3D printing device and hot end switching method

Abstract

The invention relates to a 3D printing device and method. The 3D printing device comprises a printing head, a tool seat and a hot end. The hot end can be installed on the printing head in the first direction or taken down from the printing head, the hot end installed on the printing head is limited in the second direction, and an angle is formed between the second direction and the first direction; the hot end can be installed on the tool base in the second direction or taken down from the tool base, and the hot end installed on the tool base is limited in the first direction; the printing head and the tool seat can move relatively, through relative movement, the hot end on the printing head can be switched to be installed on the tool seat, and the hot end on the tool seat can be switched to be installed on the printing head. According to the hot end switching mechanism, the printing head is moved to the switching position of the corresponding tool base for hot end switching, the printing head and the tool base have the restraining effect on the hot end in different directions, the complexity of the hot end switching mechanism can be greatly simplified, and the switching process is rapid and high in reliability.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and specifically to a 3D printing apparatus and a method for switching the hot end. Background Technology

[0002] 3D printing is a process that constructs objects by printing layer by layer based on digital model files. One such process is Fused Filament Fabrication (FFF) or Fused Deposition Modeling (FDM). According to the layer pattern information in the digital model file, the nozzle moves relative to the platform in the XY plane. While the nozzle moves above the platform, it extrudes the flowable printing material along the printing path at an appropriate speed until one layer is printed. After one layer is printed, the print head and the printing platform move away from each other by a certain distance, such as the layer thickness, and then a new layer is printed. This process is repeated until a three-dimensional solid is formed.

[0003] Printhead nozzles may require periodic replacement, such as when they become clogged or worn, or when different printing materials necessitate replacing the nozzle or heating element. In traditional 3D printers, replacing the heating element or nozzle presents significant challenges to operation and maintenance. Replacing a nozzle requires heating the heating element or heating block to keep the resin molten before manually detaching the nozzle from the heating block. This manual nozzle replacement process is also difficult to control in terms of stress on the printhead; improper operation can lead to excessive stress on the printhead, affecting printing accuracy and consistency. Manually removing and installing nozzles is time-consuming and labor-intensive, significantly reducing the user experience. Replacing the entire printhead would substantially increase costs. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a 3D printing device and a method for switching the hot end, which solves the problems of existing manual nozzle replacement, such as affecting printing accuracy and consistency, as well as waste and manpower, and achieves a simple structure or low cost, and realizes a fast hot end switching process.

[0005] The technical solution to achieve the above objectives is:

[0006] This invention provides a 3D printing apparatus, including a print head, a tool holder, and a hot end;

[0007] The hot end can be installed onto the print head along the first direction or removed from the print head, and the hot end installed on the print head is limited along the second direction;

[0008] The hot end can be installed onto or removed from the tool holder along the second direction, and the hot end installed on the tool holder is limited along the first direction; wherein the second direction is set at an angle to the first direction.

[0009] The present invention also provides a method for switching the hot end of a 3D printing device, comprising the following steps:

[0010] When a hot end is installed on the print head, the print head is moved to a first switching position or a second switching position of the tool holder without a hot end installed. By relatively moving the print head and the tool holder without a hot end installed, the hot end on the print head is removed from the print head along a first direction and then installed onto the tool holder without a hot end installed along a second direction; or...

[0011] When the hot end is not installed on the print head, the print head is moved to the second switching position or the first switching position of the corresponding tool holder with the hot end installed. By moving the print head and the tool holder with the hot end installed relative to each other, the hot end on the tool holder with the hot end installed is removed from the corresponding tool holder in the second direction and then installed on the print head in the first direction.

[0012] The relative movement of the print head and the tool holder includes the print head moving relative to the tool holder, the tool holder moving relative to the print head, or the print head and the tool holder moving simultaneously.

[0013] The beneficial effects of the 3D printing device and hot-end switching method of this invention are as follows: By setting hot ends on each tool holder and switching the hot end by moving the print head to the corresponding tool holder's switching position through relative movement between the print head and the tool holder (e.g., print head movement), and by utilizing the constraint effect of the print head and tool holder on the hot end in different directions, the complexity of the hot-end switching mechanism is greatly simplified, resulting in a fast and highly reliable switching process. The switching process mainly relies on the relative movement between the print head and the tool holder, and may eliminate the need for electrical connections to the hot end, resulting in a simple structure, fast switching, and reliable long-term operation. Alternatively, the switching process can be completed automatically without human intervention, ensuring consistent force on the print head during the switching process. For example, the force on the print head can be minimized each time, and the force on the print head can be kept roughly consistent during each hot-end switching process, avoiding the influence of human operation on the print head force and improving the long-term reliability and printing accuracy of the print head. Furthermore, the switching process avoids manual replacement of the hot end, reducing the workload of the printing process and providing a better user experience. The simple structure, small size, and light weight of the hot-end allow for easy and consistent interchangeability between multiple hot ends and the print head or tool holder, ensuring higher repeatability and guaranteeing printing accuracy after hot end replacement. It also enables high-speed and precise multi-color or multi-material model printing. For example, each hot end corresponds to a specific color or material of printing material. By replacing the hot end with the corresponding color or material, and simultaneously changing the printing material in the feed tube of the print head, rapid switching between different colors or materials is possible. It also allows for rapid switching between hot ends with different extrusion nozzle diameters or different materials. The simple and compact hot-end structure, especially with heat dissipation fins on the tool holder and / or print head, and heat dissipation surfaces in the heat dissipation section of the hot end contacting the heat dissipation surfaces on the tool holder or print head, further simplifies the structure. The lighter weight and smaller size of the hot end improve positioning accuracy during repeated assembly and disassembly. Furthermore, as a consumable, the lower cost of the hot end contributes to reduced application costs in the printing process. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of a 3D printing device with an automatic heat exchange end equipped with multiple tool holders according to the present invention.

[0015] Figure 2a This is a three-dimensional structural diagram of a hot end according to the present invention.

[0016] Figure 2b This is a three-dimensional structural diagram of a printhead according to the present invention.

[0017] Figure 3a This is a schematic diagram from a first perspective of the three-dimensional structure of a tool holder according to the present invention.

[0018] Figure 3b This is a schematic diagram from a second perspective of the three-dimensional structure of a tool holder according to the present invention.

[0019] Figure 4a This is a three-dimensional structural diagram of the 3D printing device with the print head located at the tool holder switching position according to the present invention.

[0020] Figure 4b This is a top view schematic diagram of a 3D printing device of the present invention, which has two tool holders and the print head is located in the switching position of one tool holder or the switching position of one tool holder.

[0021] Figure 4c for Figure 4a The MM cross-sectional view shows the state of the print head at the switching position A of the tool holder.

[0022] Figure 4d To Figure 4c A cross-sectional schematic diagram of another implementation scheme of the shown scheme.

[0023] Figure 4e for Figure 4a The NN cross-sectional view shows the state of the print head at the switching position A of the tool holder.

[0024] Figure 4f for Figure 4a The MM cross-sectional view shows the printhead positioned at point T.

[0025] Figure 4g for Figure 4a The NN cross-sectional view shows the state of the printhead at point T.

[0026] Figure 4h for Figure 4a The MM cross-sectional view shows the printhead positioned at point B.

[0027] Figure 4i for Figure 4a The NN cross-sectional view shows the printhead positioned at point B.

[0028] Figure 4j for Figure 4a The MM cross-sectional view shows the print head at point C, and is also a cross-sectional schematic diagram of another implementation scheme.

[0029] Figure 4k for Figure 4a The diagram shows the NN cross-section, the print head at point C, and a cross-sectional schematic of another implementation scheme.

[0030] Figure 4L for Figure 4aThe MM cross-sectional view shows the print head at point C, and is also a cross-sectional schematic diagram of another implementation scheme.

[0031] Figure 4M This is a schematic diagram of the three-dimensional structure of the printhead located at point C.

[0032] Figure 4N This is a three-dimensional structural diagram of a printhead for an alternative implementation located at point C.

[0033] Figure 4O for Figure 4N A three-dimensional structural diagram of the other side of the printhead is shown.

[0034] Figure 4P This is a top view schematic diagram of the 3D printing device of the present invention, in which two printheads are on the left and a tool holder is on the right, with the tool holder located at the printhead switching position or one printhead located at the tool holder switching position.

[0035] Figure 5 This is a schematic diagram of the heat exchange end structure of the printhead of the present invention, which can move directly from point A to point B.

[0036] Figure 6 This is a schematic diagram of the heat exchange end structure of the tool holder of the present invention, which can also move along the Z direction.

[0037] Figure 7a This is a three-dimensional structural diagram of the 3D printing device for an automatic heat exchange end with heat dissipation fins on the hot end of the present invention.

[0038] Figure 7b for Figure 7a A three-dimensional structural diagram of the mid-heating end.

[0039] Figure 8a This is a three-dimensional structural diagram of a 3D printing device with another hot-end switching method according to the present invention.

[0040] Figure 8b for Figure 8a The MM cross-sectional view shows the state of the print head at the switching position A of the tool holder.

[0041] Figure 8c for Figure 8a The MM cross-sectional view shows the printhead positioned at point T.

[0042] Figure 8d for Figure 8a The MM cross-sectional view shows the printhead positioned at point B.

[0043] Figure 8e for Figure 8a The MM cross-sectional view shows the printhead at point C.

[0044] Figure 8f for Figure 8a The NN cross-sectional view shows the state of the printhead at point T.

[0045] Figure 8g This indicates the print head is positioned at point B.

[0046] Figure 8h for Figure 8a The NN cross-sectional view shows the printhead at point C.

[0047] Figure 9a This is a first-view schematic diagram of the three-dimensional structure of a 3D printing device with another hot-end switching method according to the present invention.

[0048] Figure 9b This is a second-view schematic diagram of the three-dimensional structure of a 3D printing device with another hot-end switching method according to the present invention.

[0049] Figure 10 This is a flowchart illustrating a method for switching printing media and the hot end. Detailed Implementation

[0050] This invention provides a 3D printing apparatus and a method for switching hot ends to address the limitations of existing 3D printer structures. For example, the method of changing printheads places higher demands on repeatability and positioning accuracy. The complex structure of the printhead makes it difficult to maintain consistent nozzle position accuracy when changing different printheads, often leading to poor bonding between the printed parts of the model and the printheads from different printheads. Furthermore, the large size of the printhead limits the number of printheads that can be placed within a given 3D printer's printing space. Manually changing hot ends or nozzles is inefficient and cannot meet the needs of multi-material printing. For instance, in existing methods, when printing multiple materials, the printing material remaining in the nozzle or hot end after the previous printing step is extruded before printing the next material, a time-consuming and wasteful process. The 3D printing apparatus and hot end switching method of this invention are described below with reference to the accompanying drawings. The various embodiments can be combined with each other.

[0051] Example 1, as Figure 1 , Figure 4b and Figure 5The diagram shows a three-dimensional structural schematic of a 3D printing device with an automatic heat exchange end having multiple tool holders according to the present invention. The 3D printing device of the present invention includes a print head 1, a tool holder 50, and a hot end 10. The hot end 10 can be mounted on either the print head 1 or the tool holder 50, thus allowing the hot end 10 to be switched from the print head 1 to the tool holder 50, and vice versa. Specifically, the hot end 10 can be mounted on or removed from the print head 1 along a first direction. The hot end 10 mounted on the print head 1 is limited along a second direction, wherein the second direction is angled to the first direction, for example, the first and second directions are perpendicular to each other. Figure 1 or Figure 4b In the embodiment shown, the first direction is the Y-axis direction, and the second direction is the X-axis direction. Figure 5 The diagram illustrates that the first and second directions are angled together. The hot end 10 can be mounted onto or removed from the tool holder 50 along the second direction. The hot end mounted on the tool holder 50 is limited along the first direction. The print head 1 and the tool holder 50 can move relative to each other. This relative movement allows the hot end 10 on the print head 1 to be switched onto the tool holder 50, and vice versa. The direction of the first direction can be interchanged with the direction of the second direction; for example, the first direction can be the X-axis and the second direction the Y-axis, depending on the spatial arrangement of the tool holder and print head. The first direction also includes a first positive direction and a first negative direction, which are opposite in direction. Similarly, the second direction includes a second positive direction and a second negative direction, which are opposite in direction. Figure 4b Tool holder 50A in the middle can be regarded as Figure 4a , Figures 4c to 4L Tool holder 50.

[0052] Thus, the 3D printing device of the present invention can automatically change the hot end through the relative movement of the print head and the tool holder, which is simple in structure, reliable in process, and low in cost. In addition, the entire process can be completed without human intervention, which can avoid the impact of human operation on the force on the print head, and is conducive to improving the long-term reliability of the print head and maintaining the printing accuracy for a long time.

[0053] The number of tool holders 50 can be multiple (which can also be understood as multiple hot ends being installed on a single tool holder). These tool holders 50 (from the perspective of installing hot ends, this can also be understood as the position or structure of the hot ends on the tool holder) can be arranged along a second direction or a direction perpendicular to the first direction. One of the tool holders (the position or structure of the hot end on the tool holder) or the print head may not have a hot end installed. That is, when a hot end is installed on the print head, at least one of the tool holders may not have a hot end installed, i.e., it may be in an idle state. When no hot end is installed on the print head, all of the tool holders may have hot ends installed, or some may be in an idle state. The specific number of tool holders 50 can be determined by the amount of printing material that needs to be replaced on the print head 1, the size of the 3D printer frame, or other factors or application requirements. The number of print heads can also be multiple. For example, multiple print heads can be arranged parallel to the second direction or perpendicular to the first direction. These multiple print heads can move independently or be interconnected as a single structure.

[0054] Figure 1 and Figure 7a The diagram shows that there are 7 tool holders, and counting from left to right, the first tool holder is idle (no hot end is set on it), and the second to seventh tool holders are each equipped with a hot end 10. The print head 1 is also equipped with a hot end 10. Figure 4b In the illustrated embodiment, there are two tool holders 50. These tool holders 50 are arranged along the X-axis. The first tool holder 50A (lower in the diagram) is idle as it does not have a hot end 10. The second tool holder 50B has a hot end 10, and the print head 1 also has a hot end 10. Multiple tool holders can be integrated together, such as... Figure 1 and Figure 7a The upper part of the base 57 of each tool holder is integrally formed, and the lower part can also be integrally formed, thus achieving a simpler, more compact and reliable structure.

[0055] like Figure 4b and Figure 5As shown, each tool holder 50 has a first switching position A and a second switching position C. The print head 1 can move relative to the tool holder 50 to either the first switching position A or the second switching position C. If the print head 1 moves to the first switching position A and then the print head 1 and the corresponding tool holder begin to move relative to each other, the hot end can be switched and installed onto the tool holder 50. If the print head 1 moves to the second switching position C and then the print head 1 and the corresponding tool holder begin to move relative to each other, the hot end on the tool holder 50 can be switched and installed onto the print head 1. It should be noted that the first switching position A and the second switching position C can be interchanged. That is, if the print head 1 moves to the second switching position C and then the print head 1 and the corresponding tool holder begin to move relative to each other, the hot end can be switched and installed onto the tool holder 50. If the print head 1 moves to the first switching position A and then the print head 1 and the corresponding tool holder begin to move relative to each other, the hot end on the tool holder 50 can be switched and installed onto the print head 1. For example, ... Figure 4b The tool holder on the left side of the middle is mirrored vertically.

[0056] like Figure 5 As shown, the movement path of printhead 1 also includes the mounting position B on tool holder 50 corresponding to the hot end 10. Figure 5 The diagram illustrates that the first switching position A is located on the extension line of the mounting position B corresponding to the hot end on the tool holder along the second direction, and the second switching position C is located on the extension line of the mounting position B corresponding to the hot end on the tool holder along the first direction. The three points, the first switching position A, the mounting position B corresponding to the hot end on the tool holder, and the second switching position C, are separated by a preset distance from each other. Position C can be a point at a preset distance from position B along the first direction or from position A along the X-axis direction. Position A can be a point at a preset distance from position B along the second direction or from position C along the X-axis direction. When the hot end 10 on the printhead 1 is switched and installed on the tool holder 50, the printhead 1 and the tool holder 50 move relative to each other, so that the printhead 1 passes through the first switching position A, the corresponding hot end installation position B on the tool holder, and the second switching position C in sequence, thereby completing the switch of the hot end on the printhead to the tool holder 1. If the tool holder and the printhead are swapped (that is, the number 50 in the figure is changed to 1, i.e., the printhead, and the number 1 is changed to 50, i.e., the tool holder, or another way of describing it is to name the original tool holder as the printhead and the original printhead as the tool holder), then the hot end on the tool holder is switched and installed on the printhead. When the hot end on the tool holder is switched and installed onto the print head, the print head and the tool holder move relative to each other, causing the print head to pass through the second switching position C, the corresponding hot end installation position B on the tool holder, and the first switching position A in sequence, thus completing the switch of the hot end on the tool holder onto the print head. If the tool holder and the print head are swapped (i.e., the number 50 in the figure is changed to 1, i.e., the print head, and the number 1 is changed to 50, i.e., the tool holder), the hot end on the print head is switched and installed onto the tool holder.

[0057] like Figure 4b As shown, the movement path of printhead 1 from the first switching position A of tool holder 50A to the mounting position B of the hot end 10 on tool holder 50A can be a curve, or the movement path of printhead 1 can also include a relay position T, which is set near the first switching position A and the mounting position B of the hot end on tool holder, that is, on the movement path between position A and position B, such as... Figure 4b As shown, the first switching position A is located on the extension line of the hot end mounting position B on the tool holder along the second direction and then along the extension line of the first direction (e.g., Figure 4b The position T is located on the extension line of the first direction, or the first switching position A is located on the extension line of the second switching position C along the second direction, and the relay position T is located on the extension line of the installation position B of the corresponding hot end on the tool holder along the second direction. Position T can be located outside the triangle formed by the three points A, B, and C. Ideally, the path between position B and position C is a straight line, and the path between position A and position B is a straight line or a combination of two connecting straight line segments. The two connecting straight line segments can be transitioned by an arc. For example, the path between position A and position T is a straight line, and the path between position T and position B is a straight line, or the path between position A and position B is a curve such as an arc. For example, when the print head is set on the swing arm, multiple tool holders can be arranged along an arc. Ideally, position T is coplanar with positions A, B, and C. Ideally, the plane containing the three points A, B, and C is parallel to the surface of the printing platform or parallel to the XY plane. Position T may not be coplanar with positions A, B, and C. Ideally, the path between positions B and C should be a diagonal or zigzag line, and the path between position T and position A should also ideally be a diagonal or zigzag line, provided the tool holder is always above the printing area during printing, i.e., the projection of the hot end of the tool holder onto the printing platform falls on the printing platform or within the printing area on the printing platform. When the printhead's movement path is a diagonal or zigzag line, position T can also be coplanar with positions A, B, and C, but this plane should not be parallel to the upper surface of the printing plane or parallel to the XY plane (set at an angle). It should be noted that in this embodiment, the movement path of printhead 1 refers to the movement path of the printhead relative to the tool holder, which can be achieved by the printhead moving, by the tool holder moving, or by the printhead and tool holder moving relative to each other. The printhead reaching position A can refer to the position of the axis of the hot end 10 of the printhead reaching position A. If no hot end is installed on the printhead, it can be assumed that the position of the axis of the printhead with the hot end installed reaches position A, and so on for other positions.

[0058] like Figure 4bAs shown, when the hot end 10 on the printhead 1 is switched and installed onto the tool holder 50, the printhead 1 and the tool holder 50 move relative to each other, causing the printhead 1 to sequentially pass through the first switching position A, the relay position T, the installation position B of the corresponding hot end on the tool holder 50A, and the second switching position C of the tool holder 50A, thereby completing the switching and installation of the hot end on the printhead 1 onto the tool holder 50A; or, refer to Figure 4b The letters in square brackets can also represent the relative movement of printhead 1 and tool holder 50A, causing tool holder 50A to sequentially pass through the first switching position AA, relay position TT, the corresponding hot end mounting position BB on the printhead, and the second switching position CC of printhead 1, thus completing the hot end switching and mounting from printhead 1 to tool holder 50A. When switching the hot end from tool holder to printhead, the relative movement of printhead and tool holder causes printhead 1 to sequentially pass through the second switching position C, the corresponding hot end mounting position B, relay position T, and the first switching position A of tool holder 50A, thus completing the hot end switching and mounting from tool holder 50A to printhead 1; or, the relative movement of printhead and tool holder causes tool holder 50A to sequentially pass through the second switching position CC, the corresponding hot end mounting position BB, relay position TT, and the first switching position AA of printhead, thus completing the hot end switching and mounting from tool holder 50A to printhead 1. For example, specifically... Figure 4b As shown, the print head 1 and the tool holder 50A move relative to each other, causing the print head 1 to move relative to the tool holder 50A from its first switching position A along a first direction that is relatively close to the tool holder 50A, and then relative to the tool holder 50A along a second direction that is relatively close to the mounting position B of the corresponding hot end 10 on the tool holder 50A, until it reaches the mounting position B of the corresponding hot end 10 on the tool holder 50A. Then, it moves relative to the tool holder 50A along a first direction that is relatively away from the tool holder 50A until it reaches the second switching position C of the tool holder 50A, thus realizing the switching and mounting of the hot end 10 on the print head 1 onto the tool holder 50A. The printhead 1 and the tool holder 50A move relative to each other, causing the printhead 1 to move relative to the tool holder 50A from the second switching position C along the first direction relative to the tool holder 50A, to the mounting position B of the corresponding hot end 10 on the tool holder 50A, and then move relative to the tool holder 50A from the second direction relative to the mounting position B of the corresponding hot end 10 on the tool holder 50A, and then move relative to the tool holder 50A from the first direction relative to the tool holder 50A to the first switching position A, so that the hot end 10 on the tool holder 50A is switched and installed on the printhead 1.

[0059] Furthermore, the direction of relative movement between the printhead and the tool holder, and / or the first direction and / or the second direction, lies within the XY plane or is perpendicular to the Z-axis, or perpendicular to the axis of the feed line of the hot end, or perpendicular to the axis of the extrusion port of the printhead, or perpendicular to the normal to the surface of the printing platform used to carry the printed material extruded by the printhead, with an error not exceeding ±40° or ±45°. Ideally, the relay position is located on the axis along the second direction past the mounting position of the hot end on the tool holder and / or on the axis along the first direction past the first switching position on the tool holder.

[0060] The relative movement between the printhead 1 and the tool holder 50 can be accomplished entirely by the movement of the printhead, entirely by the movement of the tool holder, or by the combined movement of the printhead and the tool holder. Alternatively, the movement can be partially accomplished by the printhead and partially by the tool holder; for example, the tool holder can perform the movement component along the Y-axis, while the printhead performs the movement component along the X-axis. For instance, if the printhead can move along the XY plane, the hot end can be replaced solely by the movement of the printhead, while the tool holder remains stationary. Alternatively, if the printhead can only move along the X-axis, such as in a gantry frame structure (I3 structure), the printhead moves along the X-axis, and the tool holder moves along the Y-axis. In yet another embodiment, if the printhead can move along the X-axis and also oscillate, the hot end can be replaced solely by the movement of the printhead, or the printhead can move along the X-axis, the tool holder along the Y-axis, or the printhead can oscillate circumferentially, and the tool holder moves radially along the swing arm. Furthermore, the tool holder 50 can be mounted on the printer frame, or it can be mounted on the X-axis rail assembly of a gantry frame structure (I3 structure), cantilever structure, or similar structure where the printhead can move along the Z-axis, allowing the tool holder to move along the Z-axis with the X-axis. The tool holder can also be mounted on the XY-axis guide rail frame of an XY-structure (box-type or rectangular coordinate structure) printer. The tool holders can also be arranged along the Z-axis, allowing for more tool holders to be mounted on the printer. Each tool holder can be used to install one hot end, and more hot ends can be installed for replacement. If the tool holder is positioned above the printing area, such as in a gantry-type 3D printer (I3 structure), the tool holder is mounted on the X-axis assembly and can move along the Z-axis with the X-axis assembly. When the hot end needs to be replaced, the tool holder can move along the Y-axis or in a direction at an angle to the Y-axis. When the tool holder moves away from the print head, the distance between the tool holder and the printing platform increases; when the tool holder moves closer to the print head, the distance between the tool holder and the printing platform decreases. In other words, the guide rail for the tool holder's movement is inclined. Furthermore, the tool holder can move along the Y-axis, as well as the X-axis or Z-axis. The tool holder can also remain fixed relative to the printer frame, the X-axis guide rail, or the Y-axis guide rail. When the tool holder can move along a third direction perpendicular to the first and second directions, it moves towards the print head or print platform when the print head needs heat exchange. After heat exchange, the tool holder moves away from the print head or print platform along the third direction, avoiding interference with the printed model on the print platform during printing. Overall, the structure is simple, the cost is low, and the heat exchange process is fast and reliable.

[0061] Combination Figure 1 , Figure 2a and Figure 7aAs shown, the hot end 10 sequentially includes an extrusion port 11, a heating section 12, a throat section 13, and a heat dissipation section 14. The heating section 12, throat section 13, and heat dissipation section 14 of the hot end 10 constitute a feed pipe. The extrusion port 11 is connected to the heating section 12. The throat section 13 connects the heating section 12 and the heat dissipation section 14, allowing the printing material to be transferred from the heat dissipation section 14 to the heating section 12 and reducing heat conduction from the heating section 12 to the heat dissipation section 14. The extrusion port 11 is used to extrude the printing material, for example, by heating and melting the printing material before extrusion. The feed pipe 72 can be connected above the printhead to deliver the printing material 70 to the heat dissipation section of the hot end. The printing material 70 can be a filamentous thermoplastic resin material, such as PLA, nylon, PETG, or ABS filamentous resin materials, or other filamentous printing materials of different materials. Of course, the printing material can also be a granular resin material or a slurry or liquid material, such as a polymer slurry or granular material. The feeding tube 72 can be made of flexible materials such as polytetrafluoroethylene (Teflon).

[0062] 3D printing devices (3D printers) can take many structural forms, such as Figure 1 As shown, the print head 1 can be constrained to move by the guide rail 81, which may be a Cartesian coordinate system 3D printer or a gantry frame (or I3 architecture) 3D printer; alternatively, it can be constrained to swing motion by the swing arm, such as a polar coordinate system 3D printer; or it can be a combination of linear movement and swing motion. It can also be a delta 3D printer, i.e., a delta parallel arm 3D printer. If the print head 1 can move along the Z-axis, the tool holder 50 can also move synchronously along the Z-axis. The Z-axis is the direction perpendicular to the X-axis and Y-axis, or perpendicular to the printing platform 89 (e.g., ...). Figure 6 The tool holder 50 can move in a direction perpendicular to the surface of the extruder 11, or in a direction generally parallel to the axis of the extruder 11, or in a direction generally parallel to the direction in which the printing material 70 is conveyed along the feed pipe of the hot end 10. The tool holder 50 can also move along the XY plane, YZ plane, or XZ plane, etc. If the print head 1 moves only along the X and Y axes, the tool holder 50 can be connected to the guide rails on which the print head is moved. The tool holder 50 can be fixed to the frame of the 3D printer. The print head can also be fixed to the frame of the 3D printer, in which case printing can be performed by moving the printing platform.

[0063] It should be noted that the concepts of printhead and tool holder in the various figures or embodiments of this application are relative, that is, the printhead and tool holder can be interchanged (swapped), that is, the printhead can be replaced by the tool holder, and the tool holder can be replaced by the printhead. For example, the printhead and tool holder can be interchanged. Figure 4bThe two tool holders on the left are considered as two printheads, and the printhead on the right is considered as a tool holder, as shown in Figure 4p. The left side represents printheads 1A and 1B, and the right side represents tool holder 50. In Figure 4p, position AA is the first switching position of printhead 1A, and position CC is the second switching position of printhead 1A. If tool holder 50 reaches the first switching position AA of printhead 1A (achieved by moving printhead 1A and / or tool holder 50), then printhead 1A and tool holder 50 move relative to each other (achieved by moving printhead 1A and / or tool holder 50) so that tool holder 50 reaches the position BB on printhead 1A corresponding to the hot end mounting position, or first passes through the intermediate position TT of the printhead and then reaches the corresponding hot end mounting position BB on the printhead. Then, from position BB to position CC, the hot end 10 is transferred from the tool holder 1A to the tool holder 50. Tool holder 50 is switched to print head 1A; if print head 1A has a hot end 10 and tool holder 50 does not have a hot end, tool holder 50 can first reach the second switching position CC of print head 1 (which can be achieved by moving print head 1A and / or tool holder 50), then print head 1A and tool holder 50 move relative to each other (which can be achieved by moving print head 1A and / or tool holder 50) so that tool holder 50 reaches the position BB on print head 1A corresponding to the position where the hot end is installed, and then moves from position BB to position AA, or from position BB to position TT and then to position AA to switch the hot end 10 from print head 1A to tool holder 50. Additionally, referring to the letters in brackets in Figure 4p, when printhead 1A reaches the first switching position A of tool holder 50, it is equivalent to tool holder 50 reaching the first switching position AA of printhead 1A. Similarly, when printhead 1A reaches the second switching position C of tool holder 50, it is equivalent to tool holder 50 reaching the second switching position CC of printhead 1A. The position B of printhead 1A reaching the hot mounting end of tool holder 50 corresponds to the position BB of tool holder 50 reaching the hot mounting end of printhead 1A. The relay position T of printhead 1A reaching tool holder 50 corresponds to the relay position TT of tool holder 50 reaching printhead 1A. Similarly... Figures 4c to 4L , Figure 5 , Figure 6 , Figures 8a to 9bIn all the figures, the tool holder on the left can be considered as printhead 1, and the printhead 1 on the right can be considered as tool holder 50. The tool holder can also slide along a guide rail, or it can move on a corresponding plane (such as the XY plane or YZ plane). A filament feeder or a feeding line can also be installed on the tool holder. The filament feeder can also be installed on the printing material delivery line connected to the feeding line on the tool holder. For example, the filament feeder delivers the printing material in the feeding line to the corresponding hot end in the tool holder, squeezing out the residual printing material in the hot end and replacing it with the printing material in the feeding line, so that the printing material in the hot end is the printing material to be used in the next step when switching the hot end with the printhead. Multiple tool holders can be provided, or multiple hot ends can be installed on a single tool holder assembly. Similarly, multiple printheads can be provided, or multiple hot ends can be installed on a single printhead. Furthermore, the first direction and the second direction are opposite and can be interchanged. Printhead 1A in Figure 4p can be considered as printhead 1 in other figures.

[0064] like Figure 4d and Figure 4L As shown, and Figure 8b and Figure 8e As shown, the print head 1 is located in the first switching position A of the tool holder 50. When the print head is equipped with a hot end 10, but the tool holder 50 is not equipped with a hot end, as shown... Figure 4d or Figure 8b As shown, the print head moves relative to the tool holder, from the first switching position A to the relay position T, and then to the hot end mounting position B of the tool holder. Figure 4d or Figure 4L The fourth swing lever 59 of the tool holder clamps the hot end, which is positioned by the positioning plate 532. Then the print head reaches the second switching position C, switching the hot end 10 from the print head 1 to the tool holder 50. Figure 4L or Figure 8e As shown. Figure 4d The second swing lever 33 continues to swing slightly toward the part or direction on the print head where the hot end is mounted, due to the action of the elastic element 241, until it is limited. Figure 4L The lower pressure plate 32 continues to move slightly under the action of the elastic element 241 until it is stopped. If the print head does not have a heated end, the tool holder 50 has a heated end, such as... Figure 4L or Figure 8e As shown, by the relative movement of the print head and the tool holder, the print head can first reach the first switching position A of the tool holder, allowing the lever 581 on the tool holder to engage with the lever 39 on the print head, as shown. Figure 4d or Figure 4L ,or Figure 8b or Figure 8e As shown in the diagram, the print head then moves along the second direction to the second switching position C of the tool holder. Figure 4dThe central lever 581 will actuate the second swing lever 33 to overcome the elastic force of the elastic element 241 and open it. Figure 4L or Figure 8e The middle deflector 581 will deflect the lower pressure plate 32 to overcome the elastic force of the elastic element 241 and open it, and then the print head will reach the position B of the mounting hot end of the tool holder along the first direction. Figure 4d or Figure 8e The positioning element 231 on the print head 1 matches the positioning structure on the hot end to position the hot end. Figure 4L The positioning post 53 in the middle matches the positioning structure on the hot end to position the hot end. Then the print head drives the hot end to the relay position T, and then to the first switching position A. Figure 4d The second swing lever 33 clamps the hot end. Figure 4L and Figure 8e The lower pressure plate 32, under the elastic force of the elastic element 241, clamps the hot end, allowing it to abut against the first heating element 21 on the print head. The hot end can then be switched from the tool holder 50 onto the print head 1, for example... Figure 4L An elastic element 243 can also be configured to act as a spring force, causing the hot end to abut against the first heating element 21. During the above process, the relay position T can be cancelled.

[0065] The first clamping mechanism has a second swinging pressure rod as its clamping component. One end of the second swinging pressure rod is rotatably mounted on the print head via a second rotating shaft. The end of the second swinging pressure rod presses against the side of the hot end facing the tool holder. The second swinging pressure rod is provided with a swing rod actuating part, and the tool holder has a corresponding actuating part. Alternatively, the clamping component is a lower pressure plate, which is movable along a second direction and mounted on the print head. The lower pressure plate is provided with a pressure plate actuating part, and the tool holder has a corresponding actuating part. The mechanism also includes an elastic element, whose elastic force presses the second swinging pressure rod or the lower pressure plate against the hot end of the print head.

[0066] The print head and tool holder move relative to each other, causing the print head to reach the first switching position of the tool holder, which engages with the lever actuating part or the pressure plate actuating part. Then, the print head reaches the second switching position, causing the lever to overcome the elastic force of the elastic element and actuate the lever actuating part or the pressure plate actuating part to open the second swinging pressure bar or the lower pressure plate (opening the clamping part to facilitate the insertion or release of the hot end from the clamping state). Then, the print head reaches the installation position of the hot end on the tool holder, which connects the hot end on the tool holder to the print head and is positioned by the first positioning mechanism on the print head. Then, the print head reaches the first switching position, and the second swinging pressure bar or the lower pressure plate clamps the hot end under the elastic force of the elastic element, thereby realizing the switching installation of the hot end on the tool holder onto the print head or the switching installation of the hot end on the print head onto the tool holder.

[0067] Alternatively, a relay position is provided near the first switching position of the tool holder and the installation position of the hot end on the tool holder. The print head and the tool holder move relative to each other so that the print head reaches the first switching position of the tool holder, so that the lever engages with the swing arm or pressure plate. Then the print head reaches the second switching position so that the lever overcomes the elastic force of the elastic element and moves the swing arm or pressure plate to open the second swing pressure bar or lower pressure plate. Then the print head reaches the installation position of the hot end on the tool holder and attaches the hot end on the tool holder to the print head and is positioned by the first positioning mechanism on the print head. Then the print head reaches the relay position, and the second swing pressure bar or lower pressure plate clamps the hot end under the elastic force of the elastic element. Then the print head reaches the first switching position, realizing the switching and installation of the hot end on the tool holder onto the print head or the switching and installation of the hot end on the print head onto the tool holder.

[0068] The relative movement of the printhead and the tool holder includes the printhead moving relative to the tool holder, or the tool holder moving relative to the printhead, or the printhead and the tool holder moving simultaneously.

[0069] In embodiment two, the printhead includes a first limiting structure that limits the hot end in a second direction; the tool holder includes a second limiting structure that limits the hot end in a first direction. Further, the first limiting structure includes a first clamping mechanism that clamps or releases the hot end in the first direction; and / or the first limiting structure includes a first positioning mechanism that limits the hot end in a second direction; and / or the second limiting structure includes a second clamping mechanism that clamps or releases the hot end in a second direction; and / or the second limiting structure includes a second positioning mechanism that limits the hot end in a first direction.

[0070] like Figure 1 and Figure 2b As shown, the first limiting structure may include a first clamping mechanism 30, which clamps the hot end 10 in a first direction. The first clamping mechanism 30 enables the hot end 10 to be installed onto or removed from the print head along the first direction. The clamping of the hot end 10 in the first direction by the first clamping mechanism 30 can also be used to limit the hot end in a second direction. The first direction is... Figure 1The first defining structure may further include a first positioning mechanism for limiting or positioning the hot end mounted on the print head along the second direction, and also for limiting or positioning a third direction perpendicular to the first and second directions. The tool holder 50 includes a second defining structure, which includes a second clamping mechanism for clamping and fixing the hot end mounted on the tool holder 50. The second clamping mechanism can be opened to allow the hot end to be mounted on or removed from the tool holder 50 along the second direction. The second defining structure also includes a second positioning mechanism for limiting or positioning the hot end mounted on the tool holder 50 along the first direction. Both the first and second clamping mechanisms may include clamping elements.

[0071] Example 3, as Figure 1 and Figure 2b As shown, the first clamping mechanism 30 includes a clamping member movably connected to the print head 1. This clamping member can be adjusted to press against the hot end 10 to achieve clamping, and can also be separated from the hot end 10 to release the clamping. In a preferred embodiment, the clamping member is rotatably mounted on the print head 1, and one end of the clamping member can rotate around the rotatable connection to press against the hot end 10 or rotate to separate from the hot end 10. In another preferred embodiment, the clamping member is movable along a second direction on the print head 1, and by moving and adjusting the clamping member, it can press against the hot end 10 or separate from the hot end 10.

[0072] For example in Figure 1 and Figure 2b As shown, the clamping component is a first swinging pressure rod 31. The middle part of the first swinging pressure rod 31 is rotatably mounted on the print head 1 via a first rotating shaft 301. A first elastic element 241 is connected to the end of the first swinging pressure rod 31 away from the hot end 10. The first elastic element 241 applies a spring force to the corresponding end of the swinging pressure rod 31, causing the first swinging pressure rod to rotate around the first rotating shaft 301. Consequently, the end of the first swinging pressure rod 31 near the hot end 10 presses against the hot end 10, fixing the hot end 10 to the print head. The first swinging pressure rod 31 is provided corresponding to the heating section 12 of the hot end 10. Two first swinging pressure rods 31 can be provided, correspondingly pressing against the upper and lower parts of the heating section 12 of the hot end 10. Further, the first rotating shaft 301 is arranged along a third direction, which can be perpendicular to the first and second directions.

[0073] The end of the first swing pressure rod 31 facing the tool seat 50 may also be provided with a slope. The slope can make it easy to install the hot end 10 onto the print head 1. When the hot end 10 moves relative to the print head 1 along the first direction, the end side of the hot end 10 contacts the slope of the end of the first swing pressure rod 31 facing the tool seat 50. The hot end 10 can slide into the corresponding part between the first swing pressure rod 31 and the print head 1 through the guidance of the slope. During the installation of the hot end 10, the elastic force of the first elastic element 241 is overcome, and the first swing pressure rod 31 rotates around the first rotating shaft 301 so that one end of it opens to allow the hot end 10 to enter. Conversely, when the hot end 10 moves relative to the print head 1 in the direction away from the print head 1 along the first direction, the hot end 10 can overcome the clamping force of the first swinging lever 31 and be removed from the print head 1. After the hot end 10 is removed, the first elastic element 241 pushes the first swinging lever 31 to rotate around the first rotating shaft 301, so that the end of the first swinging lever 31 facing the tool holder 50 continues to rotate. The end of the first swinging lever 31 can be in contact with the corresponding surface of the print head 1, or be limited as... Figure 4c As shown, the swing limiting structure 272 provided on the print head 1, for example, is set on the swing path of the first swing pressure rod 31 along the elastic force of the first elastic member 241. When the hot end 10 is not installed on the print head 1, the first swing pressure rod 31 continues to swing in the pressing direction under the action of the first elastic member 241 until it is limited by the swing limiting structure 272, so that the end of the first swing pressure rod 31 maintains a certain distance from the opposite structure (such as the heating element) of the print head 1, so that the hot end can be reinstalled later. The swing limiting structure 272 can be set on the base 27 of the print head 1. The base 27 has a through hole corresponding to the first swing pressure rod 31. The end of the first swing pressure rod 31 passes through the through hole and is connected to the first elastic member 241. The other end of the first elastic member 241 is connected to the corresponding part of the base 27. Figure 1 and Figure 7a As shown, the printhead 1 also includes a base 27. For example, the hot end 10 can be clamped between the first swinging pressure rod 31 and the base 27. For example, the first elastic element 241 can be a cylindrical compression spring, which is supported and connected between the corresponding parts of the printhead base 27 and the first swinging pressure rod 31. Figure 2b As shown, the middle part of the first swing pressure rod 31 is rotatably mounted on the printing base 27 via the first rotating shaft 301.

[0074] Furthermore, such as Figure 2a As shown, a boss 154 is provided on the heating section 12 of the hot end 10. The boss 154 is located on the second surface 152 of the heating section 12. The first swinging pressure rod 31 has a corresponding abutment part that matches the boss 154. When the first swinging pressure rod 31 presses the hot end 10, it combines with... Figure 4cAs shown, the abutment portion abuts against the inclined side of the boss near the tool seat 50, so that the first swinging pressure rod 31 reliably presses the hot end 10 onto the print head 1. Of course, the boss 154 can also be a groove structure, for example, allowing the protruding abutment portion on the first swinging pressure rod 31 to press into the groove, reliably securing the hot end 10 onto the print head. Figure 4c As shown, the abutment portion is a protrusion 311, and the outer surface of the protrusion 311 is preferably an arc-shaped surface. The protrusion 311 presses against the side of the boss 154 or groove on the heating section 12, thereby more reliably securing the hot end 10. Figure 4j As shown, the abutment part can also be a roller 313, which is rotatably mounted on the first swing pressure rod 31. The rotation of the roller 313 can reduce friction and wear during hot-end replacement. Furthermore, Figure 4j The diagram also illustrates that the first heating element 21, corresponding to the first swing pressure rod, can also be mounted on another swing pressure rod and can rotate around the pivot 302. In this way, when the hot end 10 is installed on the print head, the hot end 10 can be clamped on both sides simultaneously. Moreover, the elastically movable first heating element 21 is also easier to attach to the heating section of the hot end, which is conducive to the rapid transfer of heat to the hot end through heat conduction.

[0075] Figure 4d and Figure 4L The diagram illustrates the fourth swinging pressure rod 59 installed on the tool holder 50. The fourth swinging pressure rod 59 rotates around the shaft 501. Through the elastic force of the third elastic element 541, the fourth swinging pressure rod 59 is pressed against the hot end 10, thus securing the hot end to the tool holder 50.

[0076] Example 4, as Figure 4dAnother type of clamping component is illustrated. The clamping component is a second swinging pressure rod 33. One end of the second swinging pressure rod 33 is rotatably disposed on the side of the print head 1 that is away from the hot end 10 and can move outward (such as the side away from the tool seat 50) via the second rotating shaft 302. The end of the second swinging pressure rod 33 presses against the outward side of the hot end 10 (such as the side facing the tool seat 50). The second swinging pressure rod 33 is provided with a swing arm actuating part 39. The tool seat 50 is provided with a lever 581 corresponding to the swing arm actuating part 39. When the print head 1 and the tool seat 50 move relative to each other along the first direction, the lever 581 cooperates with the swing arm actuating part 39. When the print head 1 and the tool seat 50 move relative to each other along the second direction, the lever 581 can actuate the swing arm actuating part 39, thereby driving the second swinging pressure rod 33 to rotate, so that the end of the second swinging pressure rod 33 separates from the hot end 10 or presses the end of the second swinging pressure rod 33 against the hot end 10. The end of the second swing lever 33 may also be provided with a stop portion, which is a protrusion 311. The outer surface of the protrusion 311 is preferably an arc-shaped surface. The protrusion 311 presses against the surface of the hot end 10 facing the side that can move outward (such as the side facing the tool holder 50). Further, the swing lever actuating part 39 is a shaft member, and the actuating member 581 is provided with an actuating groove 5811. When the print head moves from the first switching position A of the tool holder to the relay position T of the tool holder, the shaft member can move into the actuating groove 5811.

[0077] Example 5, as Figure 8a As shown, the clamping component is a lower pressure plate 32, which is movable along the second direction and is mounted on the print head 1. The lower pressure plate 32 is provided with a pressure plate actuating part 39, and the tool holder 50 is provided with a lever 581 corresponding to the pressure plate actuating part 39. When the print head 1 and the tool holder 50 move relative to each other along the first direction, the lever 581 cooperates with the pressure plate actuating part 39. When the print head 1 and the tool holder 50 move relative to each other along the second direction, the lever 581 can actuate the pressure plate actuating part 39, thereby driving the lower pressure plate 32 to move so that the end of the lower pressure plate 32 separates from the hot end 10 or makes the lower pressure plate 32 press against the hot end 10.

[0078] Furthermore, the pressure plate actuating part 39 can be a hole or a groove, and the actuating element 581 can be a corresponding matching shaft, or the pressure plate actuating part 39 can be a shaft, and the actuating element 581 can be a matching hole or groove.

[0079] like Figure 8b and 8c As shown, the lever 581 is a shaft, and the pressure plate actuating part 39 is a hole; when the print head 1 moves relative to the tool holder 50, causing the print head 1 to move from the first switching position A to the relay position T, the lever 581 is inserted into the pressure plate actuating part 39, and then... Figure 8dAs shown, when the print head 1 moves from the relay position T to the corresponding hot end mounting position B on the tool holder, the lever 581 moves the pressure plate lever 39 away from the hot end 10, causing the lower pressure plate 32 to separate from the hot end 10, releasing the restriction on the hot end 10, and then engaging... Figure 8e As shown, when the print head moves from the corresponding hot end mounting position B on the tool holder to the second switching position C, the hot end 10 is replaced and mounted from the print head 1 onto the tool holder 50. Conversely, from... Figures 8e to 8b By moving the printhead in sequence, the hot end 10 can be switched from the tool holder 50 to the printhead 1. The above-mentioned moving process can also be achieved by moving the tool holder 50 relative to the printhead 1.

[0080] In addition, such as Figure 4L As shown, a first heating element 21 can also be provided on the lower pressure plate 32, which can be used to heat the heating section of the hot end. For example, the lower pressure plate 32 can be moved along the shaft 303, for example, the shaft 303 can be set along the second direction. An elastic element 241 can also be provided to make the lower pressure plate 32 move closer to the hot end or the position where the hot end is installed. If there is a hot end, it is pressed against the hot end. If there is no hot end, the lower pressure plate 32 is limited after moving a certain distance, for example, it can be limited by the limiting structure fixed to the base 27. The end of the lower pressure plate can be regarded as a toggle part. The structure on the corresponding tool seat that can push the end can be set as a toggle. During the relative movement of the print head and the tool seat along the second direction, the toggle can push the toggle part to open the lower pressure plate 32 or, under the action of the elastic element 541, make the lower pressure plate 32 clamp the hot end installed on the print head 1. At the same time, the first heating element 21 can be in contact with the heating surface of the hot end to heat the hot end.

[0081] Example 6, as Figure 9a As shown, the clamping component is a lower pressure plate 32. One end of the lower pressure plate 32 is rotatably mounted on the print head 1 on the side opposite the hot end 1 and close to the tool seat 50 via a third rotating shaft 303. The axis of the third rotating shaft 303 is arranged along a first direction. The lower pressure plate 32 is provided with a pressure plate actuating part 39, and the tool seat 50 is provided with a lower actuating part 58 corresponding to the pressure plate actuating part 39. When the print head 1 and the tool seat 50 move relative to each other along the first direction, the lower actuating part 58 cooperates with the pressure plate actuating part 39. When the print head 1 and the tool seat 50 move relative to each other along a second direction, the lower actuating part 58 can actuate the pressure plate actuating part 39, thereby driving the lower pressure plate 32 to rotate, causing the end of the lower pressure plate 32 to separate from the hot end 10 or to press the end of the lower pressure plate 32 against the hot end 10. The pressure plate actuating part 39 can also be an elongated hole structure, and the lower actuating part 58 can be a shaft structure. Thus, as the print head and tool holder move along the second direction, the lower pressure plate 32 can be released from or pressed against the hot end 10 by the lowering member 58.

[0082] The various clamping components described in Embodiments 3 to 6 above are based on the print head 1. However, as explained in Embodiment 1, the print head 1 in each figure can also be a tool holder. That is, the implementation schemes of these clamping components can also be implementation schemes of clamping components for the tool holder, used to clamp the hot end installed on the tool holder. For example Figure 4c The lower pressure plate 32 on the tool holder 50 shown is... Figure 4L The structure of the lower pressure plate 32 of the printhead 1 is similar. Figure 4j The structure of the third swinging pressure rod 34 is similar to that of the first swinging pressure rod 31 in Embodiment 1. The difference is that the third swinging pressure rod 34 has a different clamping part on the hot end, and can clamp the hot end so that the hot end is not easy to slip out in the second direction.

[0083] In Example 7, both the printhead and the tool holder have positioning mechanisms, and corresponding matching positioning structures are set on the hot end.

[0084] like Figure 2a As shown in Figure 4m or Figure 4n, a first positioning structure 153 extending along a first direction is provided on the hot end. The first limiting structure of the print head 1 includes a first positioning mechanism, which limits the hot end in a second direction. Further, the first positioning mechanism includes a positioning part 23 corresponding to and matching the first positioning structure 153, which also extends along the first direction. When the hot end 10 is installed on the print head 1, the positioning part 23 cooperates with the first positioning structure 153 to position the hot end 10 in a third direction perpendicular to the first and second directions, or in the axial direction of the feed pipe of the hot end 10, and / or in the second direction. The positioning part 23 on the print head 1 can be a positioning plate, positioning post, or edge extending along the first direction, and the first positioning structure 153 on the hot end 10 can be a positioning groove, positioning hole, or boss extending along the first direction.

[0085] like Figure 2a As shown in Figure 41, the first positioning structure 153 on the hot end 10 is a boss extending along the first direction. Referring to Figure 41, the print head 1 has an edge corresponding to the boss. When the hot end 10 is installed on the print head 1, the boss on the hot end 10 overlaps with the edge. The outer contour of the boss and the side of the hot end is U-shaped, fitting snugly onto the corresponding part of the print head 1. The upper boss is placed on the corresponding edge, and the lower boss is in contact with the lower surface of the edge, thus restricting the displacement of the hot end 10 in the third direction or the Z-axis direction. (Refer to Figure 4n and...) Figure 5 The heating surface 211 and the positioning element 231 of the first heating element 21 can position or limit the hot end 10 along the second direction or the X-axis direction. The hot end can move along the first direction on the print head, for example, by inserting into the print head or removing from the print head, which requires the cooperation of the clamping or opening actions of the various clamping mechanisms described above.

[0086] Furthermore, the second defining structure includes a second positioning mechanism that limits the hot end in the first direction. The hot end 10 is provided with a second positioning structure extending in the second direction; the second positioning mechanism on the tool holder 50 includes a positioning element corresponding to and matching the second positioning structure, which also extends in the second direction; when the tool holder 50 and the print head 1 move relative to each other along the second direction, the positioning element and the second positioning structure can cooperate to limit the hot end 10 in the first direction, or the positioning element and the second positioning structure can move away from each other to release the limitation on the hot end 10 in the first direction.

[0087] like Figure 1 and Figure 2a As shown, the positioning element on the tool holder 50 is a positioning post 53 extending along the second direction, and the second positioning structure on the hot end 10 is a positioning hole 155 extending along the second direction. When the hot end 10 is installed on the tool holder 50, the positioning post 53 is inserted into the positioning hole 155, thereby limiting the hot end 10 on the tool holder 50. Further, the positioning element on the tool holder 50 is a limiting groove 55, which includes a groove segment extending along the second direction and a notch or passage extending along the first direction, the notch or passage communicating with the groove segment; the second positioning structure on the hot end 10 is a heat dissipation section 14 of the hot end, and the limiting groove 55 is adapted to the heat dissipation section 14. When the hot end 10 is installed on the tool holder 50, the heat dissipation section 14 is engaged in the limiting groove 55, thereby limiting the hot end 10 on the tool holder 50. The tool holder's positioning element includes both a positioning pin 53 and a limiting groove 55. Alternatively, the tool holder's positioning element may only have a positioning pin 53 or only a limiting groove 55. For example... Figure 4c As shown, the positioning element on tool holder 50 is positioning pin 53. (As indicated...) Figure 4d As shown, the positioning element on the tool holder 50 is a positioning plate 532 extending along the second direction. Figure 4d The position of the middle positioning plate 532 can be swapped with the position of the fourth swing pressure rod 59 by exchanging the vertical mirror image of the two. After the transformation, it can be as follows: Figure 4L As shown. When Figure 4d The heated end is installed onto the tool holder, and the positioning part 532 is positioned by abutting against one side surface of the heated end 10. Figure 4L As shown, the positioning plate 532 can also be a second heating element 51. The second heating element 51 can be provided on the side of the tool holder adjacent to the positioning part 532, or on the fourth swing rod 59 on the side opposite to the positioning part 532. For example... Figure 8a and 8bAs shown, the positioning element on the tool holder 50 is a positioning plate 532 extending along the second direction, and the second positioning structure on the hot end 10 is a positioning groove 156 extending along the second direction. When the hot end 10 is installed on the tool holder 50, the positioning plate 532 is inserted into the positioning groove 156, thereby limiting the hot end 10 on the tool holder 50. Figure 9a and 9b As shown, the positioning element on the tool holder 50 includes a positioning post 53 and a limiting groove 55. The hot end 10 has a positioning hole 155 corresponding to the positioning post 53. The positioning element on the tool holder can also be an edge extending along a second direction, and the second positioning structure on the hot end is a boss extending along a second direction. When the hot end is installed on the tool holder, the boss overlaps with the edge, thereby limiting the hot end. The positioning element on the tool holder includes one or more of a positioning plate, a positioning post, an edge, and a limiting groove; correspondingly, the second positioning structure on the hot end is one or more of a positioning groove, a positioning hole, a boss, and a heat dissipation section.

[0088] Example 8: A heating element may also be provided on the print head and / or tool holder to heat the heating section of the hot end. For example... Figure 1 , Figure 2a and Figure 2b As shown, the printhead 1 has a first heating element 21 corresponding to the heating section 12 of the hot end 10, which is used to heat the heating section 12. For example, the first heating element 21 can be arranged opposite to the first clamping mechanism 30 on the printhead 1. The first clamping mechanism 30 presses the heating section 12 of the hot end 10 against the first heating element 21, so that the heating section 12 is in close contact with the first heating element 21. Further, a heating block 15 is provided on the heating section 12. The side of the heating block 15 facing the first heating element 21 forms a first heating surface 151. The first heating surface 151 is parallel to the first direction with an error of no more than ±40° or no more than ±45°. When the hot end 10 is installed on the printhead 1, the first heating surface 151 can be in contact with the first heating element 21, that is, in contact with the second heating surface on the first heating element 21. Furthermore, the first heating element 21 can be made of ceramic heating elements, heating rods, or induction coils, which can heat the hot end through heat conduction or through electromagnetic induction. A temperature sensor can also be installed on the first heating element 21 to detect the temperature of the first heating element 21 and / or the hot end. Furthermore, a thermally conductive medium, such as thermal grease, a thermal pad, or other thermally conductive medium, can be provided on the surface of the first heating element 21 that is in contact with the heating block 15 on the hot end 10.

[0089] like Figure 1 , Figure 2a and Figure 2bAs shown, the first heating element 21 is disposed on the printing substrate 27. The hot end 10 is placed between the first heating element 21 and the first swinging pressure rod 31. The first swinging pressure rod 31 presses the heating block 15 of the hot end 10 so that the heating block 15 is in close contact with the first heating element 21, thereby heating the heating block 15 through the first heating element 21. Figure 4c As shown, a first heating element 21 can be disposed on the substrate 27. The first heating element 21 includes a first portion that is in contact with the first heating surface of the hot end 10 and a second portion connected to the first portion. The second portion is in contact with the end face of the hot end 10 near the printhead. A first heater 63-1 and a third heater 63-3 are disposed on the side of the first and second portions away from the hot end. The first heater 63-1 and the third heater 63-3 are ceramic heating plates or heating rods. The first heating element 21 can heat the first heating surface of the hot end 10 and the end face of the hot end near the printhead. Figure 8b As shown, a heating coil 63 is provided inside the first heating element 21. The first heating element 21 is either in contact with or does not need to be in contact with the hot end 10, and the hot end 10 is inductively heated by the heating coil 63. Figure 9a As shown, the first heating element 21 has a heating surface that matches the heating surface of the hot end 10, preferably a flat surface. Similarly, the first heating element 21 can also be a ceramic heating plate, a heating rod, or an induction coil to heat the heating block 15 of the hot end 10 mounted on the printhead. The first heating element 21 can be used to heat the printing material that needs to be heated and melted in the hot end before it is extruded from the extrusion port of the hot end. For printing material that does not need to be heated and melted before extrusion, the first heating element may not be necessary.

[0090] Similarly, the tool holder can also be equipped with a heating element to heat the hot end mounted on the tool holder, such as... Figure 1 and Figure 3a As shown, a second heating element 51 is provided on the tool holder 50 corresponding to the heating section 12 of the hot end 10. The second heating element 51 is used to heat the heating section 12. When the hot end 10 is mounted on the tool holder 50 by the second limiting mechanism, the second heating element 51 is in contact with the heating section 12.

[0091] By installing a second heating element 51 on the tool holder 50, the hot end 10 can be preheated. That is, when the print head 1 needs to use a particular hot end, the tool holder 50 first heats that hot end to a preset temperature, achieving preheating before switching the hot end 10. This ensures that the temperature of the hot end 10 has reached the preset value before it is transferred from the tool holder to the print head 1. Thus, when the hot end is switched from the tool holder to the print head, the time spent heating the hot end by the print head is reduced, or the hot end can be switched to the print head at the required printing temperature for direct printing. This greatly improves printing efficiency after switching hot ends and reduces the time spent switching hot ends and maintaining the temperature of the newly installed hot end on the print head.

[0092] The second heating element 51 is provided with a third heating surface. When the hot end 10 is installed on the tool holder 50, the first heating surface 151 of the heating block 15 on the heating section 12 of the hot end 10 is in contact with the third heating surface. The first heating surface 151 is parallel to the first direction with an error of no more than ±40° and no more than ±45°. The heating block 15 is provided with a first heating surface 151, which can be in contact with the first heating element 21 on the print head 1 and also with the second heating element 51 on the tool holder 50, so that the heating block 15 has only one heating surface. This allows both the print head and the tool holder to be in contact with the first heating surface 151 of the hot end. For heating by conduction, this reduces the number of heating surfaces on the hot end, simplifies the hot end structure, and allows the remaining surfaces of the heating block 15 to be insulated to slow down the heat dissipation rate of the remaining surfaces, making it easier to insulate the hot end, improve the heating speed, and reduce power consumption.

[0093] The second heating element 51 can be heated by means of ceramic heating element, heating rod or induction coil, etc., and can heat the hot end installed on the tool holder by means of heat conduction or electromagnetic induction. Similarly, a heat-conducting medium, such as thermal grease, thermal pad or other heat-conducting medium, can be provided on the surface of the second heating element 51 that is in contact with the heating block 15 on the hot end 10.

[0094] Furthermore, the first heating element can be fixedly connected to the print head or flexibly connected to the print head; similarly, the second heating element can be fixedly connected to the tool holder or flexibly connected to the tool holder. Figure 4j The first heating element 21 is oscillatingly connected to the print head via a rotating shaft 302. Figure 4L The first heating element 21 shown is slidably connected to the print head 1, and the movable first heating element 21 can also serve as a first clamping mechanism. Figure 1 , Figure 2a , Figure 3a and Figure 3b As shown, the second heating element 51 on the tool holder 50 is movable along the first direction. A third elastic element 541 (spring) is provided between the second heating element 51 and the corresponding part of the tool holder 50. The third elastic element 541 applies a force to the second heating element 51 so that the second heating element 51 is in contact with the hot end 10. The second heating element 51 can also be rotatably connected to the tool holder. The movably connected second heating element 51 can also serve as a second clamping mechanism. Figure 4b , Figure 4f and Figure 4jAs shown, when the hot end 10 is switched from the print head 1 to the tool holder 50, the print head 1 and the tool holder 50 move relative to each other, causing the print head 1 to move from the first switching position A to the relay position T. At this time, the hot end 10 on the print head 1 pushes the second heating element 51 (the second clamping mechanism) to move along the first direction and compress the third elastic element 541. When the print head moves from the relay position T to the corresponding hot end mounting position B on the tool holder, the limiting mechanism on the tool holder limits the hot end. When the print head moves from position B to the second switching position C, the hot end 10 remains on the tool holder 50, and the second heating element 51 is reset under the action of the third elastic element 541. The second heating element 51 is in contact with the first heating surface 151 of the heating block 15 of the hot end 10.

[0095] Figure 3a and Figure 3b The diagram illustrates a specific structure where the tool holder 50 includes a frame 57. A track structure 502 is provided on the frame 57 corresponding to the second heating element 51. This track structure 502 is used to restrict the movement direction of the second heating element 51, for example, restricting its movement along a first direction. Specifically, the track structure 502 is a rod-shaped structure. The track structure 502 can be a linear guide, such as a corresponding linear bearing or slider connected to the frame 57. It can also be equipped with elastic elements, such as a third elastic element 541 whose two ends can be connected (or abut against) the second heating element 51 and the frame 57 respectively. For example, the third elastic element 541 can be sleeved on the track structure 502 and act on the second heating element 51. When it is necessary to switch the hot end of the printhead to the tool holder, the corresponding part on the printhead (equivalent to a toggle) moves or pushes the second heating element 51. The second heating element and the track structure 502 move, and drive the limiting element 531 connected to the track structure 502 to move together, so that the limiting element 531 triggers the sensor 61. When the hot end is installed on the tool holder, as... Figure 4j As shown, the trigger state of sensor 61 remains unchanged, indicating that the hot end is installed on the tool holder. When the hot end on the tool holder is removed, the elastic force of the third elastic member 541 causes the second heating member 51 to move along the first direction (along the track structure 502), pushing the track structure 502 and causing the limiting member 531 to move until the limiting member 531 abuts against the base 57, thus limiting the second heating member 51. At the same time, sensor 61 can be triggered, indicating that no hot end is currently installed on the tool holder. The track structure 502 on the tool holder 50 guides the movement of the second heating member 51, and the limiting member limits the displacement of the second heating member pushed by the elastic force of the third elastic member 541. The second heating member 51 can be provided on the back support 56, and the third elastic member 541 can be connected to the second heating member 51 or to the back support 56. Alternatively, the third elastic member 541 can be omitted, and a toggle part can be provided on the second heating member or the back support, with a corresponding toggle part provided on the print head to move the second heating member to a preset position.

[0096] like Figure 4c and 4d As shown, a second heater 63-2, which is a ceramic heating element or heating rod, can be provided on the second heating element 51. The second heating element 51 can heat the first heating surface of the hot end 10. Additionally, to ensure a tight fit between the hot end mounted on the tool holder and the second heating element 51, a spring 243 connected to the base 57 can be provided. The spring force acting on the hot end mounted on the tool holder pushes the hot end against the second heating element 51. Similarly, Figure 4L A spring 243 can also be installed on the print head, connected to the print head base 27. The spring force it provides will push the heated end mounted on the print head against the first heating element 21. The second heating element 51 can adopt an induction heating technology, such as... Figure 8e As shown, the second heating element 51 contains an induction coil 63, which inductively heats the heating block of the hot end 10. The second heating element 51 can be fixed on the base 57. In the case of induction heating, the hot end does not need to be tightly attached; the heating block on the hot end 10 only needs to have a first heating surface that cooperates with the first heating element on the print head (assuming the print head uses thermal sensing heating). Of course, a fourth heating surface can also be added to the hot end. The first heating surface and the fourth heating surface are arranged opposite each other. When the hot end 10 is installed on the print head 1, the second heating surface of the first heating element 21 is in contact with the first heating surface. When the hot end 10 is installed on the tool holder 50, the third heating surface of the second heating element 51 is in contact with the fourth heating surface. In this way, the tool holder can also use heat conduction to heat the hot end. The first heating surface is perpendicular to the first direction, with an error of no more than ±40° or no more than ±45°. Figure 9a and Figure 9b The hot end shown also has a first heating surface 151 and a fourth heating surface, the fourth heating surface being the second surface 152 on the hot end 10. When the hot end 10 is installed on the print head 1, the second heating surface of the first heating element 21 is in contact with the first heating surface. When the hot end 10 is installed on the tool holder 50, the third heating surface of the second heating element 51 is in contact with the fourth heating surface. The first heating surface is perpendicular to the first direction, with an error of no more than ±40° and no more than ±45°.

[0097] Depend on Figure 4c , Figure 4f , Figure 4h , Figure 4jAs shown in Figures 4m and 4n, a shielding portion 271 corresponding to the heating section 12 can also be provided on the print head 1 or the tool holder 50 to enhance the heat preservation of the heating section 12. The shielding portion 271 shields the heating section mounted on the hot end of the print head, reducing heat loss to the surrounding air and minimizing heat loss from the surrounding airflow to the heating section. A gap can also be provided between the shielding portion 271 and the hot end along the second direction. This gap allows the positioning element on the tool holder to extend into it. Furthermore, when the print head and the tool holder move relative to each other along the second direction or the X-axis direction, this gap ensures that the print head will not interfere with the tool holder.

[0098] Additionally, a heating element can be installed on the hot end 10. For example, it can be electrically connected to the circuitry on the print head via a connector to power the heating element on the hot end 10 and control its heating temperature. Heat dissipation fins can also be installed on the heat dissipation section of the hot end 10, such as... Figure 7a and Figure 7b As shown, the heat dissipation fins 142 are disposed on the heat dissipation section of the hot end 10 to dissipate heat from the feeding pipe that feeds material to the extrusion port 11. With the third heat dissipation fin 142 disposed on the hot end 10, heat dissipation fins are not required on the print head 1 and the tool holder 50, simplifying their structure. Magnets or magnetic materials can also be disposed on the third heat dissipation fin 142 to facilitate attraction and fixation with corresponding magnetic materials or magnets on the print head or tool holder. Alternatively, the heat dissipation fins 142 may not be necessary on the hot end; corresponding heat dissipation fins or heat dissipation mechanisms can be disposed on the print head or tool holder.

[0099] Example 9: The print head and / or tool holder may also be provided with heat dissipation fins or heat dissipation mechanisms to dissipate heat from the heat dissipation section of the hot end.

[0100] like Figure 1 , Figure 2a and Figure 2b As shown, the printhead 1 is provided with a first heat dissipation fin 22 that is in contact with the heat dissipation section 14 of the hot end 10 mounted on the printhead 1. The first heat dissipation fin 22 can be in direct contact with the heat dissipation section 14 or can be provided with thermal grease, thermal pad or other thermal medium in between for heat dissipation.

[0101] Furthermore, as shown in Figures 4m, 4n, and... Figure 4k As shown, the first heat dissipation fin 22 on the printhead 1 has a laterally open first heat dissipation surface 221, and the first clamping mechanism 30 includes a movable and adjustable first clamping member corresponding to the first heat dissipation fin 22. The first clamping member can be movable and adjusted to clamp the heat dissipation section 14 of the hot end installed on the printhead 1 so that the heat dissipation section 14 is in contact with the first heat dissipation fin.

[0102] In a preferred embodiment, a first clamping member is rotatably disposed on the print head 1. The first clamping member can rotate around the rotating connection to press the heat dissipation section 14 against the first heat dissipation fin 22, thereby making the heat dissipation section 14 and the first heat dissipation fin 22 in contact. When no hot end is installed on the print head 1, the first clamping member abuts against a limiting structure disposed on the print head.

[0103] In another preferred embodiment, the first clamping member is movable along the second direction on the print head 1. By moving and adjusting the first clamping member, the first clamping member can press the heat dissipation section 14 so that the heat dissipation section 14 is in contact with the first heat dissipation fin 22. When no hot end is installed on the print head, the first clamping member abuts against a limiting structure provided on the print head.

[0104] like Figure 1 , Figure 2b and Figure 4e As shown, the first clamping element is a swing wing 41, which is rotatably mounted on the print head 1 via a fourth rotating shaft 401. A second elastic element 242 is provided on the fourth rotating shaft 401. The second elastic element 242 drives the swing wing 41 to rotate and press against the heat dissipation section 14, so that the heat dissipation section 14 comes into contact with the first heat dissipation fin 22. By pressing the heat dissipation section 14 at the hot end against the first heat dissipation surface 221 of the first heat dissipation fin 22 through the swing wing 41, the hot end 10 can be more reliably fixed, and the heat conduction between the heat dissipation section 14 and the heat dissipation fin 22 can be enhanced. Preferably, the second elastic element 242 is a coil spring, which can drive the swing wing 41 to swing around the fourth rotating shaft 401. Furthermore, the heat dissipation section 14 of the hot end 10 can be tubular or cylindrical, with matching grooves formed on the corresponding side of the first heat dissipation fin 22. When the hot end 10 is installed onto the print head 1, the heat dissipation section 14 snaps into the groove, and the inner wall of the groove forms a laterally open first heat dissipation surface 221 for contact with the heat dissipation section 14. Figure 4eAs shown, when the hot end 10 is installed on the print head 1, the end of the swing wing 41 presses against the heat dissipation section 14, so that the heat dissipation section 14 is in contact with the first heat dissipation wing 22. When there is no hot end 10 on the print head 1, the end of the swing wing 41 can be in contact with the part of the first heat dissipation wing 22 near the first heat dissipation surface 221, and the part of the first heat dissipation wing 22 near the first heat dissipation surface 221 can be used as a limiting mechanism. On the side of the end of the swing wing 41 near the hot end insertion or removal (the side near the tool holder 50), there can be a slope with a larger outward opening. This slope can act as a guide to facilitate the heat dissipation section 14 sliding into the space between the swing wing 41 and the first heat dissipation wing 22. The swing wing 41 can also be a heat dissipation wing, which can also have a heat dissipation function. The part of the swing wing 41 that is in contact with the heat dissipation section 14 of the hot end 10 has an arc shape that matches the heat dissipation section, so as to make it fit tightly against the heat dissipation section 14. The swing fin 41 can also be regarded as the first heat dissipation fin 22. The first heat dissipation fin 22 marked in the figure can be regarded as the limiting structure of the swing fin 41 (first heat dissipation fin 22) or another first heat dissipation fin 22. The swing fin 41 (first heat dissipation fin 22) can be provided with a side-open heat dissipation surface for contact with the heat dissipation section of the hot end 10. In this way, the first heat dissipation fin 22 (swing fin 41) is movably connected to the print head.

[0105] like Figure 8a As shown, the first clamping member is an upper pressure plate 42, which is movable along the second direction and mounted on the print head 1. The upper pressure plate 42 has an upper actuating part 421, and the tool holder 50 has an upper actuating member 582 corresponding to the upper actuating part 421. When the print head 1 and the tool holder 50 move relative to each other along the first direction, the upper actuating member 582 engages with the upper actuating part 421. When the print head 1 and the tool holder 50 move relative to each other along the second direction, the upper actuating member 582 can actuate the upper actuating part 421, thereby moving the upper pressure plate 42 to separate it from the heat dissipation section 14 or to press the upper pressure plate 42 against the heat dissipation section 14. Further, the upper actuating part 421 can be a hole or slot, and the upper actuating member 582 can be a corresponding matching shaft, or the upper actuating part 421 can be a shaft, and the upper actuating member 582 can be a matching hole or slot. Figure 8f and Figure 8h As shown, taking the upper lever 582 as a shaft and the upper actuating part 421 as a hole as an example, when the print head 1 moves relative to the tool holder 50, causing the print head 1 to move from the first switching position A to the relay position T, the upper lever 582 is inserted into the upper actuating part 421. When the print head 1 moves from the relay position T to the corresponding hot end mounting position B on the tool holder, the upper lever 582, along with the upper actuating part 421, moves away from the hot end 10, causing the upper pressure plate 42 to separate from the hot end 10, thus releasing the restriction on the hot end 10. When the print head moves from the corresponding hot end mounting position B on the tool holder to the second switching position C, the hot end 10 is replaced and mounted from the print head 1 onto the tool holder 50. Conversely, from... Figures 8e to 8bThe sequential relative movement of the printhead allows the hot end 10 to be switched from the tool holder 50 to the printhead 1. This movement can also be achieved by moving the tool holder. The swing fin 41 can also be a swing-type upper pressure plate.

[0106] Other examples Figure 8g As shown, the upper pressure plate 42 is rotatably connected to the print head. The upper pressure plate 42 is rotatably mounted on the print head 1 via the fifth rotating shaft 402. The upper pressure plate 42 is provided with a toggle part 422, and the tool holder 50 is provided with an upper toggle member 582 corresponding to the toggle part 422. When the print head 1 and the tool holder 50 move relative to each other along the first direction, the upper toggle member 582 cooperates with the toggle part 422. When the print head 1 and the tool holder 50 move relative to each other along the second direction, the upper toggle member 582 can toggle the toggle part 422, thereby driving the upper pressure plate 42 to rotate so that the upper pressure plate 42 separates from the heat dissipation section 14 or presses the heat dissipation section 14 with the upper pressure plate 42. Furthermore, the actuating part 422 can be a shaft member, and the upper actuating member 582 is provided with an upper actuating groove 5821. When the print head moves from the first switching position A of the tool holder to the intermediate position T of the tool holder, the shaft member can move into the upper actuating groove 5821. When the print head moves relative to the tool holder, causing the print head to move from the intermediate position T to the corresponding hot end mounting position B of the tool holder, the actuating part 422 is actuated by the upper actuating member 582, and the upper pressure plate 42 will rotate clockwise around the fifth rotating shaft 402, releasing the clamping state of the hot end. Then, the print head moves from the corresponding hot end mounting position B of the tool holder to the second switching position C, and the hot end is switched from the print head to the tool holder. The above movement sequence can be reversed to transfer the hot end from the tool holder to the print head. The above movement process can also be achieved by moving the tool holder.

[0107] The structure of the first clamping member of the present invention can be the same as that of the clamping member. The first clamping member is an optional structure. When the first heat dissipation fins are provided on the print head, the first clamping member can be optionally provided.

[0108] like Figure 9aAs shown, the printhead 1 is provided with a first heat dissipation fin 22. The side of the first heat dissipation fin 22 facing the mounting hot end (the side facing the tool holder 50) is a laterally open first heat dissipation surface 221. The first heat dissipation surface 221 can be a plane, and a matching plane is provided on the heat dissipation section of the hot end 10. For example, a heat dissipation block 16 can be provided on the heat dissipation section, and a plane heat dissipation surface 161 can be provided on the heat dissipation block 16. When the hot end is mounted on the printhead, the heat dissipation surface 161 is in contact with the first heat dissipation surface 221, which can be used for heat conduction. A first magnetic element 441 can also be provided on the first heat dissipation surface 221, and a second magnetic element 442 can be provided on the heat dissipation block 16. The first magnetic element 441 and the second magnetic element 442 can attract the heat dissipation block 16 to be in contact with the first heat dissipation surface 221. Of course, the plane heat dissipation surface 161 does not have to be provided on a dedicated heat dissipation block 16, and can be formed directly on the heat dissipation section 14. For example, the heat dissipation section 14 with a rectangular tube on the outside can be made.

[0109] The aforementioned first heat dissipation fin 22 can be fixedly connected to the print head, for example, fixedly connected to the base 27. Alternatively, the first heat dissipation fin 22 can be elastically or movably connected to the print head, allowing it to better contact the heat dissipation section of the hot end. Furthermore... Figure 4kAs shown in Figures 4n and 4o, the first heat dissipation fin can also be flexibly connected to the print head. For example, the first heat dissipation fin may include a left first heat dissipation fin 22a and a right first heat dissipation fin 22b. The left first heat dissipation fin 22a and the right first heat dissipation fin 22b can be rotatably connected to the print head, for example, on the base 27 of the print head, through the fourth rotating shaft 401 and the fifth rotating shaft 402, respectively. The left first heat dissipation fin 22a and the right first heat dissipation fin 22b are respectively provided with a laterally open first heat dissipation surface 221 at the corresponding part of the heat dissipation section of the hot end. Second elastic members 242 can be provided respectively, and each second elastic member 242 provides elastic force to rotate the left first heat dissipation fin 22a and the right first heat dissipation fin 22b in a direction closer to each other on the side where the hot end is installed. Optimally, the fourth rotating shaft 401 and the fifth rotating shaft 402 are located at the position of the hot end on the print head (such as the axis of the feed pipe of the hot end) and parallel to the plane of the second direction. More preferably, they are located on the side away from the hot end. When no hot end is installed, the left first heat dissipation fin 22a and the right first heat dissipation fin 22b abut against each other and are limited, or are limited by their respective corresponding limiting structures. When a hot end is installed, the first heat dissipation surface 221 of the left first heat dissipation fin 22a and the right first heat dissipation fin 22b respectively abut against the heat dissipation section of the hot end. Of course, the left first heat dissipation fin 22a and the right first heat dissipation fin 22b do not necessarily have to be rotatably connected to the print head around their respective axes, but can be translatably mounted on the print head in a second direction (such as moving in a straight line). Elastic elements can be provided separately, or a tension spring can be provided between the two to provide elastic force to bring the left first heat dissipation fin 22a and the right first heat dissipation fin 22b closer to each other. This eliminates the need for a first clamping element, or for the left first heat dissipation fin 22a and the right first heat dissipation fin 22b to act as each other's first clamping elements. Furthermore, since the first heat dissipation fins are flexibly connected to the hot end or print head, it makes it easier and more reliable for the first heat dissipation fins (left first heat dissipation fin 22a and right first heat dissipation fin 22b) to abut against the heat dissipation section of the hot end. This avoids the problem that the heat dissipation section 14 and the heating section 12 cannot reliably abut against the first heat dissipation fin and the first heating element on the print head at the same time due to the size error of the hot end or print head. Guide slopes 225 are respectively provided on the side of the left first heat dissipation fin 22a and the right first heat dissipation fin 22b facing the hot end for installation and removal. The two guide slopes 225 form an opening shape that is larger on the outside and smaller on the inside, which facilitates the pushing and separating of the left first heat dissipation fin 22a and the right first heat dissipation fin 22b when the hot end is installed from the outside, so as to install the hot end onto the print head. At the same time, when the hot end is removed from the print head, it can also guide the left first heat dissipation fin 22a and the right first heat dissipation fin 22b to gradually move closer to each other to avoid collision. Figure 4kAs shown in Figure 4n, the left first heat dissipation fin 22a and the right first heat dissipation fin 22b can be provided with laterally open heat dissipation surfaces 221. If the heat dissipation section 14 is cylindrical or tubular, the heat dissipation surfaces 221 of the left first heat dissipation fin 22a and the laterally open heat dissipation surfaces 221 of the right first heat dissipation fin 22b can be semi-circular tubes facing each other.

[0110] The aforementioned printhead can also be a tool holder, meaning the aforementioned first heat dissipation fin 22 and first clamping member can also be the heat dissipation fin (second heat dissipation fin) and clamping member (second clamping member) on the tool holder. Additionally, as... Figure 3a and Figure 3b This diagram illustrates a specific structure of a heat dissipation fin on a tool holder, for a second heat dissipation fin 52 that contacts the heat dissipation section 14 of the hot end 10 mounted on the tool holder 50. A first or second clamping mechanism may include a rotatable second heat dissipation fin 52, which is rotatably mounted on the base 57 of the tool holder 50 via a sixth rotating shaft 501. It also includes a fourth elastic member 542, which applies a force to the second heat dissipation fin 52 to cause it to rotate towards the hot end 10 or the print head 1. When the hot end 10 is not mounted on the tool holder 50, [the mechanism] combines [the following components]. Figure 4e As shown, the second heat dissipation fin 52 abuts against a limiting structure 522 provided on the tool holder 50 to prevent the second heat dissipation fin 52 from rotating excessively.

[0111] like Figure 1 and Figure 3a As shown, the fourth elastic element 542 can be sleeved on the sixth rotating shaft 501. This fourth elastic element 542 can be a coil spring. A mounting frame can also be provided on the base 57 of the tool holder 50 corresponding to the second heat dissipation fin 52. One end of the coil spring is connected to the side frame corresponding to the mounting frame, and the other end is connected to the portion of the second heat dissipation fin 52 away from the sixth rotating shaft 501. The fourth elastic element can also be a cylindrical compression spring, pushing or pulling the second heat dissipation fin to rotate. A limiting groove 55 can also be provided on the mounting frame. The second positioning mechanism in Embodiment Seven can also include this limiting groove 55. Of course, the second heat dissipation fin 52 on the tool holder can also be translated by the cylindrical spring providing elastic force, thus compressing the cylindrical spring to translate the second heat dissipation fin 52 away from the print head. A laterally open second heat dissipation surface 521 is formed on the second heat dissipation fin 52, which is in contact with the heat dissipation section 14 of the hot end 10. Figure 4a and Figure 4b When switching the hot end 10 onto the tool holder 50, combined with Figure 4e and Figure 4g As shown, the relative movement of printhead 1 and tool holder 50 causes the printhead to move from the first switching position A to the relay position T. The corresponding part of printhead 1 pushes the second heat dissipation fin 52, and then combines... Figure 4i As shown, the print head moves from relay position T to the corresponding hot end mounting position B on tool holder 50, and then combines... Figure 4kAs shown, the print head moves from position B to the second switching position C, with the hot end 10 remaining on the tool holder 50. When the print head 1 leaves the tool holder 50, the second heat dissipation fin 52, under the action of the fourth elastic member 542, comes into close contact with the heat dissipation section 14 on the hot end 10. The second heat dissipation fin 52 can also be regarded as a second clamping member, used to press the heat dissipation section of the hot end onto the tool holder.

[0112] like Figure 9a and Figure 9b As shown, the tool holder 50 is provided with a second heat dissipation fin 52 corresponding to the heat dissipation section 14. The second positioning mechanism in Embodiment 7 may further include a limiting groove 55 provided on the second heat dissipation fin 52 for limiting the heat dissipation section 14. By using the limiting groove 55 to clamp the heat dissipation section 14 on the hot end 10 or the heat dissipation block 16 provided on the heat dissipation section 14, the hot end 10 can be limited on the tool holder 50. Further, the first heat dissipation fin 22 may be provided with a relief groove 2211 on the first heat dissipation surface 221 for avoiding the limiting groove 22. The second heat dissipation fin 52 may be fixed to the tool holder.

[0113] A first heat dissipation fin is installed on the print head, and a second heat dissipation fin is installed on the tool holder for heat dissipation. This eliminates the need for a separate heat dissipation fin on the hot end, simplifying the hot end structure, reducing its size and weight, and facilitating hot end switching. Furthermore, when the hot end wears out and needs replacement, there is no need to replace the heat dissipation fins, reducing application costs. Additionally, the heat dissipation fins fixed to the print head or tool holder can provide better heat dissipation. For example, connecting the heat dissipation fins to the body of the print head or tool holder (such as the base or frame) forms a larger heat sink with better heat dissipation capacity. It also allows the heat dissipation fins to contact the coolant for even stronger heat dissipation, enabling multiple heat dissipation methods. Fans or liquid circulation can be installed on the print head or tool holder to dissipate heat from the heat dissipation fins. Figure 6 As shown, a first heat dissipation mechanism may be provided on the heat dissipation section 14 corresponding to the hot end 10 on the printhead 1. This first heat dissipation mechanism is used to dissipate heat from the heat dissipation section. Further, the first heat dissipation mechanism may be a fan, an air duct, or a coolant circulation device. Figure 6 As shown, the first heat dissipation mechanism on the printhead 1 is a coolant circulation device. Coolant 224 flows into the heat dissipation chamber from the inlet 222 and then flows out from the outlet 222. The coolant 224 can dissipate heat from the heat dissipation section 14 of the hot end 10 and also dissipate heat from the first heat dissipation fins 22 on the printhead 1. The heat dissipation fins on the first heat dissipation fins 222 are in contact with the coolant 224, and the flow of the coolant 224 carries away the heat from the first heat dissipation fins 222. The first heat dissipation fins dissipate heat from the heat dissipation section 14 of the hot end through heat conduction via the first heat dissipation surface 221 that is in contact with the heat dissipation section 14. Similarly, the coolant circulation device can also be installed on the tool holder, where the coolant 224 contacts and flows with the second heat dissipation fins 52 to carry away heat. Figure 9a and Figure 9bAs shown, the first heat dissipation mechanism provided on the printhead 1 can be a fan 62, which blows air to dissipate heat from the heat dissipation section 14 at the hot end of the printhead 1 and / or the first heat dissipation fins 22 provided on the printhead 1.

[0114] A heat dissipation mechanism can also be installed on the tool holder, such as... Figure 1 As shown, a second heat dissipation mechanism is provided on the tool holder 50 corresponding to the heat dissipation section 14 or the second heat dissipation fin 52 of the hot end 10. This second heat dissipation mechanism is used to dissipate heat from the heat dissipation section. Further, the second heat dissipation mechanism can be a fan, an air duct, or a coolant circulation device. Figure 1 As shown, the second heat dissipation mechanism on each tool holder 50 is a fan 62, which blows air to dissipate heat from the corresponding hot end's heat dissipation section and / or heat dissipation fins. Figure 7a As shown, a third heat dissipation fin is provided on the hot end 10, and a fan 62 corresponding to the third heat dissipation fin is provided on the tool holder 50. The fan 62 is used to blow air to dissipate heat from the third heat dissipation fin.

[0115] In embodiment 10, a presence sensor 61 for detecting the presence of the hot end 10 may be provided on the print head 1 and / or tool holder 50. For example... Figure 1 , Figure 2b , Figure 3a , Figure 3b and Figure 4b As shown, the presence or absence of the hot end 10 is detected by the presence sensor 61. Furthermore, the presence sensor 61 can be a contact switch, Hall effect switch, or photoelectric switch, etc., which determines the presence or absence of a hot end by detecting the different states of the print head and tool holder when a hot end is present and when it is absent. Figure 4e and Figure 4k As shown, a presence sensor 61 is provided on the print head 1. This presence sensor 61 is positioned opposite the swing fin 41. When a hot end 10 is installed on the print head 1, the swing of the swing fin 41 triggers the presence sensor 61, for example, by bringing it into contact. When no hot end 10 is installed on the print head 1, the reverse swing of the swing fin 41 triggers the presence sensor 61 again, for example, by no longer bringing it into contact. This allows the presence sensor 61 to determine whether a hot end 10 is installed on the print head 1 based on different states. Of course, the presence sensor 61 can also determine the presence of a hot end by detecting the state of the first swing pressure rod 31, or the presence sensor 61 can directly detect the presence of a hot end by being triggered by the hot end itself. Figure 3a , Figure 3b and Figure 4b As shown, a presence sensor 61 is provided on the tool holder 50. The presence sensor 61 can be installed on the base 57 of the tool holder 50 and is positioned opposite to the limiting member 531. Figure 4bThe image shows two tool holders, tool holder 50A and tool holder 50B. Tool holder 50A has a presence sensor 61-1, and tool holder 50B has a presence sensor 61-2. Tool holder 50A does not have a heated end. A limiting member 531-1 on tool holder 50A triggers the presence sensor 61-1, for example, by contacting the presence sensor 61-1. The limiting member 531-1 is positioned against the holder 57. Tool holder 50B has a heated end 10. The heated end 10 cooperates with a second heating element 51 to cause the limiting member 531-2 to move in the opposite direction, triggering the presence sensor 61-2. For example, the limiting member 531-2 may not be in contact with the presence sensor 61-2, but may be positioned with a certain distance between it and the holder 57. Similarly, this method of implementing presence sensors can also be used in printheads, such as... Figure 4L As shown, the only difference is that the bracket 57 is replaced by the base 27, and the second heating element 51 is replaced by the first heating element 21. The overall structure is changed from being arranged in the second direction to being arranged along the first direction. This mounting structure of the detection sensor is only for illustrative purposes. The detection sensor can also be installed in other ways, such as directly corresponding to the hot end mounting position, using the hot end to trigger the sensor to achieve detection, etc. The detection sensor can be triggered by the first clamping mechanism of the print head or the second clamping mechanism of the tool holder, or it can be triggered by the hot end, or by other means through the installation and removal process of the hot end.

[0116] Example 11, as follows Figure 4b This illustrates a hot-end switching process. Figure 4b The diagram illustrates two tool holders arranged along the X-axis. Tool holder 50A is idle (no hot end), while tool holder 50B has a hot end 10. The printhead 1 also has a hot end 10. The following explanation uses printhead movement as an example to illustrate the hot end switching process. This printhead movement can also be achieved by reversing the movement of the tool holders. Figure 4b , Figure 4c , Figure 4d and Figure 4e This indicates that printhead 1 has moved to the first switching position A of tool holder 50A. Figure 4c for Figure 4a MM cross-sectional diagram, Figure 4d yes Figure 4c A schematic diagram of an improved scheme, Figure 4e for Figure 4a A schematic diagram of the NN cross-section. The relative movement of the printhead and the tool holder causes, as... Figure 4bThe print head 1 shown can move from point A (position A) to point T (position T) along the dotted line in the figure, then move from point T to position B along the second direction, and finally move from position B to the second switching position C along the first direction to switch the hot end 10 on the print head 1 to the tool holder 50A. Specifically, as shown... Figure 4f and Figure 4g This illustrates the state where the print head moves relative to the tool holder, causing the print head to move from position A to the intermediate position T. Figure 4f The second heating element 51 of the tool holder is pushed open. For example, the second clamping mechanism of the tool holder may include the second heating element 51. The end of the second heating element 51 is equivalent to a toggle part, and the part on the print head that pushes the toggle part is equivalent to a toggle, for example, moving away from the print head in the first direction. The positioning element 53 on the tool holder is opposite to the second positioning structure (positioning hole 155) of the hot end 10 on the print head. In addition, the second heat dissipation fins 52 of the tool holder can also be pushed open slightly, such as... Figure 4g As shown, for example, it swings away from the print head.

[0117] Figure 4h and Figure 4i This illustrates the state where the print head moves relative to the tool holder, causing it to move from point T to point B (position B). Figure 4h The positioning element (such as positioning post 53) on the schematic tool holder cooperates with the second positioning structure (positioning hole 155) of the hot end 10 on the print head. For example, the positioning element is inserted into the second positioning structure to achieve positioning of the hot end 10. Figure 4i The second heat dissipation fin 52 of the tool holder can be pushed open, for example, by swinging it away from the print head. Of course, the second heat dissipation fin 52 on the tool holder can also be moved by a cylindrical spring, which can compress the cylindrical spring to move the second heat dissipation fin 52 away from the print head. Figure 4j and Figure 4k The illustration shows the state where the printhead moves relative to the tool holder, causing it to move from point B to point C (position C). Positioning elements on the tool holder (such as positioning post 53) restrict the movement of the hot end 10 along the first direction, keeping it on the tool holder. Simultaneously, the first swinging pressure rod 31 on the printhead is pushed by the boss 154 on the hot end 10, overcoming the action of the first elastic element 241 and slightly lifting, causing the hot end 10 to detach from the printhead. The heat dissipation section of the hot end 10 also overcomes the action of the swinging fins 41, causing the swinging fins 41 to lift and detach the heat dissipation section of the hot end 10 from the printhead. The second heating element 51 of the tool holder moves towards the hot end under the action of the fourth elastic element 542 until it abuts against the heat dissipation section of the hot end 10. At this point, the heating surface of the second heating element 51 of the tool holder can fit against the heating surface of the hot end 10. (Refer to...) Figure 4cThe spring 243 in the figure acts as a spring force, causing the heating section of the hot end to come into contact with the second heating element 51. The second heat dissipation fin 52 of the tool holder swings towards the hot end 10 under the action of the fourth elastic element 542 (spring), causing the heat dissipation surface of the second heat dissipation fin 52 to contact the heat dissipation surface on the heat dissipation section of the hot end 10. The figure illustrates that the presence sensor 61 on the print head detects the hot end has moved out by the change in the state of the swing fin 41 or the first swing pressure rod 31, while the presence sensor on the tool holder can also detect that the hot end has been installed on the tool holder by detecting the state of the limiting element 531. This achieves the switching of the hot end 10 from the print head to the tool holder. If the tool holder and print head are swapped (i.e., the original labels 50, 50A, or 50B in the figure are changed to 1, 1A, or 1B, i.e., the print head, and the original label 1 is changed to 50, i.e., the tool holder), or another way of describing it is to name the original tool holder the print head and the original print head the tool holder, the modified version would look like this. Figure 4P As shown), the above process switches the hot end from the tool holder to the print head, as follows: Figure 4P As shown. Figure 4j The diagram also illustrates that, to reduce the frictional resistance of the protrusion 311 at the end of the first swinging pressure rod, the protrusion 311 can be replaced with a roller 313, which reduces friction by acting as a roller on the hot end. The first swinging pressure rod 31 is limited by the swing limiting structure 272 on the base 27 to prevent excessive swinging of the first swinging pressure rod 31 without the hot end constraint. The state of the print head after the hot end moves out of the print head is shown in Figure 4m, Figure 4n, or Figure 4o.

[0118] In addition, such as Figure 4dThe diagram also illustrates a second swing lever 33, around which a second pivot 302 can be positioned away from the hot end inlet / outlet (relative to the direction away from the tool holder of the hot end 10). The protrusion 311 of the second swing lever 33 presses against the surface of the hot end 10 facing the hot end inlet / outlet (facing the tool holder). Restrictive structures or limiting structures are distributed on the print head opposite the first and second surfaces of the hot end to limit the hot end 10, thus ensuring more reliable pressure against the print head. A swing lever actuation part 39 can also be provided on the second swing lever 33, and a corresponding matching actuation part 581 can be provided on the tool holder. The actuation part 581 can be fixedly connected to the base frame 57. For example, an actuation groove 5811 can be provided on the actuation part 581. When the print head moves from point A of the tool holder to point T of the tool holder, the actuation part 581 cooperates with the swing lever actuation part 39. For example, the swing lever actuation part 39 can be a shaft that moves into the actuation groove of the actuation part 581. When the print head moves relative to the tool holder, causing the print head to move from the relay position T to the corresponding hot end installation position B of the tool holder, the second swing lever 33 is actuated by the actuation part 581. As shown in the figure, the second swing lever will rotate clockwise around the second rotating shaft 302, which can release the fastening state of the hot end. Then, when the print head moves from the corresponding hot end installation position B of the tool holder to the second switching position C of the tool holder, the hot end is switched from the print head to the tool holder due to the limiting effect of the positioning part of the tool holder.

[0119] Conversely, if the print head is not equipped with a hot end (idle state), but the tool holder 50B has a hot end, the print head 1 first moves to the second switching position C of the tool holder 50B, and then the print head moves relative to the tool holder, so that the print head moves to position B along the first direction, and then moves to point T and then to the first switching position A to realize the hot end switching from the tool holder 50B to the print head. Figure 4j and Figure 4k This illustrates the state of printhead 1 moving to the second switching position C point of tool holder 50B. Then, as... Figure 4h and Figure 4i The illustration shows the state where the print head moves relative to the tool holder, causing it to move from the second switching position C to the corresponding hot end mounting position B. The second heating element 51 and the second heat dissipation fin 52 of the tool holder are pushed aside, and the first positioning structure 153 on the hot end (see reference)... Figure 2a The first clamping mechanism on the print head, in conjunction with the positioning part 23 on the print head, positions the hot end. For example, the first swinging pressure rod 31 on the print head clamps the hot end onto the second surface of the hot end or the boss 154 on the second surface (see reference). Figure 2a On the print head, the oscillating fins 41 press the heat dissipation section of the hot end against the heat dissipation surface of the first heat dissipation fin 22. Then... Figure 4f and Figure 4gThis illustrates the state where the print head moves relative to the tool holder, causing it to move from point B to the intermediate position T. The hot end 10 then disengages from the positioning constraint of the positioning element (such as positioning post 53) on the tool holder. Figure 4c and Figure 4e This illustrates the state where the print head moves relative to the tool holder, causing the print head to move from point T to point A. This allows the hot end 10 to switch from the tool holder to the print head. The presence sensor 61 on the tool holder detects that the hot end has been removed from the tool holder by detecting the state of the limiting member 531 or the second heat dissipation fin 52, or by directly detecting the hot end 10. The presence sensor on the print head detects that the hot end has been installed on the print head by detecting the state of the swing fin 41 or the first swing pressure rod 31, or by directly detecting the hot end. This achieves the switching of the hot end 10 from the tool holder to the print head. If the tool holder and the print head are interchanged (i.e., the label 50 or 50A in the figure is changed to 1 (print head), and the label 1 is changed to 50 or 50A (tool holder), then the above achieves the switching of the hot end from the print head to the tool holder. Figure 4P As shown. It should be noted that each movement can be relative, that is, the movement of the print head or the movement of the tool holder. For example, the movement of the print head is relative to the movement of the tool holder, or the print head is stationary but the relative movement of the tool holder relative to the print head is generated by the movement of the tool holder relative to the print head, or the print head and the tool holder move together.

[0120] Figure 4b The diagram illustrates that movement between position A and position B can occur via point T, or via an arc-shaped path where the print head moves directly from position A to position B, or vice versa. Alternatively, the print head can move directly from position A to position B in a straight line, or vice versa. Figure 5 As shown. The line connecting AB indicates the second direction, and the line connecting BC indicates the first direction. The positioning element on the tool holder (such as positioning post 53) extends along the second direction, and the second positioning structure on the hot end (such as positioning hole 155) also extends along the second direction. When the print head moves from position A to position B on the tool holder, the second positioning structure of the hot end cooperates with the positioning element on the tool holder to position the hot end. For example, the positioning element is the positioning post 53 extending along the second direction, and the second positioning structure is the positioning hole 155 extending along the second direction. The positioning element is inserted into the second positioning structure to position the hot end. Then the print head moves from position B to position C along the first direction, and the hot end is positioned on the tool holder by the positioning element. The hot end is switched from the print head to the tool holder. Conversely, if the hot end is set on the tool holder and there is no hot end on the print head, the print head first moves to the second switching position C on the tool holder, and then moves to position B along the first direction. The hot end cooperates with the positioning structure on the print head (refer to the aforementioned implementation scheme), and then the print head moves from position B to position A along the second direction. The hot end is switched from the tool holder to the print head.

[0121] The printhead reaching the first switching position A can be the position of the hot end of the printhead. Similarly, it can reach position B, position T, or position C.

[0122] Example 12, as Figure 6 This illustrates a hot-end switching process. See also: Figure 1 and Figure 7a The print head 1 moves along the guide rail 81 in a defined direction (such as perpendicular to the drawing surface, X-axis direction, etc.). A slider 83 (or linear bearing) can be set on the guide rail 81. The print head 1 can be fixedly connected to the slider 83. The guide rail 81 can not move along the Y-axis direction. For example, in a gantry frame 3D printer, the X-axis, i.e., the guide rail 81, can move along the Z-axis, such as the up and down direction or the direction perpendicular to the printing platform 89 as shown in the figure. The tool holder 50 is connected to the guide rail 81 and can move along the Z-axis with the guide rail 81. For example, the holder 57 is fixedly connected to the guide rail 81. For example, when the printhead moves to the first switching position (point A) of the tool holder, the movement in the first direction requires the cooperation of the tool holder. That is, the tool holder needs to move towards the printhead along the first direction (Y-axis direction) so that the printhead moves from point A to point T. Then, the printhead moves along the second direction (X-axis direction or the direction of guide rail 81) so that the printhead moves from point T to point B. Then, the tool holder 50 moves away from the printhead along the second direction so that the printhead moves from point B to point C, and the hot end switches from the printhead to the tool holder. In addition, when the printing material 70 is a filamentous material, the printhead 1 can move to the cutting position of the cutting mechanism 64 before moving to the first switching position of the tool holder. The cutting blade of the cutting mechanism 64 can move along the first direction (such as extending or swinging along the first direction) so that the blade cuts the printing material in the gap above the hot end of the printhead. Then the printhead moves to the first switching position of the tool holder. Additionally, when the printhead moves to the second switching position (point C) of the tool holder, the movement in the first direction requires the cooperation of the tool holder. Specifically, the tool holder needs to move towards the printhead along the first direction (Y-axis), causing the printhead to move from point C to point B. Then, the printhead moves along the second direction (X-axis or the direction of guide rail 81), causing the printhead to move from point B to point T. Finally, the printhead moves away from the tool holder along the first direction, causing the printhead to move from point T to point A, and the hot end switches from the tool holder to the printhead. Assuming... Figure 6 The guide rail 81 shown cannot move along the Y-axis. When the tool holder 50 is connected to the guide rail 81 (e.g., fixedly connected), the hot end on the tool holder may interfere with the model being printed on the printing platform 89. Therefore, ideally, after switching the hot end, the tool holder 50 should move a certain distance away from the printing platform along the Z-axis, for example, from point P or O to point Q, to avoid interference between the extrusion port of the hot end on the tool holder and the model being printed on the printing platform. Let point O in the figure correspond to... Figure 4bPoint A or C, point P corresponds to Figure 4b Point B or T in the diagram. For example, the tool holder can move along OP, i.e., along the first direction, and after completing the hot end switching, it can move along PQ away from the print platform. Alternatively, the tool holder can move along QO, such as moving along a guide rail in the QO direction, i.e., when the tool holder is at point A or C, its Z-axis height is aligned with the print head, but when it moves away from the print head, it moves along an inclined track away from the print platform. Or, the tool holder can move along an arc trajectory of QO, for example, the tool holder can swing around an axis fixedly connected to guide rail 81, and when it moves away from the print head, the tool holder increases the distance between itself and the print platform.

[0123] Of course if Figure 6 The central guide rail 81 can also move along the Y direction (the horizontal direction in the figure or the direction shown by PQ), which can be achieved by moving the print head. Figure 4b The tool holder 50 can remain stationary during the movement from point A, point B to point C. For example, the tool holder frame 57 can be fixedly connected to the printer frame or to the Y-axis guide rail.

[0124] As can be seen from the foregoing, the tool holder can be mounted on the frame of the 3D printing device, or connected to the guide rail (X-axis guide rail) on which the print head slides, or can be slidably mounted on a guide rail set along a Z-axis direction or perpendicular to the first and second directions. The tool holder can also be mounted on the drive mechanism or actuator and can move in the corresponding plane, for example, in the XY plane, XZ plane or YZ plane, for example, moving to the vicinity of the print head to reduce the travel distance of the print head when switching the hot end.

[0125] In embodiment 13, the 3D printing apparatus of the present invention may further include a cutting mechanism for cutting the filamentous printing material before changing the hot end. For example, before the print head moves to point A, it can first move to the cutting position of the cutting mechanism 64, and the print head and the cutting mechanism move relative to each other, for example, the print head moves towards the cutting mechanism, so that the printing material at the gap contact point above the hot end is cut by the cutting blade 641 of the cutting mechanism. Then the print head moves to the first switching position of the first tool holder. The cutting mechanism may be disposed on the print head, or connected to the guide rail (X-axis guide rail) slidably disposed on the print head, on the frame of the 3D printing apparatus, or on the tool holder, or can be slidably disposed on a guide rail disposed in a direction perpendicular to the first and second directions along a Z-axis direction; the cutting blade may also be disposed on the drive mechanism or the execution mechanism and can move in the corresponding plane, for example, in the XY plane, XZ plane, or YZ plane, for example, moving to the vicinity of the print head to reduce the moving distance of the print head when cutting the printing material. The cutting mechanism may use blades or lasers, etc. Preferably, the hot end mounted on the print head has a gap above it (such as a gap or notch in the feed tube), for example, a gap between the heat dissipation section and the feed tube above (away from the nozzle direction). A cutting mechanism can be used at this gap to cut the printing material for hot end replacement and material replacement. A near-end extruder (filament feeder) can also be provided on the print head, and this gap can be located between the hot end and the extruder. The filament feeder (extruder) can be a gear-driven type, a multi-screw type, or other filament feeding mechanism capable of driving the feeding of filamentous printing material, used to drive the printing material 70 to be conveyed to the hot end 10. Figure 1 , Figure 2b , Figure 6 and Figure 7a The schematic diagram of the 3D printing apparatus illustrates a cutting mechanism 64 for cutting the filamentous printing material above the hot end 10. The cutting mechanism 64 may not be located on the print head 1, for example... Figure 1 and Figure 7a The diagram illustrates that a cutting mechanism 64 can be installed next to (on the left side) of the first tool holder. The cutting mechanism 64 can be fixedly connected to the tool holder 50. The movement of the print head 1 towards the cutting mechanism 64 causes the printed material 70 to collide with the cutting blade of the cutting mechanism 64 and be cut off. Alternatively, the cutting blade can be driven to move by an actuator (such as a servo or motor). When the print head moves to the cutting position of the cutting mechanism 64, as shown... Figure 6 As shown, the actuator (not shown) drives the cutting blade to move toward the print head to cut the print material 70 on the print head. Figure 1 and Figure 2b The cutting mechanism 64 shown in the diagram uses a cutting blade. Figure 1 and Figure 7aThe cutting mechanism can also be equipped with a protective structure 642 to protect the cutting edge 641 of the cutting blade. For example, two protrusions can be provided at the cutting edge 641, with a channel of a certain width between the two protrusions. This channel allows the printing material to pass through, but it is not easy for a human finger to pass through and touch the cutting edge 641. Of course, the protrusions can also be movably connected to the cutting mechanism. During the cutting process, the protrusions can be moved away by the print head or other actuators to expose the cutting blade and cut the filamentous printing material on the print head. The protective structure makes the cutting mechanism safer. In addition, the cutting mechanism 64 can be set on the print head 1, for example... Figure 2b As shown, for example, the cutting mechanism 64 (cutting blade) can move along an axis generally perpendicular to the printing material 70. When cutting is required, the print head can move to a protrusion fixed to the printer frame or the X-axis or Y-axis assembly, allowing the protrusion to strike the cutting blade of the cutting mechanism 64. Alternatively, the cutting blade can be connected to a rocker arm, allowing the protrusion to strike the rocker arm, which in turn moves the cutting blade of the cutting mechanism 64 to cut the printing material 70. Alternatively, an actuator such as a servo or motor can be provided on the print head to drive the cutting blade of the cutting mechanism 64 to move via a rocker arm or gear to cut the printing material 70.

[0126] Example 14: The present invention also provides a method for switching the hot end of a 3D printing device.

[0127] The process includes the following steps: When a hot end is installed on the print head, the print head is moved to a tool holder without a hot end (e.g., the first switching position). By relatively moving the print head and the tool holder without a hot end, the hot end on the print head is removed from the print head along a first direction and then installed onto the tool holder without a hot end along a second direction. Alternatively, when a hot end is not installed on the print head, the print head is moved to a corresponding tool holder with a hot end installed (e.g., the second switching position). By relatively moving the print head and the tool holder with a hot end installed, the hot end on the tool holder with a hot end installed is removed from the corresponding tool holder along a second direction and then installed onto the print head along a first direction. The relative movement of the print head and the tool holder includes the print head moving relative to the tool holder, or the tool holder moving relative to the print head, or the print head and the tool holder moving simultaneously.

[0128] In one specific embodiment, when the print head and the tool holder without a hot end are moved relative to each other, the print head and the tool holder without a hot end are moved relative to each other, sequentially passing through a first switching position of the tool holder without a hot end, a hot end mounting position on the tool holder without a hot end, and a second switching position of the tool holder without a hot end, thereby achieving the switching and mounting of the hot end on the print head to the tool holder without a hot end; or, when the print head and the tool holder with a hot end are moved relative to each other, the print head and the tool holder with a hot end are moved relative to each other, causing the print head to sequentially pass through a second switching position of the tool holder with a hot end, a hot end mounting position on the tool holder with a hot end, and a first switching position of the tool holder with a hot end, thereby achieving the switching and mounting of the hot end on the tool holder with a hot end to the print head.

[0129] In one specific embodiment, when the print head and the tool holder without a hot end are moved relative to each other, the print head and the tool holder without a hot end are moved relative to each other so that the print head sequentially passes through a first switching position of the tool holder without a hot end, a relay position of the tool holder without a hot end, a hot end mounting position on the tool holder without a hot end, and a second switching position of the tool holder without a hot end. This achieves the switching and mounting of the hot end on the print head onto the tool holder without a hot end. The second switching position is located on the extension line of the hot end mounting position on the tool holder along a first direction, and the first switching position is located on the extension line of the hot end mounting position on the tool holder along a second direction. Alternatively, the first switching position is located on the extension line of the second switching position along a second direction, or the first switching position is located on the extension line of the point of the hot end mounting position on the tool holder along the second direction along the first direction. The relay position is set near the first switching position and the hot end mounting position on the tool holder.

[0130] When the print head and the tool holder with the hot end are moved relative to each other, the print head and the tool holder with the hot end are moved relative to each other so that the print head passes through the second switching position of the tool holder with the hot end, the installation position of the hot end on the tool holder with the hot end, the relay position of the tool holder with the hot end, and the first switching position of the tool holder with the hot end in sequence, thereby realizing the switching and installation of the hot end on the tool holder with the hot end onto the print head.

[0131] Alternatively, when a hot end is installed on the print head and no hot end is installed on the tool holder, the print head and the tool holder are moved relative to each other. The print head moves relative to the tool holder from the first switching position of the tool holder along the first direction, which is relatively closer to the tool holder. Then it moves relative to the tool holder along the second direction, which is relatively closer to the installation position of the hot end on the tool holder. After reaching the installation position of the hot end on the tool holder, it moves relative to the tool holder along the first direction, which is relatively farther away from the tool holder, and then reaches the second switching position of the tool holder. This achieves the switching and installation of the hot end on the print head onto the tool holder.

[0132] When the printhead is not equipped with a hot end and the tool holder is equipped with a hot end, the printhead and tool holder are moved relative to each other. The printhead moves from the second switching position on the tool holder along a first direction, moving closer to the tool holder, until it reaches the hot end mounting position on the tool holder. Then, it moves relative to each other along a second direction, moving away from the hot end mounting position on the tool holder. Finally, it moves relative to each other along the first direction, moving away from the tool holder, to reach the first switching position. This achieves the switching and mounting of the hot end from the tool holder onto the printhead; or...

[0133] When a hot end is installed on the printhead and no hot end is installed on the tool holder, the printhead moves from the first switching position on the tool holder towards the tool holder in a first direction. Then, it moves relative to the hot end mounting position on the tool holder in a second direction. After reaching the hot end mounting position on the tool holder, it moves relative to the tool holder in the first direction away from the tool holder to reach the second switching position on the tool holder, thereby achieving the switching and installation of the hot end on the printhead onto the tool holder.

[0134] When the printhead has no hot end installed and the tool holder has a hot end installed, the printhead moves from the second switching position on the tool holder towards the tool holder in the first direction. After reaching the hot end installation position on the tool holder, it moves away from the hot end installation position in the second direction, and then moves away from the hot end installation position in the first direction to reach the first switching position. This achieves the switching and installation of the hot end from the tool holder onto the printhead; or...

[0135] The process of switching the hot end from the printhead to the tool holder includes: moving the printhead with the hot end mounted relatively closer to the tool holder along a first direction, pushing away the second heating element on the tool holder so that the second positioning structure of the hot end corresponds to the positioning element on the tool holder, and then moving relatively along a second direction, where the second positioning structure on the hot end engages with the positioning element on the tool holder. At this time, the heat dissipation section on the hot end can also push away the second heat dissipation fins, so that the second heat dissipation surface on the second heat dissipation fins is in contact with the heat dissipation section under the action of a spring, and then moving away from each other relative to the first direction. The second heating element moves and abuts against the hot end under the action of a spring; the clamping mechanism on the printhead disengages from the hot end.

[0136] The process of switching the hot end from the tool holder to the print head includes: moving the print head relatively closer to the tool holder in a first direction, pushing away the second heating element on the tool holder, engaging the clamping mechanism on the print head with the hot end, and then moving relatively away in a second direction, disengaging the second positioning structure on the hot end from the positioning element on the tool holder. The heat dissipation section on the hot end can also push away the second heat dissipation fins and disengage from them. Then, the hot end moves away from each other in a relative first direction. The second heating element moves under the action of a spring until it is limited by a limiting structure in the first direction.

[0137] Alternatively, the print head and the tool holder can move relative to each other so that the print head passes through the first switching position, the second switching position, the hot end mounting position on the tool holder, and the first switching position in sequence, thereby switching the hot end on the tool holder to the print head or switching the hot end on the print head to the tool holder.

[0138] Alternatively, a relay position is provided near the first switching position of the tool holder and the installation position of the hot end on the tool holder. The print head and the tool holder move relative to each other so that the print head passes through the first switching position, the second switching position, the installation position of the hot end on the tool holder, the relay position, and the first switching position in sequence, so as to switch the hot end on the tool holder to the print head or switch the hot end on the print head to the tool holder.

[0139] The second switching position is located on the extension line of the mounting position of the hot end on the tool holder along the first direction, and the first switching position is located on the extension line of the mounting position of the hot end on the tool holder along the second direction, or the first switching position is located on the extension line of the second switching position along the second direction, or the first switching position is located on the extension line of the point of the mounting position of the hot end on the tool holder along the second direction along the first direction. The relay position is set near the first switching position and the mounting position of the hot end on the tool holder. Preferably, the relay position is set at the intersection of the axis of the mounting position of the hot end on the tool holder along the second direction and the axis of the first switching position of the tool holder along the first direction.

[0140] In one specific embodiment, before switching the hot end, the print head is first moved to the corresponding cutting position of the cutter. The cutter is equipped with a cutting blade, and the cutting blade moves relatively close to the print head, causing the cutting blade to cut the printing material connected to the hot end on the print head at the notch on the print head; or, the cutting blade, mounted on an actuator that can move in the XY plane, moves to the corresponding cutting position of the print head, and then moves relatively close to the print head, causing the cutting blade to cut the printing material connected to the hot end on the print head at the notch on the print head; wherein, the relative movement of the cutting blade and the print head includes the print head moving towards the cutting blade, or the cutting blade moving towards the print head, or the cutting blade and the print head moving towards each other simultaneously; or...

[0141] Before the hot end is switched from the tool holder to the printhead, the second heating element on the tool holder heats the hot end to a preset temperature; or...

[0142] Before the hot end switches from the tool holder to the printhead, the printing material in the feed line connected to the tool holder is transferred to the hot end via the filament feeder. Residual printing material in the hot end is extruded and replaced with the material to be used in the next step, or the empty hot end is filled with the material to be used in the next step; or...

[0143] The printing material delivered to the print head is replaced at the same time as the hot end is replaced. The hot end replaced on the print head corresponds to the printing material replaced on the print head. Figure 10 This diagram illustrates a method for replacing a heat exchanger and a printing ink, including a heat exchanger step and a printing ink replacement step. Steps A1 and A2 are printing ink replacement steps, and steps B1 to B4 are heat exchanger steps. The printing ink replacement step and the heat exchanger step can be performed in parallel, serially, or partially in parallel.

[0144] The size or diameter of the extrusion port of each of the switching hot ends may be different, the shape of the extrusion port of the hot ends may be different, the material of the hot ends or the extrusion port may be different, or the structure of each hot end may be different.

[0145] For filamentous printing material, before changing the printing material, perform step 102 to cut off the first printing material (the original printing material of the print head) at the gap above the first hot end of the print head. If it is a flowable printing material, such as a paste, granular or liquid printing material, this step can be omitted.

[0146] The steps for changing printing ink include:

[0147] In step A1, the first print material on the print head is retracted to a position outside the print head sufficient to clear the feed path of the print head;

[0148] Execute step A2, the second printing material (the printing material newly replaced on the print head) is fed into the inlet position of the hot end of the print head (the first hot end (the original hot end on the print head) or the second hot end (the hot end newly replaced on the print head)).

[0149] The steps at the heat exchange end include:

[0150] Execute step B1, the print head moves to the switching position of the first tool holder corresponding to the first hot end of the print head (used to switch the hot end from the print head to the tool holder);

[0151] Execute step B2, and switch the first hot end of the print head to the first tool holder;

[0152] Execute step B3, and the print head moves to the switching position of the second tool holder corresponding to the second hot end that will be used in the next step (used to switch the hot end from the tool holder to the print head);

[0153] Perform step B4, and switch the second hot end on the second tool holder to the print head.

[0154] The heat exchange end step and the printing material replacement step may overlap in time, and step B2 is performed after step 102 is completed, while step B1 can be performed before, after or simultaneously with step 102.

[0155] The method of the present invention may further include the following steps: Step 101 may be performed before step 102: the first printing material on the print head is retracted by a preset length; or, Step 103 may be performed before step A1: the first printing material on the print head presses the broken end of the printing material in the first hot end into the hot end; or, Step 106 may be performed after step A2: the print head moves to the waste extrusion area and extrudes the printing material of a preset length; or, Step 107 may be performed after step A2: the printing material to be used in the next step is prepared in advance, for example, the printing material to be used in the next step can be conveyed to the vicinity of the print head in advance; or, Step 111 may be performed before step B1: the distance between the print head and the printing platform is increased to a second distance; or, Step 117 may be performed after step B4: the distance between the print head and the printing platform is reduced to a first distance; or, Step 115 may be performed before step B4: the second hot end on the second tool holder is heated to a preset temperature.

[0156] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A 3D printing device, characterized by The hot end, the tool seat and the printing head; The hot end is mounted on or removed from the printing head along a first direction, and the hot end mounted on the printing head is limited along a second direction; The hot end is mounted on or removed from the tool seat along a second direction, and the hot end mounted on the tool seat is limited along a first direction; wherein the second direction is arranged at an angle with the first direction.

2. The 3D printing device of claim 1, wherein, The tool seat has a first switching position and a second switching position; wherein, The printing head and the tool seat are relatively moved so that the printing head passes through the first switching position, the mounting position of the hot end on the tool seat and the second switching position in sequence, to realize switching mounting of the hot end on the printing head to the tool seat or switching mounting of the hot end on the tool seat to the printing head; Or, the printing head and the tool seat are relatively moved so that the printing head passes through the second switching position, the mounting position of the hot end on the tool seat and the first switching position in sequence, to realize switching mounting of the hot end on the tool seat to the printing head or switching mounting of the hot end on the printing head to the tool seat; Or, The first switching position and the mounting position of the hot end on the tool seat are provided with a relay position; the printing head and the tool seat are relatively moved so that the printing head passes through the first switching position, the relay position, the mounting position of the hot end on the tool seat and the second switching position in sequence, to realize switching mounting of the hot end on the printing head to the tool seat or switching mounting of the hot end on the tool seat to the printing head; Or, the first switching position and the mounting position of the hot end on the tool seat are provided with a relay position, and the printing head and the tool seat are relatively moved so that the printing head passes through the second switching position, the mounting position of the hot end on the tool seat, the relay position and the first switching position in sequence, to realize switching mounting of the hot end on the tool seat to the printing head or switching mounting of the hot end on the printing head to the tool seat; Or, The printing head and the tool seat are relatively moved so that the printing head is relatively moved along a first direction to relatively approach the tool seat from the first switching position of the tool seat, then is relatively moved along a second direction to relatively approach the mounting position of the hot end on the tool seat, reaches the mounting position of the hot end on the tool seat, and then is relatively moved along a first direction to relatively move away from the tool seat to reach the second switching position of the tool seat, to realize switching mounting of the hot end on the printing head to the tool seat or switching mounting of the hot end on the tool seat to the printing head; Or, the print head and the tool seat are relatively moved so that the print head is relatively moved from the first switching position to the second switching position, is relatively moved to the mounting position of the hot end on the tool seat in a first direction relatively close to the tool seat, is relatively moved away from the mounting position of the hot end on the tool seat in a second direction, and is relatively moved away from the tool seat in the first direction to the first switching position, so as to switch the mounting of the hot end on the tool seat to the print head or switch the mounting of the hot end on the print head to the tool seat; Or, the print head and the tool seat are relatively moved so that the print head sequentially passes through the first switching position, the second switching position, the mounting position of the hot end on the tool seat, and the first switching position, so as to switch the mounting of the hot end on the tool seat to the print head or switch the mounting of the hot end on the print head to the tool seat; Or, a relay position is arranged near the first switching position and the mounting position of the hot end on the tool seat, and the print head and the tool seat are relatively moved so that the print head sequentially passes through the first switching position, the second switching position, the mounting position of the hot end on the tool seat, the relay position, and the first switching position, so as to switch the mounting of the hot end on the tool seat to the print head or switch the mounting of the hot end on the print head to the tool seat; And / or, The direction of the relative movement of the print head and the tool seat and / or the first direction and / or the second direction are in the XY plane or perpendicular to the Z axis or perpendicular to the axis of the feeding pipe of the hot end or perpendicular to the axis of the extrusion outlet of the print head or perpendicular to the normal of the surface of the print platform for carrying the extrusion printing material of the print head, with an error of not more than ±45°; And / or, The first switching position and the mounting position of the hot end on the tool seat are near a relay position, and the relay position is arranged on the axis in the second direction passing through the mounting position of the hot end on the tool seat and / or on the axis in the first direction passing through the first switching position of the tool seat; The relative movement of the print head and the tool seat includes that the print head moves relative to the tool seat, or the tool seat moves relative to the print head, or the print head and the tool seat move simultaneously.

3. The 3D printing device of claim 1, wherein, The print head comprises a first limiting structure for limiting the hot end in the second direction; The tool seat comprises a second limiting structure for limiting the hot end in the first direction.

4. The 3D printing device of claim 3, wherein, The first limiting structure comprises a first clamping mechanism for clamping the hot end in the first direction; and / or The first limiting structure comprises a first positioning mechanism for limiting the hot end in the second direction; and / or The second limiting structure comprises a second clamping mechanism for clamping the hot end in the second direction; and / or The second limiting structure comprises a second positioning mechanism for limiting the hot end in the first direction. The second limiting structure comprises a second positioning mechanism for limiting the hot end in the first direction.

5. The 3D printing device of claim 4, wherein, The first clamping mechanism comprises a clamping member movably connected to the print head, and / or the second clamping mechanism comprises a clamping member movably connected to the tool holder, the clamping member being capable of being pressed against the hot end by movement to clamp the hot end, and being capable of being separated from the hot end to release the clamping of the hot end.

6. The 3D printing device of claim 5, wherein, The clamping member is rotatably arranged on the print head or the tool holder, and one end of the clamping member is rotatable about a rotating connection to press against the hot end or to be separated from the hot end. Alternatively, the clamping member is movably arranged on the print head in a second direction, and / or the clamping member is movably arranged on the tool holder in a first direction, and the clamping member is capable of being pressed against the hot end or being separated from the hot end by movement.

7. The 3D printing device of claim 5, wherein the clamping member of the first clamping mechanism is a second swing press rod, one end of the second swing press rod being rotatably arranged on the print head through a second rotating shaft, the end of the second swing press rod being pressed against a side of the hot end facing the tool holder, a swing lever actuating portion being arranged on the second swing press rod, a corresponding actuating member being arranged on the tool holder, or the clamping member is a lower press plate, the lower press plate being movably arranged on the print head in a second direction, a press plate actuating portion being arranged on the lower press plate, a corresponding actuating member being arranged on the tool holder, and further comprising an elastic member, the elastic force of the elastic member pressing the second swing press rod or the lower press plate towards the hot end of the print head; wherein the print head and the tool holder are relatively moved to make the print head reach a first switching position of the tool holder to make the actuating member cooperate with the swing lever actuating portion or the press plate actuating portion, then the print head reaches a second switching position to make the actuating member actuate the swing lever actuating portion or the press plate actuating portion to open the second swing press rod or the lower press plate against the elastic force of the elastic member, then the print head reaches a mounting position of the hot end on the tool holder to combine the hot end on the tool holder to the print head and position the hot end by the first positioning mechanism on the print head, then the print head reaches the first switching position, the second swing press rod or the lower press plate clamps the hot end under the elastic force of the elastic member to realize the switching of the hot end on the tool holder to the print head or the switching of the hot end on the print head to the tool holder. Alternatively, a relay position is provided near the first switching position of the tool seat and the mounting position of the hot end on the tool seat, the printhead and the tool seat are relatively moved so that the printhead reaches the first switching position of the tool seat so that the dial element cooperates with the swing lever dialing part or the pressing plate dialing part, then the printhead reaches the second switching position so that the dial element dials the swing lever dialing part or the pressing plate dialing part to open the second swing pressing plate or the lower pressing plate against the elastic force of the elastic element, then the printhead reaches the mounting position of the hot end on the tool seat to combine the hot end on the tool seat to the printhead and position by the first positioning mechanism on the printhead, then the printhead reaches the relay position, the second swing pressing plate or the lower pressing plate clamps the hot end under the elastic force of the elastic element, then the printhead reaches the first switching position to switch the hot end on the tool seat to the printhead or switch the hot end on the printhead to the tool seat; Wherein, the relative movement of the printhead and the tool seat includes that the printhead moves relative to the tool seat, or the tool seat moves relative to the printhead, or the printhead and the tool seat move simultaneously.

8. The 3D printing device of claim 5, wherein, The clamping element is a first swing pressing plate, a middle part of the first swing pressing plate is rotatably arranged on the printhead or the tool seat through a first rotating shaft, one end of the first swing pressing plate away from the hot end is connected with a first elastic element, the first elastic element applies an elastic force to the corresponding end of the first swing pressing plate to make the first swing pressing plate rotate around the first rotating shaft, and then one end of the first swing pressing plate close to the hot end presses the hot end in the first direction and / or the second direction; Alternatively, the clamping element is a second swing pressing plate, one end of the second swing pressing plate is rotatably arranged on the printhead away from the tool seat relative to the hot end through a second rotating shaft, the end of the second swing pressing plate is pressed on the side of the hot end facing the tool seat, the second swing pressing plate is provided with a swing lever dialing part, the tool seat is provided with a dial element corresponding to the swing lever dialing part, or the clamping element is a second swing pressing plate, one end of the second swing pressing plate is rotatably arranged on the tool seat away from the printhead relative to the hot end through a second rotating shaft, the end of the second swing pressing plate is pressed on the side of the hot end facing the printhead, the second swing pressing plate is provided with a swing lever dialing part, the printhead is provided with a dial element corresponding to the swing lever dialing part; when the printhead and the tool seat relatively move in the first direction, the dial element cooperates with the swing lever dialing part, when the printhead and the tool seat relatively move in the second direction, the dial element can dial the swing lever dialing part, and then drive the second swing pressing plate to rotate so that the end of the second swing pressing plate separates from the hot end or the end of the second swing pressing plate presses the hot end; Alternatively, the clamping member is a lower pressing plate, the lower pressing plate is arranged on the print head and is movable along the second direction, the lower pressing plate is provided with a pressing plate actuating part, and the tool seat is provided with an actuating member corresponding to the pressing plate actuating part; alternatively, the clamping member is a lower pressing plate, the lower pressing plate is arranged on the tool seat and is movable along the second direction, the lower pressing plate is provided with a pressing plate actuating part, and the print head is provided with an actuating member corresponding to the pressing plate actuating part; when the print head and the tool seat move relatively along the first direction, the actuating member and the pressing plate actuating part are matched, and when the print head and the tool seat move relatively along the second direction, the actuating member can actuate the pressing plate actuating part, thereby driving the lower pressing plate to move so that the end of the lower pressing plate is separated from the hot end or the lower pressing plate presses the hot end. Alternatively, the clamping member is a lower pressing plate, one end of the lower pressing plate is rotatably arranged on the print head on the side close to the tool seat relative to the hot end, the third rotating shaft is arranged along the first direction, the lower pressing plate is provided with a pressing plate actuating part, and the tool seat is provided with a lower actuating member corresponding to the pressing plate actuating part; alternatively, the clamping member is a lower pressing plate, one end of the lower pressing plate is rotatably arranged on the tool seat on the side close to the print head relative to the hot end, the third rotating shaft is arranged along the first direction, the lower pressing plate is provided with a pressing plate actuating part, and the print head is provided with a lower actuating member corresponding to the pressing plate actuating part; when the print head and the tool seat move relatively along the first direction, the lower actuating member and the pressing plate actuating part are matched, and when the print head and the tool seat move relatively along the second direction, the lower actuating member can actuate the pressing plate actuating part, thereby driving the lower pressing plate to rotate so that the end of the lower pressing plate is separated from the hot end or the end of the lower pressing plate presses the hot end. The relative movement of the print head and the tool seat includes that the print head moves relative to the tool seat, or the tool seat moves relative to the print head, or the print head and the tool seat move simultaneously.

9. The 3D printing device of claim 8, wherein, The first rotating shaft is arranged along the third direction, the end of the first swing pressing rod in the direction of the tool seat is provided with an inclined surface, and the print head is further provided with a swing limiting structure; when the hot end is not installed on the print head, the first swing pressing rod continues to swing in the pressing direction under the action of the first elastic member until it is limited by the swing limiting structure, and the inclined surface of the end can still ensure that the hot end can push away the first swing pressing rod and be installed on the print head when the hot end moves relative to the print head along the first direction; and / or The hot end is provided with a boss or a groove, and the first swing pressing rod is provided with a corresponding abutting part corresponding to the boss or the groove; when the first swing pressing rod presses the hot end, the abutting part is attached to the inclined side surface of the boss or the groove, so that the hot end is clamped by the first swing pressing rod.

10. The 3D printing device of claim 4, wherein The hot end is provided with a second positioning structure extending in the second direction; the second positioning mechanism on the tool seat comprises a positioning member corresponding to the second positioning structure, which also extends in the second direction; When the tool seat and the print head move relative to each other in the second direction, the positioning member and the second positioning structure can cooperate to limit the hot end in the first direction, or the positioning member and the second positioning structure move away to release the limitation of the hot end in the first direction; And / or The hot end is provided with a first positioning structure extending in the first direction, and the first positioning mechanism on the print head comprises a positioning part corresponding to the first positioning structure, which also extends in the first direction; When the hot end is mounted on the print head, the positioning part cooperates with the first positioning structure to position the hot end in a third direction perpendicular to the first direction and the second direction, or in the axial direction of the feeding pipe of the hot end, and / or in the second direction.

11. The 3D printing device of claim 10, wherein, The positioning member is a positioning plate or a positioning column or an edge extending in the second direction, and the second positioning structure on the hot end is a positioning groove or a positioning hole or a boss extending in the second direction; Alternatively, the positioning member or the positioning part is a limiting groove comprising a groove segment extending in the second direction and a notch or a passage extending in the first direction, which communicates with the groove segment; the second positioning structure or the first positioning structure on the hot end is a heat dissipation segment on the hot end, and the limiting groove is adapted to the heat dissipation segment; Alternatively, the positioning part is a positioning plate or a positioning column or an edge extending in the first direction, and the first positioning structure on the hot end is a positioning groove or a positioning hole or a boss extending in the first direction.

12. The 3D printing device of claim 1, wherein, The hot end sequentially comprises an extrusion port, a heating segment, a throat segment and a heat dissipation segment; wherein: The print head is provided with a first heat dissipation mechanism corresponding to the heat dissipation segment of the hot end, which is used for heat dissipation of the heat dissipation segment; and / or, The tool seat is provided with a second heat dissipation mechanism corresponding to the heat dissipation segment of the hot end, which is used for heat dissipation of the heat dissipation segment; and / or, The print head is provided with a first heating member corresponding to the heating segment of the hot end, which is used for heating of the heating segment, and the first heating member is fixedly connected to the print head or movably connected to the print head; and / or The tool seat is provided with a second heating member corresponding to the heating segment of the hot end, which is used for heating of the heating segment, and the second heating member is fixedly connected to the tool seat or movably connected to the tool seat; and / or, The print head is provided with a first heat dissipation fin having a second heat dissipation surface, and the heat dissipation segment of the hot end mounted on the print head has a first heat dissipation surface, which is attached to the second heat dissipation surface, and the first heat dissipation fin is fixedly connected to the print head or movably connected to the print head; and / or, The tool seat is provided with a second heat dissipation fin, the second heat dissipation fin has a third heat dissipation surface, the heat dissipation section of the heat end mounted on the tool seat has a first heat dissipation surface, the first heat dissipation surface is attached to the third heat dissipation surface, the second heat dissipation fin is fixedly connected to the tool seat or movably connected to the tool seat; and / or, The printing head and / or the tool seat is provided with a detection sensor for detecting whether the heat end exists; and / or, The printing head or the tool seat is provided with a shielding part corresponding to the heating section for strengthening the heat preservation of the heating section; or, The heat dissipation section is provided with a third heat dissipation fin; or, The printing head is provided with a first heat dissipation fin, the first heat dissipation fin has a second heat dissipation surface, and the second heat dissipation surface is a laterally open heat dissipation surface; or, The tool seat is provided with a second heat dissipation fin, the second heat dissipation fin has a third heat dissipation surface, and the third heat dissipation surface is a laterally open heat dissipation surface; or, The printing head is provided with two first heat dissipation fins, namely a left first heat dissipation fin and a right first heat dissipation fin, the left first heat dissipation fin and the right first heat dissipation fin are rotatably connected to the printing head through a fourth rotating shaft and a fifth rotating shaft respectively, the left first heat dissipation fin and the right first heat dissipation fin are respectively provided with a second elastic member, and the second elastic member respectively provides the left first heat dissipation fin and the right first heat dissipation fin with elastic force for swinging the left first heat dissipation fin and the right first heat dissipation fin towards each other or towards the direction of mounting the heat end; or, The printing head is provided with two first heat dissipation fins, namely a left first heat dissipation fin and a right first heat dissipation fin, the left first heat dissipation fin and / or the right first heat dissipation fin is movably connected to the printing head, the left first heat dissipation fin and the right first heat dissipation fin are respectively provided with a laterally open heat dissipation surface matched with the heat dissipation section, the laterally open heat dissipation surface is attached to the heat dissipation section when the heat end is mounted on the printing head, and / or a guide inclined surface is arranged on the side of the left first heat dissipation fin and the right first heat dissipation fin towards the mounting and removal of the heat end, the two guide inclined surfaces form an opening shape with an outer large and inner small shape, facilitating the heat dissipation section of the heat end to be mounted on the printing head after pushing away the left first heat dissipation fin and the right first heat dissipation fin from the outside between the left first heat dissipation fin and the right first heat dissipation fin; and / or, when there is no heat end mounted, the left first heat dissipation fin and the right first heat dissipation fin abut against each other to be limited or are respectively limited by the corresponding limiting structure; or, The printing head is provided with two first heat dissipation fins, namely a left first heat dissipation fin and a right first heat dissipation fin, the left first heat dissipation fin and / or the right first heat dissipation fin is movably connected to the printing head, the left first heat dissipation fin and the right first heat dissipation fin are respectively provided with a laterally open heat dissipation surface matched with the heat dissipation section, and the heat dissipation surface of the left first heat dissipation fin and the heat dissipation surface of the right first heat dissipation fin are respectively semicircular tubular surfaces facing each other; or, The printing head is provided with a first heat dissipation mechanism and / or the tool seat is provided with a second heat dissipation mechanism, and the first heat dissipation mechanism and / or the second heat dissipation mechanism is a fan, an air supply pipe or a cooling liquid circulating device; or, The first heating member is installed on the print head and / or the second heating member is installed on the tool seat, and the first heating member and / or the second heating member is a ceramic heating sheet, a heating rod or an induction coil; or, The first heating member is installed on the print head and / or the second heating member is installed on the tool seat, and the first heating member and / or the second heating member is a ceramic heating sheet, a heating rod or an induction coil; or, The first heating member is installed on the print head and / or the second heating member is installed on the tool seat, and the first heating member and / or the second heating member is a ceramic heating sheet, a heating rod or an induction coil; or, The first heating member is installed on the print head and / or the second heating member is installed on the tool seat, and the first heating member and / or the second heating member is a ceramic heating sheet, a heating rod or an induction coil; or, 13. The 3D printing device of claim 4, wherein The hot end comprises an extrusion port, a heating section, a throat section and a heat dissipation section in sequence; the print head is provided with a first heat dissipation fin and a first heating member, wherein The heating section is provided with a first heating surface, the print head is provided with a first heating member, the first heating member is provided with a second heating surface; the tool seat is provided with a second heating member, the second heating member is provided with a third heating surface, the second clamping mechanism comprises the second heating member or the third heating surface, or the first clamping mechanism comprises the first heating member or the second heating surface, when the hot end is installed on the print head, the first heating surface is attached to the second heating surface, when the hot end is installed on the tool seat, the first heating surface is attached to the third heating surface, the first heating surface is parallel to the first direction, and the error is not more than ± 45°; Or, the heating section is provided with a first heating surface and a fourth heating surface, the first heating member on the print head is provided with a second heating surface, the tool seat is provided with a second heating member, the second heating member is provided with a third heating surface, the second clamping mechanism comprises the second heating member or the third heating surface, the first heating surface and the fourth heating surface are oppositely arranged, when the hot end is installed on the print head, the first heating surface is attached to the second heating surface or oppositely arranged, when the hot end is installed on the tool seat, the fourth heating surface is attached to the third heating surface or oppositely arranged, the first heating surface is perpendicular to the first direction, and the error is not more than ± 45°; Or, the first heat dissipation fin on the print head has an open first heat dissipation surface, the first clamping mechanism comprises a first pressing member movably adjusted corresponding to the first heat dissipation fin, the first pressing member can press the heat dissipation section of the hot end installed on the print head through movable adjustment to make the heat dissipation section attached to the first heat dissipation fin; The first pressing member is rotatably arranged on the print head, and is rotatable about a rotating connection to press the heat dissipation section against the first heat dissipation fin, so that the heat dissipation section is in contact with the first heat dissipation fin. When the hot end is not installed on the print head, the first pressing member is in abutment with a limiting structure arranged on the print head. Alternatively, the first pressing member is movably arranged on the print head along a second direction, and is adjusted by movement to press the heat dissipation section, so that the heat dissipation section is in contact with the first heat dissipation fin. When the hot end is not installed on the print head, the first pressing member is in abutment with a limiting structure arranged on the print head. The second clamping mechanism on the tool seat comprises a rotatable second heat dissipation fin, and further comprises a fourth elastic member, which applies a force to the second heat dissipation fin to rotate the second heat dissipation fin in the direction of the hot end or the print head. When the hot end is not installed on the tool seat, the second heat dissipation fin is in abutment with a limiting structure arranged on the tool seat. Alternatively, the tool seat is provided with a second heat dissipation fin corresponding to the heat dissipation section, and the second positioning mechanism comprises a limiting groove arranged on the second heat dissipation fin for limiting the heat dissipation section.

14. The 3D printing device of claim 13, wherein, The first pressing member is a swing fin, which is rotatably arranged on the print head through a fourth rotating shaft, and the fourth rotating shaft is provided with a second elastic member. The second elastic member drives the swing fin to rotate and press against the heat dissipation section, so that the heat dissipation section is in contact with the first heat dissipation fin. Alternatively, the first pressing member is an upper pressing plate, which is movably arranged on the print head along a second direction. The upper pressing plate is provided with an upper actuating part, and the tool seat is provided with an upper actuating member corresponding to the upper actuating part. Alternatively, the second pressing member is an upper pressing plate, which is movably arranged on the tool seat along a second direction. The upper pressing plate is provided with an upper actuating part, and the print head is provided with an upper actuating member corresponding to the upper actuating part. When the print head and the tool seat move relative to each other along a first direction, the upper actuating member cooperates with the upper actuating part. When the print head and the tool seat move relative to each other along a second direction, the upper actuating member actuates the upper actuating part, thereby driving the upper pressing plate to move, so that the upper pressing plate is separated from the heat dissipation section or the upper pressing plate presses the heat dissipation section. Or, the first pressing member is an upper pressing plate, the upper pressing plate is rotatably arranged on the print head through a fifth rotating shaft, the upper pressing plate is provided with a pushing part, the tool seat is provided with an upper pushing member corresponding to the pushing part, or the second pressing member is an upper pressing plate, the upper pressing plate is rotatably arranged on the tool seat through a fifth rotating shaft, the upper pressing plate is provided with a pushing part, the print head is provided with an upper pushing member corresponding to the pushing part; when the print head and the tool seat move relatively along the first direction, the upper pushing member cooperates with the pushing part, when the print head and the tool seat move relatively along the second direction, the upper pushing member can push the pushing part, and then drive the upper pressing plate to rotate, so that the upper pressing plate is separated from the heat dissipation section or the upper pressing plate presses the heat dissipation section.

15. The 3D printing device of claim 1, wherein, The tool seat is arranged at least two, the tool seat is arranged along the second direction or a direction perpendicular to the first direction, one of the tool seats or the print head is not provided with a hot end; and / or, And / or, the print head is arranged at least two; The tool seat can move along a third direction perpendicular to the first direction and the second direction; And / or, the direction of the first direction and the direction of the second direction can be exchanged; And / or, The print head and the tool seat can move relatively, through relative movement, the hot end on the print head can be switched to be installed on the tool seat, and the hot end on the tool seat can be switched to be installed on the print head; And / or, the tool seat is connected with a feeding pipeline, a wire feeder is arranged on the conveying line of the print material in the feeding pipeline, the wire feeder conveys the print material in the feeding pipeline into the corresponding hot end in the tool seat, extrudes the residual print material in the hot end, and replaces the print material in the feeding pipeline, so that the print material in the hot end is the print material to be used in the next step or the empty hot end is filled with the print material to be used in the next step when the hot end is switched with the print head.

16. A method for switching hot end of a 3D printing device, characterized in that, The steps include: When the print head is provided with a hot end, the print head is moved to the first switching position or the second switching position of the tool seat without the hot end, and through relative movement of the print head and the tool seat without the hot end, the hot end on the print head is removed from the print head along the first direction, and then is installed on the tool seat without the hot end along the second direction; Or, When the print head is not provided with a hot end, the print head is moved to the second switching position or the first switching position of the corresponding tool seat provided with the hot end, and through relative movement of the print head and the tool seat provided with the hot end, the hot end on the tool seat provided with the hot end is removed from the corresponding tool seat along the second direction, and then is installed on the print head along the first direction; The relative movement of the print head and the tool seat includes movement of the print head relative to the tool seat, movement of the tool seat relative to the print head, or simultaneous movement of the print head and the tool seat.

17. The 3D printing device switching hot end method of claim 16, wherein, In the relative movement of the print head and the tool seat without the hot end, the print head and the tool seat without the hot end pass through the first switching position of the tool seat without the hot end, the hot end mounting position of the tool seat without the hot end and the second switching position of the tool seat without the hot end in the relative movement, so as to realize the switching and mounting of the hot end on the print head to the tool seat without the hot end; or, In the relative movement of the print head and the tool seat with the hot end, the print head and the tool seat with the hot end pass through the second switching position of the tool seat with the hot end, the hot end mounting position of the tool seat with the hot end and the first switching position of the tool seat with the hot end in the relative movement, so as to realize the switching and mounting of the hot end on the tool seat with the hot end to the print head.

18. The 3D printing apparatus switching hot end method of claim 16, wherein, In the relative movement of the print head and the tool seat without the hot end, the print head and the tool seat without the hot end pass through the first switching position of the tool seat without the hot end, the relay position of the tool seat without the hot end, the hot end mounting position of the tool seat without the hot end and the second switching position of the tool seat without the hot end in the relative movement, so as to realize the switching and mounting of the hot end on the print head to the tool seat without the hot end; Or, in the relative movement of the print head and the tool seat with the hot end, the print head and the tool seat with the hot end pass through the second switching position of the tool seat with the hot end, the hot end mounting position of the tool seat with the hot end, the relay position of the tool seat with the hot end and the first switching position of the tool seat with the hot end in the relative movement, so as to realize the switching and mounting of the hot end on the tool seat with the hot end to the print head; Or, When the print head is mounted with the hot end and the tool seat is not mounted with the hot end, the print head and the tool seat pass through the first switching position of the tool seat, and then pass through the hot end mounting position of the tool seat in the relative movement, and then pass through the second switching position of the tool seat in the relative movement, so as to realize the switching and mounting of the hot end on the print head to the tool seat. When the hot end is not installed on the print head and the hot end is installed on the tool seat, the print head and the tool seat are relatively moved so that the print head is relatively moved from the second switching position of the tool seat to the first direction relative to the direction of approaching the tool seat, reaches the installation position of the hot end on the tool seat, is relatively moved from the installation position of the hot end on the tool seat to the second direction relative to the direction of moving away, and then is relatively moved from the tool seat to the first direction relative to the direction of moving away to reach the first switching position, so that the hot end on the tool seat is switched and installed on the print head; or, When the hot end is installed on the print head and the hot end is not installed on the tool seat, the print head is moved from the first switching position of the tool seat to the tool seat in the first direction, is relatively moved to the direction of approaching the installation position of the hot end on the tool seat in the second direction, is moved from the installation position of the hot end on the tool seat to the second direction relative to the direction of moving away to reach the second switching position of the tool seat, so that the hot end on the print head is switched and installed on the tool seat; or, When the hot end is not installed on the print head and the hot end is installed on the tool seat, the print head is moved from the second switching position of the tool seat to the direction of approaching the tool seat in the first direction, is moved from the installation position of the hot end on the tool seat to the second direction relative to the direction of moving away after reaching the installation position of the hot end on the tool seat, and then is moved from the tool seat to the first direction relative to the direction of moving away to reach the first switching position, so that the hot end on the tool seat is switched and installed on the print head; or When the hot end is not installed on the print head and the hot end is installed on the tool seat, the print head is moved from the second switching position of the tool seat to the direction of approaching the tool seat in the first direction, is moved from the installation position of the hot end on the tool seat to the second direction relative to the direction of moving away after reaching the installation position of the hot end on the tool seat, and then is moved from the tool seat to the first direction relative to the direction of moving away to reach the first switching position, so that the hot end on the tool seat is switched and installed on the print head; or The switching of the hot end from the print head to the tool seat includes: moving the print head with the installed hot end in the first direction relative to the tool seat, pushing away the second heating element on the tool seat with the installed hot end, combining the clamping mechanism on the print head with the hot end, then relatively moving in the second direction relative to the tool seat, disengaging the second positioning structure on the hot end from the positioning element on the tool seat, and the heat dissipation section on the hot end can also push away the second heat dissipation fin and disengage from the second heat dissipation fin, and then relatively moving away from each other in the first direction, and the second heating element moves under the action of the fourth elastic element until it is limited by a limiting structure in the first direction; The switching of the hot end from the tool seat to the print head includes: moving the print head in the first direction relative to the tool seat, pushing away the second heating element on the tool seat with the installed hot end, combining the clamping mechanism on the print head with the hot end, then relatively moving away in the second direction, disengaging the second positioning structure on the hot end from the positioning element on the tool seat, and the heat dissipation section on the hot end can also push away the second heat dissipation fin and disengage from the second heat dissipation fin, and then relatively moving away from each other in the first direction, and the second heating element moves under the action of the fourth elastic element until it is limited by a limiting structure in the first direction. Or, the print head and the tool seat are relatively moved so that the print head passes through the first switching position of the tool seat, the second switching position, the mounting position of the hot end on the tool seat and the first switching position in sequence, to realize switching mounting of the hot end on the tool seat to the print head or switching mounting of the hot end on the print head to the tool seat. Or, the first switching position of the tool seat and the mounting position of the hot end on the tool seat are provided with a relay position in the vicinity, the print head and the tool seat are relatively moved so that the print head passes through the first switching position, the second switching position, the mounting position of the hot end on the tool seat, the relay position and the first switching position in sequence, to realize switching mounting of the hot end on the tool seat to the print head or switching mounting of the hot end on the print head to the tool seat. The second switching position of the tool seat is located on the extension line of the mounting position of the hot end on the tool seat in the first direction, the first switching position of the tool seat is located on the extension line of the mounting position of the hot end on the tool seat in the second direction, or the first switching position is located on the extension line of the second switching position in the second direction, or the first switching position is located on the extension line of the mounting position of the hot end on the tool seat in the second direction, and the relay position is provided in the vicinity of the first switching position and the mounting position of the hot end on the tool seat.

19. The 3D printing device switching hot end method according to any one of claims 16 to 18, characterized in that, Before switching the hot end, the print head is moved to a corresponding cutting position of a cutter, the cutter is provided with a cutting knife, the cutting knife is relatively moved close to the print head so that the cutting knife cuts the printing material connected with the hot end at the notch on the print head; or the cutting knife provided on the actuator movable in the XY plane is moved to the corresponding cutting position of the print head, and then the cutting knife is relatively moved close to the print head so that the cutting knife cuts the printing material connected with the hot end at the notch on the print head, wherein the relatively moving close of the cutting knife to the print head includes moving the print head close to the cutting knife, or moving the cutting knife close to the print head, or simultaneously moving the cutting knife and the print head close to each other; or Before the hot end is switched from the tool seat to the print head, the second heating member on the tool seat heats the hot end to a preset temperature; or Before the hot end is switched from the tool seat to the print head, the printing material in the feeding pipe connected to the tool seat is delivered into the hot end by a wire feeder, the residual printing material in the hot end is replaced by the printing material to be used in the next step or the empty hot end is filled with the printing material to be used in the next step; or The hot end is replaced, and the filament printing material connected to the print head is also replaced, and the replaced hot end on the print head corresponds to the replaced printing material on the print head.

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