3D printing device and method for heterogeneous continuous fiber reinforced composite material

Abstract

The invention provides a 3D printing device and method for a heterogeneous continuous fiber reinforced composite material. The 3D printing device comprises a rack, a moving mechanism, a printing head assembly, a wire feeding assembly and a control device. A printing platform is arranged on the rack; the moving mechanism is mounted on the rack; the printing head assembly comprises a machining head and a heating block, and the machining head is connected with the moving mechanism; the machining head is provided with a first wire outlet hole and at least one side hole for wires to enter, and the wires entering the side holes all penetrate out of the first wire outlet hole. The heating block is connected with the processing head; the wire feeding assembly comprises a wire feeding disc, a wire feeding support, a wire feeding motor and a guide pipe. The wire feeding disc is rotationally installed on the rack. The wire feeding bracket is connected with the moving mechanism; the wire feeding motor is mounted on the wire feeding bracket; the guide pipe is installed on the wire feeding support. By means of the device, synchronous melting and compacting of the wire can be achieved, the phenomena that a machining head is blocked and the wire is broken are avoided, and the additive manufacturing process is more continuous and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a 3D printing device and process for a heterogeneous continuous fiber reinforced composite material. Background Art

[0002] Fiber-reinforced polymer composites have many advantages such as high specific strength, high specific stiffness, and strong designability. They are widely used in aerospace, transportation equipment, energy equipment, sports equipment and other fields. 3D printing is an emerging technology that constructs three-dimensional objects through layered slicing and layered deposition of materials. 3D printing technology has a wide range of applications in aerospace, rail transportation, electronics and biomedicine. Through 3D printing technology, a variety of heterogeneous continuous fibers can be printed and manufactured simultaneously, which can significantly improve the durability of composite materials and improve the mechanical properties of components. In the 3D printing process, the fused filament fabrication (FFF) process has the characteristics of moldless molding, strong designability, rapid prototyping, and low cost, which further expands the application range of continuous fiber reinforced composite materials.

[0003] The current mainstream FFF technology is to feed the wire into a closed print head, heat and melt it inside, and then extrude it. In this forming method, the wire is heated and melted inside the print head, and the temperature drops when it is extruded to the outlet, and the extruded material is partially solidified, which can easily cause the extrusion outlet to be blocked, thereby reducing the forming accuracy or even making it impossible to form; only a single specification of wire can be fed in, and the wire feeding position is not stable enough, which affects the manufacturing accuracy and forming process. Summary of the invention

[0004] In view of this, the present invention proposes a 3D printing device and method for heterogeneous continuous fiber reinforced composite materials to solve the technical problem proposed in the above-mentioned background technology that the filament is heated and melted inside the print head, the temperature decreases when extruded to the outlet, and the extruded material is partially solidified, which easily causes the extrusion port to be blocked, thereby reducing the forming accuracy or even making it impossible to form.

[0005] The technical solution of the present invention is achieved in this way: In a first aspect, the present invention provides a 3D printing device for heterogeneous continuous fiber reinforced composite materials, comprising a frame, a moving mechanism, a print head assembly, a wire feeding assembly and a control device, wherein: A printing platform is provided on the frame, and the printing platform is equipped with a preheating device; The moving mechanism is installed on the frame; The printing head assembly comprises a processing head and a heating block, wherein the processing head is connected to the moving mechanism; the processing head is provided with a first wire outlet hole and at least one side hole for wire material to enter, the first wire outlet hole is located on the bottom surface of the processing head, and the wire materials entering the plurality of side holes all pass through the first wire outlet hole; the heating block is connected to the processing head, and is used to heat the processing head and the wire material when the processing head presses the wire material passing through the first wire outlet hole onto the printing platform or the deposited layer; The wire feeding assembly comprises a wire feeding disc, a wire feeding bracket, a wire feeding motor and a guide tube, wherein the wire feeding disc is rotatably mounted on the frame; the wire feeding bracket is connected to the moving mechanism; the wire feeding motor is mounted on the wire feeding bracket and is used to drive the wire on the wire feeding disc to move into the guide tube; the guide tube is mounted on the wire feeding bracket and is used to guide the wire into the side hole and the first wire outlet hole in sequence; The control device is connected with the moving mechanism, the heating block and the wire feeding motor by electrical signals.

[0006] On the basis of the above technical solution, preferably, the moving mechanism includes a connecting plate, a moving base and a moving unit, the connecting plate is respectively connected to the processing head and the wire feeding bracket, and the moving base is respectively connected to the moving unit and the connecting plate, so as to drive the connecting plate to move with multiple degrees of freedom under the drive of the mobile unit.

[0007] On the basis of the above technical solution, preferably, the mobile unit includes an X-axis, a Y-axis, a Z-axis and three driving members, the X-axis and the Y-axis are slidably arranged on the frame, the Z-axis is respectively connected to the motion base and the connecting plate, the motion base is slidably installed on the X-axis and the Y-axis, and the three driving members are installed on the motion base, and are respectively used to drive the motion base to move along the X-axis and the Y-axis and the connecting plate to move along the Z-axis.

[0008] On the basis of the above technical solution, preferably, the mobile unit adopts a robotic arm or a five-axis machine tool.

[0009] On the basis of the above technical solution, preferably, the side holes are provided with multiple ones, and the first wire outlet hole is connected to the side hole; one end of the guide tube is located at the wire outlet position of the wire feeding motor, and the other end faces the side hole, and the first wire outlet hole is located in the extension direction of the guide tube.

[0010] On the basis of the above technical solution, preferably, the wire feeding bracket is provided with a wire inlet hole and a second wire outlet hole, and the wire on the wire feeding disc passes through the wire inlet hole and passes through the second wire outlet hole before entering the guide tube; The wire feeding assembly also includes two wire feeding rollers rotatably mounted on the wire feeding bracket, the wire feeding motor is drivingly connected to one of the wire feeding rollers, the two wire feeding rollers clamp the wire and are used to pull the wire to release it from the wire feeding disc and move it into the guide tube to provide the wire to the first wire outlet hole.

[0011] On the basis of the above technical solution, preferably, the print head assembly also includes a mounting frame, the mounting frame is connected to the connecting plate, a hollow structure is provided on the mounting frame, the heating block is installed on the hollow structure and is thermally connected to the processing head.

[0012] Based on the above technical solution, preferably, the print head assembly also includes a pressure sensor installed above the heating block, and the pressure sensor is used to monitor the pressure value of the processing head and feed back the pressure value to the control device to control the processing head to maintain the clamping force between the wire and the printing platform or the deposited layer.

[0013] In a second aspect, the present invention provides a 3D printing method for a heterogeneous continuous fiber reinforced composite material, using the 3D printing device for a heterogeneous continuous fiber reinforced composite material as described in the first aspect, comprising: The control device controls the moving mechanism to drive the processing head, so that the processing head moves to the top of the printing platform, maintains a set layer height distance with the printing platform or the deposited layer, and passes the front end of the wire through the side hole and the first wire outlet hole; The wire feeding motor is controlled by a control device to drive the wire on the wire feeding disc to move into the guide tube; The control device controls the moving device to drive the processing head to move along a given path, and controls the processing head to keep applying a constant pressing force to the wire material passing through the first wire outlet hole; The control device controls the heating block to heat the processing head and the wire when the processing head presses the wire passing through the first wire outlet hole onto the printing platform or the deposited layer, so as to achieve synchronous melting and compaction of the wire.

[0014] Based on the above technical solution, preferably, the wire feeding speed of the wire feeding motor driving the wire on the wire feeding disk to move into the guide tube is 120~240mm / min; the temperature of the heating block heating the processing head and the wire is 175~205℃; the thickness of each deposition layer is 0.12~0.22mm.

[0015] The 3D printing device and method of the heterogeneous continuous fiber reinforced composite material of the present invention have the following beneficial effects compared with the prior art: (1) The wire feeding motor drives the wire on the wire feeding disc to move into the guide tube, and the guide tube guides the wire into the side hole and the first wire outlet hole in sequence, and the wires entering the side holes all pass through the first wire outlet hole; the heating block heats the processing head and the wire when the processing head presses the wire passing through the first wire outlet hole onto the printing platform or the deposited layer, thereby achieving synchronous melting and compaction of the wire. Compared with the method of heating in the processing head before extrusion in the prior art, the phenomenon of clogging the processing head and breaking the wire is avoided, making the additive manufacturing process more continuous and reliable; (2) The connecting plate is respectively connected to the processing head and the wire feeding bracket, and the moving base is respectively connected to the moving unit and the connecting plate, so as to drive the connecting plate to move with multiple degrees of freedom under the drive of the moving unit, so that the processing head and the wire feeding bracket move together with the connecting plate, and the processing head for outputting wire and the wire feeding bracket for supplying wire move synchronously, so that the processing head can move according to the preset processing path, thereby improving the reliability of the device; (3) By designing multiple side holes, wires of different types of continuous fiber reinforced composite materials can be fed into the corresponding side holes of the processing head respectively. Under the coordinated action of each wire feeding mechanism, they can be fed into the first wire outlet hole of the processing head synchronously, and the synchronous melting and compaction of wires of multiple specifications can be achieved. The operation is simple and the forming effect is good, so as to achieve the purpose of synchronous coupling printing of multiple materials. One end of the guide tube is located at the wire outlet position of the wire feeding motor, and the other end faces the side hole, and the first wire outlet hole is located in the extension direction of the guide tube, so that the wire feeding position of the wire is very stable, the manufacturing accuracy is improved, and the forming process is avoided from being affected. (4) The wire is clamped by the two wire feeding rollers, and the wire feeding motor is connected to one of the wire feeding rollers. During the rotation of the wire feeding roller, the wire is pulled to be released from the wire feeding disc and moved into the guide tube to provide the wire to the first wire outlet. The wire feeding motor can stop feeding the wire immediately when it stops, and the wire can be clamped and fixed. This wire feeding method is simple and reliable, ensuring the continuous processing and stopping the processing is convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic structural diagram of a 3D printing device for a heterogeneous continuous fiber reinforced composite material in an embodiment of the present invention; Figure 2 It is a schematic diagram of the wire feeding principle of the 3D printing device of the heterogeneous continuous fiber reinforced composite material in the embodiment of the present invention; Figure 3 is a schematic structural diagram of a print head assembly in an embodiment of the present invention; Figure 4 It is a schematic structural diagram of a wire feeding support and a guide tube in an embodiment of the present invention; Figure 5 is a schematic structural diagram of a print head in an embodiment of the present invention; Figure 6 It is a schematic diagram of the printing principle of the 3D printing device of the heterogeneous continuous fiber reinforced composite material in the embodiment of the present invention; Figure 7 It is a schematic flow chart of a 3D printing method of a heterogeneous continuous fiber reinforced composite material in an embodiment of the present invention; Figure 8 is a schematic diagram of the relationship between the bending strength and the thickness of the deposited layer, the heating temperature and the wire feeding speed in an embodiment of the present invention; Fig. 9 Schematic diagram of the relationship between the bending modulus and the thickness of the deposited layer, the heating temperature and the wire feeding speed in an embodiment of the present invention; Fig.10 The following are photos of a formed product with a deposition thickness of 0.15 mm (a) and a formed product with a deposition thickness of 0.12 mm (b) in an embodiment of the present invention.

[0018] Description of reference numerals: 1-frame, 2-moving mechanism, 3-print head assembly, 4-wire feeding assembly; 11- Printing platform; 21-moving base, 22-connecting plate, 23-moving unit, 231-X axis, 232-Y axis, 233-Z axis; 31-processing head, 311-side hole, 312-first wire outlet hole, 32-heating block, 33-mounting frame; 41 - wire feeding disc, 42 - wire feeding bracket, 421 - wire inlet hole, 422 - second wire outlet hole, 43 - guide tube, 44 - wire feeding roller. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Reference Figure 1-6As shown, the first embodiment of the present invention provides a 3D printing device for heterogeneous continuous fiber reinforced composite materials, including a frame 1, a moving mechanism 2, a print head assembly 3, a wire feeding assembly 4 and a control device, wherein: The frame 1 is provided with a printing platform 11, and the printing platform 11 is equipped with a preheating device, which can preheat the printing platform 11; The moving mechanism 2 is installed on the frame 1 and is used to drive the print head assembly 3 and the wire feeding assembly 4 to move; The printing head assembly 3 includes a processing head 31 and a heating block 32, and the processing head 31 is connected to the moving mechanism 2; the processing head 31 is provided with a first wire outlet hole 312 and at least one side hole 311 for wire material to enter, the first wire outlet hole 312 is located on the bottom surface of the processing head 31, and the wire materials entering the plurality of side holes 311 all pass through the first wire outlet hole 312; the heating block 32 is connected to the processing head 31, and is used to heat the processing head 31 and the wire material when the processing head 31 presses the wire material passing through the first wire outlet hole 312 onto the printing platform 11 or the deposited layer; The wire feeding assembly 4 includes a wire feeding disc 41, a wire feeding bracket 42, a wire feeding motor and a guide tube 43. The wire feeding disc 41 is rotatably mounted on the top surface of the frame 1 and is used to store unformed wires. The wire feeding bracket 42 is connected to the moving mechanism 2. The wire feeding motor is mounted on the wire feeding bracket 42 and is used to drive the wire on the wire feeding disc 41 to move into the guide tube 43. The guide tube 43 is mounted on the wire feeding bracket 42 and is used to guide the wire into the side hole 311 and the first wire outlet hole 312 in sequence. The control device is connected with the moving mechanism 2, the heating block 32 and the wire feeding motor by electrical signals to control the operation of the moving mechanism 2, the heating block 32 and the wire feeding motor.

[0021] In this embodiment, the 3D printing device is installed, and the modeling, slicing, path planning and export of the path code are completed in the computer. When planning the path, the required characteristics of different materials are set according to the characteristics of the formed part, and the path code is imported into the control device; according to the requirements of the formed part, the respective wire feeding components 4 are automatically selected, and the specific model of prepreg wire is determined, and they are respectively fed into different side holes 311 in the processing head 31, and the temperature and wire feeding speed of the preheating mechanism are adjusted; the processing head 31 presses the wire passing through the first wire outlet hole 312 onto the printing platform 11 or the deposited layer, and the heating block 32 synchronously heats the wire passing through the first wire outlet hole 312.

[0022] The 3D printing device of heterogeneous continuous fiber reinforced composite materials proposed in this embodiment drives the wire on the wire feeding disk 41 to move into the guide tube 43 through the wire feeding motor, and the guide tube 43 guides the wire into the side hole 311 and the first wire outlet hole 312 in sequence, and the wires entering the multiple side holes 311 all pass through the first wire outlet hole 312; the heating block 32 heats the processing head 31 and the wire when the processing head 31 presses the wire passing through the first wire outlet hole 312 onto the printing platform 11 or the deposited layer, thereby realizing synchronous melting and compaction of the wire. Compared with the method of heating in the processing head 31 first and then extruding in the prior art, the phenomenon of clogging the processing head 31 and wire breakage is avoided, making the additive manufacturing process more continuous and reliable.

[0023] In some embodiments, the mobile mechanism 2 includes a connecting plate 22, a moving base 21 and a moving unit 23, wherein the connecting plate 22 is respectively connected to the processing head 31 and the wire feeding bracket 42, and the moving base 21 is respectively connected to the moving unit 23 and the connecting plate 22, and is used to drive the connecting plate 22 to move with multiple degrees of freedom under the drive of the moving unit 23. The moving base 21 drives the connecting plate 22 to move with multiple degrees of freedom under the drive of the moving unit 23, so that the processing head 31 and the wire feeding bracket 42 move together with the connecting plate 22, and the processing head 31 for outputting wire and the wire feeding bracket 42 for supplying wire move synchronously, so that the processing head 31 can move according to a preset processing path, thereby improving the reliability of the device.

[0024] In some embodiments, the moving unit 23 includes an X-axis 231, a Y-axis 232, a Z-axis 233 and three driving members. The X-axis 231 and the Y-axis 232 are slidably disposed on the frame 1, and the Z-axis 233 is connected to the motion base 21 and the connecting plate 22 respectively. The motion base 21 is slidably mounted on the X-axis 231 and the Y-axis 232. The three driving members are mounted on the motion base 21, and are respectively used to drive the motion base 21 to move along the X-axis 231 and the Y-axis 232, and the connecting plate 22 to move along the Z-axis 233. The three driving members drive the motion base 21 to move along the X-axis 231 and the Y-axis 232, and the connecting plate 22 to move along the Z-axis 233, respectively, so as to realize the three-way movement of the connecting plate 22 along the X-axis 231, the Y-axis 232 and the Z-axis 233, so that the processing head 31 can move according to the preset processing path.

[0025] In other embodiments, the mobile unit 23 is a robot arm or a five-axis machine tool. The robot arm or the five-axis machine tool drives the motion base 21 and the connecting plate 22 to move together, thereby realizing multi-degree-of-freedom movement of the processing head 31 to adapt to the complex movement path of the processing head 31 and improve the scope of use.

[0026] In some embodiments, there are multiple side holes 311, and the first wire outlet hole 312 is connected to the side hole 311. Prepreg wires of different types and specifications are placed in each side hole 311. According to the needs of the target parts, prepreg wires of different brands and specifications are selected and fed into different side holes 311 at the same time to achieve combined printing of multiple wires, and can realize synchronous coupling printing of multiple fibers to form an overall forming of a mixed fiber reinforced composite material; one end of the guide tube 43 is located at the wire outlet position of the wire feeding motor, and the other end faces the side hole 311, and the first wire outlet hole 312 is located in the extension direction of the guide tube 43, and the angle between the guide tube 43 and the horizontal plane is 60-70°. By designing multiple side holes 311, each side hole 311 corresponds to a wire feeding assembly 4, and multiple wire feeding assemblies 4 can feed wires of different types of continuous fiber reinforced composite materials into the corresponding side holes 311 of the processing head 31 respectively. Under the synergistic effect of each wire feeding mechanism, they can be synchronously fed into the first wire outlet hole 312 of the processing head 31, and realize the synchronous melting and compaction of wires of multiple specifications, which is simple to operate and has a good forming effect, achieving the purpose of synchronous coupling printing of multiple materials; one end of the guide tube 43 is located at the wire outlet position of the wire feeding motor, and the other end faces the side hole 311, and the first wire outlet hole 312 is located in the extension direction of the guide tube 43, so that the wire feeding position of the wire is very stable, the manufacturing accuracy is improved, and the forming process is avoided. By setting the angle between the guide tube 43 and the horizontal plane to 60-70°, the guiding effect on the wire is the best, and the wire can be better introduced into the side hole 311 and the first wire outlet hole 312 in sequence.

[0027] In some embodiments, the wire feeding bracket 42 is provided with a wire inlet hole 421 and a second wire outlet hole 422, and the wire on the wire feeding disc 41 passes through the wire inlet hole 421 and passes through the second wire outlet hole 422 and then enters the guide tube 43; the wire feeding assembly 4 also includes two wire feeding rollers 44 rotatably mounted on the wire feeding bracket 42, and the wire feeding motor is drivingly connected to one of the wire feeding rollers 44, and the two wire feeding rollers 44 clamp the wire and are used to pull the wire to release it from the wire feeding disc 41 and move it into the guide tube 43 to provide the wire to the first wire outlet hole 312. The wire is clamped by the two wire feeding rollers 44, and the wire feeding motor is drivingly connected to one of the wire feeding rollers 44. During the rotation of the wire feeding rollers, the wire is pulled to be released from the wire feeding disc 41 and moved into the guide tube 43 to provide the wire to the first wire outlet hole 312. The wire feeding motor can stop feeding the wire immediately when it stops, and the wire can be clamped and fixed. This wire feeding method is simple and reliable, ensuring the continuous processing and stopping the processing is relatively convenient and quick.

[0028] In some embodiments, the print head assembly 3 further includes a mounting frame 33, the mounting frame 33 is connected to the connecting plate 22, a hollow structure is provided on the mounting frame 33, the heating block 32 is mounted on the hollow structure and is thermally connected to the processing head 31. The mounting frame 33 and the connecting plate 22 can be connected by bolts, and a hollow structure is provided in the middle of the mounting frame 33, which can reduce the weight of the print head assembly 3 and allow the connecting wire of the heating block 32 to pass through.

[0029] In some embodiments, the print head assembly 3 further includes a pressure sensor installed above the heating block 32, the pressure sensor is used to monitor the pressure value of the processing head 31, and feed the pressure value back to the control device to control the processing head 31 to maintain the pressing force between the wire and the printing platform 11 or the deposited layer. The processing head 31 is subjected to pressure by the force control mechanism, and the control device controls the pressure applied by the force control mechanism according to the pressure value of the processing head 31 detected by the pressure sensor, so that the processing head 31 maintains the constant pressing force between the wire and the printing platform 11 or the deposited layer. The processing head 31 is heated and heated by the heating block 32 during the process of pressing the wire, and the wire is melted and compacted at the first wire outlet 312, thereby realizing the synchronous coupling 3D printing of heterogeneous continuous fiber reinforced composite prepreg wire.

[0030] Based on the same concept, the second embodiment of the present invention is combined with Figure 7 As shown, a 3D printing method for a heterogeneous continuous fiber reinforced composite material is provided, using the 3D printing device for a heterogeneous continuous fiber reinforced composite material as described in the first aspect of the embodiment, comprising: Step S1: installing a continuous carbon fiber reinforced PLA prepreg composite material on the wire feeding disc 41; In step S1, PLA is the abbreviation of Polylactic Acid, and its Chinese name is polylactic acid, also known as polylactide; Step S2: The control device controls the moving mechanism 2 to drive the processing head 31, so that the processing head 31 moves to the top of the printing platform 11, maintains a set layer height distance with the printing platform 11 or the deposited layer, and passes the front end of the wire through the side hole 311 and the first wire outlet hole 312; Step S3: controlling the wire feeding motor through the control device to drive the wire on the wire feeding disc 41 to move into the guide tube 43; Step S4: controlling the moving device to drive the processing head 31 to move along a given path through the control device, and controlling the processing head 31 to keep applying a constant pressing force to the wire passing through the first wire outlet hole 312; Step S5: Control the heating block 32 through the control device to heat the processing head 31 and the wire when the processing head 31 presses the wire passing through the first wire outlet hole 312 onto the printing platform 11 or the deposited layer, so as to achieve synchronous melting and compaction of the wire.

[0031] In some embodiments, the wire feeding motor drives the wire on the wire feeding disk 41 to move into the guide tube 43 at a wire feeding speed of 120~240mm / min; the temperature of the heating block 32 heating the processing head 31 and the wire is 175~205℃; the thickness of each deposition layer is 0.12~0.22mm.

[0032] Experimental Example 1 The wire feeding speed is 200 mm / min, the temperature of the heating block 32 heating the processing head 31 and the wire is 195° C. The parameter settings of the thickness of each deposition layer are shown in Table 1. The following four groups of experiments are conducted: Table 1

[0033] The product was obtained according to the above experimental parameters, and the bending strength and bending modulus of the product were tested. The relationship between the bending strength and bending modulus and the layer thickness is shown in Table 2: Table 2

[0034] Experimental Example 2 The wire feeding speed is 200 mm / min, the thickness of each deposition layer is 0.15 mm, and the parameter settings of the temperature of the heating block 32 heating the processing head 31 and the wire are shown in Table 3. The following four groups of experiments were conducted: Table 3

[0035] The product was obtained according to the above experimental parameters, and the bending strength and bending modulus of the product were tested. The relationship between the bending strength and bending modulus and the temperature is shown in Table 4: Table 4

[0036] Experimental Example 3 The thickness of each deposition layer is 0.15 mm. The temperature of the processing head 31 and the wire material heated by the heating block 32 is 195° C. The parameter setting of the wire feeding speed is shown in Table 5. The following four groups of experiments are conducted: Table 5

[0037] The product was obtained according to the above experimental parameters, and the bending strength and bending modulus of the product were tested. The relationship between the bending strength and bending modulus and the temperature is shown in Table 6: Table 6

[0038] Plot the above test results into a line graph and get the following Figure 7 and Figure 8 , and the formed products with a deposition layer thickness of 0.12mm and 0.15mm were photographed. Fig.10 , Fig.10 In the figure, (a) is a photo of a formed product with a thickness of 0.15 mm, and (b) is a photo of a formed product with a thickness of 0.12 mm. It can be seen from the figure that the bending strength of the deposited layer with a thickness of 0.12 mm and 0.15 mm is equivalent, and there is a difference in the bending modulus, but the surface quality of the 0.15 mm formed product is better and smoother, and the optimal value of the thickness of the deposited layer is 0.15 mm; when the heating temperature is 195 ° C, the bending strength and bending modulus are the best; when the wire feeding speed is 200 mm / min, the bending strength and bending modulus are the best.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A 3D printing device for heterogeneous continuous fiber reinforced composite materials, characterized in that: It includes a frame, a moving mechanism, a print head assembly, a wire feeding assembly and a control device, wherein: A printing platform is provided on the frame, and the printing platform is equipped with a preheating device; The moving mechanism is installed on the frame; The printing head assembly comprises a processing head and a heating block, wherein the processing head is connected to the moving mechanism; the processing head is provided with a first wire outlet hole and at least one side hole for wire material to enter, the first wire outlet hole is located on the bottom surface of the processing head, and the wire materials entering the plurality of side holes all pass through the first wire outlet hole; the heating block is connected to the processing head, and is used to heat the processing head and the wire material when the processing head presses the wire material passing through the first wire outlet hole onto the printing platform or the deposited layer; The wire feeding assembly comprises a wire feeding disc, a wire feeding bracket, a wire feeding motor and a guide tube, wherein the wire feeding disc is rotatably mounted on the frame; the wire feeding bracket is connected to the moving mechanism; the wire feeding motor is mounted on the wire feeding bracket and is used to drive the wire on the wire feeding disc to move into the guide tube; the guide tube is mounted on the wire feeding bracket and is used to guide the wire into the side hole and the first wire outlet hole in sequence; The control device is connected with the moving mechanism, the heating block and the wire feeding motor by electrical signals.

2. The 3D printing device of heterogeneous continuous fiber reinforced composite material according to claim 1, characterized in that: The moving mechanism includes a connecting plate, a moving base and a moving unit. The connecting plate is respectively connected to the processing head and the wire feeding bracket, and the moving base is respectively connected to the moving unit and the connecting plate, and is used to drive the connecting plate to move with multiple degrees of freedom under the drive of the moving unit.

3. The 3D printing device of heterogeneous continuous fiber reinforced composite material according to claim 2, characterized in that: The mobile unit includes an X-axis, a Y-axis, a Z-axis and three driving members. The X-axis and the Y-axis are slidably arranged on the frame. The Z-axis is respectively connected to the motion base and the connecting plate. The motion base is slidably installed on the X-axis and the Y-axis. The three driving members are installed on the motion base, and are respectively used to drive the motion base to move along the X-axis and the Y-axis and the connecting plate to move along the Z-axis.

4. The 3D printing device of heterogeneous continuous fiber reinforced composite material according to claim 2, characterized in that: The mobile unit adopts a mechanical arm or a five-axis machine tool.

5. The 3D printing device of heterogeneous continuous fiber reinforced composite material according to claim 1, characterized in that: The side holes are provided in plurality, and the first wire outlet hole is connected to the side hole; one end of the guide tube is located at the wire outlet position of the wire feeding motor, and the other end faces the side hole, and the first wire outlet hole is located in the extension direction of the guide tube.

6. The 3D printing device of heterogeneous continuous fiber reinforced composite material according to claim 5, characterized in that: The wire feeding bracket is provided with a wire inlet hole and a second wire outlet hole, and the wire on the wire feeding disc passes through the wire inlet hole and passes through the second wire outlet hole before entering the guide tube; The wire feeding assembly also includes two wire feeding rollers rotatably mounted on the wire feeding bracket, the wire feeding motor is drivingly connected to one of the wire feeding rollers, the two wire feeding rollers clamp the wire and are used to pull the wire to release it from the wire feeding disc and move it into the guide tube to provide the wire to the first wire outlet hole.

7. The 3D printing device of heterogeneous continuous fiber reinforced composite material according to claim 2, characterized in that: The print head assembly also includes a mounting frame, which is connected to the connecting plate. A hollow structure is provided on the mounting frame. The heating block is mounted on the hollow structure and is thermally connected to the processing head.

8. The 3D printing device of heterogeneous continuous fiber reinforced composite material according to claim 1, characterized in that: The print head assembly also includes a pressure sensor installed above the heating block, which is used to monitor the pressure value of the processing head and feed back the pressure value to the control device to control the processing head to maintain the pressing force between the wire and the printing platform or the deposited layer.

9. A 3D printing method for a heterogeneous continuous fiber reinforced composite material, using the 3D printing device for a heterogeneous continuous fiber reinforced composite material according to any one of claims 1 to 8, characterized in that: include: The control device controls the moving mechanism to drive the processing head, so that the processing head moves to the top of the printing platform, maintains a set layer height distance with the printing platform or the deposited layer, and passes the front end of the wire through the side hole and the first wire outlet hole; The wire feeding motor is controlled by a control device to drive the wire on the wire feeding disc to move into the guide tube; The control device controls the moving device to drive the processing head to move along a given path, and controls the processing head to keep applying a constant pressing force to the wire material passing through the first wire outlet hole; The control device controls the heating block to heat the processing head and the wire when the processing head presses the wire passing through the first wire outlet hole onto the printing platform or the deposited layer, so as to achieve synchronous melting and compaction of the wire.

10. The 3D printing method of heterogeneous continuous fiber reinforced composite material according to claim 9, characterized in that: The wire feeding motor drives the wire on the wire feeding disc to move into the guide tube at a wire feeding speed of 120-240 mm / min; the temperature of the heating block heating the processing head and the wire is 175-205° C.; the thickness of each deposition layer is 0.12-0.22 mm.

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