3D printing head of double-extrusion system and 3D printing method

Abstract

The invention belongs to the technical field of 3D printing, and particularly relates to a 3D printing head with double extrusion systems and a 3D printing method.The 3D printing head comprises a first material conveying system, a second material conveying system, a heating output system, a nozzle and a heat dissipation direction adjuster; the output end of the first material conveying system and the output end of the second material conveying system are connected with the feeding end of the heating output system through the first heat dissipation system and the second heat dissipation system respectively, a nozzle is arranged at the discharging end of the heating output system, and the included angle between the output direction of the first material conveying system and the output direction of the second material conveying system is smaller than 90 degrees. A third heat dissipation system matched with the output port is arranged below the nozzle or a third heat dissipation system matched with the output port of the nozzle is arranged through a heat dissipation direction regulator; the problem that a heat dissipation device on an existing 3D printing head is poor in heat dissipation effect on a continuous fiber reinforced composite material is solved.

Description

Technical Field

[0001] The present application belongs to the field of 3D printing technology, and specifically relates to a 3D print head of a dual extrusion system and a 3D printing method. Background Art

[0002] Fused deposition modeling (FDM) 3D printer has a simple mechanical structure and the lowest manufacturing and maintenance costs. Therefore, FDM is the most widely used 3D printing technology in the world today. Existing 3D printers use two print heads when printing composite continuous fiber materials. The first print head prints out the continuous fiber material, and the second print head prints out the resin material and attaches it to the continuous fiber material printed by the first print head. In order to allow the printed material to form the shape of the product, a heat dissipation device is set on the print head so that the printed material can solidify.

[0003] However, continuous fiber 3D printing adds fiber materials to traditional FDM printing. If you want to ensure the printing effect, higher requirements are placed on the heat dissipation during the printing process, such as the straightness of the limit in the printed straight line segment and the offset of the fiber at the corner. These require the resin in the extruded material to drop below the glass transition temperature faster to fix the limit. In other words, the heat dissipation system needs to have a higher ability to remove heat from the resin, so a more precise heat dissipation direction is required. Summary of the invention

[0004] The purpose of this application is to address the shortcomings of the prior art and to design a 3D print head with a dual extrusion system by adopting a third heat dissipation system in conjunction with a heat dissipation direction regulator, so that the material coming out of the nozzle can be accurately dissipated to avoid wire drawing, thereby solving the problem of poor heat dissipation effect of the heat dissipation device on the current 3D print head for continuous fiber reinforced composite materials.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A 3D print head of a dual extrusion system comprises a first feeding system, a second feeding system, a heating output system, and a nozzle, wherein the output end of the first feeding system and the output end of the second feeding system are respectively connected to the feed end of the heating output system through a first heat dissipation system and a second heat dissipation system, the nozzle is arranged at the discharge end of the heating output system, the angle between the output direction of the first feeding system and the output direction of the second feeding system is less than 90 degrees, and a third heat dissipation system is arranged at the nozzle or a third heat dissipation system matched with the output port of the nozzle is arranged through a heat dissipation direction regulator.

[0007] Preferably, the heating output system includes a heating block, a linear feed cavity, and a feed pipe. The linear feed cavity is arranged in the heating block, the inner diameter of the linear feed cavity is larger than the outer diameter of the feed pipe, one end of the feed pipe is coaxially inserted into the linear feed cavity, and a preset gap is provided between the end of the feed pipe inserted into the linear feed cavity and the end of the linear feed cavity facing away from the feed pipe. The nozzle is arranged on the end of the heating block facing away from the feed pipe, and the nozzle is coaxially connected to the end of the linear feed cavity facing away from the feed pipe. The discharge end of the second heat dissipation system is connected to the input end of the feed pipe, and the discharge end of the first heat dissipation system is communicated with the side wall of the linear feed cavity.

[0008] Preferably, the first heat dissipation system includes a first fan, a heat sink, and a throat. The output end of the first feeding system is coaxially connected to one end of the throat, and the other end of the throat is connected to the feed end of the heating output system. A heat sink is provided on the throat, and the heat sink is provided on the heat sink. The first fan is installed on the heat sink.

[0009] Preferably, the first feed system includes a first feed pipe A, a first feed wheel group, and a first feed pipe B. The first feed wheel group is arranged between the first feed pipe A and the first feed pipe B. The first feed pipe A is coaxial with the first feed pipe B. The axis of the first feed wheel group is perpendicular to the axis of the first feed pipe A. The end of the first feed pipe B facing away from the first feed wheel group is connected to the feed end of the first heat dissipation system.

[0010] Preferably, the second heat dissipation system includes a discharge pipe, the output end of the discharge pipe is conical, the discharge pipe is coaxial with the feed pipe, the input end of the discharge pipe is connected to the output end of the second feeding system, the output end of the discharge pipe extends into the feed end of the feed pipe, a preset gap is provided between the output end of the feed pipe and the inner wall of the linear feeding cavity, and a preset gap is provided between the outer wall of the output end of the discharge pipe and the inner wall of the feed of the feed pipe.

[0011] Preferably, the feed end of the feed pipe is funnel-shaped to match the output end of the discharge pipe.

[0012] Preferably, the second feed system includes a second feed pipe A, a second feed wheel group, and a second feed pipe B. The second feed wheel group is arranged between the second feed pipe A and the second feed pipe B. The second feed pipe A is coaxial with the second feed pipe B. The axis of the second feed wheel group is perpendicular to the axis of the second feed pipe A. The end of the second feed pipe B facing away from the second feed wheel group is connected to the feed end of the second heat dissipation system.

[0013] Preferably, the second feed wheel group includes a second feed wheel A and a second feed wheel B, the second feed wheel A and the second feed wheel B are both rotatably arranged on the front side of the back plate, the second feed motor is fixedly arranged on the back side of the back plate, a second gear A is coaxially arranged on the end face of the second feed wheel A, a second gear B is coaxially arranged on the end face of the second feed wheel B, the transmission ratios of the second gear A and the second gear B are equal, the second gear A and the second gear B are meshed, and the output shaft of the second feed motor is coaxially fixedly connected to the second gear B.

[0014] Preferably, a second mounting block is provided on the front side of the back plate on one side of the conveying direction of the second feeding system, and a second positioning axis of the back plate is perpendicular to the back plate on the other side of the conveying direction of the second feeding system on the front side of the back plate, the projection of a connecting line segment between the second positioning axis and the second mounting block in the conveying direction of the second feeding system is a line segment with a length, a second screw hole is provided on the second mounting block, the axis of the second screw hole is perpendicular to the conveying direction of the second feeding system, the axis of the second screw hole is parallel to the back plate, a second connecting rod is rotatably connected to the second positioning axis, a second axial hole is provided between the two ends of the second connecting rod, the second axial hole is sleeved on the axle of the second feeding wheel A, the other end of the second connecting rod is provided with a second through hole coaxial with the second screw hole, the inner diameter of the second through hole is larger than the inner diameter of the second screw hole, and the second extruder fixing knob passes through the second through hole from the side of the second connecting rod facing away from the second mounting block and is threadedly connected to the second screw hole.

[0015] Preferably, a material cutting device is also provided between the second material conveying pipe B and the feed end of the second heat dissipation system.

[0016] Preferably, the material cutting device includes a material cutting shell, a circular cavity, an arc-shaped blade, and a material channel. The material channel and the circular cavity are arranged in the material cutting shell, the material channel is coaxial with the second material conveying pipe B, the circular cavity is arranged between the two ends of the material channel, the axis of the circular cavity is perpendicular to the axis of the material channel, the arc-shaped blade is arranged in the circular cavity, the radius of the virtual circle where the outer arc surface of the arc-shaped blade is located is equal to the radius of the circular cavity, the outer arc surface of the arc-shaped blade is in sliding contact with the inner circumferential surface of the circular cavity, the curvature of the outer arc surface of the arc-shaped blade is less than π, the projection of the arc-shaped blade on a plane perpendicular to the axis of the material channel surrounds the projection of the material channel on a plane perpendicular to the axis of the material channel, the driving motor is arranged on the back side of the back plate, the output shaft of the driving motor passes through the circular cavity and is fixedly connected to the arc-shaped blade, the output shaft of the driving motor is coaxial with the virtual circle where the outer arc surface of the arc-shaped blade is located, one end of the material channel is connected with the output end of the second material conveying pipe B, and the other end of the material channel is connected with the feed end of the second heat dissipation system.

[0017] Preferably, the third heat dissipation system includes an annular air outlet duct, the air outlet end of the second fan is connected to the interior of the annular air outlet duct from the annular outer wall of the annular air outlet duct, an annular air outlet is coaxially provided on the annular inner wall of the annular air outlet duct, and the outlet of the nozzle is located in the ring of the annular air outlet duct.

[0018] Preferably, the first feed wheel group includes a first feed wheel A and a first feed wheel B, the first feed wheel A and the first feed wheel B are both rotatably arranged on the front side of the back plate, the first feed motor is fixedly arranged on the back side of the back plate, a first gear A is coaxially arranged on the end face of the first feed wheel A, a first gear B is coaxially arranged on the end face of the first feed wheel B, the transmission ratios of the first gear A and the first gear B are equal, the first gear A and the first gear B are meshed, and the output shaft of the first feed motor is coaxially fixedly connected to the first gear B.

[0019] Preferably, a first mounting block is provided on the front side of the back plate on one side of the conveying direction of the first feeding system, and a first positioning axis perpendicular to the back plate is provided on the front side of the back plate on the other side of the conveying direction of the first feeding system, the projection of a connecting line segment between the first positioning axis and the first mounting block in the conveying direction of the first feeding system is a line segment with a length, a first screw hole is provided on the first mounting block, the axis of the first screw hole is perpendicular to the conveying direction of the first feeding system, and the axis of the first screw hole is parallel to the back plate, a first connecting rod is rotatably connected to the first positioning axis, a first axial hole is provided between the two ends of the first connecting rod, the first axial hole is sleeved on the axle of the first feeding wheel A, the other end of the first connecting rod is provided with a first through hole coaxial with the first screw hole, the inner diameter of the first through hole is larger than the inner diameter of the first screw hole, and the first extruder fixing knob passes through the first through hole from the side of the first connecting rod facing away from the first mounting block and is threadedly connected to the first screw hole.

[0020] Preferably, the heat dissipation direction regulator includes a mounting frame, a rotation adjustment device, and a pitch adjustment device. The mounting frame is arranged on the whole composed of the first feeding system, the second feeding system, the heating output system and the nozzle. The mounting frame is located below the nozzle. A discharge gap is provided on the mounting frame directly below the nozzle. The rotation adjustment device is arranged on the mounting frame. The rotation axis of the rotation adjustment device is colinear with the axis of the output port of the nozzle. The pitch adjustment device is arranged on the execution end of the rotation adjustment device. The third heat dissipation system is fixedly arranged on the execution end of the pitch adjustment device.

[0021] Preferably, the rotation adjustment device includes an outer gear ring, a first rotating motor, and a pinion gear, the mounting frame is radially provided with a plurality of support rods, the gaps between the support rods constitute the discharge gap, an annular notch is coaxially provided on the inner circumferential surface of the outer gear ring, the ends of all the support rods facing away from the mounting frame are slidably connected to the notch, the outer gear ring is concentric with the nozzle, the first rotating motor is arranged on the mounting frame away from the support rod, the pinion gear is coaxially fixed on the output shaft of the first rotating motor, the pinion gear is meshed with the outer gear ring, at least one pitch adjustment device is arranged on the lower surface of the outer gear ring around the center of the outer gear ring, the output port of the third heat dissipation system faces the central axis of the outer gear ring, the central axis of the outer gear ring is perpendicular and passes through the area surrounded by a virtual triangle formed by the connecting line segments between the ends of the three support rods facing away from the mounting frame.

[0022] Preferably, the pitch adjustment device includes a second rotating motor, which is fixed on the lower surface of the outer ring gear, the output shaft of the second rotating motor is parallel to the lower surface of the outer ring gear, the output shaft of the second rotating motor is parallel to the tangent of the outer ring gear where the second rotating motor is installed, and the output shaft of the second rotating motor is fixedly connected to the third heat dissipation system.

[0023] Preferably, the third heat dissipation system is a fan.

[0024] A 3D printing method comprises the following steps:

[0025] 1) Installing the 3D print head of the dual extrusion system of claim 1 on a 3D printer;

[0026] 2) Initially importing the 3D model into the slicing software matched with the 3D printer;

[0027] 3) Using the editing function of the slicing software, editing a part of the area on the 3D model into a specified color;

[0028] 4) The slicing software uses path optimization calculation to specify the material to process the area of ​​the specified color, and other areas of unspecified color are processed with other materials;

[0029] 5) The result file processed by the slicing software is imported into the printer, and 3D printing is performed according to the set path, so as to achieve the effect of individually strengthening the specific area.

[0030] Compared with the prior art, the beneficial effects of this application are:

[0031] 1. This application adopts a third heat dissipation system in combination with a heat dissipation direction regulator to design a 3D print head with a dual extrusion system, which can accurately dissipate the heat of the material coming out of the nozzle, thereby avoiding the occurrence of wire drawing, and solving the problem that the heat dissipation device on the current 3D print head has poor heat dissipation effect for continuous fiber reinforced composite materials.

[0032] 2. In the present application, a preset gap is provided between the outer wall of the output end of the discharge pipe and the inner wall of the feed end of the material pipe, so that heat transfer between the feed pipe and the discharge pipe can be avoided without using a heat dissipation device such as a fan. Such a design reduces the use of components, simplifies the overall structure, and reduces the cost of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of this application;

[0034] Figure 2 yes Figure 1 The structural diagram of the lower middle part;

[0035] Figure 3 It is a diagram showing the relationship between the heating block, the feed pipe and the nozzle;

[0036] Figure 4 is a schematic diagram showing the first feeding wheel set and the second feeding wheel set of the present invention;

[0037] Figure 5 is a schematic diagram of the top of the second feeding system;

[0038] Figure 6 is a schematic diagram of the second feeding system;

[0039] Figure 7 It is a schematic diagram of the interruption device in this application;

[0040] Figure 8 yes Figure 1 The structural diagram at the bottom;

[0041] Fig. 9 This is a schematic structural diagram of a second implementation of the third heat dissipation system in this application;

[0042] Fig.10 For display Fig. 9 The structural diagram on the back;

[0043] Fig.11 for Fig. 9 The structural diagram at the bottom;

[0044] Fig.12 A diagram showing the relationship between the support rod and the nozzle in the second embodiment of the third heat dissipation system;

[0045] Fig.13 Flow chart of the 3D printing method in this application.

[0046] Among them, 1, back plate; 2, nozzle; 3, first fan; 4, second extruder fixing knob; 5, throat; 6, second feed pipe A; 7, second feed pipe B; 8, heating block; 9, linear feed cavity; 10, feed pipe; 11, discharge pipe; 12, first extruder fixing knob; 13, cone; 14, funnel; 15, second feed wheel A; 16, second feed wheel B; 17, second feed motor; 18, second gear A; 19, second gear B; 20, second mounting block; 21, second positioning shaft; 22, second screw hole; 23, second connecting rod; 24, second shaft hole; 25, second through hole; 26, second fan; 27, annular air outlet pipe; 28, annular Air outlet; 29, feed cutter; 30, circular cavity; 31, arc blade; 32, drive motor; 33, material channel; 34, first feed pipe A; 35, first feed pipe B; 36, first feed wheel A; 37, first feed wheel B; 38, first feed motor; 39, first gear A; 40, first gear B; 41, first mounting block; 42, first positioning shaft; 43, first screw hole; 44, first connecting rod; 45, first shaft hole; 46, first through hole; 47, mounting frame; 48, outer gear ring; 49, first rotating motor; 50, third heat dissipation system; 51, pinion; 52, notch; 53, support rod; 54, second rotating motor; 55, virtual triangle. DETAILED DESCRIPTION

[0047] like Figure 1-13 As shown, it includes a first feeding system, a second feeding system, a heating output system, and a nozzle 2. The output end of the first feeding system and the output end of the second feeding system are connected to the feed end of the heating output system through a first heat dissipation system and a second heat dissipation system respectively. The nozzle 2 is arranged at the discharge end of the heating output system. The angle between the output direction of the first feeding system and the output direction of the second feeding system is less than 90 degrees. A third heat dissipation system 50 is arranged at the nozzle 2, or a third heat dissipation system 50 matched with the output port of the nozzle 2 is arranged through a heat dissipation direction regulator.

[0048] In this embodiment, when in use, the relative position relationship between the first feeding system, the second feeding system, the heating output system, the nozzle 2, and the third heat dissipation system can be fixed by the back plate 1, that is, the first feeding system, the second feeding system, the heating output system, the nozzle 2, the heat dissipation direction regulator, and the third heat dissipation system are all fixedly installed on the front side of the back plate 1, and then the back plate 1 is installed on the execution end of the 3D printer, and then the resin material is transported through the first feeding system, and the continuous fiber composite consumables are transported by the second feeding system. The resin material and the continuous fiber composite consumables are heated and melted in the heating output system, and the formed composite material flows out of the nozzle 2. The composite material extruded from the nozzle 2 is stacked into the shape of the product preset in the 3D printer under the movement of the execution end of the 3D printer; due to the first feeding system The system, the second feeding system, the heating output system, and the nozzle 2 are all arranged on the front of the back plate 1. Therefore, the structure of the present application is relatively simple, the space occupied is relatively small, and it is also very convenient to install and disassemble. It is only necessary to install the back plate 1 on the execution end of the 3D printer; the setting of the third heat dissipation system prompts the material to cool down quickly after coming out of the nozzle 2, thereby avoiding the occurrence of wire drawing, and the third heat dissipation system can include a heat dissipation direction regulator for adjusting the heat dissipation direction of the third heat dissipation system. For example, if the third heat dissipation system is a fan, the heat dissipation direction is the air outlet direction. If the third heat dissipation system is a coolant, the heat dissipation direction is the direction of spraying the coolant; the setting of the first heat dissipation system and the second heat dissipation system is to prevent heat from being transferred along the resin material or the continuous fiber composite consumables so that the consumables are bonded during the feeding process. Of course, if the third heat dissipation direction regulator is not used and the third heat dissipation system is directly installed, due to the presence of three heat dissipation systems, the effect of precise heat dissipation is also achieved, but compared with the way the third heat dissipation system cooperates with the heat dissipation direction regulator, its accuracy is relatively low.

[0049] As a preferred method, Figure 2 , Figure 3As shown, the heating output system includes a heating block 8, a linear feed cavity 9, and a feed pipe 10. The linear feed cavity 9 is arranged in the heating block 8, the inner diameter of the linear feed cavity 9 is larger than the outer diameter of the feed pipe 10, one end of the feed pipe 10 is coaxially inserted into the linear feed cavity 9, a preset gap is set between the end of the feed pipe 10 inserted into the linear feed cavity 9 and the end of the linear feed cavity 9 facing away from the feed pipe 10, the nozzle 2 is arranged on the end of the heating block 8 facing away from the feed pipe 10, the nozzle 2 is coaxially connected to the end of the linear feed cavity 9 facing away from the feed pipe 10, the discharge end of the second heat dissipation system is connected to the input end of the feed pipe 10, the discharge end of the first heat dissipation system is connected to the side wall of the linear feed cavity 9, and the distance from the output end of the first feed system to the nozzle 2 is larger than the distance from the output end of the feed pipe 10 to the nozzle 2. After such design, the continuous fiber composite material input from the second feeding system enters vertically into the linear feeding cavity 9 from the feeding pipe 10, while the resin material input from the first feeding system enters into the linear feeding cavity 9 from the side wall of the linear feeding cavity 9 and is wrapped around the surface of the continuous fiber composite material input from the second feeding system. In this way, the entire 3D printing uses the continuous fiber material as the skeleton and the resin material as the filler. Under the extrusion pressure of the continuously input resin material, the resin material is wrapped around the fiber bundle and extruded together through the nozzle 2. Under the control of the 3D printer, 3D printing of the composite material is realized.

[0050] As a preferred mode, the first heat dissipation system comprises a first fan 2, a heat sink, and a throat 5. The output end of the first feeding system is coaxially connected to one end of the throat 5, and the other end of the throat 5 is connected to the feed end of the heating output system. A plurality of heat sinks 4 are radially arranged on the outer surface between the two ends of the throat 5. The first fan 3 is installed on all the heat sinks 4, and the air inlet of the first fan 3 faces the heat sink 4. In this way, the heat dissipation effect is improved by the combination of the first fan 2 and the heat sink 4.

[0051] As a preferred embodiment, the first feed system includes a first feed pipe A34, a first feed wheel group, and a first feed pipe B35. The first feed wheel group is arranged between the first feed pipe A34 and the first feed pipe B35. The first feed pipe A34 is coaxial with the first feed pipe B35. The axis of the first feed wheel group is perpendicular to the axis of the first feed pipe A34. The end of the first feed pipe B35 facing away from the first feed wheel group is connected to the feed end of the first heat dissipation system.

[0052] As a preferred mode, the second heat dissipation system includes a discharge pipe 11, the output end of the discharge pipe 11 is a cone 13, the discharge pipe 11 is coaxial with the feed pipe 10, the input end of the discharge pipe 11 is connected to the output end of the second feeding system, the output end of the discharge pipe 11 extends into the feed end of the feed pipe 10, a preset gap is provided between the output end of the feed pipe 10 and the inner wall of the linear feed cavity 9, and a preset gap is provided between the outer wall of the output end of the discharge pipe 11 and the inner wall of the feed end of the feed pipe 10. After such a setting, heat transfer between the feed pipe 10 and the discharge pipe 11 can be avoided without using a heat dissipation device such as a fan. Such a design reduces the use of components, simplifies the overall structure, and reduces the cost.

[0053] As a preferred mode, the feed end of the feed pipe 10 is funnel-shaped 14, that is, open-mouthed, which matches the output end of the discharge pipe 11, and the inner diameter of the end of the feed pipe 10 facing the discharge pipe 11 is larger than the inner diameter of the end of the feed pipe 10 facing away from the discharge pipe 11. This arrangement facilitates the material transported by the second feeding system to enter the feed pipe 10.

[0054] As a preferred embodiment, the second feed system includes a second feed pipe A6, a second feed wheel group, and a second feed pipe B7. The second feed wheel group is arranged between the second feed pipe A6 and the second feed pipe B7. The second feed pipe A6 is coaxial with the second feed pipe B7. The axis of the second feed wheel group is perpendicular to the axis of the second feed pipe A6. The end of the second feed pipe B7 facing away from the second feed wheel group is connected to the feed end of the second heat dissipation system.

[0055] As a preferred mode, the second feed wheel group includes a second feed wheel A15 and a second feed wheel B16, the second feed wheel A15 and the second feed wheel B16 are both rotatably arranged on the front side of the back plate 1, the second feed motor 17 is fixedly arranged on the back side of the back plate 1, the second feed wheel A15 is coaxially provided with a second gear A18 on the end face, the second feed wheel B16 is coaxially provided with a second gear B19 on the end face, the second gear A18 and the second gear B19 have the same transmission ratio, the second gear A18 and the second gear B19 are meshed, and the output shaft of the second feed motor 17 is coaxially fixedly connected to the second gear B19. With this design, the second feed motor 17 drives the second feed wheel A15 and the second feed wheel B16 at the same time to transport the fiber composite material.

[0056] As a preferred embodiment, a second mounting block 20 is provided on the front side of the back plate 1 on one side of the conveying direction of the second material conveying system, a second positioning axis 21 is perpendicular to the back plate 1 on the front side of the back plate 1 on the other side of the conveying direction of the second material conveying system, the projection of the connecting line segment between the second positioning axis 21 and the second mounting block 20 in the conveying direction of the second material conveying system is a line segment with a length, a second screw hole 22 is provided on the second mounting block 20, the axis of the second screw hole 22 is perpendicular to the conveying direction of the second material conveying system, and the axis of the second screw hole 22 is perpendicular to the conveying direction of the second material conveying system. Parallel to the back plate 1, the second positioning shaft 21 is rotatably connected with a second connecting rod 23, a second axial hole 24 is provided between the two ends of the second connecting rod 23, the second axial hole 24 is sleeved on the axle of the second feed wheel A15, the other end of the second connecting rod 23 is provided with a second through hole 25 coaxial with the second screw hole 22, the inner diameter of the second through hole 25 is larger than the inner diameter of the second screw hole 22, and the second extruder fixing knob 4 passes through the second through hole 25 from the side of the second connecting rod 23 facing away from the second mounting block 20 and is threadedly connected with the second screw hole 22. After such a setting, the second extruder fixing knob 4 can be screwed into the length of the second screw hole 22 to drive the second connecting rod 23 to squeeze the axle of the second feed wheel A15, which plays the role of a brake, thereby adjusting the extrusion force of the second feed system, and is suitable for consumables of different diameters, improving the wire feeding effect of the feed system, and avoiding slipping.

[0057] As a preferred embodiment, a first mounting block 41 is provided on the front side of the back plate 1 on the side of the conveying direction of the first material conveying system, and a first positioning axis 42 perpendicular to the back plate 1 is provided on the front side of the back plate 1 on the other side of the conveying direction of the first material conveying system, and the projection of the connecting line segment between the first positioning axis 42 and the first mounting block 41 in the conveying direction of the first material conveying system is a line segment with a length, and a first screw hole 43 is provided on the first mounting block 41, and the axis of the first screw hole 43 is perpendicular to the conveying direction of the first material conveying system, and the axis of the first screw hole 43 is perpendicular to the conveying direction of the first material conveying system. The line is parallel to the back plate 1, and the first positioning shaft 42 is rotatably connected to the first connecting rod 44, and a first axial hole 45 is provided between the two ends of the first connecting rod 44, and the first axial hole 45 is sleeved on the axle of the first feed wheel A36, and the other end of the first connecting rod 44 is provided with a first through hole 46 coaxial with the first screw hole 43, and the inner diameter of the first through hole 46 is larger than the inner diameter of the first screw hole 43, and the first extruder fixing knob 43 passes through the first through hole 46 from the side of the first connecting rod 44 facing away from the first mounting block 41 and is threadedly connected with the first screw hole 43.

[0058] As a preferred embodiment, a material cutting device is further provided between the second material conveying pipe B7 and the feeding end of the second heat dissipation system.

[0059] As a preferred method, Figure 7 As shown, the material cutting device includes a material cutting shell 29, a circular cavity 30, an arc-shaped blade 31, and a material channel 33. The material channel 33 and the circular cavity 30 are arranged in the material cutting shell 29. The material channel 33 is coaxial with the second material conveying pipe B7. The circular cavity 30 is arranged between the two ends of the material channel 33. The axis of the circular cavity 30 is perpendicular to the axis of the material channel 33. The arc-shaped blade 31 is arranged in the circular cavity 30. The radius of the virtual circle where the outer arc surface of the arc-shaped blade 31 is located is equal to the radius of the circular cavity 30. The outer arc surface of the arc-shaped blade 31 is in sliding contact with the inner circumferential surface of the circular cavity 30. The curvature of the outer arc surface of the arc-shaped blade 31 is less than π, the projection of the arc blade 31 on a plane perpendicular to the axis of the material channel 33 surrounds the projection of the material channel 33 on a plane perpendicular to the axis of the material channel 33, the width of the arc blade 31 is equal to the length of the circular cavity 30, the drive motor 32 is arranged on the back of the back plate 1, the output shaft of the drive motor 32 penetrates into the circular cavity 30 and is fixedly connected to the arc blade 31, the output shaft of the drive motor 32 is coaxial with the virtual circle where the outer arc surface of the arc blade 31 is located, one end of the material channel 33 is connected to the output end of the second material delivery pipe B7, and the other end of the material channel 33 is connected to the feed end of the second heat dissipation system. The drive motor 32 drives the arc blade 31 to rotate and cut off the continuous fiber composite consumables, so that the material is cut off, and the remaining consumables continue to be printed. At the same time, due to the setting of the arc blade 31, the arc blade 31 can prevent the fiber composite consumables located in the second material delivery pipe B7 from continuing to enter the second heat dissipation system after cutting off the fiber composite consumables.

[0060] As a preferred embodiment, the second feed system includes a second feed pipe A6, a second feed wheel group, and a second feed pipe B7. The second feed wheel group is arranged between the second feed pipe A6 and the second feed pipe B7. The second feed pipe A6 is coaxial with the second feed pipe B7. The axis of the second feed wheel group is perpendicular to the axis of the second feed pipe A6. The end of the second feed pipe B7 facing away from the second feed wheel group is connected to the feed end of the second heat dissipation system.

[0061] As a preferred embodiment, the third heat dissipation system has two implementation modes:

[0062] The first implementation method:

[0063] like Figure 1 , Figure 2 , Figure 8As shown, the third heat dissipation system includes an annular air outlet pipe 27, the air outlet end of the second fan 26 is connected to the inside of the annular air outlet pipe 27 from the annular outer wall of the annular air outlet pipe 27, an annular air outlet 28 is coaxially arranged on the annular inner wall of the annular air outlet pipe 27, and the outlet of the nozzle 2 is located in the annular shape of the annular air outlet pipe 27. With this design, the third heat dissipation system can dissipate the heat of the material flowing out of the nozzle 2 more thoroughly.

[0064] The second implementation of the third heat dissipation system:

[0065] The third heat dissipation system includes a fan,

[0066] like Fig. 9 , Fig.10 , Fig.11 As shown, the heat dissipation direction regulator includes a mounting frame 47, a rotation adjustment device, and a pitch adjustment device. The mounting frame 47 is arranged on the whole composed of the first feeding system, the second feeding system, the heating output system and the nozzle 2. The mounting frame 47 is located below the nozzle 2. The mounting frame 47 is provided with a discharge gap just below the nozzle 2. The rotation adjustment device is arranged on the mounting frame 47. The rotation axis of the rotation adjustment device is parallel to the axis of the output port of the nozzle 2. The pitch adjustment device is arranged on the execution end of the rotation adjustment device. The third heat dissipation system is fixedly arranged on the execution end of the pitch adjustment device.

[0067] As a preferred embodiment, the rotation adjustment device includes an outer gear ring 48, a first rotating motor, and a pinion 51. A plurality of support rods 53 are radially arranged on the mounting frame 47 (preferably three support rods 53, so that the material for making the mounting frame 47 can be saved as much as possible while ensuring that the outer gear ring 48 can rotate stably, thereby saving manufacturing costs). The gaps between the support rods 53 constitute the discharge gap. An annular notch 52 is coaxially arranged on the inner circumferential surface of the outer gear ring 48. The ends of all the support rods 53 facing away from the mounting frame 47 are slidably connected to the notch 52. The outer gear ring 48 and the first rotating motor 51 are slidably connected to the notch 52. The nozzle 2 is concentric, the first rotating motor 49 is arranged on the mounting frame 47 away from the supporting rod 53, the pinion 51 is coaxially fixedly arranged on the output shaft of the first rotating motor 49, the pinion 51 is meshed with the outer gear ring 48, and at least one pitch adjustment device is arranged on the lower surface of the outer gear ring 48 around the center of the outer gear ring 48, the output port of the third heat dissipation system 50 faces the central axis of the outer gear ring 48, and the central axis of the outer gear ring 48 is perpendicular to and passes through the area surrounded by the virtual triangle 55 formed by the connecting line segments between the ends of the three supporting rods 53 facing away from the mounting frame 47.

[0068] As a preferred embodiment, the pitch adjustment device includes a second rotating motor 54, which is fixed on the lower surface of the outer ring gear 48, the output shaft of the second rotating motor 54 is parallel to the lower surface of the outer ring gear 48, the output shaft of the second rotating motor 54 is parallel to the tangent of the outer ring gear 48 where the second rotating motor 54 is installed, and the output shaft of the second rotating motor 54 is fixedly connected to the third heat dissipation system 50.

[0069] After such arrangement, the pinion 51 is driven to rotate by the first rotating motor 49, and then the outer gear ring 48 is driven to rotate, so that the heat dissipation module 50 installed on the outer gear ring 48 can rotate around the axis of the nozzle 2 to dissipate heat for the material coming out of the nozzle 2, thereby achieving a better heat dissipation effect. The heat dissipation module 50 may include a compressor and a vortex tube or an AC air conditioner and an electrical proportional valve, so that the heat dissipation fluid compressed air, liquid, and liquid nitrogen with controllable temperature and flow rate are output from the heat dissipation module 50. The arrangement of the three support rods 53 allows the outer gear ring 48 to be installed below the nozzle 2, and the arrangement of the outer gear ring 48 will not affect the nozzle 2 from ejecting printing materials; of course, if Fig.12 As shown, a roller may be provided at the end of the support rod 23 facing away from the mounting frame 47, which is shown in the figure but not numbered, so that the outer gear ring 48 can be rotated better. The central axis of the outer gear ring 48 is vertical and passes through the area surrounded by the virtual triangle 55 formed by the connecting line segments between the ends of the three support rods 53 facing away from the mounting frame 47, mainly to enable the outer gear ring 48 to be stably installed on the structure formed by the three support rods 23. Of course, the support rod 53 is detachably connected to the mounting frame 47, which is convenient for installing the outer gear ring 48.

[0070] In addition, the second rotating motor 54 drives the heat dissipation module 50 to change its pitch angle. Cooperating with the setting of the first rotating motor 49, the rotation direction of the heat dissipation module 50 can be adjusted in real time according to the printing path of the print head, and the air duct direction of the heat dissipation module 50 is positively aligned with the fiber printing direction, thereby achieving the best heat dissipation effect.

[0071] As a preferred manner, in order to reduce costs, the heat dissipation module 50 may also be a fan.

[0072] A 3D printing method comprises the following steps:

[0073] 1) Installing the 3D print head of the dual extrusion system of claim 1 on a 3D printer;

[0074] 2) Initially importing the 3D model into the slicing software matched with the 3D printer;

[0075] 3) Using the editing function of the slicing software, editing a part of the area on the 3D model into a specified color;

[0076] 4) The slicing software uses path optimization calculation to specify the material to process the area of ​​the specified color, and other areas of unspecified color are processed with other materials;

[0077] 5) The result file processed by the slicing software is imported into the printer, and 3D printing is performed according to the set path, so as to achieve the effect of individually strengthening the specific area.

[0078] Because for reinforced fiber filaments, fiber volume fraction and distribution are two key factors that affect printing quality and final structural performance. Therefore, through customized slicing software, the model coloring function module is used in the software for simple operation. The user uses the mouse to color the area of ​​the specified color of the specified model. The slicing software automatically calculates the slice contour of the area of ​​the specified color based on the area of ​​the specified color, and performs a separate enhancement process on the contour area, that is, using the specified continuous fiber material, and performing fiber filling according to the specified reinforcement filling scheme, and finally generating the specified operation G code. The G code includes the operation of switching the extruder head, continuous fiber laying and cutting operations, path optimization, and flow control, so that the printing device can perform fiber laying operations on the area of ​​the specified color.

Claims

1. A 3D printing head with a dual extrusion system, characterized in that: The invention comprises a first feeding system, a second feeding system, a heating output system, and a nozzle (2); the output end of the first feeding system and the output end of the second feeding system are connected to the feed end of the heating output system via a first heat dissipation system and a second heat dissipation system respectively; the nozzle (2) is arranged at the discharge end of the heating output system; the angle between the output direction of the first feeding system and the output direction of the second feeding system is less than 90 degrees; a third heat dissipation system (50) is arranged at the nozzle (2) or a third heat dissipation system (50) matched with the output port of the nozzle (2) is arranged via a heat dissipation direction regulator.

2. The 3D printing head of a dual extrusion system according to claim 1, characterized in that: The heating output system comprises a heating block (8), a linear feed cavity (9), and a feed pipe (10). The linear feed cavity (9) is arranged in the heating block (8). The inner diameter of the linear feed cavity (9) is larger than the outer diameter of the feed pipe (10). One end of the feed pipe (10) is coaxially inserted into the linear feed cavity (9). A gap is preset between the end of the feed pipe (10) inserted into the linear feed cavity (9) and the end of the linear feed cavity (9) facing away from the feed pipe (10). The nozzle (2) is arranged on the end of the heating block (8) facing away from the feed pipe (10). The nozzle (2) is coaxially connected to the end of the linear feed cavity (9) facing away from the feed pipe (10). The discharge end of the second heat dissipation system is connected to the input end of the feed pipe (10). The discharge end of the first heat dissipation system is communicated with the side wall of the linear feed cavity (9).

3. The 3D printing head of a dual extrusion system according to claim 1, characterized in that: The first heat dissipation system comprises a first fan (2), a heat sink, and a throat (5); the output end of the first feeding system is coaxially connected to one end of the throat (5), and the other end of the throat (5) is connected to the feed end of the heating output system; a heat sink is provided on the throat (5), the heat sink is provided on the heat sink, and the first fan (3) is installed on the heat sink.

4. The 3D printing head of a dual extrusion system according to claim 1, characterized in that: The first material conveying system comprises a first material conveying pipe A (34), a first material conveying wheel group, and a first material conveying pipe B (35). The first material conveying wheel group is arranged between the first material conveying pipe A (34) and the first material conveying pipe B (35). The first material conveying pipe A (34) and the first material conveying pipe B (35) are coaxial. The axis of the first material conveying wheel group is perpendicular to the axis of the first material conveying pipe A (34). The end of the first material conveying pipe B (35) facing away from the first material conveying wheel group is connected to the feed end of the first heat dissipation system.

5. The 3D printing head of a dual extrusion system according to claim 2, characterized in that: The second heat dissipation system comprises a discharge pipe (11), the output end of the discharge pipe (11) is tapered (13), the discharge pipe (11) is coaxial with the feed pipe (10), the input end of the discharge pipe (11) is connected to the output end of the second feeding system, the output end of the discharge pipe (11) extends into the feed end of the feed pipe (10), a gap is preset between the output end of the feed pipe (10) and the inner wall of the linear feed cavity (9), and a gap is preset between the outer wall of the output end of the discharge pipe (11) and the inner wall of the feed cavity of the feed pipe (10).

6. The 3D printing head of a dual extrusion system according to claim 5, characterized in that: The feed end of the feed pipe (10) is in the shape of a funnel (14) that matches the output end of the discharge pipe (11).

7. The 3D printing head of a dual extrusion system according to claim 1, characterized in that: The second material conveying system comprises a second material conveying pipe A (6), a second material conveying wheel group, and a second material conveying pipe B (7). The second material conveying wheel group is arranged between the second material conveying pipe A (6) and the second material conveying pipe B (7). The second material conveying pipe A (6) and the second material conveying pipe B (7) are coaxial. The axis of the second material conveying wheel group is perpendicular to the axis of the second material conveying pipe A (6). The end of the second material conveying pipe B (7) facing away from the second material conveying wheel group is connected to the feed end of the second heat dissipation system.

8. The 3D printing head of the dual extrusion system according to claim 7, characterized in that: The second feed wheel assembly comprises a second feed wheel A (15) and a second feed wheel B (16). The second feed wheel A (15) and the second feed wheel B (16) are both rotatably arranged on the front side of the back plate (1). The second feed motor (17) is fixedly arranged on the back side of the back plate (1). A second gear A (18) is coaxially arranged on the end face of the second feed wheel A (15). A second gear B (19) is coaxially arranged on the end face of the second feed wheel B (16). The transmission ratios of the second gear A (18) and the second gear B (19) are equal. The second gear A (18) and the second gear B (19) are meshed. The output shaft of the second feed motor (17) is coaxially fixedly connected to the second gear B (19).

9. The 3D printing head of the dual extrusion system according to claim 8, characterized in that: A second mounting block (20) is provided on the front side of the back plate (1) on one side of the conveying direction of the second material conveying system, a second positioning axis (21) perpendicular to the back plate (1) is provided on the front side of the back plate (1) on the other side of the conveying direction of the second material conveying system, a connecting line segment between the second positioning axis (21) and the second mounting block (20) is projected as a line segment having a length in the conveying direction of the second material conveying system, a second screw hole (22) is provided on the second mounting block (20), an axis of the second screw hole (22) is perpendicular to the conveying direction of the second material conveying system, and an axis of the second screw hole (22) is parallel to the back plate (1), A second connecting rod (23) is rotatably connected to the second positioning shaft (21), a second axial hole (24) is provided between the two ends of the second connecting rod (23), the second axial hole (24) is sleeved on the axle of the second feed wheel A (15), the other end of the second connecting rod (23) is provided with a second through hole (25) coaxial with the second screw hole (22), the inner diameter of the second through hole (25) is larger than the inner diameter of the second screw hole (22), and the second extruder fixing knob (4) passes through the second through hole (25) from the side of the second connecting rod (23) facing away from the second mounting block (20) and is threadedly connected to the second screw hole (22).

10. The 3D printing head of the dual extrusion system according to claim 7, characterized in that: A material cutting device is also provided between the second material conveying pipe B (7) and the feeding end of the second heat dissipation system.

11. The 3D printing head of the dual extrusion system according to claim 10, characterized in that: The material cutting device comprises a material cutting shell (29), a circular cavity (30), an arc-shaped blade (31), and a material channel (33). The material channel (33) and the circular cavity (30) are arranged in the material cutting shell (29). The material channel (33) is coaxial with the second material conveying pipe B (7). The circular cavity (30) is arranged between the two ends of the material channel (33). The axis of the circular cavity (30) is perpendicular to the axis of the material channel (33). The arc-shaped blade (31) is arranged in the circular cavity (30). The radius of the virtual circle where the outer arc surface of the arc-shaped blade (31) is located is equal to the radius of the circular cavity (30). The outer arc surface of the arc-shaped blade (31) is in sliding contact with the inner circumferential surface of the circular cavity (30). The curvature of the outer curved surface of the curved blade (31) is less than π, the projection of the curved blade (31) on a plane perpendicular to the axis of the material channel (33) surrounds the projection of the material channel (33) on a plane perpendicular to the axis of the material channel (33), the drive motor (32) is arranged on the back side of the back plate (1), the output shaft of the drive motor (32) penetrates into the circular cavity (30) and is fixedly connected to the curved blade (31), the output shaft of the drive motor (32) is coaxial with the virtual circle where the outer curved surface of the curved blade (31) is located, one end of the material channel (33) is connected to the output end of the second material delivery pipe B (7), and the other end of the material channel (33) is connected to the feed end of the second heat dissipation system.

12. The 3D printing head of a dual extrusion system according to claim 1, characterized in that: The third heat dissipation system comprises an annular air outlet pipe (27), the air outlet end of the second fan (26) is connected to the interior of the annular air outlet pipe (27) from the annular outer wall of the annular air outlet pipe (27), an annular air outlet (28) is coaxially provided on the annular inner wall of the annular air outlet pipe (27), and the outlet of the nozzle (2) is located in the ring of the annular air outlet pipe (27).

13. The 3D printing head of a dual extrusion system according to claim 5, characterized in that: The first feed wheel assembly comprises a first feed wheel A (36) and a first feed wheel B (37). The first feed wheel A (36) and the first feed wheel B (37) are both rotatably arranged on the front side of the back plate (1). The first feed motor (38) is fixedly arranged on the back side of the back plate (1). A first gear A (39) is coaxially arranged on the end face of the first feed wheel A (36). A first gear B (40) is coaxially arranged on the end face of the first feed wheel B (37). The transmission ratios of the first gear A (39) and the first gear B (40) are equal. The first gear A (39) and the first gear B (40) are meshed. The output shaft of the first feed motor (38) is coaxially fixedly connected to the first gear B (40).

14. The 3D printing head of the dual extrusion system according to claim 13, characterized in that: A first mounting block (41) is provided on the front side of the back plate (1) on one side of the conveying direction of the first material conveying system, and a first positioning axis (42) perpendicular to the back plate (1) is provided on the front side of the back plate (1) on the other side of the conveying direction of the first material conveying system, the projection of a connecting line segment between the first positioning axis (42) and the first mounting block (41) in the conveying direction of the first material conveying system is a line segment with a length, and a first screw hole (43) is provided on the first mounting block (41), the axis of the first screw hole (43) is perpendicular to the conveying direction of the first material conveying system, and the axis of the first screw hole (43) is parallel to the back plate (1). A first connecting rod (44) is rotatably connected to the first positioning shaft (42), a first axial hole (45) is provided between the two ends of the first connecting rod (44), the first axial hole (45) is sleeved on the axle of the first feeding wheel A (36), the other end of the first connecting rod (44) is provided with a first through hole (46) coaxial with the first screw hole (43), the inner diameter of the first through hole (46) is larger than the inner diameter of the first screw hole (43), the first extruder fixing knob (43) passes through the first through hole (46) from the side of the first connecting rod (44) facing away from the first mounting block (41) and is threadedly connected to the first screw hole (43).

15. The 3D printing head of a dual extrusion system according to claim 1, characterized in that: The heat dissipation direction regulator comprises a mounting frame (47), a rotation adjustment device, and a pitch adjustment device. The mounting frame (47) is arranged on the whole composed of the first feeding system, the second feeding system, the heating output system and the nozzle (2). The mounting frame (47) is located below the nozzle (2). A discharge gap is arranged on the mounting frame (47) just below the nozzle (2). The rotation adjustment device is arranged on the mounting frame (47). The rotation axis of the rotation adjustment device is colinear with the axis of the output port of the nozzle (2). The pitch adjustment device is arranged on the execution end of the rotation adjustment device. The third heat dissipation system (50) is fixedly arranged on the execution end of the pitch adjustment device.

16. The 3D printing head of the dual extrusion system according to claim 15, characterized in that: The rotation adjustment device comprises an outer gear ring (48), a first rotating motor, and a pinion (51); a plurality of support rods (53) are radially arranged on the mounting frame (47); the gaps between the support rods (53) constitute the discharge gap; an annular notch (52) is coaxially arranged on the inner circumferential surface of the outer gear ring (48); the ends of all the support rods (53) facing away from the mounting frame (47) are slidably connected to the notch (52); the outer gear ring (48) is concentric with the nozzle (2); the first rotating motor is arranged on the mounting frame (47) at a position away from the support rods (53); The first rotating motor (49) comprises a pinion (51) coaxially fixedly arranged on the output shaft of the first rotating motor (49), the pinion (51) meshing with the outer gear ring (48), at least one pitch adjustment device being arranged on the lower surface of the outer gear ring (48) around the center of the outer gear ring (48), the output port of the third heat dissipation system (50) facing the central axis of the outer gear ring (48), the central axis of the outer gear ring (48) being perpendicular to and passing through the area enclosed by the virtual triangle (55) formed by the connecting line segments between the ends of the three support rods (53) facing away from the mounting frame (47).

17. The 3D printing head of the dual extrusion system according to claim 16, characterized in that: The pitch adjustment device comprises a second rotating motor (54), the second rotating motor (54) is fixedly arranged on the lower surface of the outer gear ring (48), the output shaft of the second rotating motor (54) is parallel to the lower surface of the outer gear ring (48), the output shaft of the second rotating motor (54) is parallel to the tangent of the outer gear ring (48) where the second rotating motor (54) is installed, and the output shaft of the second rotating motor (54) is fixedly connected to the third heat dissipation system (50).

18. The 3D printing head of a dual extrusion system according to claim 15, characterized in that: The third heat dissipation system (50) is a fan.

19. A 3D printing method, characterized in that: The steps include: 1) Installing the 3D print head of the dual extrusion system of claim 1 on a 3D printer; 2) Initially importing the 3D model into the slicing software matched with the 3D printer; 3) Using the editing function of the slicing software, editing a part of the area on the 3D model into a specified color; 4) The slicing software uses path optimization calculation to specify the material to process the area of ​​the specified color, and other areas of unspecified color are processed with other materials; 5) The result file processed by the slicing software is imported into the printer, and 3D printing is performed according to the set path, so as to achieve the effect of individually strengthening the specific area.

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