Litz wire manufacturing process

Abstract

The invention relates to a Litz wire manufacturing process, and belongs to the technical field of electromagnetic wire manufacturing technologies, and the Litz wire manufacturing process comprises the following steps: S1, preparing a twisted wire core: enabling a plurality of insulated wires to form the wire core through a multi-level twisting process; s2, compression molding: adjusting parameters of a molding die according to the target section graph, enabling a die orifice of the molding die to be switched in a trapezoidal or rectangular manner, and performing square pressing treatment on the wire core to obtain a molded litz wire with a trapezoidal or rectangular section; and S3, insulation coating: carrying out insulation coating on the molded litz wire. According to the compression molding process, the trapezoidal or rectangular cross section is flexibly generated through the forming die, the requirement of special-shaped litz wire equipment for the customized cross section is met, the space adaptability of the litz wire is improved, and the problems that a traditional circular or single rectangular wire rod is low in groove fullness rate and high in eddy current loss are solved.

Description

Technical Field

[0001] This application relates to the field of electromagnetic wire manufacturing technology, and particularly to a manufacturing process for Litz wire. Background Art

[0002] Litz wire is a high-frequency wire composed of multiple mutually insulated fine wires twisted together, and is widely used in electromagnetic devices such as transformers and motors. Traditional Litz wire mostly uses a circular cross-section, but in high-frequency applications, the eddy current loss of the circular cross-section is relatively high. To solve the problem of eddy current loss, in the prior art, a square pressing die has been used to perform square pressing on the Litz wire to press the wire core into a rectangular cross-section. The rectangular cross-section can reduce the high-frequency eddy current loss and improve the winding filling efficiency by optimizing the spatial arrangement of the conductors. However, limited by the structural design of the traditional square pressing die, the prior art can only generate a rectangular cross-section of a single size. In an irregular winding slot or an asymmetric electromagnetic device, the rectangular Litz wire cannot be closely arranged due to the angular gap, resulting in a reduction in space utilization (for example, the filling rate of the rectangular wire in a circular winding slot is less than 60%), and in some scenarios, it is even necessary to additionally increase the thickness of the insulating layer to compensate for the gap, which instead increases the overall volume. Summary of the Invention

[0003] To improve the spatial adaptability of Litz wire, this application provides a manufacturing process for Litz wire.

[0004] A manufacturing process for Litz wire provided by this application adopts the following technical solutions:

[0005] A manufacturing process for Litz wire includes:

[0006] S1. Stranded wire core preparation: forming a wire core by twisting multiple insulated wires through a multi-level twisting process;

[0007] S2. Mold pressing and forming: adjusting the parameters of the forming mold according to the target cross-sectional shape, and the die orifice of the forming mold can be switched between a trapezoid and a rectangle, and performing mold pressing on the wire core to obtain a formed Litz wire with a trapezoidal or rectangular cross-section;

[0008] S3. Insulation coating: performing insulation coating on the formed Litz wire.

[0009] Optionally, the forming mold includes an upper adjusting seat, a lower adjusting seat, a left adjusting seat, and a right adjusting seat; an upper pressing wheel is provided on the upper adjusting seat, a lower pressing wheel is provided on the lower adjusting seat, a left pressing wheel is provided on the left adjusting seat, and a right pressing wheel is provided on the right adjusting seat; the upper pressing wheel, the lower pressing wheel, and the left pressing wheel and the right pressing wheel are combined to form a variable die orifice, corresponding to the top edge, bottom edge, and two side edges of the target cross-sectional shape respectively.

[0010] Optionally, the forming mold further includes:

[0011] The first displacement adjustment module is used to adjust the distance between the upper pressing wheel and the lower pressing wheel;

[0012] The second displacement adjustment module is used to control the horizontal displacement of the left adjustment seat;

[0013] The third displacement adjustment module is used to control the horizontal displacement of the right adjustment seat;

[0014] The first angle adjustment module is used to drive the left adjustment seat to deflect around its preset axis;

[0015] The second angle adjustment module is used to drive the right adjustment seat to deflect around its preset axis;

[0016] The control module generates displacement and angle adjustment instructions based on the parameters of the target cross-sectional graph, and drives the first displacement adjustment module, the second displacement adjustment module, the third displacement adjustment module, the first angle adjustment module and the second angle adjustment module.

[0017] Optionally, the coaxial plane of the upper pressing wheel and the lower pressing wheel is the first plane, and the coaxial plane of the left pressing wheel and the right pressing wheel is the second plane, and the first plane and the second plane are arranged in parallel;

[0018] One of the upper pressing wheel and the lower pressing wheel is used as a reference wheel, and its spatial position is fixed, and the other is connected to the first displacement adjustment module;

[0019] The second displacement module is connected with a left sliding plate, the left adjustment seat is hinged to the left sliding plate through a first rotating shaft, and the first angle adjustment module is arranged on the left sliding plate and connected with the left adjustment seat;

[0020] The third displacement module is connected with a right sliding plate, the right adjustment seat is hinged to the right sliding plate through a second rotating shaft, and the second angle adjustment module is arranged on the right sliding plate and connected with the right adjustment seat.

[0021] Optionally, taking the upper pressing wheel as the reference wheel, the vertical projection point of the center point at the bottom end of it on the second plane is the origin O of the coordinate system, and the rectangular coordinate system of the second plane is defined, where:

[0022] In the initial state, the upper pressing wheel and the lower pressing wheel are closely arranged, the left pressing wheel and the right pressing wheel are vertical and closely arranged on both sides of the y-axis, and the variable die orifice is closed into a point;

[0023] The positive direction of the x-axis is from the origin O of the coordinate system to the initial position of the right sliding plate;

[0024] The clockwise deflection of the left pressing wheel is the positive direction of its deflection angle;

[0025] The counterclockwise deflection of the right pressing wheel is the positive direction of its deflection angle.

[0026] Optionally, S2 includes:

[0027] S21. Inputting target cross-sectional graphic parameters: Input the target cross-sectional graphic parameters into the control module. The target cross-sectional graphic parameters include the top edge T, bottom edge B, height H, left bottom angle α, and right bottom angle β. Each parameter is set with a preset range, and input is not allowed when the range is exceeded.

[0028] S22. Judging the target cross-sectional graphic: The control module judges the category of the target cross-sectional graphic according to the target cross-sectional graphic parameters.

[0029] When it is judged in step S22 that the target cross-sectional graphic is a trapezoid, step S231 and step S232 are executed.

[0030] S231. Generating displacement and angle adjustment instructions: The control module generates the vertical displacement amount △Y of the lower pressing wheel, the horizontal displacement amount △X1 of the left sliding plate, the horizontal displacement amount △X2 of the right sliding plate, the deflection angle θ1 of the left pressing wheel, and the deflection angle θ2 of the right pressing wheel.

[0031] S232. Adjusting the trapezoid forming die parameters: First, the control module synchronously drives the first displacement adjustment module, the second displacement adjustment module, and the third displacement adjustment module according to △Y, △X1, and △X2. Second, the control module synchronously drives the first angle adjustment module and the second angle adjustment module according to θ1 and θ2.

[0032] Optionally, when it is judged in step S22 that the target cross-sectional graphic is a rectangle, step S23a and step S23b are executed.

[0033] S23a. Generating displacement adjustment instructions: The control module generates the vertical displacement amount △Y of the lower pressing wheel, the horizontal displacement amount △X1 of the left sliding plate, and the horizontal displacement amount △X2 of the right sliding plate.

[0034] S23b. Adjusting the rectangle forming die parameters: The control module synchronously drives the first displacement adjustment module, the second displacement adjustment module, and the third displacement adjustment module according to △Y, △X1, and △X2.

[0035] Optionally, when it is judged in step S22 that the target cross-sectional graphic is neither a rectangle nor a trapezoid, the control module reports an error and repeats step S21.

[0036] Optionally, the forming die further includes an online detection module for real-time monitoring of the external dimensions of the variable die orifice. The online detection module includes a laser profiler, a data feedback unit, and a lifting drive device for driving the laser profiler to move up and down. The laser profiler and the lifting drive device are arranged on the outlet side of the variable die orifice, and the data feedback unit is signal-connected to the laser profiler and the control module respectively.

[0037] In summary, the present application includes at least one of the following beneficial technical effects:

[0038] 1. Through a multi-level stranding process, the present application forms a high-density wire core, combines a molding process to flexibly generate a trapezoidal or rectangular cross-section, and coordinates with the insulation coating process to achieve full-process control from wire core preparation to final shaping of the Litz wire. This is beneficial for improving the mechanical strength, high-frequency performance, and cross-section stability of the wire, while meeting the demand for customized cross-sections of special-shaped Litz wire equipment, improving the space adaptability of the Litz wire, and solving the problems of low slot filling rate and high eddy current loss of traditional circular or single rectangular wires.

[0039] 2. By setting up a forming die and constructing a variable die orifice structure, independent control or adjustment of the upper pressing wheel, lower pressing wheel, left pressing wheel, and right pressing wheel is achieved. This is beneficial for quickly switching between trapezoidal and rectangular cross-sections, significantly improving the versatility of the die, adapting to the production requirements of Litz wires of different sizes and shapes. At the same time, through the coordinated pressure application of the multi-pressing wheel structure, it ensures uniform stress on the Litz wire during the forming process, reducing the risk of insulation layer damage.

[0040] 3. By arranging the coaxial planes of the upper pressing wheel and the lower pressing wheel parallel to the coaxial planes of the left pressing wheel and the right pressing wheel, it is beneficial for reducing the risk of mechanical interference during multi-axis linkage, ensuring the stability and reliability of the adjustment process. At the same time, through the design of a fixed reference wheel, the logic of establishing a coordinate system is simplified, improving the accuracy and repeatability of parameter adjustment.

[0041] 4. Through the combined design of a laser profiler and a lifting drive device, during the detection stage, the lifting drive device adjusts the position of the laser profiler to align it with the cross-section on the outlet side of the variable die orifice, ensuring that the scanning range completely covers the variable die orifice cross-section, which is beneficial for reducing measurement errors and significantly improving the detection accuracy; after the detection is completed, the laser profiler is driven to return to avoid interfering with the wire traveling path, avoiding the risk of interference and ensuring the smoothness of continuous production; in addition, combined with the real-time linkage of the data feedback unit and the control module, the control module is assisted to dynamically correct the displacement and angle adjustment parameters to ensure the dimensional consistency of the formed wire; at the same time, through the lifting drive device, it adapts to the wire detection requirements of different heights, optimizes the flexibility and process compatibility of the detection module, and improves the yield and production efficiency of special-shaped cross-section Litz wires. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is the overall process flow chart of the first example of the present application.

[0043] Figure 2 is a schematic structural diagram of the forming die in the first embodiment of the present application.

[0044] Figure 3 is a schematic structural diagram of the variable die orifice in the first embodiment of the present application.

[0045] Figure 4 It is a schematic structural diagram showing the first displacement adjustment module in Embodiment 1 of the present application.

[0046] Figure 5 It is a schematic diagram showing the displacement and angle adjustment methods of the left pressing wheel and the right pressing wheel in Embodiment 1 of the present application.

[0047] Figure 6 It is a schematic control principle diagram of the control module in Embodiment 1 of the present application.

[0048] Figure 7 It is a schematic structural diagram showing the forming die in the initial state in Embodiment 1 of the present application.

[0049] Figure 8 It is a specific flowchart showing Step S2 in Embodiment 1 of the present application.

[0050] Figure 9 It is a schematic structural diagram showing the on-line detection module in Embodiment 2 of the present application, wherein the dotted line indicates the scanning area of the laser profiler.

[0051] Figure 10 It is a schematic control principle diagram of the control module in Embodiment 2 of the present application.

[0052] Explanation of reference numerals: 1, upper adjustment seat; 11, upper pressing wheel; 2, lower adjustment seat; 21, lower pressing wheel; 22, first displacement adjustment module; 3, left adjustment seat; 31, left pressing wheel; 32, second displacement adjustment module; 33, first angle adjustment module; 34, left sliding plate; 35, first rotating shaft; 4, right adjustment seat; 41, right pressing wheel; 42, third displacement adjustment module; 43, second angle adjustment module; 44, right sliding plate; 45, second rotating shaft; 5, variable die orifice; 6, control module; 7, on-line detection module; 71, laser profiler; 72, data feedback unit; 73, lifting drive device. Detailed implementation manners

[0053] The following is a further detailed description of the present application in conjunction with Figures 1 - 10 ,

[0054] Embodiment 1:

[0055] Embodiment 1 of the present application discloses a manufacturing process for a litz wire. Referring to Figure 1 , a manufacturing process for a litz wire includes the following steps:

[0056] S1. Stranded conductor preparation: multiple insulated conductors are formed into a conductor through a multi-level stranding process;

[0057] S2. Molding: Adjust the parameters of the molding die according to the target cross-sectional shape. The die orifice of the molding die can be switched between trapezoidal and rectangular shapes, and the wire core is molded to obtain a formed Litz wire with a trapezoidal or rectangular cross-section.

[0058] S3. Insulation coating: Apply insulation coating to the formed Litz wire.

[0059] Refer to Figure 2 and Figure 3 , the molding die includes an upper adjusting seat 1, a lower adjusting seat 2, a left adjusting seat 3 and a right adjusting seat 4. An upper pressing wheel 11 is rotatably arranged on the upper adjusting seat 1, a lower pressing wheel 21 is rotatably arranged on the lower adjusting seat 2, a left pressing wheel 31 is rotatably arranged on the left adjusting seat 3, and a right pressing wheel 41 is rotatably arranged on the right adjusting seat 4. The upper pressing wheel 11, the lower pressing wheel 21 and the left pressing wheel 31, the right pressing wheel 41 are combined to form a variable die orifice 5, corresponding to the top edge, bottom edge and two side edges of the target cross-sectional shape respectively. By constructing the variable die orifice 5 structure, independent control or adjustment of the upper pressing wheel 11, the lower pressing wheel 21, the left pressing wheel 31 and the right pressing wheel 41 is realized, which is beneficial to quickly switch between trapezoidal and rectangular cross-sections, significantly improves the versatility of the die, adapts to the production requirements of Litz wires with different sizes and shapes, and at the same time, through the cooperative pressing of the multi-pressing wheel structure, it ensures that the Litz wire is evenly stressed during the forming process and reduces the risk of insulation layer damage.

[0060] Refer to Figures 4 - 6 , the molding die further includes a first displacement adjustment module 22, a second displacement adjustment module 32, a third displacement adjustment module 42, a first angle adjustment module 33, a second angle adjustment module 43 and a control module 6. Among them, the first displacement adjustment module 22 is used to adjust the distance between the upper pressing wheel 11 and the lower pressing wheel 21; the second displacement adjustment module 32 is used to control the horizontal displacement of the left adjusting seat 3; the third displacement adjustment module 42 is used to control the horizontal displacement of the right adjusting seat 4; the first angle adjustment module 33 is used to drive the left adjusting seat 3 to deflect around its preset axis; the second angle adjustment module 43 is used to drive the right adjusting seat 4 to deflect around its preset axis; the control module 6 generates displacement and angle adjustment instructions based on the parameters of the target cross-sectional shape and is signal-connected to the first displacement adjustment module 22, the second displacement adjustment module 32, the third displacement adjustment module 42, the first angle adjustment module 33 and the second angle adjustment module 43 respectively.

[0061] Specifically, the coaxial plane of the upper pressing wheel 11 and the lower pressing wheel 21 is the first plane, and the coaxial plane of the left pressing wheel 31 and the right pressing wheel 41 is the second plane. The first plane and the second plane are arranged in parallel; one of the upper pressing wheel 11 and the lower pressing wheel 21 serves as a reference wheel with a fixed spatial position, and the other is connected to the first displacement adjustment module 22; the second displacement module is connected to a left sliding plate 34. The left adjustment seat 3 is hinged to the left sliding plate 34 through a first rotating shaft 35. The first angle adjustment module 33 is installed on the left sliding plate 34 and is hinged to the left side of the left adjustment seat 3; the third displacement module is connected to a right sliding plate 44. The right adjustment seat 4 is hinged to the right sliding plate 44 through a second rotating shaft 45. The second angle adjustment module 43 is installed on the right sliding plate 44 and is hinged to the right side of the right adjustment seat 4. In this embodiment, the first displacement adjustment module 22, the second displacement adjustment module 32, the third displacement adjustment module 42, the first angle adjustment module 33, and the second angle adjustment module 43 are one of a pneumatic drive module, an electric drive module, and a hydraulic drive module.

[0062] Through the multi-axis collaborative design of the first displacement adjustment module 22, the second displacement adjustment module 32, the third displacement adjustment module 42, the first angle adjustment module 33, and the second angle adjustment module 43 in this application, combined with the instruction driving logic of the control module 6, precise linkage control of the size and angle of the variable die orifice 5 is achieved, which is beneficial to avoiding manual adjustment errors, improving the forming accuracy and consistency. At the same time, the mechanical structure is simplified through modular drive design, and the equipment maintenance complexity is reduced. In addition, by arranging the coaxial plane of the upper pressing wheel 11 and the lower pressing wheel 21 parallel to the coaxial plane of the left pressing wheel 31 and the right pressing wheel 41, it is beneficial to reduce the risk of mechanical interference during multi-axis linkage, ensure the stability and reliability of the adjustment process, and at the same time simplify the coordinate system establishment logic through the design of the fixed reference wheel, improving the accuracy and repeatability of parameter adjustment.

[0063] Further, referring to Figure 3 and Figure 7 , to achieve the standardized modeling of the target cross-sectional graphic parameters, simplify the operation logic of the control module 6, and improve the consistency and repeatability of parameter adjustment, the upper pressing wheel 11 is used as the reference wheel, and the vertical projection point of its bottom center point on the second plane is the coordinate origin O. A rectangular coordinate system on the second plane is defined, where: in the initial state, the upper pressing wheel 11 and the lower pressing wheel 21 are closely arranged, the left pressing wheel 31 and the right pressing wheel 41 are vertical and closely arranged on both sides of the y-axis, and the variable die orifice 5 is closed into a point; the positive direction of the x-axis is from the coordinate origin O to the initial position of the right sliding plate 44; the clockwise deflection of the left pressing wheel 31 is the positive direction of its deflection angle; the counterclockwise deflection of the right pressing wheel 41 is the positive direction of its deflection angle.

[0064] Referring to Figure 8 , step S2 specifically includes:

[0065] S21. Input the parameters of the target cross-sectional shape: Input the parameters of the target cross-sectional shape into the control module 6. The parameters of the target cross-sectional shape include the top edge T, the bottom edge B, the height H, the left bottom angle α, and the right bottom angle β. Each parameter is set with a preset range, and when it exceeds its respective preset range, it cannot be input.

[0066] S22. Judgment of the target cross-sectional shape: The control module 6 judges the category of the target cross-sectional shape according to the parameters of the target cross-sectional shape. The judgment method is as follows:

[0067] ① If the input parameters of the target cross-sectional shape satisfy T = B and α = β = 90°, then the target cross-sectional shape is a rectangle.

[0068] ② If the input parameters of the target cross-sectional shape satisfy T > B and α and β are not both 90° at the same time, then the target cross-sectional shape is a trapezoid.

[0069] ③ If the input parameters of the target cross-sectional shape satisfy T < B, or satisfy T > B and α = β = 90°, then the target cross-sectional shape is neither a rectangle nor a trapezoid (an illegal cross-sectional shape).

[0070] When it is judged in step S22 that the target cross-sectional shape is a trapezoid, execute step S231 and step S232.

[0071] S231. Generate displacement and angle adjustment instructions: The control module 6 generates the vertical displacement amount △Y of the lower pressing wheel 21, the horizontal displacement amount △X1 of the left sliding plate 34, the horizontal displacement amount △X2 of the right sliding plate 44, the deflection angle θ1 of the left pressing wheel 31, and the deflection angle θ2 of the right pressing wheel 41.

[0072] S232. Adjust the parameters of the trapezoid forming die: First, the control module 6 synchronously drives the first displacement adjustment module 22, the second displacement adjustment module 32, and the third displacement adjustment module 42 according to △Y, △X1, and △X2. Secondly, the control module 6 synchronously drives the first angle adjustment module 33 and the second angle adjustment module 43 according to θ1 and θ2.

[0073] When it is judged in step S22 that the target cross-sectional shape is a rectangle, execute step S23a and step S23b.

[0074] S23a. Generate displacement adjustment instructions: The control module 6 generates the vertical displacement amount △Y of the lower pressing wheel 21, the horizontal displacement amount △X1 of the left sliding plate 34, and the horizontal displacement amount △X2 of the right sliding plate 44.

[0075] S23b. Adjust the parameters of the rectangle forming die: The control module 6 synchronously drives the first displacement adjustment module 22, the second displacement adjustment module 32, and the third displacement adjustment module 42 according to △Y, △X1, and △X2.

[0076] When it is determined in step S22 that the target cross-sectional shape is an illegal cross-sectional shape (neither a rectangle nor a trapezoid), the control module 6 reports an error and repeats step S21.

[0077] When adjusting the forming die, through the preset range limit of the target cross-sectional shape parameters and the classification processing logic (trapezoid / rectangle / illegal cross-sectional shape), the automatic interception of illegal parameter input and the intelligent allocation of the process path are realized, which is beneficial to avoiding ineffective adjustment actions, ensuring the rationality and safety of the forming process. At the same time, through step-by-step adjustment (first synchronous displacement adjustment and then synchronous angle adjustment), interference conflicts are avoided while ensuring the adjustment efficiency.

[0078] When the target cross-sectional shape is a rectangle, through the independent adjustment process of the rectangular cross-section (only displacement adjustment), the rapid generation of the rectangular variable die orifice 5 is realized, avoiding redundant angle adjustment actions, which is beneficial to shortening the process cycle and improving the production efficiency of rectangular Litz wires. At the same time, through the compatible design of rectangular parameters and trapezoid adjustment, it is ensured that the forming die can seamlessly switch between the two modes, enhancing the process flexibility.

[0079] In addition, through the real-time judgment and error reporting mechanism for illegal cross-sectional types, the dynamic verification of process parameters is realized, which is beneficial to blocking ineffective adjustment processes. At the same time, through error feedback, the operator is prompted to correct the input parameters, improving the process controllability and user experience.

[0080] The implementation principle of the first embodiment of this application is as follows: a high-density wire core is formed through a multi-level stranding process, combined with a molding process to flexibly generate a trapezoidal or rectangular cross-section, and coordinated with the insulation coating process, realizing the full-process control of the Litz wire from wire core preparation to final forming, which is beneficial to improving the mechanical strength, high-frequency performance and cross-sectional stability of the wire, while meeting the requirements of special-shaped Litz wire equipment for customized cross-sections, improving the space adaptability of the Litz wire, and solving the problems of low slot filling rate and high eddy current loss of traditional circular or single rectangular wires.

[0081] Embodiment 2:

[0082] This embodiment 2 discloses a manufacturing process of a Litz wire. Referring to Figures 9 - 10 , the difference between this embodiment 2 and embodiment 1 is that: the forming die in step S2 further includes an on-line detection module 7 for real-time monitoring of the external dimensions of the variable die orifice 5. The on-line detection module 7 includes a laser profiler 71, a data feedback unit 72, and a lifting drive device 73 for driving the laser profiler 71 to move up and down. The laser profiler 71 and the lifting drive device 73 are arranged on the outlet side of the variable die orifice 5, and the data feedback unit 72 is respectively connected to the laser profiler 71 and the control module 6 in signal.

[0083] Compared with the first embodiment, an online detection module 7 is added in the second embodiment. Through the collaborative design of the laser profiler 71 and the lifting drive device 73, during the detection stage, the lifting drive device 73 adjusts the position of the laser profiler 71 to align it with the cross-section on the outlet side of the variable die orifice 5, ensuring that the scanning range completely covers the cross-section of the variable die orifice 5, which is beneficial to reducing measurement errors and significantly improving the detection accuracy. After the detection is completed, the laser profiler 71 is driven to return to avoid the wire traveling path, avoiding the risk of interference and ensuring the smoothness of continuous production. In addition, combined with the real-time linkage of the data feedback unit 72 and the control module 6, the control module 6 is assisted to dynamically correct the displacement and angle adjustment parameters to ensure the dimensional consistency of the formed wire. At the same time, the lifting drive device 73 is adapted to the wire detection requirements of different heights, optimizing the flexibility and process compatibility of the detection module, and improving the yield and production efficiency of the special-shaped cross-section Litz wire.

[0084] The above are all the preferred embodiments of this application. The protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A manufacturing process of a litz wire, characterized in that, Including the following steps: S1. Stranded core preparation: Multiple insulated wires are formed into a core through a multi-level stranding process; S2. Mold pressing and forming: Adjust the parameters of the forming die according to the target cross-sectional shape. The die orifice of the forming die can be switched between a trapezoid and a rectangle, and the core is subjected to mold pressing to obtain a formed Litz wire with a trapezoidal or rectangular cross-section; S3. Insulation coating: Insulation coating is performed on the formed Litz wire.

2. The manufacturing process of a litz wire according to claim 1, characterized in that: The forming die includes an upper adjusting seat (1), a lower adjusting seat (2), a left adjusting seat (3), and a right adjusting seat (4); an upper pressing wheel (11) is provided on the upper adjusting seat (1), a lower pressing wheel (21) is provided on the lower adjusting seat (2), a left pressing wheel (31) is provided on the left adjusting seat (3), and a right pressing wheel (41) is provided on the right adjusting seat (4); the upper pressing wheel (11), the lower pressing wheel (21), and the left pressing wheel (31), the right pressing wheel (41) are combined to form a variable die orifice (5), corresponding to the top edge, bottom edge, and two side edges of the target cross-sectional shape respectively.

3. The manufacturing process of a litz wire according to claim 2, characterized in that, The forming die further includes: A first displacement adjustment module (22) for adjusting the distance between the upper pressing wheel (11) and the lower pressing wheel (21); A second displacement adjustment module (32) for controlling the horizontal displacement of the left adjusting seat (3); A third displacement adjustment module (42) for controlling the horizontal displacement of the right adjusting seat (4); A first angle adjustment module (33) for driving the left adjusting seat (3) to deflect around its preset axis; A second angle adjustment module (43) for driving the right adjusting seat (4) to deflect around its preset axis; A control module (6) that generates displacement and angle adjustment instructions based on the parameters of the target cross-sectional shape and drives the first displacement adjustment module (22), the second displacement adjustment module (32), the third displacement adjustment module (42), the first angle adjustment module (33), and the second angle adjustment module (43).

4. The manufacturing process of a litz wire according to claim 3, characterized in that: The coaxial plane of the upper pressing wheel (11) and the lower pressing wheel (21) is the first plane, and the coaxial plane of the left pressing wheel (31) and the right pressing wheel (41) is the second plane. The first plane and the second plane are arranged in parallel; One of the upper pressing wheel (11) and the lower pressing wheel (21) is used as a reference wheel, and its spatial position is fixed, and the other is connected to the first displacement adjustment module (22); The second displacement module is connected to a left sliding plate (34). The left adjusting seat (3) is hinged to the left sliding plate (34) through a first rotating shaft (35). The first angle adjustment module (33) is arranged on the left sliding plate (34) and connected to the left adjusting seat (3); The third displacement module is connected to a right sliding plate (44). The right adjusting seat (4) is hinged to the right sliding plate (44) through a second rotating shaft (45). The second angle adjustment module (43) is arranged on the right sliding plate (44) and connected to the right adjusting seat (4).

5. The manufacturing process of a litz wire according to claim 4, characterized in that, Taking the upper pressing wheel (11) as the reference wheel, the vertical projection point of the center point at the bottom end of it on the second plane is the origin O of the coordinate system, and a rectangular coordinate system of the second plane is defined, where: In the initial state, the upper pressing wheel (11) and the lower pressing wheel (21) are closely arranged, the left pressing wheel (31) and the right pressing wheel (41) are vertical and closely arranged on both sides of the y-axis, and the variable die orifice (5) is closed into a point; The positive direction of the x-axis is from the origin O of the coordinate system to the initial position of the right sliding plate (44); The positive direction of the deflection angle of the left pressing wheel (31) is clockwise deflection; The positive direction of the deflection angle of the right pressing wheel (41) is counterclockwise deflection.

6. The manufacturing process of a litz wire according to claim 5, characterized in that, The S2 includes: S21. Input the parameters of the target cross-sectional graph: Input the parameters of the target cross-sectional graph into the control module (6). The parameters of the target cross-sectional graph include the top side T, the bottom side B, the height H, the left bottom angle α, and the right bottom angle β. Each parameter is set with a preset range, and when it exceeds its respective preset range, it cannot be input; S22. Judgment of the target cross-sectional graph: The control module (6) judges the category of the target cross-sectional graph according to the parameters of the target cross-sectional graph; When it is judged in step S22 that the target cross-sectional graph is a trapezoid, step S231 and step S232 are executed; S231. Generate displacement and angle adjustment instructions: The control module (6) generates the vertical displacement amount △Y of the lower pressing wheel (21), the horizontal displacement amount △X1 of the left sliding plate (34), the horizontal displacement amount △X2 of the right sliding plate (44), the deflection angle θ1 of the left pressing wheel (31), and the deflection angle θ2 of the right pressing wheel (41); S232. Adjust the parameters of the trapezoid forming die: First, the control module (6) synchronously drives the first displacement adjustment module (22), the second displacement adjustment module (32), and the third displacement adjustment module (42) according to △Y, △X1, and △X2; Second, the control module (6) synchronously drives the first angle adjustment module (33) and the second angle adjustment module (43) according to θ1 and θ2.

7. The manufacturing process of a litz wire according to claim 6, characterized in that: When it is judged in step S22 that the target cross-sectional graph is a rectangle, step S23a and step S23b are executed; S23a. Generate displacement adjustment instructions: The control module (6) generates the vertical displacement amount △Y of the lower pressing wheel (21), the horizontal displacement amount △X1 of the left sliding plate (34), and the horizontal displacement amount △X2 of the right sliding plate (44).; S23b. Adjust the parameters of the rectangle forming die: The control module (6) synchronously drives the first displacement adjustment module (22), the second displacement adjustment module (32), and the third displacement adjustment module (42) according to △Y, △X1, and △X2.

8. The manufacturing process of a litz wire according to claim 6, characterized in that: When it is judged in step S22 that the target cross-sectional graph is neither a rectangle nor a trapezoid, the control module (6) reports an error and repeats step S21.

9. The manufacturing process of a litz wire according to claim 4, characterized in that: The forming die further includes an on-line detection module (7) for real-time monitoring of the external dimensions of the variable die orifice (5). The on-line detection module (7) includes a laser profiler (71), a data feedback unit (72), and a lifting drive device (73) for driving the lifting and moving of the laser profiler (71). The laser profiler (71) and the lifting drive device (73) are arranged on the outlet side of the variable die orifice (5), and the data feedback unit (72) is signal-connected to the laser profiler (71) and the control module (6) respectively.

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