阅读说明：本技术 用于3d打印的设备及其控制方法 (Apparatus for 3D printing and control method thereof ) 是由 黄卫东 黄芃 于 2020-04-03 设计创作，主要内容包括：提供一种用于3D打印的设备及其控制方法。该设备包括：输料管,其外壁上设置有沿输料管的轴向延伸的开口；套管,套在输料管上,套管的外壁上设置有可与开口连通的出料口,套管可相对输料管绕输料管的轴线旋转,以使得出料口与开口连通或者不再连通。与传统设计方式相比,上述设备利用套管提供出料口,并将套管和输料管套接在一起,使得整个设备的结构更加紧凑,此外,通过套管相对输料管绕输料管的轴线旋转来实现暂停打印,可以实现暂停打印的快速响应。(An apparatus for 3D printing and a control method thereof are provided. The apparatus comprises: the outer wall of the material conveying pipe is provided with an opening extending along the axial direction of the material conveying pipe; the sleeve is sleeved on the material conveying pipe, a material outlet which can be communicated with the opening is formed in the outer wall of the sleeve, and the sleeve can rotate around the axis of the material conveying pipe relative to the material conveying pipe so that the material outlet is communicated with the opening or is not communicated with the opening any more. Compared with the traditional design mode, the equipment utilizes the sleeve to provide the discharge port, and the sleeve and the conveying pipeline are sleeved together, so that the structure of the whole equipment is more compact, in addition, the printing is suspended by the relative rotation of the sleeve around the axis of the conveying pipeline, and the quick response of the printing is suspended can be realized.)

1. An apparatus for 3D printing, comprising:

the outer wall of the material conveying pipe is provided with an opening extending along the axial direction of the material conveying pipe;

the sleeve is sleeved on the material conveying pipe, a material outlet communicated with the opening is formed in the outer wall of the sleeve, and the sleeve can rotate around the axis of the material conveying pipe relative to the material conveying pipe, so that the material outlet is communicated with the opening or is not communicated with the opening any more.

2. Apparatus according to claim 1, wherein said sleeve is rotatable relative to said feed conveyor about the axis of said feed conveyor so that said spout is no longer in communication with said opening in the event that printing is to be suspended.

3. The apparatus of claim 2, further comprising:

and the first driving device is used for driving the sleeve to rotate around the axis of the conveying pipe relative to the conveying pipe under the condition that printing is required to be suspended, so that the discharge hole is not communicated with the opening any more.

4. The apparatus of any of claims 1-3, further comprising:

and the second driving device is used for driving the sleeve to rotate around the axis of the conveying pipe relative to the conveying pipe under the condition that printing needs to be started, so that the discharge hole is communicated with the opening.

5. The apparatus of claim 3 or 4, further comprising:

control means for controlling the drive means in the apparatus.

6. The apparatus of any one of claims 1 to 5, wherein the passage of the discharge port is configured such that the cross section gradually decreases to a size required for the discharge port in the material outflow direction.

7. The apparatus of claim 6, wherein the passage of the discharging hole is a structure whose cross section gradually shrinks to a width required by the discharging hole along the material flowing direction.

8. The apparatus of claim 7, wherein the passage of the discharge port has a cross section in a length direction of a stepped flow passage cross section or a streamlined flow passage cross section.

9. The apparatus of any one of claims 1-8, wherein the outer wall of the sleeve comprises a first portion and a second portion, the first portion and the second portion being relatively slidable in the axial direction to adjust the length of the spout;

the abutting surface between the first part and the second part has a step-shaped structure along the material outflow direction, so that the channel of the discharge port is a structure with a cross section gradually reduced to the size required by the discharge port along the material outflow direction.

10. A control method of an apparatus for 3D printing, characterized in that the apparatus for 3D printing comprises:

the outer wall of the material conveying pipe is provided with an opening extending along the axial direction of the material conveying pipe;

the sleeve is sleeved on the material conveying pipe, a discharge hole which can be communicated with the opening is formed in the outer wall of the sleeve, and the sleeve can rotate around the axis of the material conveying pipe relative to the material conveying pipe;

the control method comprises the following steps:

and controlling the sleeve to rotate around the axis of the feed delivery pipe relative to the feed delivery pipe so that the discharge hole is communicated with the opening or is not communicated any more.

11. The method of controlling the rotation of said sleeve relative to said feed conveyor pipe about the axis of said feed conveyor pipe as defined in claim 10, comprising:

and under the condition that printing needs to be suspended, the sleeve is controlled to rotate around the axis of the feed delivery pipe relative to the feed delivery pipe, so that the discharge port is not communicated with the opening any more, and a material delivery channel is blocked.

12. A method according to claim 10 or 11, wherein said controlling of said sleeve to rotate relative to said feed conveyor pipe about the axis of said feed conveyor pipe comprises:

and under the condition that printing needs to be started, the sleeve is controlled to rotate around the axis of the conveying pipe relative to the conveying pipe, so that the discharge port is communicated with the opening, and a material conveying channel is opened.

Technical Field

The present application relates to the field of 3D printing, and more particularly, to an apparatus for 3D printing and a control method thereof.

Background

Fused Deposition Modeling (FDM) is a common 3D printing technique. FDM techniques generally require heating a material to a molten state (or semi-flow state) and extruding the molten material from a discharge port (or extrusion port) of a 3D print head, where the material is deposited layer by layer on a printing platform to form a 3D object.

The conventional 3D print head has a feeding portion and a nozzle for forming a discharge hole. The nozzle is usually mounted at the lower end of the delivery section, resulting in an apparatus that is not compact enough.

Disclosure of Invention

The application provides a device for 3D printing and a control method thereof, which can enable the structure of the device to be more compact.

In a first aspect, there is provided an apparatus for 3D printing, comprising: the outer wall of the material conveying pipe is provided with an opening extending along the axial direction of the material conveying pipe; the sleeve is sleeved on the material conveying pipe, a material outlet communicated with the opening is formed in the outer wall of the sleeve, and the sleeve can rotate around the axis of the material conveying pipe relative to the material conveying pipe, so that the material outlet is communicated with the opening or is not communicated with the opening any more.

In a second aspect, there is provided a method of controlling an apparatus for 3D printing, the apparatus for 3D printing including: the outer wall of the material conveying pipe is provided with an opening extending along the axial direction of the material conveying pipe; the sleeve is sleeved on the material conveying pipe, a discharge hole which can be communicated with the opening is formed in the outer wall of the sleeve, and the sleeve can rotate around the axis of the material conveying pipe relative to the material conveying pipe; the control method comprises the following steps: and controlling the sleeve to rotate around the axis of the feed delivery pipe relative to the feed delivery pipe so that the discharge hole is communicated with the opening or is not communicated any more.

In a third aspect, a computer-readable storage medium is provided, on which instructions for executing the control method according to the second aspect are stored.

In a fourth aspect, a computer program product is provided, comprising instructions for performing the control method according to the second aspect.

Compare with traditional design (with the nozzle setting in the bottom of defeated material part), this application utilizes the sleeve pipe to provide the discharge gate to cup joint sleeve pipe and conveying pipeline together, make the structure of whole equipment compacter, and rotate around the axis of conveying pipeline through the relative conveying pipeline of sleeve pipe and realize the printing of pausing, can realize the quick response of pausing printing.

Drawings

Fig. 1 is a schematic diagram of the overall structure of a conventional 3D printing apparatus.

Fig. 2 is a schematic structural view of a conventional 3D printhead.

Fig. 3a is an exemplary diagram of a print area of a layer to be printed.

FIG. 3b is an exemplary diagram of the arrangement of the passes.

Fig. 4 is a diagram of an example of a structure of an apparatus for 3D printing provided in an embodiment of the present application.

FIG. 5 is a three-dimensional structure of a feed delivery pipe according to an embodiment of the present invention.

Fig. 6 is a two-dimensional plan view of the feed conveyor pipe shown in fig. 5.

FIG. 7 is a schematic cross-sectional view of a feed delivery tube and sleeve in the direction of an extrusion passage through a discharge orifice according to an embodiment of the present invention.

Fig. 8 is a block diagram of the apparatus shown in fig. 4 after removal of the holder.

FIG. 9 is an illustration of an example of a three-dimensional structure of a detachable portion of a breakaway cannula provided by one embodiment of the present application.

Fig. 10 is a two-dimensional plan view of the detachable portion shown in fig. 9.

FIG. 11 is a schematic view of the detachable part shown in FIG. 9 in an assembled state with a feed conveyor pipe.

FIG. 12 is an exploded view of the separable portions of a split sleeve provided in accordance with one embodiment of the present application.

Fig. 13 is an assembly view of the various separable portions shown in fig. 12.

FIG. 14 is an exploded view of the separable portions of a split sleeve provided in accordance with another embodiment of the present application.

FIG. 15 is an assembly view of the detachable sleeve and feed delivery tube of FIG. 14.

Fig. 16 is an illustration of a detachable sleeve with a closed-loop design at the end provided by an embodiment of the present application.

FIG. 17 is an illustration of an exemplary three-dimensional structure of a detachable portion of a breakaway cannula provided in another embodiment of the present application.

FIG. 18 is an assembly view of the sleeve and feed delivery tube shown in FIG. 17, assembled from separable parts.

Fig. 19 is a diagram illustrating an example of a printing process of the apparatus provided in the embodiment of the present application.

Fig. 20 is a comparison graph of the printing effect of the apparatus provided by the embodiment of the present application and the printing effect of the conventional 3D printing mode.

Fig. 21 is an exemplary diagram of a pass switching manner in the conventional 3D printing manner.

Fig. 22 is an exemplary diagram of a feeding device provided in an embodiment of the present application.

FIG. 23 is a side view of an open channel in an apparatus for 3D printing provided by yet another embodiment of the present application.

Fig. 24 is a block diagram of a first portion of the cannula in the device shown in fig. 26.

Fig. 25 is a block diagram of a cannula in the device shown in fig. 26.

Fig. 26 is a perspective view of an apparatus for 3D printing according to still another embodiment of the present application.

Fig. 27 is a schematic flowchart of a control method provided in an embodiment of the present application.

Detailed Description

For ease of understanding, a brief description of a conventional 3D printing apparatus will be given.

As shown in fig. 1, the conventional 3D printing apparatus 1 may generally include a feeding device 11, a 3D printing head 12, a printing platform 13, and a control device 14 (the above structural division is only an example, and actually, other structural division may be adopted, for example, the control device and/or the feeding device 11 may be part of the 3D printing head 12).

The feeding device 11 may be connected to a wire disc 15. During the actual printing process, the feeding device 11 may take filamentary material from the filament tray 15 and deliver the filamentary material to the 3D print head 12. The materials used in the 3D printing process are typically thermoplastic materials such as high molecular weight polymers, low melting point metals, and other materials that can be formulated into a flowable paste (e.g., ceramic paste, high melting point metal powder mixture, cement, etc.).

As shown in fig. 2, the 3D print head 12 may generally include a feeding portion 121, a nozzle 122, and a temperature control device 123. The temperature control device 123 is generally disposed outside the feeding portion 121, and is used for heating the material fed from the feeding device 11 to the feeding portion 121 to a molten state. The temperature control device 123 may be, for example, a heating device. The nozzle 122 is installed at the lower end of the feeding portion 121. The nozzle may be provided with a discharge port 124 so that the material in a molten state fed by the feeding portion 121 can be extruded onto the printing platform 13.

Control device 14 may be used to control 3D print head 12 to print the article layer by layer. In the process of printing each layer, the 3D print head 12 may be controlled to print all the printing areas of the layer to be printed (i.e. all the areas surrounded by the cross-sectional outline of the layer to be printed) completely according to the preset printing path.

The overall process of conventional 3D printing is roughly as follows:

prior to printing the item, a 3D model of the item may be created using modeling software. The modeling software may be, for example, Computer Aided Design (CAD) software. And then, carrying out layering processing on the created 3D model, dividing the 3D model into a plurality of layers to be printed, and obtaining layering data of each layer to be printed. By layering the 3D model, the printing process of the 3D object is decomposed into a plurality of 2D printing processes, and the printing process of each layer to be printed is similar to the planar 2D printing process. After obtaining the hierarchical data of each layer to be printed, the control device 14 may control the 3D print head 12 to move along a certain printing path according to the hierarchical data of each layer to be printed, and in the moving process, extrude the material in the molten state onto the printing platform 13 through the discharge port 124, and print or fill the printing area of each layer to be printed. And when all the layers to be printed of the object are printed, solidifying the material layer by layer to form the 3D object.

For ease of understanding, the following describes in detail a printing process of a layer to be printed by a conventional 3D printing apparatus, taking fig. 3a and 3b as an example.

Referring to fig. 3a and 3b, the printing area of the layer to be printed is area 31, and the cross-sectional outline of area 31 is cross-sectional outline 32.

To print region 31 completely, region 31 is typically divided into multiple passes (pass) based on cross-sectional profile 32, as shown in FIG. 3b as pass A1-pass A25.

During printing, the control device 14 controls the z-coordinate of the 3D print head 12 to remain unchanged, and controls the 3D print head 12 to print all passes completely in a sequence, such as the sequential printing of passes a1-a25 in parallel reciprocating linear paths.

Taking the printing process of pass a1 as an example, the control device 14 may move the 3D print head 12 to above the position point p1 shown in fig. 3a, then control the 3D print head 12 to move from above the position point p1 to above the position point p2, and extrude the material in the molten state to pass a1 through the discharge port 124 in the moving process, so as to print pass a1, and the printing manner of other passes is similar, and is not described herein again. After all the passes of printing are finished, the printing process of the layer to be printed is finished, and the 3D printing head 12 or the working platform 13 may be controlled to move along the z-axis direction to prepare for printing the next layer.

As described above, the conventional 3D print head 12 has the feeding portion 121 and the nozzle 122 for providing the discharge port 124. The nozzle 122 is generally installed at the lower end of the feeding portion 121, resulting in a less compact structure of the 3D print head 12.

The following describes in detail an apparatus for 3D printing provided in an embodiment of the present application. It should be noted that the apparatus for 3D printing may refer to a 3D printing head, and may also refer to an entire 3D printer or a 3D printing system.

As shown in fig. 4, the apparatus 4 for 3D printing may comprise a feed conveyor pipe 5 and a sleeve 6. The sleeve 6 can be placed over the feed conveyor pipe 5, thus forming a compact sleeve assembly.

With reference to fig. 5-6, the outer wall of the feed conveyor pipe 5 is provided with an opening 52 (which may, for example, extend in the axial direction of the feed conveyor pipe 5).

In some embodiments the feed conveyor 5 may belong to one of the entire feed conveyor sections of the apparatus 4. The feeding section may comprise, in addition to the feeding duct 5, other sections communicating with the feeding duct 5.

In other embodiments, where the feed conveyor 5 is the feeding part of the apparatus 4, the feed inlet 54 may be provided on the end surface of the feed conveyor 5 or on the outer wall of the feed conveyor 5.

The inner part of the feed conveyor pipe 5, which will be referred to as feed conveyor channel in the following, may be designed as a circular arc. For example, referring to FIGS. 5 to 6, the feed passage may be designed as a cylindrical passage. In addition, in some embodiments, the cylindrical channel also has a rounded transition between its ends. The circular arc design is adopted for the material conveying channel, so that not only can materials in a molten state be smoothly conveyed in the material conveying channel, but also the material conveying channel can be conveniently cleaned, and the material waste caused by the retention of the materials in the material conveying channel is avoided as much as possible.

The sleeve 6 can be sleeved on the feed delivery pipe 5, i.e. the feed delivery pipe 5 can be regarded as the inner pipe of the sleeve 6. The outer wall of the sleeve 6 is provided with a discharge hole 65 which can communicate with the opening 52. In some embodiments, similar to the opening 52, the outlet 65 may also be an outlet 65 extending in the axial direction of the feed conveyor pipe 5, i.e. the length of the outlet 52 may be in the axial direction of the feed conveyor pipe 5. The outer wall of the sleeve 6 may be provided with one discharge hole 65, or a plurality of discharge holes 65. For example, the outer wall of the sleeve 6 can be provided with 2 discharge ports, 3 discharge ports, 4 discharge ports and 8 discharge ports. The sleeve 6 is movable relative to the feed conveyor pipe 5 so that the different outlets 65 communicate with the openings 52 (i.e. switching between the different outlets 65 is effected).

The sleeve 6 can be rotated relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 so that the outlet 65 is in communication with the opening 52 or no longer.

For example, rotation of the sleeve 6 relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 may cause the discharge opening 65 to be no longer in communication with the opening 52, thereby blocking the material conveying path and allowing printing to be suspended.

An example is described in connection with fig. 7. Two outlets 65 are schematically shown in fig. 7, and for the sake of distinction and not limitation, the two outlets are respectively designated as an outlet 65(1) and an outlet 65 (2). Assuming that the discharge port 65(1) is initially communicated with the opening 52, as shown in the left side of fig. 7, and the discharge port 65(1) is communicated with the opening 52, when printing is to be suspended, the sleeve 6 is rotated relative to the feed delivery pipe by an angle (in the example of fig. 7, clockwise) about the axis of the feed delivery pipe 5 so that the discharge port 65(1) is not communicated with the opening 52 any more, as shown in the right side of fig. 7, thereby blocking the material delivery path and achieving suspension of printing.

Therefore, the device 4 provided by the embodiment of the application realizes printing pause by rotating the sleeve relative to the conveying pipe around the axis of the conveying pipe, and can realize quick response of printing pause.

For example, the sleeve 6 may be rotated relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 by a small angle, so that the outlet 65 is or is no longer in communication with the opening 52. For example, the smaller angle means the smallest angle that enables the discharge port 65 to be no longer in communication with the opening 52 by communication.

As an example, in the case where printing is to be suspended, assuming that a minimum rotation of the sleeve 6 relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 by a first angle makes it possible to bring the discharge opening 65 out of communication with the opening 52, the sleeve 6 is rotated relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 by the first angle so that the discharge opening 65 is brought out of communication with the opening 52.

In this example, when printing is to be started subsequently, the sleeve 6 is rotated in the opposite direction about the axis of the feed conveyor pipe 5 by the first angle relative to the feed conveyor pipe, so that the discharge opening 65 communicates with the opening 52, and printing is resumed quickly.

In 3D printing processes, it is often necessary to pause the printing process. For example, printing to the edge of the outline of the target print area requires pausing the printing process and waiting until the print head is moved to the new print start position and the printing process is resumed. The 3D printing extrusion material is generally a high-viscosity substance, for example, has the viscoelastic property of a high polymer material, and when the material conveying device stops conveying the printing material, the flow of the material does not stop suddenly, and at this time, the printing material continues to be stacked outside the contour edge of the target printing area, which may damage the shape of the cross-sectional contour line of the target printing area, resulting in reducing the geometric accuracy of the printed piece.

The equipment 4 that this application embodiment provided, at the in-process that 3D printed, when printing and going on the contour edge that the target printed the region and need pause printing, when material conveyor stopped to carry the printing material, sleeve 6 rotated a less angle around the axis of conveying pipeline 5 relatively the conveying pipeline to make discharge gate 65 no longer communicate with opening 52, block the material transfer passage, thereby made the printing material quick response control system's instruction and stopped flowing out from discharge gate 65.

Therefore, the apparatus 4 provided in the embodiment of the present application can achieve a quick response of suspending printing.

In some embodiments, the sleeve 6 rotates around the axis of the feeding pipe 5 relative to the feeding pipe, so that the discharge hole 65 communicates with the opening 52 to open the material conveying passage to start printing under the condition that printing needs to be started.

Also take fig. 7 as an example. Assuming that the discharge port 65(1) is not initially communicated with the opening 52, as shown in the right side of fig. 7, when printing is to be started, the sleeve 6 is rotated by an angle (in the example of fig. 7, by an angle in the counterclockwise direction) with respect to the axis of the feed conveyor pipe 5 so that the discharge port 65(1) is communicated with the opening 52, as shown in the left side of fig. 7, thereby opening the material conveying passage and starting printing.

The equipment 4 that this application embodiment provided, it is rotatory around the axis of conveying pipeline 5 to realize starting printing through the relative conveying pipeline of sleeve pipe 6, can realize starting the quick response of printing.

The rotation of the sleeve 6 relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 can be effected by means of a drive. As shown in fig. 4, the device 4 comprises a drive means 7.

The drive means 7 can be used to rotate the drive sleeve 6 relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 so that the outlet 65 is in communication with the opening 52 or no longer in communication therewith.

The drive means 7 are used, for example, to rotate the drive sleeve 6 relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 in the event that printing needs to be suspended, so that the discharge opening 65 is no longer in communication with the opening 52.

For another example, the drive means 7 is adapted to rotate the drive sleeve 6 relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 in order to bring the discharge opening 65 into communication with the opening 52 in the event that printing needs to be initiated.

The specific implementation of the driving device 7 may be various, and the present embodiment is not limited to this, and may be, for example, a rack and pinion mechanism, or a slider-crank mechanism.

In some embodiments, port 65 may always be in communication with opening 52. For example, the discharge port 65 may be fixed below the opening 52. In the case where printing is to be suspended, the sleeve 6 is rotated relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 so that the discharge opening 65 is no longer in communication with the opening 52.

In other embodiments, the sleeve 6 can be moved relative to the feed conveyor pipe 5 so that the outlet 65 can be moved below the opening 52 and thus communicate with the opening 52. In the case where printing is to be suspended, the sleeve 6 is rotated relative to the feed conveyor pipe about the axis of the feed conveyor pipe 5 so that the discharge opening 65 is no longer in communication with the opening 52.

In some embodiments, the sleeve 6 may be a unitary sleeve, such as an integrally formed sleeve. In other embodiments, the sleeve 6 may be a split sleeve, i.e. the outer wall of the sleeve 6 may comprise separable parts, or the outer wall of the sleeve 6 may be spliced from separable parts.

As shown in fig. 8-10, the outer wall of the sleeve 6 may include separable first and second portions 61, 62. The first part 61 can be assembled with the feed conveyor pipe 5 in the manner shown in fig. 11. The second portion 62 may have a complementary configuration to the first portion 61 and may be spliced together in the manner shown in figure 8 to form the outer wall of the sleeve 6.

In some embodiments, the outer wall of the cannula 6 may also be composed of three or more separable sections. As shown in fig. 12 to 13, the outer wall of the sleeve 6 comprises a first separable part 61, a second separable part 62, a third separable part 63 and a fourth separable part 64, the edges of which are joined to each other to form the outer wall of the sleeve 6.

The sleeve 6 can be fixed to the feed conveyor pipe 5 or can be movable relative to the feed conveyor pipe 5. For example, the sleeve 6 can be moved in the axial direction of the feed conveyor pipe 5; for another example, the sleeve 6 can rotate around the axis of the feed delivery pipe 5; as another example, the sleeve 6 can be moved both axially along the feed conveyor pipe 5 and also rotationally along the axis of the feed conveyor pipe 5.

The discharge hole 65 may be a discharge hole of a fixed size or a discharge hole of an adjustable size. The adjustable size of the outlet 65 may indicate that the length of the outlet 65 is adjustable (or the length is continuously adjustable), may indicate that the width of the outlet 65 is adjustable (or the width is continuously adjustable), or may indicate that both the length and the width of the outlet 65 are adjustable (or continuously adjustable).

The manner in which the outlet 65 is designed as a size-adjustable outlet can be varied. Several possible implementations are given below.

For example, as one possible implementation, one or more shutters may be provided at the spout 65 to adjust the size of the spout 65.

As another example, as another possible implementation, the sleeve 6 may comprise separable portions. The abutting surfaces of the sections may enclose the discharge openings and the sections may be moved relative to each other, e.g. in the axial direction of the feed conveyor pipe 5, to adjust the size of the discharge opening 65.

Taking fig. 8 as an example, the sleeve 6 may comprise a first portion 61 and a second portion 62. The first portion 61 and the second portion 62 are slidable relative to each other in the axial direction of the feed conveyor pipe 5, so that a discharge opening 65 having an adjustable length (or a continuously adjustable length) can be formed.

The shape of the first and second portions 61,62 and the manner in which they form the spout 65 may be varied.

As one example, as shown in fig. 8, the first part 61 may include a first upper step surface 611, a first lower step surface 612, and a first connection surface 613 connecting the first upper step surface 611 and the first lower step surface 612. The second portion 62 may include a second upper stepped surface 621, a second lower stepped surface 622, and a second connection surface 623 connecting the second upper stepped surface 621 and the second lower stepped surface 622. The first upper step surface 611 contacts with the second lower step 622, and the two can slide relatively along the axial direction of the feed delivery pipe 5 (in other words, the first upper step surface 611 and the second lower step 622 are connected slidably along the axial direction of the feed delivery pipe 5). The first lower step surface 612 is in contact with the second upper step 621, and the two are capable of sliding relatively along the axial direction of the feed delivery pipe 5 (in other words, the first lower step surface 612 is in sliding connection with the second upper step 621 along the axial direction of the feed delivery pipe 5). The hollow area formed by the first lower step surface 612, the first connecting surface 613, the second lower step surface 622 and the second connecting surface 623 serves as the discharge hole 65.

In this example, the first part 61 and the second part 62 are butted together in a staggered and complementary stepped configuration, and they are slid relative to each other in the axial direction of the feed conveyor pipe 5 to form a discharge opening 65 with a continuously adjustable length. The width of the discharge hole 65 depends on a height difference between the first upper step surface 611 and the first lower step surface 612 (or the second upper step surface 621 and the second lower step surface 622). This embodiment of the discharging hole can form the discharging hole 65 having a small width (the width of the discharging hole may affect the printing accuracy) while ensuring the size and strength of the first and second portions 61 and 62.

As another example, the first portion 61 and the second portion 62 may have a concavo-convex complementary structure. The relative sliding movement of the first part 61 and the second part 62 in the axial direction of the feed conveyor pipe 5 modifies the relative positional relationship between the concave and convex portions, and the hollow area between the concave and convex portions forms the discharge opening 65.

It is pointed out that the first part 61 and the second part 62 are relatively slidable in the axial direction of the feed conveyor pipe 5. It should be noted that the embodiment of the present application does not require that both the first portion 61 and the second portion 62 are slidable relative to the feed conveyor pipe 5.

As a possible realization, both the first part 61 and the second part 62 are slidable relative to the feed conveyor pipe 5.

As another possible implementation, as shown in FIGS. 14 to 15, the first section 61 is slidable relative to the feed conveyor pipe 61, and the second section 62 is fixedly connected to the feed conveyor pipe 62 or is formed integrally with the feed conveyor pipe 5. This implementation can simplify the control of the device 4.

In some embodiments, as shown in fig. 8 or 16, the end 614 of the first portion 61 may be configured as a closed ring that fits over the delivery conduit 5; and/or end 624 of second portion 62 (end 614 and end 624 may define the axial length of sleeve 6) may be configured as a closed ring that fits over delivery conduit 5. This enhances the overall rigidity and sealing of the sleeve 6.

In some embodiments, when the first part 61 is a sliding part and the second part 62 is a fixed part, as shown in fig. 14 to 15, both ends of the first part 61 may be designed as a closed circular ring. This enhances the overall rigidity and sealing of the sleeve 6.

The embodiment of the present application does not specifically limit the relationship between the size of the discharge hole 65 and the size of the opening 52. The size of the discharge hole 65 may be the same as the size of the opening 52 or may be different from the size of the opening 52.

For example, the length of the outlet 65 (when the outlet 65 is a length-adjustable outlet, the length of the outlet 65 may indicate the maximum length of the outlet 65) may be less than the length of the opening 52; for another example, the width of the outlet 65 (when the outlet 65 is a width-adjustable outlet, the width of the outlet 65 may indicate the maximum width of the outlet 65) may be smaller than the width of the opening 52.

The size of the discharge port 65 can be adjusted by a driving device. Taking fig. 4 as an example, a bracket 91 for fixing the first portion 61 and a bracket 92 for fixing the second portion 62 may be provided on the sleeve 6. The driving means 7 can provide the carrier 91 and the carrier 92 with power for axial movement along the conveyor pipe 5, so that the first part 61 is moved axially by the carrier 91 and the second part 62 is moved axially by the carrier 92.

The specific implementation of the driving device 7 may be various, and the present embodiment is not limited to this, and may be, for example, a rack and pinion mechanism, or a slider-crank mechanism.

As described above, the outer wall of the casing 6 may be provided with one discharge port 65, and also with a plurality of discharge ports 65. For example, the outer wall of the sleeve 6 can be provided with 2 discharge ports, 3 discharge ports, 4 discharge ports and 8 discharge ports. The sleeve 6 is movable relative to the feed conveyor pipe 5 so that the different outlets 65 communicate with the openings 52 (i.e. switching between the different outlets 65 is effected).

As an example, a plurality of discharge openings 65 may be arranged in the axial direction of the feed conveyor pipe 5. In this case, the sleeve 6 can be translated in the axial direction of the feed conveyor pipe 5 so that the various outlet openings 65 communicate with the openings 52.

As another example, a plurality of discharge ports 65 may be arranged in a circumferential direction of the sleeve 6. In this case, the sleeve 6 is rotatable about the axis of the feed conveyor pipe 5, so that different outlet openings 65 communicate with the openings 52. The device 4 can also be provided with a corresponding drive for the rotation of the sleeve 6 about the axis of the feed conveyor pipe 5. The drive device may be a gear mechanism, for example.

Of course, a combination of the two above is also possible.

Next, a mode of forming the plurality of discharge ports 65 in the outer wall of the sleeve 6 will be described in detail with reference to fig. 12, 13, 17, and 18.

As a possible implementation, with reference to fig. 17 to 18, the sleeve 6 may comprise a first portion 61 and a second portion 62. The first and second parts 61,62 are similar to the first and second parts 61,62 shown in fig. 8 and 9, except that in fig. 17 to 18, both abutment surfaces of the first and second parts 61,62 are stepped abutment surfaces, wherein the stepped abutment surfaces 611a, 612a and 613a of the first part 61 and the corresponding surfaces of the second part are used to form the spout 65 a; stepped abutment surfaces 611b, 612b and 613b of the first part 61 and corresponding surfaces of the second part are used to form the spout 65 b.

As another possible implementation, referring to fig. 12 to 13, the sleeve 6 is formed by splicing 4 portions 61,62,63,64, each two adjacent portions forming a discharge opening, and the two adjacent portions forming 4 discharge openings 65a,65b,65c,65 d. Of course, in some embodiments, the abutting surface of two adjacent portions may also be designed to be a plane, so that the two adjacent portions do not form the discharge ports, and thus, various numbers of discharge ports may be designed according to actual needs (for example, an odd number of discharge ports may be designed, and an even number of discharge ports may also be designed).

The size of a plurality of discharge ports 65 is not specifically limited in the embodiment of the present application. The plurality of discharging holes 65 may be discharging holes having the same size (if the discharging holes 65 are discharging holes with adjustable size, the same size here may indicate that the largest sizes of the discharging holes 65 are the same), or discharging holes having different sizes.

As one example, the lengths (or maximum lengths) of the plurality of discharging holes 65 are different.

As another example, the plurality of spouts 65 may have different widths. The width of the discharge port 65 affects the width of the extruded material, thereby affecting the 3D printing accuracy. The design of the plurality of discharge ports 65 with different widths enables the device 4 to select discharge ports with different accuracies for printing according to actual needs.

For example, if the layer to be printed includes a first printing region in which the cross-sectional profile line changes sharply in the vertical direction and a second printing region in which the cross-sectional profile line changes gently in the vertical direction, when the device 4 is used to print the first printing region, the discharge port with a smaller width may be switched to improve the printing accuracy; when the second printing area is printed by using the device 4, the discharge port with the larger width can be switched, so that the printing efficiency is improved on the premise of ensuring the printing precision.

Of course, a combination of the above may be possible, that is, the plurality of outlets 65 may have different widths and lengths (or maximum lengths).

It is noted that the discharging hole 65 provided in the embodiment of the present application may be the discharging hole 65 with a continuously adjustable length. Compare with the design of traditional 3D printer head's discharge gate, design discharge gate 65 length continuously adjustable's discharge gate, overcome the constraint of traditional discharge gate design theory, this kind of neotype discharge gate has obvious advantage and wide application prospect. This is analyzed as follows.

The discharge port of the conventional 3D printing head is usually designed as a nozzle with a fixed shape, and common nozzle shapes include a round hole, a square hole or a slightly deformed equal-diameter special-shaped hole. The orifice diameter of the nozzle is usually about 1mm, and the orifice diameter is usually 0.4 mm. When the printing precision requirement of the object is higher, a nozzle with a smaller caliber is usually selected, the material extrusion amount of the nozzle in unit time is less, and the printing efficiency is lower; when the printing efficiency requirement of the object is high, a nozzle with a larger caliber is usually selected, the shape of the object printed by the nozzle is rough, and the printing precision is low. Therefore, the traditional 3D printing head cannot give consideration to both the efficiency and the precision of 3D printing. The formation process of this design of the conventional spout is analyzed below.

The 3D printing technology is a more advanced manufacturing technology developed on the basis of the 2D printing technology. Before 3D printing, layered processing is generally required to be performed on a 3D model of an article to be printed, and after the layered processing, it is equivalent to decompose a printing process of the 3D article into a plurality of 2D printing processes, that is, the printing process of each layer can be regarded as a one-time flat printing process. Therefore, the conventional 3D printing apparatus follows many design concepts of the 2D printing apparatus. Most obviously, the discharge port of the 2D printing head is generally designed as a nozzle with a fixed shape, and the discharge port of the 3D printing head follows the design of the discharge port of the 2D printing head, and is also designed as a nozzle with a fixed shape. As described above, such nozzle design results in a failure of the 3D print head to achieve both efficiency and precision, which is a key obstacle hindering the development of 3D printing technology.

The discharge hole 65 is designed into a discharge hole with the length continuously adjustable within a certain range in the embodiment of the application. The 3D printing device is designed on the basis of fully considering the characteristics of a 3D printing object, compared with the traditional 3D printing device, the 3D printing device provided by the embodiment of the application enables the balance between the efficiency and the precision of 3D printing to be possible, and is more suitable for 3D printing. The specific discussion is as follows.

The size of the 2D printing object is generally small, and the printing object is mainly text or images. The characters or images can be freely arranged on a two-dimensional plane without regularity. Therefore, the discharge port of the 2D printing device is designed to be a nozzle with a fixed shape, so that the design is reasonable in the field of 2D printing. Unlike the 2D printed object, the 3D printed object is generally a 3D article that needs to be actually used. A 3D object has a certain physical profile, and therefore, a sectional line of the 3D object along a certain section is usually one or more closed and continuously varying curves. This application embodiment make full use of 3D prints this characteristic of object, relates to discharge gate 65 for length continuously adjustable's discharge gate. The continuous adjustable length of the discharge port 65 is matched with the characteristics of closed and continuous change of the section contour line of the 3D printing object, and the discharge port 65 is more suitable for 3D printing, so that the printing efficiency can be greatly improved.

For example, with the discharging hole provided by the embodiment of the present application, continuous printing can be performed along the cross-sectional contour line, and the discharging hole 65 is controlled to change along with the change of the cross-sectional contour line during the printing process, which can be understood as having ultrahigh printing efficiency compared with the conventional way of printing pass by pass.

Further, the width of the discharging port 65 can be set to a fixed value with a small value, so that the printing precision of the 3D object is kept unchanged and kept at a high precision, and the printing precision is kept unchanged in the continuous change process of the discharging port 65, which is difficult to achieve by a traditional 3D printing head. Therefore, the discharge gate that length continuously adjustable that this application embodiment provided makes efficiency and the precision of taking into account 3D printing possible, is suitable for 3D more and prints.

The variation of the length of the outlet 65 will be described in detail with reference to the following specific examples.

Alternatively, the length of the discharging hole 65 may be controlled to be continuously changed according to the shape of the target printing area (or the length of the discharging hole 65 may be controlled to be changed along with the change of the shape of the target printing area), wherein the target printing area may be a partial printing area of the layer to be printed or may be the entire printing area of the layer to be printed.

For example, in some embodiments, the size of the spout 65 may be adjusted such that the length of the spout 65 matches the length of the section line of the cross-sectional contour of the target print area of the layer to be printed.

For another example, in some embodiments, the size of spout 65 may be adjusted such that both ends of spout 65 are vertically aligned with the cross-sectional contour of the target print area.

The two ends of the discharging hole 65 are aligned with the cross-sectional contour line of the target printing area in the vertical direction, and the projections of the two ends of the discharging hole 65 in the vertical direction fall on the section line of the cross-sectional contour line of the target printing area. For convenience of description, this printing manner will be hereinafter referred to as tracing printing of the cross-sectional outline of the target printing region.

The following describes the trace printing in more detail with reference to fig. 19.

Referring to fig. 19, reference numeral 100 denotes a target printing area of a layer to be printed, and the length direction of the discharge hole 65 extends in the x direction. During printing of the target printing area 100, the apparatus 4 may be controlled to move in the y direction as a whole. During the movement of the apparatus 4, the length and/or position of the discharging port 65 is changed in real time so that both ends of the discharging port 65 are always aligned with the sectional contour line of the target printing area 100 in the vertical direction z (perpendicular to the x-y plane), even if it is found that the projections of both ends of the discharging port 65 in the vertical direction z always fall on the sectional contour line of the target printing area 100.

For example, assuming that the y coordinate of the current position of the discharging hole 65 is y1, and y1 cuts the cross-sectional contour line of the target printing area 100 along the x direction to obtain two points (x1, y1) and (x2, y1), the positions of the two ends of the discharging hole 65 can be changed to make the first end be located right above (x1, y1) and the second end be located right above (x2, y1), so that the cross-sectional contour line of the target printing area 100 can be accurately tracked and printed.

The tracing printing of the cross-sectional contour of the target print area may be implemented in various ways. Alternatively, as a first implementation, the positions of both ends of the discharging hole 65 may be adjusted so that both ends of the discharging hole 65 are aligned with the cross-sectional outline of the target printing area in the vertical direction.

Optionally, as a second implementation manner, the size of the discharging hole 65 may be adjusted so that the length of the discharging hole 65 matches the section line length of the section contour line of the target printing area of the layer to be printed; and the relative position between the feed delivery pipe 5 and the sleeve 6 as a whole and the printing platform is adjusted by the driving device so that both ends of the discharge port 65 are aligned with the sectional contour line of the target printing area in the vertical direction.

In the process of printing the target printing area, the device 4 may implement tracking printing by using one of the two implementation manners according to actual needs; alternatively, different tracing print modes may be employed when printing different portions of the target print area.

For example, the target print area may include a portion having a shorter stub length and a portion having a longer stub length. When printing the portion with the shorter stub length, the tracing printing can be performed in the first implementation to simplify the control of the apparatus 4; when printing the part where the stub length is long, the tracing printing can be performed in the second implementation.

Compared with the printed article from the traditional discharge port, the tracking printing of the section contour line of the target printing area also significantly improves the mechanical property and the shape uniformity of the printed article, which is discussed in detail below with reference to fig. 20 and 21.

The conventional 3D printing is generally performed channel by channel according to a certain pass sequence. Because the size of the discharge port of the conventional 3D printing apparatus is small (the caliber is usually in the millimeter level), it takes a long time to print each pass. When the current pass is ready to be printed, the material on the previous pass adjacent to the current pass may already be at or near a solidified state while the material on the current pass is still in a molten state. The material in the molten state on the current pass needs to be fused with the material in the previous pass which is already in or close to the solidification state to form a whole, and the process of material fusion between the adjacent passes is called pass overlapping.

In the process of pass overlapping, if the previous pass of the current pass is solidified or nearly solidified and the current pass is still in a molten state, the phenomenon of poor fusion can occur in the material fusion process between the adjacent passes, so that the mechanical property of the printed article is poor. In addition, because the material states are asynchronous, the shape of an object obtained after materials on adjacent passes are fused with each other is rough. Taking a printing cylinder as an example, as shown in fig. 20, the cylinder 101 is a cylinder printed by using a conventional 3D printing technique and using a pass lap joint method. The cylindrical body 101 not only has a rough overall shape and outline, but also has a plurality of notches 103 caused by poor material fusion in the process of pass overlapping.

The device 4 provided by the embodiment of the application enables the device to perform tracing printing on the section contour line of the target printing area by adjusting the length and the position of the discharge hole 65. Therefore, in the process of printing the target printing area, the device 4 does not need to perform pass-by-pass printing according to the pass, and also does not need to perform pass overlapping, so that the problem of poor fusion cannot be caused. Therefore, the printed article by the device 4 has high mechanical properties. As shown in fig. 20, the cylinder 102 is a cylinder printed by the apparatus 4, and compared with the cylinder 101, the fusion of the filling material of the cylinder 102 is good, and the problem of poor fusion caused by pass overlapping does not exist.

Still taking the printing of a cylinder as an example, referring to fig. 21, in the conventional 3D printing process, the switching between the passes uses a polygonal line 104 instead of the real profile curve, i.e., the polygonal line is used to approximate the real profile curve, which results in a rough profile of the printed cylinder 102. The device 4 provided by the embodiment of the application does not need to print according to the pass, but tracks and prints the section contour line of the target printing area by adjusting the length and the position of the discharge hole 65, so that the contour line of the cylinder 102 printed by the device 4 is smoother and more real.

The target print area may be determined in various ways. For example, whether the printing is performed by dividing the printing area of the layer to be printed into the plurality of target printing areas, or by setting the entire printing area of the layer to be printed as the target printing area, may be determined according to one or more of the factors of the shape of the cross-sectional contour line of the layer to be printed, the length of the longest sectional line, and the size of the discharge opening.

For example, when the length of the longest sectional line of the cross-sectional outline of the layer to be printed is less than or equal to the maximum length of the discharge opening, all the printing areas of the layer to be printed may be determined as target printing areas; when the length of the longest sectional line of the cross-sectional contour line of the layer to be printed is greater than the maximum length of the discharge port, the entire printing area of the layer to be printed may be divided into a plurality of target printing areas.

For another example, when the cross-sectional contour line of the layer to be printed includes a plurality of closed regions that are not connected, each closed region may be printed as one or more target print regions.

For another example, in some embodiments, the entire printing area of the layer to be printed may be directly used as the target printing area without dividing the entire printing area of the layer to be printed. For example, the apparatus 4 may be designed as a dedicated apparatus dedicated to printing a specific article, and the length of the discharge opening 65 of the apparatus 4 may be designed to be able to print all the printing areas of each printing layer of the article at once. In this way, in operation, the device 4 can print each layer of the article in a fixed manner without the need for on-line division of the print zone.

As shown in fig. 22, the apparatus 4 may further include a feeding device 200. The feeding device 200 can feed the material to the discharge hole 65 through the material conveying pipe 5. The device 4 may also comprise a drive device (not shown) for driving the feeding device 200, the drive of the feeding device being such that the material throughput of the discharge opening 65 matches the length of the discharge opening.

The feeding device 200 may be a screw type feeding device as shown in fig. 22 (a), a pneumatic type feeding device as shown in fig. 22 (b), or a piston type feeding device as shown in fig. 22 (c).

When the feeding device 200 is a screw type feeding device, the rotation speed of the screw can be adjusted by the driving device, so that the material extrusion amount of the discharge port 65 can be controlled; in the case that the feeding device 200 is a pneumatic feeding device, the material extrusion amount of the discharge port 65 can be controlled by adjusting the pressure acting on the material liquid level; in the case that the feeding device 200 is a piston type feeding device, the moving speed of the piston in the cylindrical feeding hole of the piston can be adjusted by the driving device, so as to control the material extrusion amount of the discharging hole 65.

The fact that the material extrusion amount of the discharge port 65 is matched with the length of the discharge port 65 means that the material extrusion amount of the discharge port 65 is changed in direct proportion to the length of the discharge port 65.

During actual printing, the material extrusion amount can be determined according to the length of the discharge port 65. Then, the material feeding amount of the feeding device 200 may be controlled so that the material feeding amount is equal to the material extrusion amount.

As shown in fig. 4, the device 4 may also comprise control means 8 for controlling the various drive means mentioned above. The control device 46 may be a dedicated numerical control device or may be a general-purpose processor. The control device 46 may be a distributed control device or a centralized control device.

In the following, method embodiments of the present application are described, and since the method embodiments may be performed by the apparatus 4 described above (specifically, may be performed by the control device 8 in the apparatus 4), parts not described in detail may be referred to above.

The embodiment of the application also provides equipment for 3D printing, and the equipment has a discharge gate with adjustable length, and the extrusion channel of the discharge gate is a structure with a variable cross section along the material flow direction.

For example, the extrusion channel of the discharge port is a structure whose section along the material flow direction gradually shrinks to the size required by the discharge port. The size of the discharge port comprises width and length.

For example, the extrusion channel of the discharge port is a structure in which the cross section along the material flow direction gradually shrinks to the width required by the discharge port. In other words, the width of the cross section of the extrusion channel of the discharge opening in the material flow direction gradually shrinks to the width required by the discharge opening.

For another example, the extrusion channel of the discharge port is a structure in which the cross section along the material flow direction gradually shrinks to the length required by the discharge port.

In order to realize that the extrusion channel of the discharge port is a structure with the section gradually shrinking to the required size of the discharge port along the material flowing direction, the discharge port can be designed in various ways.

As an example, as shown in (b) of fig. 23, the cross section of the extrusion passage of the discharge port in the length direction is a stepped flow passage cross section.

As another example, as shown in (c) of fig. 23, the cross section of the extrusion channel of the discharge port in the length direction is a streamlined flow passage cross section.

Alternatively, the cross section of the extrusion channel of the discharge port in the length direction may also be designed into other feasible shapes or patterns as long as the extrusion channel of the discharge port is in a structure that the cross section in the material flow direction gradually shrinks to the size required by the discharge port.

As still another example, the cross section of the extrusion channel of the discharge port in the width direction may also be a stepped flow channel cross section or a streamlined flow channel cross section (not shown in the drawings).

The 3D printing extrusion material is generally a high-viscosity substance, the resistance generated by the extrusion material is proportional to the channel length of the discharge port, and when the width of the discharge port is small (when the printing precision is high, the width of the discharge port is required to be small), the discharge port is equivalent to a slit channel, as shown in (a) of fig. 23, the resistance of the extrusion material is very large, which may reduce the printing efficiency. In such a case, extruding the material out of the slit passage at a high speed to efficiently achieve high-precision 3D printing requires a very large extrusion pressure, and a very large conveying power of the material conveying system, which significantly increases the printing cost and makes the printing process uneconomical.

In the equipment that this application embodiment provided, the passageway of extruding of discharge gate is for following the structure of the required size of material flow direction ascending cross-section shrink gradually to this discharge gate, and this can effectively reduce the resistance that the material was extruded to be favorable to improving and print fashioned efficiency. In addition, because the resistance to material extrusion can be reduced, the requirement for the conveying power of the material conveying system can be reduced, and the printing cost can be reduced.

The application scenario of the present embodiment includes, but is not limited to, the device 4 provided in the above embodiment.

For example, the apparatus for 3D printing provided in this embodiment is the apparatus 4 provided in the above embodiment, and the discharging port in this embodiment is the discharging port 65 in the apparatus 4.

In the case that the sleeve 6 is integrally formed, the extrusion channel may be formed by a die of the sleeve 6 as a discharge hole 65 whose cross section gradually shrinks to a size required by the discharge hole along the material flowing direction.

In the case where the sleeve 6 includes a plurality of separable portions, the extrusion passage may be formed as a discharge port 65 whose cross section gradually narrows to a size required for the discharge port in the material flow direction by providing a stepped structure on the abutting surface of the adjacent two portions.

For example, in the above embodiments shown in fig. 8 to 10, and fig. 17 to 18, the abutting surface between the first portion 61 and the second portion 62 may have a stepped structure in the material outflow direction, so that the passage of the discharge port 65 is a structure whose cross section gradually narrows to the size of the discharge port 65 in the material outflow direction.

For example, in the above embodiment as shown in fig. 12 and 13, the abutting surfaces between the two spliced portions of the first portion 61, the second portion 62, the third portion 63 and the fourth portion 64 may have a stepped structure in the material outflow direction, so that the passage of the discharge hole 65 has a structure in which the cross section gradually shrinks to the size of the discharge hole 65 in the material outflow direction.

Taking the embodiment shown in fig. 8 to 10 as an example, the abutting surface 612 of the first portion 61 includes a step-shaped structure along the material outflow direction, as shown in fig. 24, the abutting surface 612 includes an upper step surface 6121 and a lower step surface 6122; the abutment surface 622 of the second portion 62 also has a stepped configuration along the outflow direction (similar to the stepped configuration of the abutment surface 612, not shown). Thus, the extrusion channel of the discharge port 65 formed by the butt joint of the first part 61 and the second part 62 is a structure with a section gradually shrinking to the size required by the discharge port along the material flow direction, as shown in fig. 25. In this example, the cross section of the extrusion passage of the discharge port 65 in the longitudinal direction is a stepped flow passage cross section as shown in fig. 23 (b).

The first part 61 and the second part 62 shown in fig. 25 are assembled with the feed conveyor pipe 5, i.e. the device 4 is formed with a discharge opening 65 having a structure in which the extrusion channel gradually narrows in cross-section in the direction of flow of the material to the size required for the discharge opening, as shown in fig. 26. In the example of fig. 26, the cross section of the feed delivery pipe 5 and the sleeve 6 in the direction of the extrusion passage through the outlet 65 is shown in fig. 7, and the outlet 65(1) shown in fig. 7 shows the outlet in a structure in which the cross section of the extrusion passage gradually shrinks to the size required by the outlet in the material flow direction.

Fig. 27 is a schematic flowchart of a control method provided in an embodiment of the present application. The control method of fig. 27 may control an apparatus for 3D printing. The device may be, for example, the device 4 described above, and the control method may be performed, for example, by the control means 8 in the device 4.

The apparatus may include a feed delivery conduit and a sleeve. An opening extending along the axial direction of the material conveying pipe is arranged on the outer wall of the material conveying pipe. The sleeve can be sleeved on the conveying pipe, a discharge hole communicated with the opening is formed in the outer wall of the sleeve, and the sleeve can rotate around the axis of the conveying pipe relative to the conveying pipe.

The method of fig. 27 may include step S2710: and controlling the sleeve to rotate around the axis of the feed delivery pipe relative to the feed delivery pipe so that the discharge hole is communicated with the opening or is not communicated any more.

Optionally, step S2710 includes: under the condition that printing needs to be suspended, the control sleeve rotates around the axis of the conveying pipe relative to the conveying pipe, so that the discharge port is not communicated with the opening any more, and the material conveying channel is blocked.

Optionally, step S2710 includes: under the condition that printing needs to be started, the control sleeve rotates around the axis of the conveying pipe relative to the conveying pipe, so that the discharge port is communicated with the opening, and the material conveying channel is opened.

Alternatively, the method of fig. 27 may include step S2720: the size of the discharge hole is adjusted.

Optionally, the outer wall of the sleeve comprises a first portion and a second portion, the first and second portions being relatively slidable in the axial direction. Step S2720 may include: the relative sliding of the first part and the second part is controlled to adjust the size of the discharge hole.

Optionally, the first portion includes a first upper step surface, a first lower step surface and a first connecting surface connecting the first upper step surface and the first lower step surface, the second portion includes a second upper step surface, a second lower step surface and a second connecting surface connecting the second upper step surface and the second lower step surface, the first upper step surface and the first lower step surface are respectively in contact with the second lower step surface and the second upper step surface and can relatively slide along the axial direction, and a hollow area formed by the first lower step surface, the first connecting surface, the second lower step surface and the second connecting surface is a discharge hole.

Alternatively, step S2720 may include: and adjusting the size of the discharge port to enable the length of the discharge port to be matched with the section line length of the section contour line of a target printing area of the layer to be printed, wherein the target printing area is part or all of the printing area of the layer to be printed.

Alternatively, step S2720 may include: the size of the discharge port is adjusted so that both ends for defining the length of the discharge port are aligned with the cross-sectional contour line of the target printing area in the vertical direction.

Optionally, the method of fig. 27 may further include: and adjusting the relative positions of the feed delivery pipe and the sleeve as a whole and the printing platform so that two ends for limiting the length of the discharge port are aligned with the section contour line of the target printing area in the vertical direction.

Optionally, the method of fig. 27 may further include: when the length of the longest sectional line of the cross-section contour line of the layer to be printed is less than or equal to the maximum length of the discharge port, determining all printing areas of the layer to be printed as target printing areas; when the length of the longest sectional line of the cross-sectional contour line of the layer to be printed is greater than the maximum length of the discharge port, the entire printing area of the layer to be printed is divided into a plurality of target printing areas.

Optionally, the method of fig. 27 may further include: and controlling the feeding device to feed materials to the discharge port, so that the extrusion capacity of the materials at the discharge port is matched with the size of the discharge port.

Optionally, a plurality of discharge ports are arranged on the outer wall of the sleeve. The method of FIG. 27 may further include: the control sleeve moves relative to the material conveying pipe, so that different discharge ports are communicated with the openings.

Optionally, a plurality of discharge gates are arranged along the circumferential direction of the sleeve, and the control sleeve moves relative to the feed delivery pipe, so that different discharge gates are communicated with the opening, and the movement can include: the control sleeve rotates around the axis of the material conveying pipe, so that different discharge ports are communicated with the openings.

Optionally, the widths of the different ports are different.

In the above embodiments, all or part of the implementation may be realized by software, hardware, firmware or any other combination. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a Digital Video Disk (DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), among others.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.