Stranded enameled wire winding process using high-temperature adhesive tape

Abstract

The invention relates to the technical field of high-frequency transformer winding manufacturing, in particular to a twisted enameled wire winding process using a high-temperature adhesive tape, which comprises the following steps: S1, removing a paint layer at the end part of a twisted enameled wire to obtain a preformed bundle; s2, coating the surface of the preformed bundle with silicon resin-based gel; s3, performing semi-lap winding treatment of staged tension control on the preformed bundle coated with the silicon resin-based gel; s4, the tail end of the polyimide film adhesive tape is folded back and pasted, and then local hot pressing is conducted to form hot melting anchoring points; s5, carrying out heat treatment to cure the silicon resin-based gel; s6, cooling is conducted, and mechanical shaping is conducted on the surface; and S7, carrying out insulation resistance detection. According to the invention, while the advantages of low cost and easy automation of an adhesive tape scheme are maintained, the problems of compression damage and easy loosening of the end part of the stranded wire in the traditional mode are effectively solved through unique winding and curing processes.

Description

Technical Field

[0001] This invention relates to the field of high-frequency transformer winding technology, and in particular to a winding process for stranded enameled wire using high-temperature tape. Background Technology

[0002] High-frequency transformers, especially in high-frequency and high-reliability applications such as OBCs in new energy vehicles and photovoltaic inverters, often use stranded enameled wire as windings to reduce skin effect losses at high frequencies. In traditional processes, the insulation and mechanical fixing of the stranded wire ends mainly rely on heat-shrink tubing or Teflon tubing. However, this process has obvious drawbacks: First, the tubing needs to be pre-cut, manually threaded, and heat-shrinked, which is a cumbersome process that is difficult to automate and results in low production efficiency. Second, the tubing material is expensive and requires additional heat-shrinking equipment, increasing manufacturing costs and energy consumption.

[0003] Specifically, stranded wires are composed of multiple independent enameled wires. This unique structure presents two deep-seated and easily overlooked technical challenges to existing tape winding processes: First, there is the problem of invasive pressure damage. Conventional uniform tape winding applies continuous radial pressure to the stranded wires, forcing the internal strands to shift and compress the insulating varnish layer. This can not only cause microscopic damage to the varnish film but also alter the relative positions and gap distribution between the strands, thereby degrading the overall high-frequency conductivity of the stranded wire and leading to an unexpected increase in AC resistance (ACR). Second, there is the problem of end-strand loosening and stress concentration. After the varnish layer is removed from the ends of the stranded wires, the individual conductors lose their bond. The circumferential binding force of the tape alone is insufficient to resist the axial movement of the conductors under bending, vibration, or thermal stress, easily leading to loosening of the end conductors. At the same time, the beginning and end ends of the tape are stress concentration points, which are prone to warping or breakage after long-term thermal cycling, seriously affecting long-term insulation reliability. These potential problems limit the application of existing tape processes in high-end fields requiring extreme reliability. Therefore, there is an urgent need for a stranded enameled wire winding process using high-temperature tape to specifically solve the above problems. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides a winding process for stranded enameled wire using high-temperature tape.

[0005] A winding process for stranded enameled wire using high-temperature adhesive tape includes the following steps: S1: Remove the enamel layer from the end of the stranded enameled wire to form a non-insulated area, and apply pressure to the non-insulated area to gather and shape it to obtain a pre-formed bundle; S2: Coat the surface of the preformed bundle with silicone-based gel; S3: Using polyimide film tape, a preformed bundle coated with silicone resin-based gel is subjected to a staged tension-controlled semi-overlay process. S4: Fold the end of the polyimide film tape back and stick it, then apply local heat pressing to the beginning and end of the tape to form a heat-melt anchor point; S5: Heat-treat the wire harness that has completed S4 to cure the silicone resin-based gel and form a buffer composite insulation layer. S6: Cool the buffer composite insulation layer and mechanically shape its surface to ensure a rounded shape without sharp edges; S7: Perform insulation resistance testing on the shaped buffer composite insulation layer.

[0006] Optionally, S1 specifically includes: S11: At the end of the stranded enameled wire, measure and mark a section with a length of 10±2mm; S12: Laser ablation is used to remove the paint layer in the marked section, forming a bare metal conductor area, which is the non-insulated area; S13: Place the non-insulated area into the arc-shaped groove of the pre-formed fixture, wherein the radius of curvature of the arc-shaped groove matches 100% of the nominal outer diameter of the stranded enameled wire; S14: Control the preforming fixture to apply a radial pressure of 0.05MPa to 0.1MPa to the non-insulated area and hold it for 2 to 3 seconds. After releasing the pressure, a preformed bundle with a compact structure and an approximately circular cross-section is obtained.

[0007] Optionally, S2 specifically includes: S21: Provides silicone-based gels with viscosities from 500 cP to 2000 cP; S22: Load the silicone-based gel into the prepared dispensing device; S23: The preformed bundle passes through the coating area of ​​the dispensing device at a uniform speed along its axial direction. The dispensing device is controlled to continuously coat the entire outer surface of the preformed bundle with silicone resin-based gel at a moving speed of 0.5 mm / s to 1.5 mm / s and a flow rate of 0.05 ml / min to 0.15 ml / min. S24: Control the thickness of the coating layer of the silicone resin-based gel on the surface of the preformed bundle to be 0.05 mm to 0.1 mm.

[0008] Optionally, the polyimide film tape has a thickness of 0.03 mm to 0.07 mm, a temperature resistance rating greater than 260°C, and a CTI value greater than 650.

[0009] Optionally, S3 specifically includes: S31: The polyimide film tape is wrapped in a first tension of 0.5N to 1.0N on the surface of the preformed bundle coated with silicone resin-based gel in the first stage of half-overlapping, and wrapped 3 to 5 times to form a low-tension inner layer. S32: Based on the low-tension inner layer, immediately increase the winding tension to a second tension of 1.5N to 2.5N, perform the second stage of half-overlap winding, and continue winding for 3 to 5 turns to form a high-tension outer layer; S33: The total coverage length of the low-tension inner layer and the high-tension outer layer is controlled to be 3-5 times the diameter of the preformed bundle.

[0010] Optionally, S4 specifically includes: S41: After completing the winding of S3, fold the end of the polyimide film tape back 2mm to 3mm along the circumference of the preformed bundle and stick it flat on the surface of the outermost tape to form a ring-shaped folded part. S42: Using a narrow-faced hot press head, the starting winding end of the polyimide film tape is subjected to localized hot pressing for 3 to 5 seconds at a temperature of 120°C to 150°C and a pressure of 0.2MPa to 0.3MPa. S43: Using the same narrow-faced hot press head, under the same temperature and pressure conditions, perform local hot pressing on the outer edge of the folded part for 3 to 5 seconds. S44: After processing with S42 and S43, a fused hot-melt anchor point is formed at the beginning and end of the tape.

[0011] Optionally, S5 specifically includes: S51: Place the wire harness that has completed S4 in a heat treatment device, and raise the ambient temperature of the wire harness from room temperature to the target treatment temperature of 80°C to 100°C at a heating rate of 1°C / s to 3°C / s. S52: Perform constant temperature heat treatment on the wire harness for 5 to 8 minutes at the target processing temperature; S53: After the constant temperature heat treatment, the silicone resin-based gel is fully cured and combined with the polyimide film tape and preformed bundle to form a buffer composite insulation layer.

[0012] Optionally, S6 specifically includes: S61: Place the wire harness with the buffered composite insulation layer in a room temperature environment and allow it to cool naturally for 5 to 10 minutes. S62: Using a smooth metal or ceramic roller, roll the outer surface of the cooled buffer composite insulation layer along its axial direction, applying a pressure of 0.1 MPa to 0.3 MPa and a rolling speed of 10 mm / s to 20 mm / s; S63: After rolling, inspect the overall appearance of the buffer composite insulation layer to ensure that its surface is smooth and without sharp edges.

[0013] Optionally, S7 specifically includes: S71: Using an insulation resistance tester, under the conditions of an ambient temperature of 23℃ and a relative humidity of less than 65%, apply a DC test voltage of 500V to the shaped buffer composite insulation layer for 60 seconds, measure and record its initial insulation resistance value R1. S72: Place the completed wiring harness into the high and low temperature cycling test chamber and perform a temperature cycling test. The temperature cycling test procedure is as follows: maintain the temperature at -40℃ for 30 minutes, then raise the temperature to 150℃ within 30 minutes and maintain it for 30 minutes, and finally lower the temperature to -40℃ within 30 minutes. This process is recorded as one cycle. S73: Repeat the loop program of step S72 until a total of 1000 temperature cycles are completed; S74: After the wire harness completed in S73 has been restored to thermal equilibrium under standard atmospheric conditions, repeat the test conditions and methods of S71, measure and record its final insulation resistance value R2. S75: The pass / fail criterion is that the initial insulation resistance value R1 and the final insulation resistance value R2 are both not less than 1GΩ.

[0014] The beneficial effects of this invention are: This invention effectively solves the problem of invasive pressure damage in traditional tape winding processes by combining pre-forming, coating with buffer gel, and layered tension winding. The low-tension winding of the inner layer of the tape and the buffering effect of the gel layer minimize the pressure on the internal structure of the stranded wire, protecting its high-frequency electrical performance. At the same time, the high-tension winding of the outer layer and the end heat-melt anchoring, together with the cured gel layer, achieve three-dimensional locking of the ends of the stranded wire, completely eliminating fraying and stress concentration points at the beginning and end of the tape, significantly improving the long-term mechanical reliability of the insulation structure under vibration and thermal shock. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the stranded enameled wire winding process according to an embodiment of the present invention; Figure 2 This is a schematic diagram of tape fixing according to an embodiment of the present invention. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more comprehensive, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0018] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0019] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0020] Example 1 like Figures 1-2 As shown, a winding process for stranded enameled wire using high-temperature tape includes the following steps: S1: Remove the enamel layer from the end of the stranded enameled wire to form a non-insulated area, and apply pressure to the non-insulated area to gather and shape it to obtain a pre-formed bundle; S2: Coat the surface of the preformed bundle with silicone-based gel; S3: Using polyimide film tape, a preformed bundle coated with silicone resin-based gel is subjected to a staged tension-controlled semi-overlay process. S4: Fold the end of the polyimide film tape back and stick it, then apply local heat pressing to the beginning and end of the tape to form a heat-melt anchor point; S5: Heat-treat the wire harness that has completed S4 to cure the silicone resin-based gel and form a buffer composite insulation layer. S6: Cool the buffer composite insulation layer and mechanically shape its surface to ensure a rounded shape without sharp edges; S7: Perform insulation resistance testing on the shaped buffer composite insulation layer.

[0021] S1 specifically includes: S11: At the end of the stranded enameled wire, measure and mark a section with a length of 10mm; S12: Laser ablation is used to remove the paint layer in the marked section, forming a bare metal conductor area, which is the non-insulated area; S13: Place the non-insulated area into the arc-shaped groove of the pre-formed fixture, the radius of curvature of the arc-shaped groove being matched with 100% of the nominal outer diameter of the stranded enameled wire; S14: Control the preforming fixture to apply a radial pressure of 0.08 MPa to the non-insulated area and hold it for 2.5 seconds. After releasing the pressure, a preformed bundle with a compact structure and an approximately circular cross-section is obtained.

[0022] S2 specifically includes: S21: Provides silicone-based gel with a viscosity of 1200 cP; S22: Load the silicone-based gel into a dispensing device with precise metering function; S23: The preformed bundle passes through the coating area of ​​the dispensing device at a uniform speed along its axial direction. The dispensing device is controlled to continuously coat the entire outer surface of the preformed bundle with silicone resin-based gel at a moving speed of 1.0 mm / s and a flow rate of 0.1 ml / min. S24: Control the thickness of the silicone resin-based gel coating on the surface of the preformed bundle to be 0.08 mm.

[0023] The polyimide film tape has a thickness of 0.05 mm, a temperature resistance rating greater than 280℃, and a CTI value greater than 650.

[0024] S3 specifically includes: S31: The polyimide film tape is wrapped with a first tension of 0.8N on the surface of the preformed bundle coated with silicone resin-based gel in the first stage of half-overlapping, and wrapped 4 times to form a low-tension inner layer. S32: Based on the low-tension inner layer, immediately increase the winding tension to a second tension of 2.0N, perform the second stage of half-overlap winding, and continue winding for 4 turns to form a high-tension outer layer; S33: The total coverage length of the low-tension inner layer and the high-tension outer layer is controlled to be 4 times the diameter of the preformed bundle.

[0025] S4 specifically includes: S41: After completing the winding of S3, fold the end of the polyimide film tape back 2.5mm along the circumference of the preformed bundle and stick it flat to the surface of the outermost tape to form a ring-shaped folded part. S42: A narrow-faced hot press head is used to perform localized hot pressing on the starting winding end of the polyimide film tape for 4 seconds at a temperature of 140℃ and a pressure of 0.25MPa. S43: Using the same narrow-faced hot press head, under the same temperature and pressure conditions, perform local hot pressing on the outer edge of the folded part for 4 seconds. S44: After processing with S42 and S43, a fused hot-melt anchor point is formed at the beginning and end of the tape.

[0026] S5 specifically includes: S51: Place the wire harness that has completed S4 in a heat treatment device, and raise the ambient temperature of the wire harness from room temperature to the target treatment temperature of 90°C at a heating rate of 2°C / s. S52: Perform constant temperature heat treatment on the wire harness for 6 minutes at the target processing temperature; S53: After constant temperature heat treatment, the silicone resin-based gel is fully cured and combined with the polyimide film tape and preformed bundle to form a buffer composite insulation layer.

[0027] S6 specifically includes: S61: Place the wire harness with the buffered composite insulation layer in a room temperature environment and allow it to cool naturally for 8 minutes. S62: Using smooth metal rollers, the outer surface of the cooled buffer composite insulation layer is rolled along its axial direction with a pressure of 0.2 MPa and a rolling speed of 15 mm / s. S63: After rolling, inspect the overall appearance of the buffer composite insulation layer to ensure that its surface is smooth and without sharp edges.

[0028] S7 specifically includes: S71: Using an insulation resistance tester, under the conditions of an ambient temperature of 23℃ and a relative humidity of less than 65%, apply a DC test voltage of 500V to the shaped buffer composite insulation layer for 60 seconds, measure and record its initial insulation resistance value R1=6.2GΩ. S72: Place the completed wiring harness into the high and low temperature cycling test chamber and perform a temperature cycling test. The temperature cycling test procedure is as follows: maintain the temperature at -40℃ for 30 minutes, then raise the temperature to 150℃ within 30 minutes and maintain it for 30 minutes, and finally lower the temperature to -40℃ within 30 minutes. This process is recorded as one cycle. S73: Repeat the loop program of step S72 until a total of 1000 temperature cycles are completed; S74: After the wire harness completed in S73 has been restored to thermal equilibrium under standard atmospheric conditions, repeat the test conditions and methods of S71, measure and record its final insulation resistance value R2=4.9G; S75: The pass / fail criterion is that the initial insulation resistance value R1 and the final insulation resistance value R2 are both not less than 1GΩ.

[0029] Example 2 S1: Measure and mark an 8mm section at the end of the stranded enameled wire; completely remove the enamel layer in this section using laser ablation to form a non-insulated area of ​​the bare metal conductor; place the non-insulated area into a pre-forming fixture in which the radius of curvature of the arc groove is perfectly matched with the outer diameter; apply a radial pressure of 0.05MPa to the non-insulated area and hold for 2s; after releasing the pressure, obtain a pre-forming bundle with an approximately circular cross-section and a compact structure. S2: Select a silicone resin-based gel with a viscosity of 500 cP and load it into the dispensing device; control the preformed bundle to move through the coating area at an axial speed of 0.5 mm / s, while controlling the dispensing flow rate to 0.05 ml / min, so that the gel uniformly and continuously covers the outer surface of the preformed bundle to form a coating layer with a thickness of 0.05 mm. S3: Select a polyimide film tape with a thickness of 0.03mm, a temperature resistance rating of 270℃, and a CTI value of 680; perform the first stage of half-overlapping with a first tension of 0.5N, wrapping 3 turns to form a low-tension inner layer; then increase the tension to 1.5N and continue half-overlapping 3 turns to form a high-tension outer layer; control the overall coverage length to be 3 times the diameter of the preformed bundle; S4: Fold the end of the tape back 2mm circumferentially and flatten it; use a narrow-faced hot press head to perform local hot pressing on the starting end and the outer edge of the folded part for 3s at 120℃ and 0.2MPa to form a stable hot melt anchor point; S5: Heat the wire harness to 80°C at a heating rate of 1°C / s and keep it at this temperature for 5 minutes to allow the silicone resin-based gel to fully cure and form a buffer composite insulation layer. S6: Allow to cool naturally at room temperature for 5 minutes; then use a smooth ceramic roller to perform axial rolling shaping at a rolling pressure of 0.1 MPa and a speed of 10 mm / s to make the shape round and without sharp edges. S7: Applying a 500V DC voltage for 60s at 23℃ and 60% relative humidity, the initial insulation resistance R1 was measured to be 5.5GΩ; after completing 1000 temperature cycles from -40℃ to 150℃, the initial insulation resistance R2 was measured to be 3.8GΩ.

[0030] Example 3 S1: Measure and mark a 12mm section at the end of the stranded enameled wire; completely remove the enamel layer in this section using laser ablation to form a non-insulated area of ​​the bare metal conductor; place the non-insulated area into a pre-forming fixture in which the radius of curvature of the arc groove is perfectly matched with the outer diameter; apply a radial pressure of 0.1MPa to the non-insulated area and hold for 3s; after releasing the pressure, obtain a pre-forming bundle with an approximately circular cross-section and a compact structure. S2: Select a silicone resin-based gel with a viscosity of 2000 cP and load it into the dispensing device; control the preformed bundle to move through the coating area at an axial speed of 0.15 mm / s, while controlling the dispensing flow rate to 0.15 ml / min, so that the gel uniformly and continuously covers the outer surface of the preformed bundle to form a coating layer with a thickness of 0.1 mm. S3: Select a polyimide film tape with a thickness of 0.07mm, a temperature resistance rating of 260℃, and a CTI value of 660; perform the first stage of half-overlapping with a first tension of 1.0N, wrapping 5 turns to form a low-tension inner layer; then increase the tension to 2.5N and continue half-overlapping 5 turns to form a high-tension outer layer; control the overall coverage length to be 5 times the diameter of the preformed bundle; S4: Fold the end of the tape back 3mm circumferentially and flatten it; use a narrow-faced hot press head to perform local hot pressing on the starting end and the outer edge of the folded part for 3s at 150℃ and 0.3MPa to form a stable hot melt anchor point. S5: Heat the wire harness to 100°C at a heating rate of 3°C / s, and keep it at this temperature for 8 minutes to allow the silicone resin-based gel to fully cure and form a buffer composite insulation layer. S6: Allow to cool naturally at room temperature for 10 minutes; then use a smooth metal roller to perform axial rolling shaping at a rolling pressure of 0.3 MPa and a speed of 20 mm / s to make the shape round and without sharp edges. S7: Applying a 500V DC voltage for 60s at 23℃ and 60% relative humidity, the initial insulation resistance R1 was measured to be 4.5GΩ; after completing 1000 temperature cycles from -40℃ to 150℃, the initial insulation resistance R2 was measured to be 3.2GΩ.

[0031] Comparative Example 1 Step 1: Remove the enamel layer from the ends of the stranded enameled wire using a mechanical scraping method, with a stripping length of 8mm, to create an exposed conductor area; Step 2: Using 0.10 mm thick PVC electrical tape, wrap it directly in the forward direction for full coverage under a constant tension of 1.0 N, wrapping it 3 times, and fixing it by the adhesive of the tape itself; Step 3: After wrapping, place the wire harness in a room temperature environment for 10 minutes to complete the operation.

[0032] Table 1 Comparison of Performance Parameters Comparison Projects Example 1 Example 2 Example 3 Comparative Example 1 Initial insulation resistance R1 (GΩ) 6.2 5.5 4.5 1.2 Insulation resistance R2 (GΩ) after cycling 4.9 3.8 3.2 0.4 Insulation resistance retention rate R2 / R1 (%) 79 69 71 33 Temperature cycle count (times) ≥1000 ≥1000 ≥1000 ≤300 End peel strength (N) 18 14 12 5 Insulation layer outer diameter consistency deviation (mm) ±0.03 ±0.05 ±0.06 ±0.15 Surface defect incidence rate (%) 0.5 1.2 2 8.5 Appearance integrity rate after high-temperature aging (%) 98 95 92 70 End stress concentration failure rate (%) 0.3 0.8 1.1 6 As can be seen from Table 1 above, Example 1 is significantly superior to other embodiments in terms of insulation stability, structural consistency, end mechanical reliability, and environmental resistance. It maintains high insulation resistance and resistance retention rate after 1000 high and low temperature cycles, exhibits the strongest end peel resistance, and has the lowest surface defect rate and failure rate. This indicates that the composite structure formed by pre-forming compaction + silicone resin buffer layer + staged tension wrapping + hot-melt anchoring can effectively reduce end stress concentration and improve long-term reliability. In contrast, Comparative Example 1, which only uses mechanical paint removal and ordinary PVC tape wrapping, lacks buffering and anchoring structures, resulting in significant deficiencies in insulation retention, temperature cycling resistance, and mechanical stability, and exhibits the worst overall performance. Considering all indicators, Example 1 can be considered the best embodiment of the present invention.

[0033] Table 2 Comparison of performance parameters in other directions Comparison Projects Example 1 Example 2 Example 3 Comparative Example 1 Vibration life at the end (Hz / cycle) <![CDATA[50 / 1×10 6 ]]> <![CDATA[40 / 8×10 5 ]]> <![CDATA[35 / 6×10 5 ]]> <![CDATA[20 / 2×10 5 ]]> Length of interlaminar peel after thermal shock (mm) ≤0.3 ≤0.6 ≤0.8 ≥2.5 Change rate of hardening index after high temperature (180℃) aging (%) 8 12 15 35 Bending fatigue life (R=10mm, cycles) <![CDATA[2.0×10 5 ]]> <![CDATA[1.5×10 5 ]]> <![CDATA[1.2×10 5 ]]> <![CDATA[3.5×10 4 ]]> Insulation degradation rate (%) under humid heat (85℃ / 85%RH) 10 16 20 45 Percentage of end structure detachment (%) 0.2 0.6 1 7.5 As can be seen from Table 2 above, Example 1 exhibits the best performance in terms of mechanical fatigue, environmental adaptability, and structural stability. It maintains an extremely low rate of interlaminar delamination and loosening even under high-frequency vibration, repeated bending, and thermal shock conditions, indicating that the end structure possesses excellent stress relief and overall constraint capabilities. Furthermore, it shows the smallest performance degradation under high-temperature aging and humid environments, demonstrating the stable long-term service characteristics of the buffer composite insulation layer. In contrast, Comparative Example 1, lacking pre-formed compaction, a buffer layer, and end anchoring structures, exhibits significant performance degradation under vibration, bending, and humid conditions, resulting in significantly insufficient reliability. Considering all indicators, Example 1 demonstrates the best durability and stability under comprehensive operating conditions and can be considered the optimal embodiment of this invention.

[0034] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0035] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A process for winding a stranded enameled wire using a high temperature adhesive tape, characterized in that, Includes the following steps: S1: Remove the enamel layer from the end of the stranded enameled wire to form a non-insulated area, and apply pressure to the non-insulated area to gather and shape it to obtain a pre-formed bundle; S2: Coat the surface of the preformed bundle with silicone-based gel; S3: Using polyimide film tape, a preformed bundle coated with silicone resin-based gel is subjected to a staged tension-controlled semi-overlay process. S4: Fold the end of the polyimide film tape back and stick it, then apply local heat pressing to the beginning and end of the tape to form a heat-melt anchor point; S5: Heat-treat the wire harness that has completed S4 to cure the silicone resin-based gel and form a buffer composite insulation layer. S6: Cool the buffer composite insulation layer and mechanically shape its surface to ensure a rounded shape without sharp edges; S7: Perform insulation resistance testing on the shaped buffer composite insulation layer.

2. A process for winding a stranded enameled wire using a high temperature adhesive tape according to claim 1, characterized in that, S1 specifically includes: S11: At the end of the stranded enameled wire, measure and mark a section with a length of 10±2mm; S12: Laser ablation is used to remove the paint layer in the marked section, forming a bare metal conductor area, which is the non-insulated area; S13: Place the non-insulated area into the arc-shaped groove of the pre-formed fixture, wherein the radius of curvature of the arc-shaped groove matches 100% of the nominal outer diameter of the stranded enameled wire; S14: Control the preforming fixture to apply a radial pressure of 0.05MPa to 0.1MPa to the non-insulated area and hold it for 2 to 3 seconds. After releasing the pressure, a preformed bundle with a compact structure and an approximately circular cross-section is obtained.

3. The stranded enameled wire winding process using high-temperature tape according to claim 1, characterized in that, S2 specifically includes: S21: Provides silicone-based gels with viscosities from 500 cP to 2000 cP; S22: Load the silicone-based gel into the prepared dispensing device; S23: The preformed bundle passes through the coating area of ​​the dispensing device at a uniform speed along its axial direction. The dispensing device is controlled to continuously coat the entire outer surface of the preformed bundle with silicone resin-based gel at a moving speed of 0.5 mm / s to 1.5 mm / s and a flow rate of 0.05 ml / min to 0.15 ml / min. S24: Control the thickness of the coating layer of the silicone resin-based gel on the surface of the preformed bundle to be 0.05 mm to 0.1 mm.

4. The stranded enameled wire winding process using high-temperature tape according to claim 1, characterized in that, The polyimide film tape has a thickness of 0.03 mm to 0.07 mm, a temperature resistance rating greater than 260°C, and a CTI value greater than 650.

5. The winding process of stranded enameled wire using high-temperature tape according to claim 1, characterized in that, S3 specifically includes: S31: The polyimide film tape is wrapped in a first tension of 0.5N to 1.0N on the surface of the preformed bundle coated with silicone resin-based gel in the first stage of half-overlapping, and wrapped 3 to 5 times to form a low-tension inner layer. S32: Based on the low-tension inner layer, immediately increase the winding tension to a second tension of 1.5N to 2.5N, perform the second stage of half-overlap winding, and continue winding for 3 to 5 turns to form a high-tension outer layer; S33: The total coverage length of the low-tension inner layer and the high-tension outer layer is controlled to be 3-5 times the diameter of the preformed bundle.

6. The stranded enameled wire winding process using high-temperature tape according to claim 1, characterized in that, S4 specifically includes: S41: After completing the winding of S3, fold the end of the polyimide film tape back 2mm to 3mm along the circumference of the preformed bundle and stick it flat on the surface of the outermost tape to form a ring-shaped folded part. S42: Using a narrow-faced hot press head, the starting winding end of the polyimide film tape is subjected to localized hot pressing for 3 to 5 seconds at a temperature of 120°C to 150°C and a pressure of 0.2MPa to 0.3MPa. S43: Using the same narrow-faced hot press head, under the same temperature and pressure conditions, perform local hot pressing on the outer edge of the folded part for 3 to 5 seconds. S44: After processing with S42 and S43, a fused hot-melt anchor point is formed at the beginning and end of the tape.

7. The winding process of stranded enameled wire using high-temperature tape according to claim 1, characterized in that, S5 specifically includes: S51: Place the wire harness that has completed S4 in a heat treatment device, and raise the ambient temperature of the wire harness from room temperature to the target treatment temperature of 80°C to 100°C at a heating rate of 1°C / s to 3°C / s. S52: Perform constant temperature heat treatment on the wire harness for 5 to 8 minutes at the target processing temperature; S53: After the constant temperature heat treatment, the silicone resin-based gel is fully cured and combined with the polyimide film tape and preformed bundle to form a buffer composite insulation layer.

8. The winding process of stranded enameled wire using high-temperature tape according to claim 1, characterized in that, S6 specifically includes: S61: Place the wire harness with the buffered composite insulation layer in a room temperature environment and allow it to cool naturally for 5 to 10 minutes. S62: Using a smooth metal or ceramic roller, roll the outer surface of the cooled buffer composite insulation layer along its axial direction, applying a pressure of 0.1 MPa to 0.3 MPa and a rolling speed of 10 mm / s to 20 mm / s; S63: After rolling, inspect the overall appearance of the buffer composite insulation layer to ensure that its surface is smooth and without sharp edges.

9. The winding process of stranded enameled wire using high-temperature tape according to claim 1, characterized in that, Specifically, S7 includes: S71: Using an insulation resistance tester, under the conditions of an ambient temperature of 23℃ and a relative humidity of less than 65%, apply a DC test voltage of 500V to the shaped buffer composite insulation layer for 60 seconds, measure and record its initial insulation resistance value R1. S72: Place the completed wiring harness into the high and low temperature cycling test chamber and perform a temperature cycling test. The temperature cycling test procedure is as follows: maintain the temperature at -40℃ for 30 minutes, then raise the temperature to 150℃ within 30 minutes and maintain it for 30 minutes, and finally lower the temperature to -40℃ within 30 minutes. This process is recorded as one cycle. S73: Repeat the loop program of step S72 until a total of 1000 temperature cycles are completed; S74: After the wire harness completed in S73 has been restored to thermal equilibrium under standard atmospheric conditions, repeat the test conditions and methods of S71, measure and record its final insulation resistance value R2. S75: The pass / fail criterion is that the initial insulation resistance value R1 and the final insulation resistance value R2 are both not less than 1GΩ.

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