Continuous fiber high-speed printing head device and high-speed printing method

Abstract

The invention discloses a continuous fiber high-speed printing head device and a high-speed printing method.The continuous fiber high-speed printing head device comprises a mounting frame, a wire feeding mechanism, a wire shearing mechanism and a hot end assembly, the wire feeding mechanism comprises a wire feeding driving device, a transmission assembly, extrusion rollers and an adjusting assembly, and the wire feeding driving device drives the extrusion rollers to move oppositely to extrude prepreg to achieve wire feeding; the adjusting assembly is used for adjusting the extrusion force between the two extrusion rollers. The wire shearing mechanism can be quickly disassembled to quickly mount and replace a blade, and the hot end assembly performs multi-stage heating on the prepreg and is matched with a high-speed printing method to realize continuous fiber high-speed printing. By arranging the adjusting assembly, adjustment of the distance between the extrusion rollers and the clamping force is achieved, the wire feeding mechanism can feed wires of different specifications, and the applicability is wide; the wire feeding mechanism, the wire shearing mechanism and the hot end assembly are all optimized, the maintenance difficulty of the printing head is reduced, and the printing stability and the working efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a continuous fiber high-speed printing head device and a high-speed printing method. Background Art

[0002] With the development of additive manufacturing technology, more and more new materials are being used in the field of additive manufacturing, and continuous fiber prepreg is no exception. Continuous fiber reinforced resin-based composite materials have the characteristics of high strength, light weight, and stable chemical properties. They are widely used in aerospace, automobile, shipbuilding, military and other fields. The use of additive manufacturing technology makes the manufacture of continuous fiber reinforced resin-based materials simpler and easier to manufacture complex structures. Compared with traditional fiber laying processes, continuous fiber additive manufacturing technology has become the main development trend in the future.

[0003] The current continuous fiber additive manufacturing technology is not mature enough, especially in the field of continuous fiber high-speed printing. The print head structure is complex and inconvenient to maintain, especially the wire feeding and wire cutting parts of the print head. Different wire bundles of different specifications use different wire feeding and wire cutting mechanisms. The wire feeding mechanism has high maintenance costs, and there are different degrees of insufficient extrusion force, wire bundle wear, and crushing during the wire feeding process. The wire cutting mechanism has complex structure, poor maintenance, poor wire cutting effect, fast blade wear, and the blade cannot be replaced quickly. In addition, in order to ensure strength in continuous fiber printing, the speed is at a low level, the production efficiency is low, and the processing time is long. These problems have seriously hindered the development of the industry. Summary of the invention

[0004] Purpose of the invention: In view of the shortcomings of the prior art that the wire feeding mechanism is not universal, the wire cutting mechanism is complicated and the wire cutting effect is poor, and the overall printing speed is low, the present invention provides a continuous fiber high-speed printing head device and a high-speed printing method.

[0005] Technical solution: To solve the above problems, the present invention adopts a continuous fiber high-speed print head device, including a mounting frame, a wire feeding mechanism, a wire cutting mechanism and a hot end assembly, wherein the wire feeding mechanism includes a wire feeding drive device, a transmission assembly, an extrusion roller and an adjustment assembly, wherein the wire feeding drive device, the transmission assembly and the adjustment assembly are all mounted on the mounting frame, the transmission assembly includes a first transmission shaft and a second transmission shaft, wherein an extrusion roller and a driven wheel are respectively mounted on the first transmission shaft and the second transmission shaft, and the driven wheel of the first transmission shaft is meshed with the driven wheel of the second transmission shaft, the first transmission shaft is connected to the wire feeding drive device, and the surfaces of the two extrusion rollers are squeezed against each other to realize wire feeding; the adjustment assembly is used to adjust the extrusion force between the two extrusion rollers;

[0006] The wire cutting mechanism comprises a wire cutting drive device, a knife frame, a push knife frame installed in the knife frame, and a movable blade installed on the push knife frame. The wire cutting drive device and the knife frame are installed on a mounting frame. One end of the push knife frame is connected to the wire cutting drive device to push the movable blade to cut the wire.

[0007] The hot end assembly includes a throat assembly mounted on a mounting frame, a multi-stage heating block mounted on the outer wall of the throat assembly, and a nozzle mounted on the bottom of the throat assembly. The throat assembly is hollow inside, and the mounting frame, the tool holder, and the throat assembly are all provided with openings for the prepreg to pass through.

[0008] Furthermore, a driving gear is sleeved on the output shaft of the wire feeding drive device, and the transmission assembly also includes a driven gear sleeved on the first transmission shaft, and the driven gear is meshed with the driving gear.

[0009] Furthermore, the extrusion roller includes a metal bushing layer located on the inner side and a rubber layer located on the outer side. The extrusion roller is also provided with a threaded hole, and a screw is installed in the threaded hole to fix the extrusion roller on the transmission shaft.

[0010] Furthermore, a side plate is rotatably mounted on the mounting frame, the second transmission shaft is mounted on the side plate, the adjustment assembly includes an adjustment bolt and a spring sleeved on the adjustment bolt, the adjustment bolt passes through the side plate and is mounted on the mounting frame, and the spring is located between the head of the adjustment bolt and the side plate.

[0011] Furthermore, the tool holder includes an upper tool holder and a lower tool holder, and the upper tool holder is installed on the lower tool holder through a rotating shaft pin; a quick-release slot for installing the tool holder is provided on the mounting frame, and the upper tool holder and the lower tool holder are installed in the quick-release slot.

[0012] Furthermore, symmetrical single-sided arc-shaped cutting edges are provided on both sides of the movable blade, and a fixed blade is also provided on the lower blade holder for cooperating with the movable blade to cut wire.

[0013] Furthermore, the wire cutting drive device is a steering gear, and one end of the push knife holder is connected to the wire cutting drive device through a rocker arm to convert the rotational motion of the steering gear into linear motion.

[0014] Furthermore, the hot end assembly also includes a radiator and a cooling fan. The radiator is installed on the outer wall of the throat assembly and is located between the multi-stage heating block and the mounting frame. The cooling fan is installed on both sides of the radiator.

[0015] Furthermore, the throat pipe assembly is made of Teflon tube.

[0016] The present invention also provides a high-speed printing method of the continuous fiber high-speed printing head device, which determines the density ρ, specific heat capacity c, thermal conductivity λ, surface heat transfer coefficient h, and radius R of the printed fiber prepreg;

[0017] The expressions of printing speed and nozzle temperature are as follows:

[0018]

[0019] According to the steady-state thermal analysis component in ANSYS-WORHBENCH software, the length of each temperature zone during multi-stage heating is calculated through thermodynamic simulation, and the temperatures of the heating blocks from top to bottom are T1, T2, T3...T n The temperature of the prepreg out of each heating zone is t1, t2, t3...t n , the length of each heating zone is L1, L2, L3...L n , then the printing speed expression of each heating zone is as follows:

[0020]

[0021]

[0022] According to the principle that the speed of each heating zone must be consistent during printing, let V1 = V2 = V3 = V n , multiple sets of solutions that meet the requirements can be solved by exhaustive method, and a set of solutions with the largest printing speed V can be selected. The temperature of each heating block is set according to the calculated temperature results to achieve maximum printing speed.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) by setting an adjustment component, the distance between the extrusion rollers and the clamping force can be adjusted, so that the wire feeding mechanism can feed wires of different specifications and has a wide range of applicability; (2) the structure of the extrusion roller is optimized, and the rubber material on the surface causes less damage to the wire; (3) the wire cutting mechanism has a simple structure, and the blade can be quickly fixed and replaced; (4) the shape of the wire cutting blade is optimized, and the arc-shaped single-sided cutting edges on both sides have good convergence and wire cutting effects, and each blade can be used twice, which reduces production costs and improves resource utilization; (5) the heating zone structure of the hot end component is optimized, and the heating temperature zone is extended by gradient multi-stage heating, the melting speed of the matrix resin is increased, the risk of clogging is reduced, and the printing speed of continuous fibers can be greatly improved; (6) a mathematical model of prepreg printing speed and temperature is established, which can conveniently calculate the gradient temperature and optimal printing speed of the multi-stage heating block, and can calculate the fastest printing speed at a certain temperature, making theoretical preparations for high-speed printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the continuous fiber high-speed printing head device of the present invention;

[0025] Figure 2 It is an exploded view of the wire feeding mechanism parts of the present invention;

[0026] Figure 3 It is an exploded view of the wire cutting mechanism parts of the present invention;

[0027] Figure 4 It is an exploded view of the hot end component parts of the present invention;

[0028] Figure 5 This is a schematic diagram of the structure of the extrusion roller of the present invention;

[0029] Figure 6 This is a schematic diagram of the blade structure of the present invention;

[0030] Figure 7 It is a cross-sectional view of the hot end component of the present invention. DETAILED DESCRIPTION

[0031] Embodiment 1

[0032] like Figure 1 As shown, a continuous fiber high-speed print head device in this embodiment includes a mounting frame 07 and a wire feeding mechanism 100, a wire cutting mechanism 200, and a hot end assembly 300 mounted on the mounting frame 07. The mounting frame 07 is provided with an opening 074 for the prepreg wire to pass through, so that the prepreg wire can smoothly enter the wire feeding mechanism 100. Figure 2 As shown, the wire feeding mechanism 100 includes a wire feeding motor 01, a back plate 02, a transmission assembly 08, an extrusion roller 03, and an adjustment assembly 05. The wire feeding motor 01 is fixed to the back plate 02 by bolts, and a driving gear 011 is sleeved on its output shaft to provide power to the wire feeding mechanism. The back plate 02 and the front cover plate 07 are locked by bolts to provide an installation position and fixed support for the transmission assembly 08 and the extrusion roller 03 during rotation.

[0033] The transmission assembly 08 includes a first transmission shaft 081, a second transmission shaft 082, and a driven gear (084) sleeved on the first transmission shaft 081. The driven gear 084 is installed between the back plate 02 and the mounting frame 07, and the driven gear 084 is meshed with the driving gear 011. An installation adjustment hole is provided on the back plate 2, and the gap between the wire feeding motor and the transmission gear can be adjusted to ensure smooth transmission.

[0034] An extrusion roller 03 and a driven wheel 083 are also installed on the first transmission shaft 081 and the second transmission shaft 082 respectively. The first transmission shaft 081 is installed on the mounting frame 07 through the bearing end cover 06. A side plate 04 is rotatably installed on one side of the mounting frame 07, and the second transmission shaft 082 is installed on the side plate 04. The driven wheels 083 on the two transmission shafts are meshed with each other, and the surfaces of the two extrusion rollers 03 are in contact to squeeze each other to realize wire feeding.

[0035] like Figure 5As shown, the extrusion roller 03 includes a metal bushing layer 032 located on the inner side and a rubber layer 031 located on the outer side. The extrusion roller 03 is also provided with a threaded hole 033, and screws are installed in the threaded hole 033 to fix the extrusion roller 03 on the transmission shaft. The flexible rubber layer structure can increase the contact area with the wire material and reduce damage such as crushing and abrasion of the wire material. Fixing with screws facilitates maintenance and replacement of the extrusion roller after wear.

[0036] The adjustment assembly 05 includes an adjustment bolt and a spring sleeved on the adjustment bolt. The adjustment bolt passes through the side plate 04 and is installed on the mounting frame 07. The mounting frame 07 is provided with a bolt hole for the adjustment bolt to be screwed in. The spring is located between the head of the adjustment bolt and the side plate 04. By tightening or loosening the bolt, the distance and clamping force between the extrusion rollers 03 can be adjusted to be suitable for wires of various specifications.

[0037] like Figure 3 As shown, the wire cutting mechanism 200 includes a wire cutting servo 09, a tool holder, a tool pusher 12, a movable blade 11, and a fixed blade 15. The tool holder includes an upper tool holder 10 and a lower tool holder 13. The upper tool holder 10 is mounted on the lower tool holder 13 through a rotating shaft pin. The lower tool holder 13 is made of 6061 aluminum alloy and is the main body of the entire wire cutting mechanism. It is locked with the upper tool holder 10 by bolts to ensure the rigidity of the entire mechanism. The upper tool holder 10 is provided with a fixing hole 101, and the mounting frame 07 is provided with a quick release slot 071 and a locking threaded hole 072 for mounting the tool holder. The bolts are installed in the fixing hole 101 and the locking threaded hole 072 to install the upper tool holder 10 and the lower tool holder 13 in the quick release slot 071. The middle of the upper tool holder 10 and the lower tool holder 13 is provided with an opening 102 for the prepreg wire to pass through.

[0038] The fixed blade 15 is installed in the lower blade holder 13, the movable blade 11 is installed on the pusher holder 12, and the pusher holder 12 is slidably installed on the lower blade holder 13. The wire cutting servo 09 is fixedly installed on the mounting frame 07, and one end of the pusher holder 12 is connected to the wire cutting drive device 09 through the rocker arm 14 to form a crank slider mechanism to convert the rotary motion of the servo into linear motion. Figure 6 As shown, the blade 11 is provided with a centrally symmetrical single-sided arc-shaped cutting edge 111, which has a gathering effect when cutting wires and a convergence effect on the fracture, which can effectively reduce the difficulty of re-feeding the wire. The blade is also provided with a bolt fixing hole 112 and a fixing groove 113. The lower knife holder 13 and the push knife holder 12 are both provided with a positioning key 131 for positioning the blade. The blade position is fixed by the cooperation of the positioning key 131 and the fixing groove 113, and the blade position can also be fixed by bolts. The push knife holder 12 is pushed by the wire cutting servo 09, so that the movable blade 11 cooperates with the fixed blade 15 to cut wires.

[0039] like Figure 4As shown, the hot end assembly 300 includes a throat assembly 19, a radiator 15, a cooling fan 16, a multi-stage heating block 17, and a nozzle 18. The throat assembly 19 is located at the bottom of the mounting frame 07. The throat assembly 19 is hollow inside, and its top is connected to the opening 102 of the wire cutting mechanism for the prepreg wire to pass through. A bayonet 073 is provided on the mounting frame 07, and the radiator 15 is fixed to the bayonet 073 by the hot end clamp 20. The throat assembly 19 is fixed to the radiator 15 by a set screw. The matching installation method of the clamp and the buckle ensures the installation strength of the hot end assembly, and can be quickly disassembled and assembled for easy maintenance. The radiator 15 surrounds the upper outer wall of the throat assembly 19. The radiator 15 is also provided with a fan mounting bracket, and the cooling fan 16 is installed on both sides of the radiator 15. The radiator plays the role of cooling the throat assembly 19, avoiding overheating of the throat assembly 19 and its interior, and can also prevent the heat of the heating block from diffusing to the wire cutting mechanism and wire feeding mechanism above, causing damage to the structure. The cooling fan can speed up the air convection speed of the radiator fins and accelerate the heat dissipation.

[0040] The multi-stage heating block 17 is installed around the lower outer wall of the throat assembly 19. The multi-stage heating block 17 includes a plurality of heating blocks, each of which is equipped with a thermocouple and a heating rod, and can accurately control the temperature of each heating block to ensure the temperature stability of each heating zone and the heating effect of the prepreg. Moreover, there is a gradient temperature difference between the heating blocks during heating, which can not only extend the heating zone and improve the heating efficiency, but also prevent the resin matrix from melting prematurely and sticking to the inside of the throat assembly, causing blockage. The nozzle 18 is installed at the bottom of the throat assembly 19 to provide downward pressure for the heated prepreg to ensure that it can be bonded to the printed substrate. The throat assembly 19 can use a Teflon tube, which provides a low friction coefficient channel for heating the prepreg, ensuring that the prepreg can be heated evenly in the heating zone, improving the printing quality and reducing the probability of blockage.

[0041] The working principle of the print head of the present invention is as follows: the prepreg wire penetrates from the opening 074 at the top of the mounting frame 7, passes between the two extrusion rollers 03, and then passes through the opening 102 of the wire cutting mechanism, enters the throat assembly 19, and finally sprays out from the nozzle 18. The two extrusion rollers 03 are driven by the wire feeding motor 01 to move toward each other and squeeze each other, bringing out the prepreg wire in the middle to complete the wire feeding. Depending on the wire used, the distance and clamping force between the extrusion rollers 03 can be adjusted by the adjustment component 05 to meet various printing requirements. After the wire is fed into the hot end assembly, it first passes through the radiator part and then through the throat assembly. In the throat assembly, the multi-stage heating block will heat the prepreg wire to melt the resin matrix on the prepreg to reach a state that can be printed. When wire cutting is required, the wire cutting servo drives the rocker arm, and the rocker arm pushes the push knife holder and the blade fixed thereto to complete the shearing action of the wire. After the wire cutting is completed, each mechanism returns to its position to prepare for the next wire feeding and wire cutting.

[0042] The high-speed print head of the present invention realizes the adjustment of the distance and clamping force between the extrusion rollers by setting an adjustment component, so that the wire feeding mechanism can feed wires of different specifications and has wide applicability; the structure of the extrusion roller is optimized, and the rubber material on the surface causes less damage to the wire; the wire cutting mechanism has a simple structure, and the blade can be quickly fixed and replaced; the shape of the wire cutting blade is optimized, and the arc-shaped single-sided cutting edges on both sides have good convergence and wire cutting effects, and each blade can be used twice, which reduces production costs and improves resource utilization; the heating zone structure of the hot end component is optimized, and the heating temperature zone is extended by gradient multi-stage heating, thereby increasing the melting rate of the matrix resin, reducing the risk of clogging, and greatly improving the printing speed of continuous fibers.

[0043] Embodiment 2

[0044] This embodiment provides a high-speed printing method of the continuous fiber high-speed printing head device, comprising the following steps:

[0045] Step 1: Determine the density ρ, specific heat capacity c, thermal conductivity λ, surface heat transfer coefficient h, and radius R of the printed fiber prepreg.

[0046] Step 2: According to the law of conservation of energy, the expression of the heating time of the prepreg in the nozzle is derived as follows:

[0047]

[0048] In the above formula, t0 is the initial temperature of the prepreg, which can be replaced by room temperature, t ∞ is the temperature at which the prepreg is heated, equivalent to the temperature of the heating block, and t is the target heating temperature, equivalent to the melting temperature of the prepreg resin matrix.

[0049] Step 3: In the print head, the heating time of the prepreg is expressed as follows:

[0050]

[0051] In the above formula, L h is the length of the heating zone, and V is the printing speed.

[0052] Step 4: Based on the expressions in steps 2 and 3, the expressions for printing speed and nozzle temperature are further derived as follows:

[0053]

[0054] Step 5: According to the steady-state thermal analysis component in ANSYS-WORHBENCH software, the length of each temperature zone during multi-stage heating is calculated through thermodynamic simulation, such as Figure 7As shown. Let the temperatures of the heating blocks from top to bottom be T1, T2, T3, ... T n The temperature of the prepreg out of each heating zone is t1, t2, t3...t n , the length of each heating zone is L1, L2, L3...L n , then the printing speed expression of each heating zone is as follows:

[0055]

[0056] Step 6: According to the principle that the speed of each heating zone must be consistent during printing, let V1 = V2 = V3 = V n , multiple sets of solutions that meet the requirements can be solved by exhaustive method, and a set of solutions with the largest printing speed V can be selected. The temperature of each heating block is set according to the calculated temperature results to achieve printing at the maximum speed.

[0057] The printing method of the present invention establishes a mathematical model of prepreg printing speed and temperature, which can conveniently calculate the gradient temperature and optimal printing speed of the multi-stage heating blocks, and can calculate the fastest printing speed at a certain temperature, making theoretical preparations for high-speed printing.

Claims

1. A continuous fiber high-speed printing head device, characterized in that: The invention comprises a mounting frame (07), a wire feeding mechanism (100), a wire cutting mechanism (200) and a hot end assembly (300), wherein the wire feeding mechanism (100) comprises a wire feeding drive device (01), a transmission assembly (08), an extrusion roller (03) and an adjustment assembly (05), wherein the wire feeding drive device (01), the transmission assembly (08) and the adjustment assembly (05) are all mounted on the mounting frame (07), and the transmission assembly (08) comprises a first transmission shaft (081), a second transmission shaft (08 2), an extrusion roller (03) and a driven wheel (083) are respectively installed on the first transmission shaft (081) and the second transmission shaft (082), and the driven wheel of the first transmission shaft (081) and the driven wheel of the second transmission shaft (082) are meshed with each other, the first transmission shaft (081) is connected to the wire feeding drive device (01), and the surfaces of the two extrusion rollers (03) are pressed against each other to realize wire feeding; the adjustment component (05) is used to adjust the extrusion force between the two extrusion rollers (03); The wire cutting mechanism (200) comprises a wire cutting drive device (09), a knife frame, a push knife frame (12) installed in the knife frame, and a movable blade (11) installed on the push knife frame (12); the wire cutting drive device (09) and the knife frame are installed on a mounting frame (07); one end of the push knife frame (12) is connected to the wire cutting drive device (09) to push the movable blade (11) to cut wire; The hot end assembly (300) comprises a throat assembly (19) mounted on a mounting frame (07), a multi-stage heating block (17) mounted on the outer wall of the throat assembly (19), and a nozzle (18) mounted on the bottom of the throat assembly (19); the throat assembly (19) is hollow inside, and the mounting frame (07), the tool holder, and the throat assembly (19) are all provided with openings for the prepreg to pass through.

2. The continuous fiber high-speed printing head device according to claim 1, characterized in that: A driving gear (011) is sleeved on the output shaft of the wire feeding drive device (01), and the transmission assembly (08) further comprises a driven gear (084) sleeved on the first transmission shaft (081), and the driven gear (084) is meshed with the driving gear (011).

3. The continuous fiber high-speed printing head device according to claim 1, characterized in that: The extrusion roller (03) comprises a metal bushing layer (032) located on the inner side and a rubber layer (031) located on the outer side. A threaded hole (033) is also provided on the extrusion roller (03), and a screw is installed in the threaded hole (033) to fix the extrusion roller (03) on the transmission shaft.

4. The continuous fiber high-speed printing head device according to claim 1, 2 or 3, characterized in that: A side plate (04) is rotatably mounted on the mounting frame (07), a second transmission shaft (082) is mounted on the side plate (04), the adjustment assembly (05) comprises an adjustment bolt and a spring sleeved on the adjustment bolt, the adjustment bolt passes through the side plate (04) and is mounted on the mounting frame (07), and the spring is located between the head of the adjustment bolt and the side plate (04).

5. The continuous fiber high-speed printing head device according to claim 1, characterized in that: The tool holder comprises an upper tool holder (10) and a lower tool holder (13), wherein the upper tool holder (10) is mounted on the lower tool holder (13) via a rotating shaft pin; a quick-release slot (071) for mounting the tool holder is provided on the mounting frame (07), and the upper tool holder (10) and the lower tool holder (13) are mounted in the quick-release slot (071).

6. The continuous fiber high-speed printing head device as claimed in claim 5, characterized in that: Symmetrical single-sided arc-shaped cutting edges (111) are provided on both sides of the movable blade (11), and a fixed blade (15) is also provided on the lower blade holder (13) for cooperating with the movable blade (11) to cut wire.

7. The continuous fiber high-speed printing head device according to claim 1, characterized in that: The wire cutting drive device (09) is a steering gear, and one end of the pusher frame (12) is connected to the wire cutting drive device (09) through a rocker arm (14) to convert the rotary motion of the steering gear into linear motion.

8. The continuous fiber high-speed printing head device as claimed in claim 1, characterized in that: The hot end assembly (300) further comprises a radiator (15) and a cooling fan (16); the radiator (15) is mounted on the outer wall of the throat assembly (19), and the radiator (15) is located between the multi-stage heating block (17) and the mounting frame (07); the cooling fan (16) is mounted on both sides of the radiator (15).

9. The continuous fiber high-speed printing head device according to claim 1, characterized in that: The throat pipe component (19) is made of Teflon tube.

10. A high-speed printing method using the continuous fiber high-speed printing head device according to any one of claims 1 to 9, characterized in that: Determine the density ρ, specific heat capacity c, thermal conductivity λ, surface heat transfer coefficient h, and radius R of the printed fiber prepreg; The expressions of printing speed and nozzle temperature are as follows: According to the steady-state thermal analysis component in ANSYS-WORHBENCH software, the length of each temperature zone during multi-stage heating is calculated through thermodynamic simulation, and the temperatures of the heating blocks from top to bottom are T1, T2, T3...T n The temperature of the prepreg out of each heating zone is t1, t2, t3...t n , the length of each heating zone is L1, L2, L3...L n , then the printing speed expression of each heating zone is as follows: According to the principle that the speed of each heating zone must be consistent during printing, let V1 = V2 = V3 = V n , multiple sets of solutions that meet the requirements can be solved by exhaustive method, and a set of solutions with the largest printing speed V can be selected. The temperature of each heating block is set according to the calculated temperature results to achieve maximum printing speed.

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