Wire winding and repairing device and method for thermoplastic additive manufacturing

Abstract

The invention discloses a wire winding and repairing device for thermoplastic additive manufacturing. The wire winding and repairing device comprises a control system, a traction device, a first wire diameter detection device, a tension detection device, a wire diameter repairing device, a second wire diameter detection device and a winding device, the invention further provides a wire winding and repairing method for thermoplastic additive manufacturing. According to the device provided by the invention, constant-tension winding of the wire rod is realized, and secondary repair is carried out on a wire diameter out-of-tolerance part while winding is carried out.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing equipment, and particularly relates to a device and method for winding and repairing wires for thermoplastic additive manufacturing. Background Technology

[0002] 3D printing, also known as additive manufacturing, is a type of rapid prototyping technology. It is a technology that uses digital model files as a basis and employs powdered metals or plastics and other bondable materials to construct objects layer by layer. This technology has applications in jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, firearms and other fields.

[0003] After 3D printing material is extruded, it needs to be wound up by a motor-driven spool. A certain tension needs to be maintained during winding, but if the tension is too high, the filament will be stretched and deformed, resulting in a smaller filament size. If the winding spool speed is too high, the filament may break. If the winding spool speed is too low, the winding efficiency will decrease. A certain match must be maintained between the winding speed and the winding tension to achieve a better winding effect. Conventional production methods cannot handle defects that occur during the 3D filament extrusion process. Manual visual inspection is often used, which is not only inefficient and labor-intensive, but also cannot remedy the filament quality and results in a lot of material waste.

[0004] Patent document CN120364504A discloses a method and system for controlling the active film take-up and unwinding speeds during continuous fiber laying. This control method controls the rotational speeds of the take-up film roll and the unwinding yarn roll through the host computer control system of the entire system. Both take into account the rotational speed and radius of the pressure roller. The pressure roller is the main device that drives the entire system to operate. At the same time, as the continuous fiber laying progresses, the thickness of the take-up film roll and the unwinding yarn roll changes continuously.

[0005] Patent document CN120055057A discloses a high-strength rare-earth magnesium alloy wire roller drawing equipment and method with a temperature control feedback system. The equipment includes a wire straightening device, a painting device, a vision inspection device, a pulse power application device, an industrial control computer, a roller drawing device, a cleaning device, and a winding device. The painting device reduces wire reflectivity and improves inspection accuracy through a "painting + air drying" method; the vision inspection device monitors the wire diameter and temperature in real time and provides feedback to adjust the pulse power supply and roller drawing parameters; the cleaning device removes surface paint and impurities. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for winding and repairing wires for thermoplastic additive manufacturing. The device achieves constant tension winding of the wires and performs secondary repair on the wire diameter deviation during winding.

[0007] To achieve the first objective of this invention, the following technical solution is provided: a wire winding and repair device for thermoplastic additive manufacturing, comprising a control system and a traction device, a first wire diameter detection device, a tension detection device, a wire diameter repair device, a second wire diameter detection device, and a winding device arranged sequentially along the wire's outward output direction; The traction device is used to traction thermoplastic additive manufacturing wire prepared and shaped by the previous process; The first wire diameter detection device is used to detect the first outer diameter of the thermoplastic additive manufacturing wire, and to collect the first outer diameter of the thermoplastic additive manufacturing wire and send it to the control system; The tension detection device is used to collect the current tension of the wire used in thermoplastic additive manufacturing and send it to the control system; The wire diameter repair device repairs the error portion of the thermoplastic additive manufacturing wire according to the repair command generated by the control system. The second wire diameter detection device is used to detect the second outer diameter of the repaired thermoplastic additive manufacturing wire and send the data to the control system; The winding device is used to wind up the repaired thermoplastic additive manufacturing wire; The control system analyzes the preset outer diameter and the first outer diameter to generate corresponding repair instructions, and adjusts the winding speed of the winding device based on the current tension.

[0008] Specifically, the traction device includes an upper traction roller and a lower traction roller for clamping thermoplastic additive manufacturing wire, and a servo motor for driving each traction roller.

[0009] Specifically, the wire diameter repair device includes an upper repairer, a lower repairer, an opening and closing mechanism, a moving bracket, a moving lead screw, a moving servo reducer, and a moving servo motor.

[0010] Specifically, the upper repair device of the wire diameter repair device consists of an upper insulation layer, an upper repair body, an upper heating resistor, an upper temperature sensor, an upper temperature controller, and an upper repair body shaping inner surface with the opening facing downward; the upper heating resistor, the upper temperature sensor, the upper temperature controller, and the upper solid-state relay form an upper temperature control circuit to control the temperature of the upper repair body. The lower repair unit of the wire diameter repair device consists of a lower insulation layer, a lower repair body, a lower heating resistor, a lower temperature sensor, a lower temperature controller, and an upper-facing inner surface of the lower repair body. The lower heating resistor, lower temperature sensor, lower temperature controller, and lower solid-state relay form a lower temperature control circuit to control the temperature of the lower repair body. Preferably, the inner surface of the cavity formed by the upper repair body shaping inner surface with the opening facing downward and the lower repair body shaping inner surface with the opening facing upward when the opening and closing mechanism is closed has the same shape as the filament used for additive manufacturing. Preferably, the controlled temperature T of the upper and lower restorations set initially is 3-5 °C higher than the melting temperature of the wire for additive manufacturing.

[0011] Specifically, the opening and closing mechanism is arranged on the moving bracket. Above the center line of the opening and closing mechanism, an upper restorator is slidably connected, and below the center line, a lower restorator is slidably connected; the opening and closing mechanism drives the upper and lower restorators to move relatively or towards each other, realizing the closing or separation between the upper and lower restorators.

[0012] Specifically, the winding device includes a rotary encoder, a winding servo motor, a winding shaft, and a winding drum. The winding shaft is connected to the shaft of the winding servo motor, and the winding drum is sleeved on the winding shaft. The rotation of the winding servo motor drives the winding shaft and the winding drum to rotate, for winding the wire for additive manufacturing pulled out by the traction device.

[0013] Specifically, when the first wire diameter detection device detects that the outer diameter d1 of the wire is greater than the upper limit value D of the set wire diameter value d, it sends an upper limit alarm to the control system. The control system triggers a metering thread Tread: The control system starts to read the value of the rotary encoder. When the metering number reaches the distance Sab between the detection point of the first wire diameter detection device and the initial position of the moving bracket of the wire repair device, the opening and closing mechanism of the wire diameter repair device closes, drives the upper and lower restorators to move towards each other, clamps the wire to be repaired and performs heating and secondary shaping, and at the same time the moving bracket starts to perform a linear positioning movement. The repair device completes the repair of the wire during the linear movement of the moving bracket. After the repair is completed, the control system resets the metering thread Tread, and the thread Tread ends.

[0014] Specifically, the second wire diameter detection device continuously detects the outer diameter d2 of the repaired wire and feeds the outer diameter value d2 back to the control system; the control system adjusts the travel Sbc of the moving bracket and the set temperature T of the upper and lower restorators according to the outer diameter value d2 in real time.

[0015] Specifically, the moving servo motor adopts a position control mode, and the travel of the moving bracket is accurately controlled by the moving servo motor; When d < d2 < D, after each metering thread Tread ends; The travel Sbc of the moving bracket = Sbc + 0.1; The set temperature T of the upper and lower restorators = T + 0.1; When d2 < d, after each metering thread Tread ends; The travel Sbc of the moving bracket = Sbc - 0.1; The set temperature T of the upper and lower restorators = T - 0.1; Sbc: The initial travel of the moving bracket, unit: mm; T: The set temperature of the upper and lower repair devices, in degrees Celsius; d: Wire outer diameter setting, in mm; d2: Outer diameter of the repaired wire, in mm; D: Upper limit alarm value for wire outer diameter, unit mm; The longer the linear motion stroke Sbc of the moving bracket, the longer the wire takes to set in the upper and lower repairers. The higher the temperature T set in the upper and lower repairers, the faster the material melts during the repair process, and the more fully the material is set and repaired. However, the higher the secondary melting temperature and the longer the repair time during the setting and repair process, the more the resin that was impregnated in the wire in the previous process will evaporate, resulting in a reduction in the outer diameter of the wire.

[0016] To achieve the second objective of this invention, the following technical solution is provided: a method for winding and repairing wire for thermoplastic additive manufacturing, implemented by the aforementioned device for winding and repairing wire for thermoplastic additive manufacturing, comprising: a winding process control system that collects the number of pulses sent by a rotary encoder in real time, and calculates the instantaneous linear speed V of the current wire winding based on the number of pulses received from the rotary encoder per unit time; the control system updates the speed of the moving servo motor in real time using the instantaneous linear speed V to ensure that the moving speed of the moving bracket is consistent with the linear speed of the wire winding; the device repairs the out-of-tolerance portion of the wire while winding the material, unaffected by the increase in winding diameter or the change in winding angular velocity during the winding process.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. An invention provides a wire winding and repair device for thermoplastic additive manufacturing. When the first wire diameter detection device detects that the outer diameter of the wire is greater than a set value, it sends an alarm to the control system. The control system triggers a meter counting thread Tread: the control system starts reading the value of the rotary encoder. When the meter count reaches the distance between the detection point of the first wire diameter detection device and the initial position of the moving bracket of the wire repair device, the opening and closing mechanism of the wire repair device closes, driving the upper repairer and the lower repairer to move inward, clamping the wire to be repaired for heating and secondary shaping, and simultaneously starting the moving bracket to perform linear positioning movement to achieve the repair of the wire. 2. The second wire diameter detection device detects the outer diameter d2 of the repaired wire and feeds the outer diameter data d2 back to the control system. The control system adjusts the stroke Sbc of the moving bracket and the set temperature T of the upper and lower repairers in real time based on the outer diameter data d2. The repair stroke parameter Sbc of the moving bracket and the temperature parameter T of the upper and lower repairers are continuously learned and optimized during the production process. 3. The winding process control system reads the number of pulses sent by the rotary encoder in real time and calculates the instantaneous linear speed V of the wire winding based on the number of pulses received from the rotary encoder per unit time. This is used to update the speed of the moving servo motor in real time, ensuring that the moving speed of the moving bracket is consistent with the winding speed of the wire. The winding process is unaffected by the increase in winding diameter or changes in winding angular velocity. The equipment can also repair out-of-tolerance parts of the wire while winding. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a wire winding and repair device for thermoplastic additive manufacturing provided in this embodiment; Figure 2 This is a schematic diagram of the encoder arrangement of the winding device provided in this embodiment; Figure 3 This is a schematic diagram of the upper and lower repairers of the wire diameter repair device provided in this embodiment; Figure 4 This is a schematic diagram of the temperature control of the upper and lower repairers in the wire diameter repair device provided in this embodiment; Figure 5 This is a schematic diagram of the tension control winding provided in this embodiment; Figure 6 This is a schematic diagram of the wire repair process provided in this embodiment. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] like Figure 1The diagram shown is a structural schematic of a wire winding and repair device for thermoplastic additive manufacturing provided in this embodiment. It includes, in sequence along the wire output direction, an upper traction roller 1, a lower traction roller 2, a first guide roller 3, a first wire diameter detection device 4, a second guide roller 5, a tension roller 6, a third guide roller 7, an upper repairer 8, a lower repairer 9, an opening and closing mechanism 10, a moving bracket 11, a moving servo motor 12, a moving servo reducer 13, a moving lead screw 14, a fourth guide roller 15, a second wire diameter detection device 16, and a fifth guide roller 17. Roller 17, meter counting wheel 18, winding device 19, winding shaft 20; point a is the detection point of the first wire diameter detection device 4, point b is the initial position of the moving support 11 of the wire repair device, point c is the end point of the movement of the moving support 11 after the wire diameter repair is completed; Sab is the distance between the wire from the detection point a of the first wire diameter detection device 4 and the initial position b of the moving support 11 of the wire repair device when the wire is wound, and Sbc is the stroke of the moving support 11 from the beginning position of wire repair to the end position of wire repair; The center height of the opening and closing mechanism 10 is consistent with the center height of the wire axis passing through the bottom surface of the third roller 7 and the bottom surface of the fourth roller 15; the upper repairer 8 is slidably connected above the center line of the opening and closing mechanism 10, and the lower repairer 9 is slidably connected below the center line of the opening and closing mechanism 10; when the opening and closing mechanism 10 is opened, it drives the upper repairer 8 and the lower repairer 9 to move away from each other, and when the opening and closing mechanism 10 is closed, it drives the upper repairer 8 and the lower repairer 9 to move closer to each other.

[0021] The second wire diameter detection device 16 is arranged between the wire diameter repair device and the winding device 19. The installation direction of the second wire diameter detection device 16 is parallel to the wire passing between the lower surface of the fourth roller 15 and the lower surface of the fifth roller 17, and it detects the outer diameter of the wire in real time and feeds it to the control system. Tension roller 6 is arranged between the first wire diameter detection device 4 and the wire diameter repair device, and tension sensor is mechanically connected to tension roller 6; like Figure 2 The schematic diagram of the encoder arrangement of the winding device shows that the rotary encoder of the winding device is arranged between the fifth guide roller 17 and the winding shaft 20. The rotary encoder is mechanically coaxially connected to the counting wheel 18. The reasonable arrangement of the fifth guide roller 17, the counting wheel 18, and the winding shaft 20 ensures that when the wire passes through the lower surface of the fifth guide roller 17, the upper surface of the counting wheel 18, and the lower surface of the winding shaft 20, the wire between the two sides of the counting wheel 2 generates a large wrap angle α. The larger the wrap angle α, the larger the contact area Sef between the wire on the two sides of the counting wheel 2 and the counting wheel 18. The wire on the two sides of the counting wheel 2 applies a downward resultant force to the counting wheel 18, and the frictional force generated therefrom drives the rotary encoder to rotate, preventing slippage between the wire and the counting wheel 18 during the winding process, which would cause the encoder data collected by the control system to be lost. like Figure 3The upper repairer 8 of the wire diameter repair device shown mainly includes an upper insulation layer 801, an upper repair body 802, an upper heating resistor 803, an upper temperature sensor 804, and an upper repair body shaping inner surface 805 with the opening facing downwards; the lower repairer 9 mainly includes a lower insulation layer 901, a lower repair body 902, a lower heating resistor 903, a lower temperature sensor 904, and a lower repair body shaping inner surface 905 with the opening facing upwards. like Figure 4 The temperature control diagram of the upper and lower repairers of the wire diameter repair device shown consists of their respective temperature sensors, heating resistors, temperature controllers, and solid-state relays, which control the operating temperature T of the upper and lower repairers respectively. like Figure 5 As shown, the electrical signal collected by the tension sensor is converted into an analog signal that the control system can receive by the signal amplifier. The control system uses the tension value collected by the tension sensor as the current value of the PID calculation and the set value of the PID calculation to calculate the speed of the winding servo motor, thereby achieving constant tension winding of the wire.

[0022] like Figure 6 As shown, this embodiment provides a method for winding and repairing wires for thermoplastic additive manufacturing. It is implemented by the device for winding and repairing wires for thermoplastic additive manufacturing provided in the above embodiment. The method includes: when the first wire diameter detection device 4 detects that the outer diameter d1 of the wire exceeds the upper limit value D of the wire set value d, it sends an upper limit alarm signal to the control system. The control system restarts a thread Tread and reads the value of the encoder to count the meters. When the counted value is equal to Sab, the opening and closing mechanism closes and the moving servo motor 12 is started to rotate. The second wire diameter detection device 16 detects the outer diameter d2 of the repaired material and feeds the outer diameter data d2 back to the control system. The control system adjusts the stroke Sbc of the moving support and the set temperature T of the upper and lower repairers in real time based on the outer diameter data d2. The repair stroke parameter Sbc of the moving support and the temperature parameter T of the upper and lower repairers are continuously learned and optimized during the production process. The winding process control system reads the number of pulses sent by the rotary encoder in real time and calculates the instantaneous linear speed V of the current wire winding based on the number of pulses received from the rotary encoder per unit time. This is used to update the speed of the moving servo motor 12 in real time, ensuring that the moving speed of the moving bracket 11 is consistent with the winding speed of the wire. The equipment can repair the wire with out-of-tolerance outer diameter at the same time as winding.

[0023] Furthermore, the terms "upper," "lower," "inner," "outer," "front," and "rear" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise specifically stated, the relative steps, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0024] Of course, the above description is only a specific embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention should be included in the scope of the claims of the present invention.

[0025] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A wire winding and repair device for thermoplastic additive manufacturing, characterized in that, It includes a control system and a traction device arranged sequentially along the outward output direction of the wire, a first wire diameter detection device, a tension detection device, a wire diameter repair device, a second wire diameter detection device, and a winding device; The traction device is used to traction thermoplastic additive manufacturing wire prepared and shaped by the previous process; The first wire diameter detection device is used to detect the first outer diameter of the thermoplastic additive manufacturing wire, and to collect the first outer diameter of the thermoplastic additive manufacturing wire and send it to the control system; The tension detection device is used to collect the current tension of the wire used in thermoplastic additive manufacturing and send it to the control system; The wire diameter repair device repairs the error portion of the thermoplastic additive manufacturing wire according to the repair command generated by the control system. The second wire diameter detection device is used to detect the second outer diameter of the repaired thermoplastic additive manufacturing wire and send the data to the control system; The winding device is used to wind up the repaired thermoplastic additive manufacturing wire; The control system analyzes the preset outer diameter and the first outer diameter to generate corresponding repair instructions, and adjusts the winding speed of the winding device based on the current tension.

2. The wire winding and repair device for thermoplastic additive manufacturing according to claim 1, characterized in that, The traction device includes an upper traction roller and a lower traction roller for clamping thermoplastic additive manufacturing wire, and a servo motor for driving each traction roller.

3. The wire winding and repair device for thermoplastic additive manufacturing according to claim 1, characterized in that, The wire diameter repair device includes an upper repairer, a lower repairer, an opening and closing mechanism, a moving bracket, a moving lead screw, a moving servo reducer, and a moving servo motor.

4. The wire winding and repair device for thermoplastic additive manufacturing according to claim 3, characterized in that, The opening and closing mechanism is arranged on the movable support. An upper repairer is slidably connected above the center line of the opening and closing mechanism, and a lower repairer is slidably connected below the center line. The opening and closing mechanism drives the upper repairer and the lower repairer to move relative to each other or towards each other, so as to realize the closing or separation between the upper repairer and the lower repairer.

5. The wire winding and repair device for thermoplastic additive manufacturing according to claim 1, characterized in that, The winding device includes a rotary encoder, a winding servo motor, a winding shaft, and a winding drum. The winding shaft is connected to the winding servo motor shaft, and the winding drum is sleeved on the winding shaft. The rotation of the winding servo motor drives the winding shaft and the winding drum to rotate, which is used to wind up the additive manufacturing wire pulled out by the traction device.

6. The wire winding and repair device for thermoplastic additive manufacturing according to claim 1, characterized in that, When the first wire diameter detection device detects that the outer diameter d1 of the wire is greater than the upper limit D of the wire diameter setting value d, it sends an upper limit alarm to the control system. The control system triggers a meter counting thread Tread: the control system starts reading the value of the rotary encoder. When the meter count reaches the distance Sab between the detection point of the first wire diameter detection device and the initial position of the moving bracket of the wire repair device, the opening and closing mechanism of the wire diameter repair device closes, drives the upper repairer and the lower repairer to move towards each other, clamps the wire to be repaired and heats and shapes it for the second time. At the same time, the moving bracket starts to make a linear positioning movement. The repair device completes the repair of the wire during the linear movement of the moving bracket. After the repair is completed, the control system resets the meter counting thread Tread, and the thread Tread ends.

7. The wire winding and repair apparatus for thermoplastic additive manufacturing according to claim 1, characterized in that, The second wire diameter detection device detects the outer diameter d2 of the repaired wire in real time and feeds the outer diameter value d2 back to the control system; the control system adjusts the stroke Sbc of the moving bracket and the set temperature T of the upper and lower repairers in real time according to the outer diameter value d2.

8. A method for winding and repairing thermoplastic additive manufacturing wire, characterized in that, This is achieved by the wire winding and repair apparatus for thermoplastic additive manufacturing as described in any one of claims 1 to 7, comprising: The winding process control system collects the number of pulses sent by the rotary encoder in real time and calculates the instantaneous linear speed V of the current wire winding based on the number of pulses received from the rotary encoder per unit time. The control system uses the instantaneous linear speed V to update the speed of the moving servo motor in real time to ensure that the moving speed of the moving bracket is consistent with the linear speed of the wire winding. The equipment can repair the out-of-tolerance parts of the wire while winding the material, and is not affected by the increase in winding diameter or the change in winding angular velocity during the winding process.

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