mechanism of the three-dimensional printer, and is convenient to realize in a real-time control system.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical solution of the present invention in any way. Any simple modification, form change and modification of the above embodiments according to the technical spirit of the present invention fall within the scope of the present invention.

Claims

1. A method of three-dimensional printing, the method comprising the steps of:

2. The three-dimensional printing method according to claim 1, wherein the step S04 is specifically:

3. The three-dimensional printing method according to claim 1, wherein the printing substrate is a three-dimensional object having at least one surface of a slant surface, a curved surface, or other irregular plane.

4. The three-dimensional printing method according to claim 1, wherein the print substrate is non-permanently affixed to the Z-axis positioning mechanism.

5. The three-dimensional printing method according to claim 1, wherein the topographic data is a two-dimensional array memory structure, wherein the row index of the two-dimensional array element corresponds to the X-axis coordinate value of the scanning point, the column index corresponds to the Y-axis coordinate value of the scanning point, and the value of the array element is the topographic variable corresponding to the scanning point.

6. The three-dimensional printing method according to claim 1, wherein the topographic data is superimposed with the three-dimensional data of the object to be printed, with the plane of the highest point, or the plane of the lowest point, or the median height, or any height of the printing area as a base plane, and the relative value of the topographic variable is added to the coordinate position below the base plane and subtracted from the coordinate position above the base plane.

7. The three-dimensional printing method according to claim 1, wherein the number of printing layers in the actual state is calculated by a direct calculation method or an iterative calculation method.

8. The three-dimensional printing method according to claim 1, wherein the actual deposition thickness is calculated according to the number of printing layers or an iterative method.

9. The three-dimensional printing method according to claim 2, wherein the printing order layers are obtained by performing lateral planning on the number of printing layers and the deposition thickness of each layer calculated in step S03 by a printing layer numbering method or a contour method.

10. A printing apparatus based on the three-dimensional printing method of claim 1, wherein the printing apparatus comprises a rigid support, an XY-axis positioning mechanism, a Z-axis positioning mechanism, a first moving platform, a second moving platform, a forming head, a distance measuring head, a printing substrate, and a three-dimensional printing controller, wherein:

the XY axis positioning mechanism is positioned at the top of the rigid support, and a first moving platform is arranged on the XY axis positioning mechanism; the first moving platform is provided with a forming action head and a distance measuring head, wherein the forming action head and the distance measuring head perform plane motion by utilizing an XY axis positioning mechanism; the Z-axis positioning mechanism is positioned on the side surface of the rigid support, and a second moving platform is arranged on the Z-axis positioning mechanism; the second moving platform is basically parallel to the first moving platform and can be close to or far away from the forming action head and the distance measuring head under the drive of the Z-axis positioning mechanism; a printing substrate is arranged on the second moving platform; the three-dimensional printing controller is respectively and electrically connected with the XY axis positioning mechanism, the Z axis positioning mechanism, the forming action head and the distance measuring head.