3D Printing Apparatus and Method

Abstract

A 3D printing apparatus and method are provided. The apparatus includes a material extrusion unit and a switch assembly. The material extrusion unit includes a material storage cavity for storing the molten material and an extrusion port communicating with the material storage cavity. The extrusion port is used to extrude the molten material onto the current printing layer. The switch assembly is coupled to the extrusion port and is configured to form a plurality of sub-extrusion ports with continuously adjustable widths by controlling the opening and closing of the area where the extrusion port is located. By configuring in this way, the molten material can be filled and printed onto the current printing layer including a plurality of sections through the plurality of sub-extrusion ports at once, thereby ensuring printing accuracy and further improving printing efficiency at the same time.

Description

Technical Field

[0001] The present invention claims the priority of a Chinese patent application filed with the Chinese Patent Office on July 5, 2022, with an application number of 2022107838531 and an invention title of "3D Printing Apparatus and Method", and all its contents are incorporated into the present invention by reference.

[0002] The present invention relates to the field of 3D printing, and specifically to 3D printing apparatuses and methods.

Background Art

[0003] 3D printing technologies based on material extrusion, such as fused deposition modeling (FDM) technology, are commonly used 3D printing technologies. Generally, the material needs to be heated until it is in a molten state (or semi-fluid state), and then the molten material is extruded from the extrusion port of the 3D printing apparatus onto the molding platform so that the material is deposited layer by layer on the molding platform and solidifies integrally to form a 3D printed part.

[0004] In conventional 3D printing technologies based on material extrusion, 3D printing apparatuses are usually provided with extrusion ports having a constant diameter. Such printing apparatuses cannot achieve both printing accuracy and printing efficiency. In related technologies, in order to achieve both printing efficiency and printing accuracy, some improvements have been made to such printing apparatuses, but the printing efficiency of the improved 3D printing apparatuses still has room for improvement.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a 3D printing apparatus and method that ensure printing accuracy while further improving printing efficiency.

Means for Solving the Problems

[0006] In a first aspect, a 3D printing device is provided. The 3D printing device includes a material extrusion part and a switch assembly. The material extrusion part includes a material storage cavity and an extrusion outlet communicating with the material storage cavity. The material storage cavity is used to store the molten material, and the extrusion outlet is used to extrude the molten material onto the current printing layer. The switch assembly is coupled to the extrusion outlet and configured to form a plurality of sub-extrusion outlets with continuously adjustable widths by controlling the opening and closing of the area where the extrusion outlet is located. The plurality of sub-extrusion outlets are used to simultaneously print a plurality of sections on the current printing layer. In the process of printing the plurality of sections using the plurality of sub-extrusion outlets, the width of each sub-extrusion outlet among the plurality of sub-extrusion outlets changes according to the change in the contour line of the section corresponding to each sub-extrusion outlet, so as to fill the section corresponding to each sub-extrusion outlet with the molten material in one go.

[0007] In a second aspect, a 3D printing device is provided. The 3D printing device includes a material extrusion part and a switch assembly. The material extrusion part includes a material storage cavity for storing the molten material and an extrusion outlet having a plurality of channels communicating with the material storage cavity. The plurality of channels are used to extrude the molten material onto the current printing layer, and the materials extruded from adjacent channels among the plurality of channels fuse with each other on the current printing layer. The switch assembly is coupled to the plurality of channels and configured to form a plurality of sub-extrusion outlets with continuously adjustable widths by controlling the opening and closing of the plurality of channels.

[0008] In a third aspect, a 3D printing method is provided. The 3D printing method includes printing a current printing layer by transporting a molten material to an extrusion port, and forming a plurality of sub-extrusion ports with continuously adjustable widths by controlling the opening and closing of the area where the extrusion port is located using a switch assembly during the process of printing the current printing layer. The plurality of sub-extrusion ports are used to simultaneously print a plurality of sections in the current printing layer, and during the process of printing the plurality of sections using the plurality of sub-extrusion ports, the width of each sub-extrusion port among the plurality of sub-extrusion ports changes according to the change of the contour line of the area corresponding to each sub-extrusion port, so as to fill the molten material into the sections corresponding to each sub-extrusion port in a batch.

[0009] In a fourth aspect, a 3D printing method is provided. The 3D printing method is to print a current printing layer by transporting a molten material to an extrusion port and using a plurality of channels in the extrusion port, wherein the materials extruded from adjacent channels among the plurality of channels fuse with each other in the current printing layer, and forming a plurality of sub-extrusion ports with continuously adjustable widths by controlling the opening and closing of the plurality of channels using a switch assembly during the process of printing the current printing layer.

[0010] In the 3D printing apparatus according to an embodiment of the present invention, a switch assembly coupled to the extrusion port is provided. The switch assembly can form a plurality of sub-extrusion ports with continuously adjustable widths by controlling the opening and closing of the area where the extrusion port is located. By configuring in this way, it is possible to perform batch filling printing on the current printing layer including a plurality of sections through the plurality of sub-extrusion ports, thereby ensuring printing accuracy and further improving printing efficiency at the same time.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0012] The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. As is clear, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that the same or similar reference numerals are used in the drawings to denote the same or similar components.

[0013] In 3D printing technology by material extrusion (such as FDM technology), since the 3D printing device can accommodate a very large variety of printable material types and has a very large span in the size range of the printed parts to be printed, it is widely applied in the 3D printing field. Such a 3D printing device extrudes the molten material through an extrusion port (also referred to as a material discharge port) onto a forming platform, so that the molten material is deposited layer by layer on the forming platform and solidifies integrally to form a 3D printed part. Therefore, generally, the 3D printing device needs to print the 3D printed part layer by layer.

[0014] Usually, printing each layer using a 3D printing device corresponds to filling the filling area of each layer. Since a conventional 3D printing device is usually provided with an extrusion port having a certain diameter, when printing one layer out of a plurality of layers using the printing device, generally, the filling area of the layer needs to be divided into a plurality of paths (the dimensions of each path match the diameter of the extrusion port) arranged closely, and the printing device needs to be controlled to fill the plurality of paths in a predetermined order in sequence. That is, when printing one of the layers using the printing device, generally, it is necessary to reciprocate multiple times to achieve complete filling of the filling area of that layer.

[0015] If the diameter of the extrusion port of a 3D printing device is small, the amount of material extruded per unit time will be small. Therefore, the number of passes for filling to print one layer will increase. In this case, while the printing accuracy increases, the printing efficiency decreases. Conversely, if the diameter of the extrusion port of a 3D printing device is large, the amount of material extruded per unit time will be large. Therefore, the number of passes required for filling when printing the same layer will decrease. In this case, while the printing efficiency increases, the printing accuracy decreases. Therefore, conventional 3D printing devices cannot achieve both high printing accuracy and high printing efficiency.

[0016] To meet the industrial requirements for high-efficiency and high-precision printing, as one feasible embodiment, it is to improve the extrusion port of the 3D printing device to an extrusion port with variable width. Such an extrusion port of a 3D printing device has the characteristics of a one-dimensional stripe, that is, the width in the one-dimensional direction of the extrusion port is much larger than the width in the other dimension, and the width of the extrusion port can change according to the change of the contour of the filling area of the current printing layer in the one-dimensional direction, thereby forming an extrusion port with variable width. For a specific description of such an embodiment, reference can be made to, for example, PCT / CN2017 / 083647 and PCT / CN2020 / 120405.

[0017] Since the extrusion port in the improved 3D printing device has a variable width, when the printing layer is an independent communication area, such a 3D printing device can be used to completely fill or partially fill the entire printing layer at once, thereby achieving both high printing accuracy and high printing efficiency.

[0018] However, for some 3D printing parts with complex structures (for example, the 3D printing parts have a watermark structure), the printing efficiency when printing using the above-mentioned improved 3D printing device is still low. Hereinafter, this will be exemplarily described with reference to FIG. 1.

[0019] As described above, the 3D printed part can have a plurality of printed layers. Shown in FIG. 1 is one of the plurality of printed layers. As shown in FIG. 1, the printed layer 1 has a plurality of cut-out regions a. When printing the printed layer shown in FIG. 1 using an improved 3D printing apparatus, the 3D printing apparatus must reciprocate six times along the printing direction y in FIG. 1 until the molten material extruded from the extrusion port completely fills the filling region of the printed layer.

[0020] Due to the existence of the cut-out regions a, this printed layer becomes a printed layer with a complex shape. Of course, the printed layer with a complex shape may not only be the printed layer shown in FIG. 1, but also other forms. As long as the filling region of the printed layer is not continuous or there is an isolation space in the filling region, the printed layer can be considered a printed layer with a complex shape.

[0021] For example, this printed layer with a complex shape may be a filling region including a plurality of communicating regions. Alternatively, the filling region of this printed layer with a complex shape may be a region having a plurality of separated structures. That is, in one movement locus of the printing apparatus (for example, the movement locus may be a straight line), the filling region may have a plurality of compartments (the compartments are also referred to as filling paths) that are separated from each other (or separated).

[0022] In some embodiments, in one movement locus of the printing apparatus, the number of the plurality of compartments in its filling region may change. For example, in some of the printing loci of the entire printing locus, the plurality of compartments are separated from each other, and in some other printing loci, some or all of the plurality of compartments form one compartment. Note that whether it is one compartment composed of a plurality of compartments or each of the plurality of compartments, a single compartment can refer to an independent communicating region, and the width of the contour line of a single compartment can all dynamically change along the printing direction (the printing direction y shown in FIG. 1).

[0023] The 3D printed part with a complex structure described in the embodiments of the present invention may be a 3D printed part including the printed layers with the above-described complex shapes. Further, the 3D printed part with a complex structure may include one or more printed layers with complex shapes.

[0024] As described above, for the printed layer shown in FIG. 1, the 3D printing apparatus improved by the related art needs to reciprocate six times to completely fill the filling area of the printed layer. When the 3D printed part includes a plurality of printed layers with complex shapes, when printing the 3D printed part using the improved 3D printing apparatus, its printing efficiency is still low and further improvement is needed.

[0025] In view of this, the embodiments of the present invention provide a 3D printing apparatus. Hereinafter, the 3D printing apparatus 2 in the embodiments of the present invention will be described in detail with reference to FIG. 2. It should be noted that the 3D printing apparatus according to the embodiments of the present invention refers to an apparatus used for 3D printing. The 3D printing apparatus may refer to the entire 3D printing system, or may refer to some components in the 3D printing system. For example, the 3D printing apparatus may refer to a 3D printing head.

[0026] Referring to FIG. 2, the 3D printing apparatus 2 may include a material extrusion part 3 and a switch assembly 4.

[0027] The material extrusion part 3 includes a material storage cavity 31 and an extrusion port 32. A material inlet 33 may be provided in the material storage cavity 31. The material storage cavity 31 can receive the molten material through the material inlet 33 and is used to store the molten material. The extrusion port 32 communicates with the material storage cavity 31, and the extrusion port 32 is used to extrude the molten material in the material storage cavity 31 onto the current printed layer.

[0028] The current printed layer may be located on a molding platform (not shown in FIG. 2). The current printed layer in the embodiments of the present invention is a printed layer being printed in the process of printing a 3D printed part, and may be, for example, the printed layer with the above-described complex shape.

[0029] Continuing to refer to FIG. 2, the switch assembly 4 is coupled to the extrusion port 32 and controls the opening and closing of the area where the extrusion port 32 is located, so that the area forms a plurality of sub-extrusion ports 34 with continuously adjustable widths.

[0030] It should be noted that the switch assembly 4 is coupled to the extrusion port 32 in order to control the opening and closing of the area where the extrusion port 32 is located. The opening and closing control means that by blocking or not blocking the extrusion of the molten material from a part of the area where the extrusion port 32 is located, the area where the extrusion port 32 is located forms a plurality of sub-extrusion ports 34 with continuously adjustable widths. Here, the specific position of the part of the area to be blocked can be dynamically adjusted according to the control of the switch assembly 4.

[0031] In other words, when the switch assembly 4 does not perform opening and closing control on the area where the extrusion port 32 is located, that is, when the switch assembly 4 does not block the extrusion of the molten material from the extrusion port 32, the extrusion port 32 can be in the form of a single extrusion port. The extrusion port 32 may be the extrusion port with continuously adjustable width described above. By using the extrusion port 32, the printing of the current printing layer constituting a single section can be completed at once.

[0032] In some embodiments, the switch assembly 4 may be understood as a shielding member that can shield the area where the extrusion port 32 is located.

[0033] When the switch assembly 4 controls the opening and closing of the area where the extrusion port 32 is located, that is, when the switch assembly 4 blocks the extrusion of the molten material from a part of the area where the extrusion port 32 is located, the extrusion port 32 becomes a plurality of sub-extrusion ports 34, and the width of each sub-extrusion port is continuously adjustable. In view of this, by using the plurality of sub-extrusion ports, the printing of the current printing layer including a plurality of sections can be completed at once.

[0034] Note that, when the 3D printing apparatus completes the printing of the current printing layer described in the embodiments of the present invention in one batch, when the 3D printing apparatus performs filling printing along the printing direction, in order to complete the filling of the filling area of the current printing layer, it is only necessary to perform a single movement along a single direction. For example, by controlling the printing apparatus to move once along a straight line direction, the filling printing for the current printing layer with the above-described complex shape can be completed in one batch.

[0035] In an embodiment of the present invention, a switch assembly coupled to an extrusion port is provided in a 3D printing apparatus, and the extrusion port is formed into a plurality of sub-extrusion ports with continuously adjustable widths by controlling the opening and closing of the extrusion port using the switch assembly. Thereby, the molten material can be filled into the current printing layer including a plurality of compartments through the plurality of sub-extrusion ports for filling printing in one batch. Therefore, while ensuring printing accuracy, the printing efficiency can be further improved.

[0036] As described above, when the current printing layer is a printing layer with the above-described complex shape, the current printing layer should include a plurality of compartments, and the width of the contour line of each of the plurality of compartments can change along the printing direction. When printing the current printing layer, the plurality of compartments of the current printing layer can be printed simultaneously using the plurality of sub-extrusion ports 34 described above. In the printing process, the width of each sub-extrusion port among the plurality of sub-extrusion ports changes according to the change of the contour line of the compartment corresponding to each sub-extrusion port, so that the molten material is filled into the compartment corresponding to each sub-extrusion port in one batch.

[0037] As can be seen from this, when the current printing layer is a printing layer with the above-described complex shape, when using the 3D printing apparatus of the embodiment of the present invention, the printing for the current printing layer can be completed in one batch, and the effect of improving the printing efficiency is particularly remarkable.

[0038] In the embodiments of the present invention, the structure of the extrusion port 32 and the coupling form between the switch assembly 4 and the extrusion port 32 are not specifically limited. The related installation of the switch assembly 4 and the extrusion port 32 only needs to satisfy that the switch assembly 4 can realize opening and closing control for the area where the extrusion port 32 is located.

[0039] As an embodiment, as shown in FIGS. 2 and 3, the extrusion port 32 may be an extrusion port formed by a gap between two movable blocks 321. The two movable blocks 321 can slide relative to each other along the x direction in FIGS. 2 and 3, thereby changing the gap between the two movable blocks 321 to form an extrusion port 32 with a variable width.

[0040] Correspondingly, the switch assembly 4 is provided to be coupled to the extrusion port 32, and controls such that a part of the area of the extrusion port 32 is blocked and another part of the area is not blocked, whereby the extrusion port 32 forms a plurality of sub-extrusion ports 34 that can be continuously adjusted. Any part of the area that is blocked or not blocked can be dynamically changed under the control of the switch assembly 4.

[0041] Exemplarily, as shown in FIGS. 2 and 3, the switch assembly 4 may be provided to include a plurality of sliding switches (41, 42, and 43 shown in FIGS. 2 and 3) whose widths can change and whose positions can move. The coupling form between the switch assembly 4 and the extrusion port 32 may be such that each sliding switch can be controlled by the switch assembly 4 to move to a position corresponding to the area where the extrusion port 32 is located in any motion form at any time. For example, each sliding switch may be provided in the material storage cavity 31 and can slide relative to each other along the x direction in FIGS. 2 and 3 and / or move along the y direction in FIGS. 2 and 3 under the control of the switch assembly 4.

[0042] In FIG. 2, the switch assembly 4 can control the sliding switches 42 and 43 to move to the area where the extrusion port 32 is located, while controlling the sliding switch 41 to move away from the area where the extrusion port 32 is located. As a result, the extrusion port 32 is isolated to become the three sub-extrusion ports 34 shown in FIG. 2. Also, the sliding switches 42 and 43 can slide relative to each other along the x direction in FIG. 2, whereby the widths of the three sub-extrusion ports 34 can be arbitrarily changed. Therefore, the filling area of the current printing layer in the printing state at this time can include three sections separated from each other.

[0043] Similarly, in FIG. 3, the switch assembly 4 can control the sliding switches 41, 42, and 43 to move to the area where the extrusion port 32 is located, thereby isolating the extrusion port 32 into the four sub-extrusion ports 34 shown in FIG. 3. Also, the filling area of the current printing layer in the printing state at this time can include four sections separated from each other. FIGS. 3 and 2 show a state where printing is performed at different printing positions along the printing direction when the printing device 2 prints the current printing layer.

[0044] By the above connection method, the area where the extrusion port is located can form a plurality of sub-extrusion ports 34 with continuously adjustable widths, and both the number of sub-extrusion ports and the widths of the sub-extrusion ports can be flexibly converted under the control of the switch assembly 4. Thereby, the molten material can perform batch filling printing on the current printing layer with a complex shape through the plurality of sub-extrusion ports. Therefore, while ensuring printing accuracy, the printing efficiency is further improved.

[0045] As another embodiment, as shown in FIGS. 4 and 5, the extrusion port 32 may include a plurality of channels 35. The plurality of channels 35 communicate with the material accommodation cavity 31 and are used to extrude the molten material onto the current printing layer. The plurality of channels 35 may be closely arranged such that the materials extruded from adjacent channels among them fuse with each other in the current printing layer. That is to say, the extrusion port 32 is divided into a plurality of channels 35, for example, divided into a channel array having at least one row of channels 35, and the channels are separated by channel walls (or separators). Due to the arrangement of the plurality of channels 35, the molten materials extruded by each of the plurality of channels can flow by their own weights when applied to the molding platform to form a continuous printing layer (or a coating layer as referred to) with each other. Of course, in some embodiments, auxiliary means (such as mechanical rolling means) may be adopted to ensure the fusion effect of the materials extruded from the plurality of channels 35.

[0046] The present invention does not specifically limit the arrangement form of the plurality of channels 35, as long as the materials extruded by adjacent channels 35 can fuse with each other in the current printing layer. In some embodiments, as shown in FIG. 7, the plurality of channels 35 may be arranged side by side in a row and closely arranged with each other. In another embodiment, as shown in FIG. 8, the plurality of closely arranged channels 35 may be arranged in a staggered pattern and closely adjacent to each other to contribute to the effective utilization of the accommodation space.

[0047] Correspondingly, the switch assembly 4 may be coupled to the plurality of channels 35 and provided to form a plurality of sub-extrusion ports 34 with continuously adjustable widths by controlling the opening and closing of the plurality of channels 35. In other words, the switch assembly 4 can control so that some of the plurality of channels 35 can extrude the molten material, while the switch assembly can also control so that some of the plurality of channels 35 cannot extrude the molten material. The channels that can extrude the molten material and are adjacent to each other can form one sub-extrusion port 34. The adjacent sub-extrusion ports 34 can be separated by the channels 35 that cannot extrude the molten material. Whether each of the plurality of channels 35 forming the extrusion port 32 can extrude the molten material can dynamically change according to the control of the switch assembly 4.

[0048] Exemplarily, as shown in FIGS. 4 and 5, the coupling form may be to provide the switch assembly 4 as a plurality of switches (A, B, C, D, E, and F shown in FIGS. 4 and 5) that correspond one-to-one to the plurality of channels 35, and each switch can individually control the corresponding channel.

[0049] In FIG. 4, the switch assembly 4 can be controlled so that switches A, D, and F are open (i.e., away from the channels 35), and some other switches are closed (i.e., in contact with the channels 35), whereby the plurality of channels 35 can be formed into three sub-extrusion ports 34 shown in FIG. 4. Therefore, the filling regions in the current printing layer in the printing state at this time can include three sections separated from each other.

[0050] In FIG. 5, the switch assembly 4 can be controlled such that switches C, D, and F are opened and several other switches are closed, thereby forming a plurality of channels 35 into two sub-extrusion outlets 34 as shown in FIG. 5. The filling regions in the current printing layer in the printing state at this time can include two separate compartments. FIGS. 4 and 5 show a state in which the printing device 2 performs printing at different printing positions along the printing direction when printing the current printing layer.

[0051] In the above-described coupling form, by controlling whether or not a part of the plurality of channels 35 constituting the extrusion outlet 32 extrudes the molten material, the plurality of channels 35 form a plurality of sub-extrusion outlets 34 with continuously adjustable widths. Both the number of the sub-extrusion outlets and the widths of the sub-extrusion outlets can be changed by the control of the switch assembly 4, whereby the molten material can perform batch filling printing on the current printing layer having a complex shape through the plurality of sub-extrusion outlets, thus guaranteeing the printing accuracy and at the same time further improving the printing efficiency.

[0052] Also, compared with the above-described means, this means can avoid the phenomenon that the width of the extrusion location becomes narrow when changing the widths of the extrusion outlet 32 and each sub-extrusion outlet 34, and the molten material is pressed and the flow rate of the material becomes non-uniform, and can effectively improve the printing quality of the 3D printed parts.

[0053] As described above, the number of a plurality of compartments in the filling area corresponding to the current printing layer with a complex shape can be changed. For example, as shown in FIG. 1, the plurality of compartments in the current printing layer 1 include a first compartment 11 and a second compartment 12. In some filling areas (the dashed-line area 10), the first compartment 11 and the second compartment 12 have areas separated from each other, and in some filling areas (the area 10' below the dashed-line area 10), the first compartment 11 and the second compartment 12 have areas communicating with each other. The dashed-line area 10 and the area 10' may be closely arranged along the printing direction y. In the area 10, the first compartment 11 and the second compartment 12 are separated from each other, that is, the first compartment 11 and the second compartment 12 together form two compartments, and in the area 10', the first compartment 11 and the second compartment 12 are integrated into one compartment 13.

[0054] Correspondingly, as shown in FIG. 6, the plurality of sub-extrusion ports 34 of the 3D printing device 2 in the embodiment of the present invention can include a first sub-extrusion port 341 and a second sub-extrusion port 342. When printing the area 10 using the 3D printing device 2, the first sub-extrusion port 341 and the second sub-extrusion port 342 are respectively used to print the first compartment 11 and the second compartment 12 that are isolated from each other by the opening and closing control of the switch assembly 4. On the other hand, when printing the area 10', the first extrusion port 341 and the second extrusion port 342 are integrated into one sub-extrusion port 343 by the opening and closing control of the switch assembly 4, and the integrated sub-extrusion port 343 is used to print the compartment 13 integrated by the first compartment 11 and the second compartment 12.

[0055] By performing different opening and closing controls of the switch assembly 4 for different filling areas of the current printing layer, the 3D printing device can further realize completing the printing of the more complex current printing layer in one batch (for example, for the current printing layer shown in FIG. 1, the printing device 2 can complete the printing by moving only once along the printing direction y), and thus effectively improve the printing efficiency of the 3D printed object including such a printing layer.

[0056] As described above, the structural form of the switch assembly 4 may be various, and the embodiments of the present invention do not specifically limit this.

[0057] As one embodiment, as shown in FIGS. 7 to 12, the switch assembly 4 can include a plurality of sheet-like switches 44. By deforming the plurality of sheet-like switches 44 under the control of temperature and / or voltage, the region (for example, the pore channel 35) where the extrusion port 32 is located can be controlled to open and close. For example, as shown in FIGS. 7 to 8, a sheet-like switch can be provided corresponding to each pore channel 35. Therefore, by utilizing the deformation of each sheet-like switch, it is possible to individually control whether the molten material is extruded from the corresponding pore channel 35. In order to further improve the blocking effect when the switch assembly 4 controls the blocking of each pore channel 35, the width of the sheet-like switch 44 can usually be provided to be equal to or greater than the pore diameter of the pore channel 35. The plurality of sheet-like switches 44 can include one or more of a piezoelectric bimorph, a bimetal, a metal resistor that expands by heat, and a shape memory alloy.

[0058] Hereinafter, with reference to FIGS. 9 to 11, the installation form of the switch assembly 4 including a plurality of sheet-like switches 44 will be described in detail. Note that in FIGS. 9 and 10, only one sheet-like switch is taken as an example, and the installation forms of other sheet-like switches are the same as the illustrated forms.

[0059] As shown in FIG. 9, the sheet-like switch 44 may be provided inside the material storage cavity 31 and above the region (for example, the pore channel 35) where the extrusion port 32 is located. Specifically, one end of the sheet-like switch 44 is fixed in a cantilever beam shape, and the other end can be distorted under the control of temperature and / or voltage to contact or separate from the region where the extrusion port 32 is located.

[0060] For example, when the sheet-like switch 44 is a piezoelectric bimorph, the electric field directions of the upper and lower two piezoelectric morphs can be controlled. Therefore, when the piezoelectric bimorph bends downward, it can realize closing the region (such as the pore channel 35) where the extrusion port 32 is located (shown in Fig. 9(a)). On the other hand, in the reverse electric field, the piezoelectric bimorph can realize bending upward to open the region (such as the pore channel 35) where the extrusion port 32 is located (as shown in Fig. 9(b)).

[0061] Similarly, when the sheet-like switch 44 is a bimetal, the active layer can be positioned downward. By controlling the active layer, in a low-temperature state, the active layer drives the passive layer to bend downward, and in a high-temperature state, the active layer drives the passive layer to bend upward.

[0062] Alternatively, when the sheet-like switch 44 is a metal resistor or a shape memory alloy that expands due to heat, both can be installed according to the above-described form. The difference is that if only one layer of such a sheet-like switch 44 is provided, it can realize opening and closing control of the region where the extrusion port 32 is located.

[0063] The shape memory alloy is also called a shape memory alloy. The shape memory alloy sheet is flat at a given temperature and bends downward at another given temperature. Therefore, by controlling the given temperature, the shape memory alloy sheet can be driven to move up and down with the transmission member. In the embodiments of the present invention, the temperature of the shape memory alloy can be controlled in different forms. For example, its temperature can be controlled by resistance heating by energizing it, or the temperature can also be controlled by a radiation heating method.

[0064] The metal resistor that expands due to heat can also be referred to as a high thermal expansion coefficient metal resistor sheet. At normal temperature, the metal resistor that expands due to heat is in a flat state. When this metal resistor that expands due to heat is energized and heated, its length increases due to the action of thermal expansion, and the metal resistor bends downward. Therefore, by controlling its temperature, the metal resistor that expands due to heat can be driven to move the transmission member up and down.

[0065] In some other embodiments, as shown in FIGS. 10 and 11, the sheet-shaped switch 44 may be provided outside the material accommodation cavity 31, and the sheet-shaped switch 44 is connected to the transmission member 45 (it should be noted that a plurality of sheet-shaped switches can be respectively connected to a plurality of transmission members 45), and the transmission member 45 controls the opening and closing of the area where the extrusion port 32 is located (for example, a plurality of channels 35).

[0066] The transmission member 45 may be a stopper, may be provided above the area where the extrusion port 32 is located, and can move up and down due to the deformation of the sheet-shaped switch 44. One end of the transmission member 45 is fixedly connected to the sheet-shaped switch 44, and the other end can abut or separate from the area where the extrusion port 32 is located (for example, the channel 35). The embodiments of the present invention do not specifically limit the shape and material of the transmission member 45. For example, the transmission member 45 may be a square or cylindrical stopper, and its material may be metal, ceramic, or other materials that can withstand high temperatures and have sufficient strength.

[0067] The embodiments of the present invention do not specifically limit the fixing form of the sheet-shaped switch 44 outside the material accommodation cavity 31. As one embodiment, as shown in FIG. 10, the sheet-shaped switch 44 can be fixed outside the material accommodation cavity 31 in a cantilever beam shape. Specifically, one end of it is fixed, the other end is connected to the transmission member 45, and the other end can be deformed by controlling the temperature and / or voltage so that the transmission member 45 moves up and down to abut or separate from the area where the extrusion port 32 is located.

[0068] For example, when the sheet-like switch 44 is a piezoelectric bimorph or a bimetal, the electric field direction of the upper and lower two piezoelectric morphs or the temperature of the bimetal can be controlled, whereby when the piezoelectric bimorph or the bimetal bends downward, the region (e.g., the pore channel 35) where the extrusion port 32 is located is closed (shown in Fig. 10(a)). On the other hand, when the piezoelectric bimorph or the bimetal bends upward or is in a flat state, the region (e.g., the pore channel 35) where the extrusion port 32 is located is opened (shown in Fig. 10(b)).

[0069] Alternatively, the sheet-like switch 44 may similarly employ a metal resistor or a shape memory alloy that expands by heat, and the fixed form is the same as described above. The difference is that if only one such sheet-like switch 44 is provided, opening and closing control can be realized for the region where the extrusion port 32 is located, whereby the structure of the sheet-like switch 44 can be simplified.

[0070] As another embodiment, as shown in Fig. 11, the sheet-like switch 44 may be fixed outside the material accommodation cavity 31 such that both ends are fixed. For example, both ends of the sheet-like switch 44 may be fixed to the bracket 36 outside the material accommodation cavity. The transmission member 45 may be disposed at any position between both ends of the sheet-like switch 44. The sheet-like switch 44 can be deformed by controlling the temperature and / or voltage, thereby driving the transmission member 45 to move up and down to contact or separate from the region where the extrusion port 32 is located.

[0071] For example, when the sheet-like switch 44 is a piezoelectric bimorph or a bimetal, the electric field direction of the upper and lower two piezoelectric morphs or the temperature of the bimetal can be controlled, and when the piezoelectric bimorph or the bimetal bends downward, the region (e.g., the pore channel 35) where the extrusion port 32 is located is closed (shown in Fig. 11(a)). On the other hand, when the piezoelectric bimorph or the bimetal bends upward or is in a flat state, the region (e.g., the pore channel 35) where the extrusion port 32 is located is opened (shown in Fig. 11(b)).

[0072] Alternatively, the sheet switch 44 may similarly employ a metal resistor or a shape memory alloy that expands due to heat, and its fixed form is the same as described above. The difference is that only one sheet switch 44 of this type is required.

[0073] By providing the sheet switch 44 outside the material storage cavity 31, it is possible to isolate the influence of voltage or temperature when controlling the sheet switch 44 on the molten material in the material storage cavity 31, thereby enabling more accurate control of the temperature of the molten material and the sheet switch.

[0074] In some embodiments, as shown in FIG. 12, the 3D printing apparatus 2 may further include a material supply system 5. The material supply system 5 communicates with the material storage cavity 31 via a material inlet 33 and is used to heat the molten material and transport the molten material into the material storage cavity 31. The material supply system 23 may be, for example, a stepless variable flow rate supply device, but the embodiments of the present invention do not specifically limit the form of the material supply system 23. For example, the material supply system 5 may be a screw-type material supply system, a gas pressure-type material supply system, or a piston-type material supply system.

[0075] When the material supply system 5 is a gas pressure-type material supply system, as shown in FIG. 12, generally, it is necessary to provide a gas pressure transport pipeline 51 in the gas pressure material supply system 5 and a material storage tank 52 communicating with the gas pressure transport pipeline 51.

[0076] In view of this, there is also pressure from the above-mentioned pressurized gas in the material storage cavity 31. This pressure may affect the movement of the transmission member 45. For example, when the sheet-shaped switch 44 is located outside the material storage cavity 31, when the sheet-shaped switch 44 drives the transmission member 45 to move downward to close the corresponding extrusion port 32 area (for example, the hole 35), this pressure gives an upward resistance to the transmission member 45. Therefore, there is a possibility that the switch assembly 4 cannot achieve interruption unless a greater force is applied to the transmission member 45, which brings a certain degree of difficulty to the opening and closing control of the switch assembly 4.

[0077] To solve the above problems, as shown in FIG. 12, the 3D printing apparatus 2 in the embodiment of the present invention further includes a control chamber 6. A plurality of sheet-shaped switches 44 are located in the control chamber 6, and the gas pressure transmission pipeline 51 may be provided to communicate with the control chamber 6 in terms of gas. By this installation, the pressure of the pressurized gas also acts on the space where the sheet-shaped switch 44 and the transmission member 45 are located, achieving pressure balance with the pressure of the extruded molten material. In this way, when the sheet-shaped switch 44 drives the up and down movement of the transmission member 45 to realize the opening and closing control of the switch assembly 4, it is not affected by the force pressing the molten material, and the control accuracy can be ensured and the power consumption of the opening and closing control can be reduced.

[0078] Note that the above has been described by taking the use of the gas pressure material supply system 5 as an example for the 3D printing apparatus 2. However, the embodiments of the present invention are not limited thereto. The pressure balance between the material storage tank 52 and the control chamber 6 may be formed by using the gas pressure transmission pipeline 51. For example, the 3D printing apparatus 2 can still use other material supply methods such as screws. By introducing the gas pressure transmission pipeline 51 and communicating the material storage tank 52 in the material supply path with the control chamber 6 where the switch assembly is located, the pressure balance between the two can be achieved, and the difficulty of opening and closing control and the power consumption of the switch assembly in the control chamber 6 can be reduced.

[0079] In addition, in the embodiments of the present invention, the switch assembly 4 is not necessarily limited to a structure including the sheet-like switch 44, and other structural forms may also be used. For example, the switch assembly 4 can include one or more of a switch controlled by motor control, a switch controlled by gas pressure, and a switch controlled by hydraulic pressure.

[0080] The switch controlled by motor control may be the motor shaft of the motor or a transmission member driven by the motor shaft of the motor. Since the motor shaft can perform linear motion when the motor is energized, by controlling the forward and reverse rotation of the motor, the motor shaft or the transmission member can be controlled to contact or separate from the region where the extrusion port 32 is located. This form is particularly suitable for controlling the opening and closing of the extrusion port 32 including a plurality of channels 35, especially when the aperture diameter of the channel 35 is large and the number of holes is small.

[0081] The switch controlled by gas pressure or hydraulic pressure may be a piston controlled by gas pressure or hydraulic pressure, or a transmission member driven by the piston. FIG. 13 shows a possible embodiment in which the switch assembly 4 includes a switch controlled by gas pressure or hydraulic pressure. Note that in FIG. 13, it is taken as an example that the switch assembly includes only one switch controlled by gas pressure or hydraulic pressure, and the installation form of other switches controlled by gas pressure or hydraulic pressure is the same as or similar to the illustrated form.

[0082] Referring to FIG. 13, the switch assembly 4 can include a chamber 46 and a piston 47. The chamber 46 is located above the material storage cavity 31 and may have a first connection port 461 and a second connection port 462 for external connection, and may be connected to, for example, a gas pressure device or a hydraulic pressure device. The piston 47 is located within the chamber 46. When the first connection port is the inlet and the second connection port is the outlet, the piston 47 can move upward. When the first connection port is the outlet and the second connection port is the inlet, the piston can move downward to control the opening and closing of the area where the extrusion port 32 is located. Note that the pressure at the inlet is greater than the pressure at the outlet. In some embodiments, a transmission member 48 may be further provided below the piston 47. When the piston 47 moves up and down, it can drive the transmission member 48 to move up and down together to achieve opening and closing control. Of course, the transmission member 48 may be a part of the piston 47, that is, the transmission member 48 and the piston 47 are integrally installed. The embodiments of the present invention are not limited to the presence or absence of the transmission member 48, as long as the opening and closing control of the switch assembly 4 can be realized by the up and down movement of the piston 47.

[0083] In some embodiments, the plurality of channels and the plurality of switches corresponding one-to-one to the plurality of channels described above may be replaced by a plurality of print heads, and the plurality of print heads may be arranged close to each other to realize the above-described functions.

[0084] Above, the embodiments of the 3D printing apparatus of the present invention have been described in detail with reference to FIGS. 1 to 13. Hereinafter, embodiments of the method of the present invention will be described with reference to FIGS. 14 and 15. Since this method can be executed by the 3D printing apparatus described above, for parts that are not described in detail, the above content can be referred to.

[0085] Referring to FIG. 14, the 3D printing method according to an embodiment of the present invention can include step S1410 and step S1420.

[0086] In step S1410, the current printing layer is printed by transporting the molten material to the extrusion port.

[0087] In step S1420, during the process of printing the current printing layer, by using the switch assembly to control the opening and closing of the area where the extrusion port is located, a plurality of sub-extrusion ports with continuously adjustable widths are formed.

[0088] Optionally, the plurality of sub-extrusion ports are used to simultaneously print a plurality of sections in the current printing layer. Accordingly, during the process of printing the plurality of sections by using the plurality of sub-extrusion ports, the width of each sub-extrusion port among the plurality of sub-extrusion ports changes according to the change of the contour line of the section corresponding to each sub-extrusion port. In this way, the molten material is filled into the sections corresponding to the respective sub-extrusion ports at once.

[0089] Optionally, the plurality of sections include a first section and a second section, and the plurality of sub-extrusion ports include a first sub-extrusion port and a second sub-extrusion port. The method of FIG. 14 further includes printing the first section and the second section by using the first sub-extrusion port and the second sub-extrusion port respectively. Here, the first section and the second section have regions isolated from each other and regions communicating with each other. When printing the regions communicating with each other, the first sub-extrusion port and the second sub-extrusion port are integrated into one sub-extrusion port by opening and closing control.

[0090] Optionally, the switch assembly includes a plurality of sheet-like switches, and the method of FIG. 14 further includes using the deformation of the plurality of sheet-like switches under the control of temperature and / or voltage to control the opening and closing of the area where the extrusion port is located.

[0091] Optionally, the plurality of sheet-like switches are provided inside the material storage cavity and above the area where the extrusion port is located.

[0092] Optionally, a plurality of sheet-like switches are provided outside the material storage cavity, and the plurality of sheet-like switches are respectively connected to a plurality of transmission members, and the plurality of transmission members control the opening and closing of the area where the extrusion port is located.

[0093] Optionally, the method of FIG. 14 further includes transporting a gas having pressure to the control chamber and the material storage tank using a gas pressure transport pipeline. The plurality of sheet-like switches are located in the control chamber, and the material storage tank communicates with the material storage cavity of the material extrusion part.

[0094] Optionally, the plurality of sheet-like switches include one or more of a piezoelectric bimorph, a bimetal, a metal resistor that expands by heat, and a shape memory alloy.

[0095] Optionally, the switch assembly includes one or more of a switch by motor control, a switch by gas pressure control, and a switch by hydraulic pressure control.

[0096] Referring to FIG. 15, another 3D printing method according to an embodiment of the present invention can include step S1510 and step S1520.

[0097] In step S1510, by transporting the molten material to the extrusion port, the current printing layer is printed using a plurality of channels at the extrusion port. Here, the materials extruded from adjacent channels among the plurality of channels are fused with each other in the current printing layer.

[0098] In step S1520, in the process of printing the current printing layer, by using the switch assembly to control the opening and closing of a plurality of channels, a plurality of sub-extrusion ports with continuously adjustable widths are formed.

[0099] Optionally, in the process of printing the current printing layer, a plurality of sub-extrusion outlets are used to simultaneously print a plurality of sections in the current printing layer. Here, the width of each sub-extrusion outlet among the plurality of sub-extrusion outlets changes according to the change of the contour line of the section corresponding to each sub-extrusion outlet, so as to fill the section corresponding to each sub-extrusion outlet with the molten material in one go.

[0100] Optionally, the plurality of sections include a first section and a second section, the plurality of sub-extrusion outlets include a first sub-extrusion outlet and a second sub-extrusion outlet, and the method of FIG. 15 further includes printing the first section and the second section respectively by using the first sub-extrusion outlet and the second sub-extrusion outlet. The first section and the second section have an isolated area from each other and a communicating area with each other. When printing the communicating area with each other, the first sub-extrusion outlet and the second sub-extrusion outlet are integrated into one sub-extrusion outlet by the opening and closing control of the switch assembly.

[0101] Optionally, the switch assembly includes a plurality of sheet-like switches corresponding one-to-one to a plurality of channels, and the method of FIG. 15 utilizes the deformation of the plurality of sheet-like switches by temperature and / or voltage control to control the opening and closing of the plurality of channels.

[0102] Optionally, the plurality of sheet-like switches are provided inside the material storage cavity and above the plurality of channels.

[0103] Optionally, the plurality of sheet-like switches are provided outside the material storage cavity, the plurality of sheet-like switches are respectively connected to a plurality of transmission members, and the opening and closing of the plurality of channels are controlled through the plurality of transmission members.

[0104] Optionally, the method of FIG. 15 further includes transporting gas having pressure to the control chamber and the material storage tank by using a gas pressure transport pipeline. The plurality of sheet-like switches are located in the control chamber, and the material storage tank communicates with the material storage cavity of the material extrusion part.

[0105] Optionally, the plurality of channels are arranged in a staggered pattern.

[0106] Optionally, the plurality of sheet switches include one or more of a piezoelectric bimorph, a bimetal, a metal resistor that expands by heat, and a shape memory alloy.

[0107] Optionally, the switch assembly includes one or more of a switch by motor control, a switch by gas control, and a switch by hydraulic control.

[0108] It should be noted that those skilled in the art can easily conceive that the units and algorithm steps of each example described in the embodiments disclosed above can be realized by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by either hardware or software depends on the specific application and design constraints of the invention. Those skilled in the art can realize the above functions in a manner corresponding to a specific application, but should not exceed the scope of the present invention.

[0109] In multiple embodiments according to the present invention, it should be understood that the disclosed methods and apparatuses can also be realized in other forms. For example, the apparatuses described above are merely schematic. For example, the division of the units described above is only an example of logical function division, and may be in another division mode when actually realized. For example, a plurality of units or modules can be combined, aggregated into another system, or some functions can be omitted or not executed. It should be noted that the above-mentioned indicated or disclosed mutual connections, direct connections, or communicable connections are connections via an interface. Indirect connections or communicable connections between apparatuses and units may be electrical, mechanical, or other forms of connections.

[0110] The unit described as the separation member may or may not be physically separated. The member displayed as a unit may or may not be a physical unit. That is, it may be in the same location or may be distributed over a plurality of network units. Some or all of the units therein are selected according to actual needs to achieve the object of the embodiments of the present invention.

[0111] In addition, each functional unit according to the embodiments of the present invention may be aggregated into one processing unit, may be physically independent, or may be aggregated into one unit with two or more.

[0112] The above description is only a specific embodiment of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be included within the protection scope of the present invention. The protection scope of the present invention should be based on the scope of the claims.

Claims

1. Comprising a material extrusion part and a switch assembly, The material extrusion part includes a material accommodation cavity for accommodating the molten material and an extrusion port communicating with the material accommodation cavity. The extrusion port is used to extrude the molten material onto the current printing layer. The switch assembly is coupled to the extrusion port and configured to form a plurality of sub-extrusion ports with continuously adjustable widths by controlling the opening and closing of the area where the extrusion port is located. The plurality of sub-extrusion ports are used to simultaneously print a plurality of compartments in the current printing layer. In the process of printing the plurality of compartments using the plurality of sub-extrusion ports, the width of each sub-extrusion port among the plurality of sub-extrusion ports changes according to the change of the contour line of the compartment corresponding to each sub-extrusion port, so as to fill the molten material into the compartments corresponding to each sub-extrusion port in one go. A 3D printing device characterized by the above.

2. The plurality of compartments include a first compartment and a second compartment. The plurality of sub-extrusion ports include a first sub-extrusion port and a second sub-extrusion port for printing the first compartment and the second compartment respectively. The first compartment and the second compartment have regions separated from each other and regions communicating with each other. When printing the regions communicating with each other, the first sub-extrusion port and the second sub-extrusion port are integrated into one sub-extrusion port by the opening and closing control of the switch assembly. The 3D printing device according to claim 1, characterized by the above.

3. The switch assembly includes a plurality of sheet-like switches. The plurality of sheet-like switches control the opening and closing of the area where the extrusion port is located by deforming under the control of temperature and / or voltage. The 3D printing device according to claim 1, characterized by the above.

4. The plurality of sheet-like switches are provided inside the material accommodation cavity and above the area where the extrusion port is located. The 3D printing device according to claim 3, characterized by the above.

5. The plurality of sheet-like switches are provided outside the material accommodation cavity. The plurality of sheet-like switches are respectively connected to a plurality of transmission members, and the opening and closing of the area where the extrusion port is located is controlled through the plurality of transmission members. The 3D printing device according to claim 3, characterized by the above.

6. The 3D printing device further includes a control chamber, a material storage tank, and a gas pressure transport pipeline. The plurality of sheet-like switches are located inside the control chamber, the material storage tank communicates with the material storage cavity of the material extrusion section, the gas pressure transport pipeline communicates with both the material storage tank and the control chamber The 3D printing apparatus according to claim 5, characterized in that.

7. The plurality of sheet-like switches include one or more of a piezoelectric bimorph, a bimetal, a metal resistor that expands by heat, and a shape memory alloy The 3D printing apparatus according to claim 3, characterized in that.

8. The switch assembly includes one or more of a switch by motor control, a switch by gas pressure control, and a switch by hydraulic pressure control The 3D printing apparatus according to claim 1, characterized in that.

9. Comprising a material extrusion section and a switch assembly, the material extrusion section includes a material storage cavity and an extrusion port, the material storage cavity is used to store the molten material, the extrusion port includes a plurality of channels communicating with the material storage cavity, the plurality of channels are used to extrude the molten material onto the current printing layer, and the materials extruded from adjacent channels among the plurality of channels fuse with each other on the current printing layer, the switch assembly is coupled to the plurality of channels and is configured to form a plurality of sub-extrusion ports with continuously adjustable widths by controlling the opening and closing of the plurality of channels A 3D printing apparatus, characterized in that.

10. The plurality of sub-extrusion ports are used to simultaneously print a plurality of sections on the current printing layer, In the process of printing the plurality of sections using the plurality of sub-extrusion ports, the width of each sub-extrusion port among the plurality of sub-extrusion ports changes according to the change of the contour line of the section corresponding to each sub-extrusion port, so as to collectively fill the section corresponding to each sub-extrusion port with the molten material The 3D printing apparatus according to claim 9, characterized in that.

11. The plurality of sections include a first section and a second section, the plurality of sub-extrusion ports include a first sub-extrusion port and a second sub-extrusion port for printing the first section and the second section respectively, the first section and the second section have regions separated from each other and regions communicating with each other, When printing the regions communicating with each other, the first sub-extrusion port and the second sub-extrusion port are integrated into one sub-extrusion port by the opening and closing control of the switch assembly The 3D printing device according to claim 10, characterized in that...

12. The switch assembly includes a plurality of sheet-shaped switches that correspond one-to-one to the plurality of channels, and the plurality of sheet-shaped switches control the opening and closing of the plurality of channels by deforming through temperature and / or voltage control. The 3D printing device according to claim 9, characterized in that...

13. The plurality of sheet-shaped switches are provided inside the material storage cavity and above the plurality of channels. The 3D printing device according to claim 12, characterized in that...

14. The plurality of sheet-shaped switches are provided outside the material storage cavity. The plurality of sheet-shaped switches are respectively connected to a plurality of transmission members, and control the opening and closing of the plurality of channels through the plurality of transmission members. The 3D printing device according to claim 12, characterized in that...

15. The 3D printing device further includes a control chamber, a material storage tank, and a gas pressure transport pipeline. The plurality of sheet-shaped switches are located inside the control chamber. The material storage tank communicates with the material storage cavity of the material extrusion part. The gas pressure transport pipeline communicates with both the material storage tank and the control chamber. The 3D printing device according to claim 12, characterized in that...

16. The plurality of channels are arranged in a staggered pattern. The 3D printing device according to claim 9, characterized in that...

17. The plurality of sheet-shaped switches include one or more of a piezoelectric bimorph, a bimetal, a metal resistor that expands by heat, and a shape memory alloy. The 3D printing device according to claim 12, characterized in that...

18. The switch assembly includes one or more of a switch controlled by motor control, a switch controlled by gas pressure control, and a switch controlled by hydraulic pressure control. The 3D printing device according to claim 9, characterized in that...

19. Printing the current printing layer by transporting the molten material to the extrusion port, In the process of printing the current printing layer, by using a switch assembly to control the opening and closing of the area where the extrusion port is located, a plurality of sub-extrusion ports with continuously adjustable widths are formed, and the plurality of sub-extrusion ports are used to simultaneously print a plurality of sections in the current printing layer. In the process of printing the plurality of sections by using the plurality of sub-extrusion ports, the width of each sub-extrusion port among the plurality of sub-extrusion ports changes according to the change of the contour line of the area corresponding to each sub-extrusion port, so as to collectively fill the molten material into the sections corresponding to each sub-extrusion port. A 3D printing method characterized by the above.

20. The plurality of sections include a first section and a second section, and the plurality of sub-extrusion ports include a first sub-extrusion port and a second sub-extrusion port. The 3D printing method includes printing the first section and the second section by using the first sub-extrusion port and the second sub-extrusion port respectively. The first section and the second section have regions separated from each other and regions communicating with each other. When printing the regions communicating with each other, the first sub-extrusion port and the second sub-extrusion port are integrated into one sub-extrusion port by the opening and closing control. The 3D printing method according to claim 1, characterized by the above.

21. The switch assembly includes a plurality of sheet-shaped switches. The 3D printing method includes controlling the opening and closing of the area where the extrusion port is located by utilizing the deformation of the plurality of sheet-shaped switches under the control of temperature and / or voltage. The 3D printing method according to claim 19, characterized by the above.

22. The plurality of sheet-shaped switches are provided inside the material storage cavity and above the area where the extrusion port is located. The 3D printing method according to claim 21, characterized by the above.

23. The plurality of sheet-shaped switches are provided outside the material storage cavity. The plurality of sheet-shaped switches are respectively connected to a plurality of transmission members, and the opening and closing of the area where the extrusion port is located is controlled through the plurality of transmission members. The 3D printing method according to claim 21, characterized by the above.

24. The method further includes transporting a gas having pressure to a control chamber and a material storage tank by using a gas pressure transport pipeline. The plurality of sheet-like switches are located within the control chamber, and the material storage tank communicates with the material accommodation cavity of the material extrusion unit. The 3D printing method according to claim 23, characterized in that.

25. The plurality of sheet-like switches include one or more of a piezoelectric bimorph, a bimetal, a metal resistor that expands by heat, and a shape memory alloy. The 3D printing method according to claim 21, characterized in that.

26. The switch assembly includes one or more of a switch by motor control, a switch by gas pressure control, and a switch by hydraulic pressure control. The 3D printing method according to claim 19, characterized in that.

27. Printing the current printing layer by using a plurality of channels at the extrusion port by transporting the material in a molten state to the extrusion port, wherein the materials extruded from adjacent channels among the plurality of channels fuse with each other in the current printing layer; In the process of printing the current printing layer, forming a plurality of sub-extrusion ports with continuously adjustable widths by using a switch assembly to control the opening and closing of the plurality of channels. A 3D printing method, characterized in that.

28. In the process of printing the current printing layer, simultaneously printing a plurality of sections in the current printing layer by using the plurality of sub-extrusion ports, and the width of each sub-extrusion port among the plurality of sub-extrusion ports changes according to the change of the contour line of the section corresponding to each sub-extrusion port, so as to fill the molten material into the sections corresponding to each sub-extrusion port in a batch. The 3D printing method according to claim 27, characterized in that.

29. The plurality of sections include a first section and a second section, and the plurality of sub-extrusion ports include a first sub-extrusion port and a second sub-extrusion port. The 3D printing method includes printing the first section and the second section respectively by using the first sub-extrusion port and the second sub-extrusion port. The first section and the second section have regions isolated from each other and regions communicating with each other. When printing the regions communicating with each other, the first sub-extrusion port and the second sub-extrusion port are integrated into one sub-extrusion port by the opening and closing control of the switch assembly. The 3D printing method according to claim 27, characterized in that.

30. The switch assembly includes a plurality of sheet-like switches that correspond one-to-one to the plurality of channels. The 3D printing method includes controlling the opening and closing of the plurality of channels by utilizing the deformation of the plurality of sheet-like switches through temperature and / or voltage control. The 3D printing method according to claim 27, characterized in that.

31. The plurality of sheet-like switches are provided inside the material storage cavity and above the plurality of channels. The 3D printing method according to claim 30, characterized in that.

32. The plurality of sheet-like switches are provided outside the material storage cavity. The plurality of sheet-like switches are respectively connected to a plurality of transmission members, and control the opening and closing of the plurality of channels through the plurality of transmission members. The 3D printing method according to claim 30, characterized in that.

33. Further including transporting gas having pressure to the control chamber and the material storage tank by using a gas pressure transport pipeline. The plurality of sheet-like switches are located in the control chamber, and the material storage tank communicates with the material storage cavity of the material extrusion part. The 3D printing method according to claim 32, characterized in that.

34. The plurality of channels are arranged in a staggered pattern. The 3D printing method according to claim 27, characterized in that.

35. The plurality of sheet-like switches include one or more of a piezoelectric bimorph, a bimetal, a metal resistor that expands by heat, and a shape memory alloy. The 3D printing method according to claim 30, characterized in that.

36. The switch assembly includes one or more of a switch controlled by motor control, a switch controlled by gas pressure control, and a switch controlled by hydraulic pressure control. The 3D printing method according to claim 27, characterized in that.

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