Stator bar less-glue insulation whole immersion process

Abstract

The invention belongs to the technical field of stator processing, and discloses a stator bar less-glue insulation whole immersion process, which comprises the following steps: S1, early-stage preparation; s2, stator bar pretreatment; s3, binding a less-glue mica tape; s4, dipping treatment; s5, curing treatment; s6, cleaning and detecting; the early-stage preparation comprises material selection and equipment inspection and debugging. According to the method, the excellent performance of an insulating layer is guaranteed from the source through the epoxy resin-based solvent-free impregnating varnish with the accurate proportion, secondly, in the link of binding the mica tape with less glue, the binding tightness and uniformity of the mica tape are guaranteed by accurately setting the speed and tension of a numerical control taping machine, the insulation defect caused by poor binding is effectively avoided, and in addition, the service life of the insulating layer is prolonged. Key technical measures such as pressure impregnation, accurate temperature control and pressure maintaining in the impregnation and curing process further promote sufficient permeation of the impregnating varnish and uniform curing of the insulating layer, and the compactness and the electrical performance of the insulating layer are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of stator processing, and in particular relates to a stator wire bar less-glue insulation whole-impregnation process. Background Art

[0002] The stator wire rod less-glue insulation full-impregnation process is an insulation treatment technology used for motor stator windings, and its main purpose is to improve the insulation performance and durability of the motor. It mainly includes less-glue insulation treatment, full-impregnation process and post-processing steps. This process is widely used in equipment such as motors, generators and transformers to ensure the long-term stable operation and safety of motor stator windings. Through this refined insulation treatment, the overall performance and reliability of the motor can be improved, ensuring the good performance of the motor in various working environments.

[0003] However, the traditional stator wire rod less-glue insulation dipping process still has certain problems in actual processing. For example, the control of the thickness of the insulation layer in the existing process may not be precise enough, resulting in unstable product performance, and the control of parameters such as temperature, pressure, and time during the dipping and curing process is not precise enough, which may cause fluctuations in the quality of the insulation layer. At the same time, the proportion and mixing process of the dipping paint may not be precise enough, affecting the curing effect, resulting in the need to optimize and improve the process to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a stator wire bar less-rubber insulation whole-impregnation process to solve the problems raised in the above background technology.

[0005] In order to achieve the above object, the present invention provides the following technical solution: a stator wire bar less glue insulation whole impregnation process, comprising the following steps:

[0006] S1: Preliminary preparation;

[0007] S2: stator bar pretreatment;

[0008] S3: Wrap with less-glue mica tape;

[0009] S4: immersion treatment;

[0010] S5: curing treatment;

[0011] S6: Cleaning and testing;

[0012] The preliminary preparation includes material selection and equipment inspection and debugging, the stator wire rod pretreatment includes cleaning and preheating, the wrapping of low-glue mica tape includes parameter setting and wrapping operation, the impregnation treatment includes impregnation paint treatment, impregnation operation, pressurized impregnation and dripping paint treatment, the curing treatment includes molding mold preparation and curing operation as well as cooling and demolding, and the cleaning and inspection include cleaning work and inspection work.

[0013] As a further technical solution of the present invention, the material selection includes selecting high-quality low-glue mica tape with a mica content of ≥70% and a glue content of 5%±2%, using epoxy resin-based solvent-free impregnating varnish, mixing according to a weight ratio of epoxy resin: anhydride curing agent: accelerator = 100:90:1, and selecting acetone, toluene and other cleaning agents, release agents, and insulating pads as auxiliary materials. The equipment inspection and debugging includes the integrity and operating status of the CNC taping machine, impregnation tank, molding die, air compressor, and vacuum pump, and adjusting the corresponding control system.

[0014] As a further technical solution of the present invention, the cleaning includes using organic solvents such as acetone and toluene to clean the surface of the stator wire rod to remove oil, impurities and old insulation layer, and drying it naturally or blowing it with a hot air gun after cleaning to ensure that there is no residual solvent on the surface. The preheating includes placing the cleaned stator wire rod into an oven or a preheating furnace, preheating it to 80°C±5°C, and maintaining it for a period of time to remove internal moisture.

[0015] As a further technical solution of the present invention, the parameter setting includes setting the speed of the CNC taping machine, which is adjusted according to the wire rod diameter and the mica tape width and controlled at about 15m / min, and performing tension control to ensure that the mica tape is tightly and evenly wrapped. The tension size needs to be determined through experiments based on the mica tape material and the wire rod size. The wrapping operation includes fixing the preheated stator wire rod on the CNC taping machine, ensuring that the straight section of the wire rod is parallel to the axis of the taping machine, starting the taping machine, and performing the wrapping operation according to preset parameters, paying attention to controlling the tape overlap rate and the number of wrapping layers, and checking the wrapping quality after the wrapping is completed to ensure that there is no missing wrapping, uneven overlapping or looseness.

[0016] As a further technical solution of the present invention, the preparation of the impregnation paint includes mixing epoxy resin, anhydride curing agent and accelerator in a weight ratio of 100:90:1 to make impregnation paint, and preheating the impregnation paint to about 50°C, keeping the temperature stable and stirring evenly. The impregnation operation includes placing the preheated stator wire rod into a tank car of the impregnation tank, and the bottom of the tank car should be provided with a drainage hole for dripping paint, closing the door of the impregnation tank and starting the vacuum pump, evacuating the impregnation tank to below 10Pa, and utilizing the pressure difference between the paint storage tank and the impregnation tank to uniformly inject the impregnation paint into the impregnation tank from the bottom to fully impregnate the wire rod. The impregnation time is determined according to the wire rod size and the performance of the impregnation paint, and is controlled to be 5-10 minutes.

[0017] As a further technical solution of the present invention, the pressurized impregnation includes closing the impregnation paint input valve after the impregnation is completed, starting the air compressor to pressurize the impregnation tank to 0.6Mpa, maintaining the pressure and continuing the impregnation for 3 hours to ensure that the impregnation paint fully penetrates the insulating layer, and regularly checking the pressure and temperature in the impregnation tank during the pressurized impregnation process to ensure that the process parameters are stable. The paint dripping treatment includes discharging the air in the impregnation tank to the atmosphere through a circulation device after the pressurized impregnation is completed, reducing the pressure in the tank to close to atmospheric pressure, and placing the wire rod in a tank truck in a free state in the impregnation tank for 10 minutes for paint dripping treatment to remove excess paint liquid.

[0018] As a further technical solution of the present invention, the molding die preparation includes checking the cleanliness and integrity of the molding die, ensuring that there are no impurities and damage, and applying an appropriate amount of mold release agent in the mold for demolding. The curing operation includes placing the impregnated stator wire rod into the molding die, ensuring that the straight section and the end of the wire rod are close to the mold, adjusting the position of the movable side iron and the upper pressure iron to fix the wire rod firmly, starting the heating system to start heating, and heating from 70°C to 145°C at a temperature rise rate of 1 to 2°C / min. When the temperature rises to 80°C, a pressure of 3MPa is applied and maintained until the curing is completed, and the temperature and pressure are kept at 145°C for 10 hours to ensure that the insulation layer is completely cured. The cooling and demolding include naturally cooling to room temperature after curing is completed and using forced cooling to accelerate the cooling rate. After cooling, the mold is removed and the wire rod is taken out for subsequent processing.

[0019] As a further technical solution of the present invention, the cleaning work includes using a cleaning agent to clean the surface of the wire rod to remove excess glue and impurities and paying attention to protecting the surface of the wire rod to avoid scratches or damage during the cleaning process. The inspection work includes measuring the size and appearance of the wire rod to ensure that there are no defects such as deformation and cracks, and performing insulation performance tests including insulation resistance and dielectric strength index tests to ensure that they meet the design requirements.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1. The present invention significantly improves the insulation quality and process stability of the stator wire rod through a series of refined steps and strict technical parameter control. First, in terms of material selection, high-quality low-glue mica tapes with a mica content of ≥70% and precisely controlled glue content, as well as epoxy resin-based solvent-free impregnating varnishes with precise proportions are selected to ensure the excellent performance of the insulation layer from the source. Secondly, in the process of wrapping the low-glue mica tape, the speed and tension of the CNC tape wrapping machine are accurately set to ensure the tightness and uniformity of the mica tape wrapping, effectively avoiding insulation defects caused by poor wrapping. In addition, key technical measures such as pressurized impregnation, precise temperature control and pressure maintenance during the impregnation and curing process further promote the full penetration of the impregnating varnish and the uniform curing of the insulation layer, significantly improving the density and electrical properties of the insulation layer.

[0022] 2. The present invention ensures the integrity and applicability of materials and equipment required for production through material selection, equipment inspection and debugging in the early preparation stage, reduces production interruptions and waste generation caused by unqualified materials or equipment failures, and on the other hand, realizes standardization and automation of the production process through precise control of various process parameters and operating procedures in core links such as wrapping, impregnation and curing, which not only reduces the difficulty and error of manual operation, but also improves production efficiency and product consistency. In addition, strict cleaning and testing work not only ensures the final quality of the product, but also avoids the influx of unqualified products by timely discovering and handling problems in the production process, further improving the yield rate and the economic benefits of the enterprise. In summary, the stator wire rod less-glue insulation whole impregnation process of the present invention not only improves the insulation quality, but also realizes the optimization of the production process and the dual improvement of production efficiency and yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall process flow of the present invention;

[0024] Figure 2 A schematic diagram of the process prepared in the early stage of the present invention;

[0025] Figure 3 It is a schematic diagram of the process of stator wire bar pretreatment of the present invention;

[0026] Figure 4 The present invention is a schematic diagram of the process of wrapping the low-resistance mica tape;

[0027] Figure 5 It is a schematic diagram of the process of the impregnation treatment of the present invention;

[0028] Figure 6 It is a schematic diagram of the curing process of the present invention;

[0029] Figure 7 It is a schematic diagram of the cleaning and detection process of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] like Figures 1 to 7 As shown, in an embodiment of the present invention, a stator wire bar less-glue insulation whole-impregnation process comprises the following steps:

[0032] S1: Preliminary preparation;

[0033] S2: stator bar pretreatment;

[0034] S3: Wrap with less-glue mica tape;

[0035] S4: immersion treatment;

[0036] S5: curing treatment;

[0037] S6: Cleaning and testing;

[0038] Preliminary preparation includes material selection and equipment inspection and debugging, stator wire bar pretreatment includes cleaning and preheating, wrapping of low-glue mica tape includes parameter setting and wrapping operation, impregnation treatment includes impregnation paint treatment, impregnation operation, pressurized impregnation and paint dripping treatment, curing treatment includes molding mold preparation and curing operation as well as cooling and demolding, cleaning and inspection include cleaning work and inspection work.

[0039] The stator wire rod less-glue insulation whole-impregnation process ensures the high-quality production of the stator wire rod insulation layer through refined step design. From preliminary preparation to final inspection, each step strictly controls material selection, equipment status, operating parameters and product quality, effectively improving the electrical performance, mechanical strength and durability of the insulation layer. This process not only improves production efficiency, but also reduces the scrap rate, providing a solid guarantee for the stable operation of motors and other equipment.

[0040] Among them, material selection includes selecting high-quality low-glue mica tape with a mica content ≥70% and a glue content between 5%±2%, using epoxy resin-based solvent-free impregnating varnish, mixing it in a weight ratio of epoxy resin: anhydride curing agent: accelerator = 100:90:1, and selecting acetone, toluene and other cleaning agents, release agents, and insulating pads as auxiliary materials. Equipment inspection and debugging include the integrity and operating status of CNC taping machines, impregnation tanks, molding molds, air compressors, and vacuum pumps, and adjusting the corresponding control systems.

[0041] By strictly controlling the selection of materials, we ensure that the low-glue mica tape has a high mica content and an appropriate glue content, and match it with epoxy resin-based solvent-free impregnation paint to optimize the ratio and improve the insulation performance. At the same time, we select cleaning agents, release agents and insulating pads to fully assist the processing process. The meticulous inspection and debugging of equipment ensures the stable and efficient operation of core equipment such as CNC taping machines and impregnation tanks. Through precise control system adjustment, it lays a solid foundation for the production of high-quality insulation layers for stator wire bars.

[0042] Among them, cleaning includes using organic solvents such as acetone and toluene to clean the surface of the stator wire rod to remove oil, impurities and old insulation layer. After cleaning, it is naturally dried or blown dry with a hot air gun to ensure that there is no residual solvent on the surface. Preheating includes placing the cleaned stator wire rod in an oven or preheating furnace, preheating to 80℃±5℃, and maintaining it for a period of time to remove internal moisture.

[0043] Through fine cleaning with organic solvents such as acetone and toluene, the oil, impurities and old insulation layer on the surface of the wire rod are effectively removed, laying a clean foundation for the subsequent insulation layer production. Subsequently, the preheating treatment not only removes the moisture inside the wire rod, but also increases its surface temperature, enhances the bonding force with the insulation material, ensures the close fit and high-quality formation of the insulation layer, and provides reliable guarantee for the long-term stable operation of equipment such as motors.

[0044] Among them, parameter settings include setting the speed of the CNC taping machine, which is adjusted according to the wire rod diameter and the width of the mica tape and controlled at about 15m / min, as well as tension control to ensure that the mica tape is tightly and evenly wrapped. The tension size needs to be determined through experiments based on the mica tape material and the wire rod size. The wrapping operation includes fixing the preheated stator wire rod on the CNC taping machine, ensuring that the straight section of the wire rod is parallel to the axis of the taping machine, starting the taping machine, and performing the wrapping operation according to the preset parameters. Pay attention to controlling the tape overlap rate and the number of wrapping layers. After wrapping, check the wrapping quality to ensure that there is no missing wrapping, uneven overlap or looseness.

[0045] By accurately setting the speed and tension of the CNC taping machine, the tightness and uniformity of the mica tape wrapping are ensured, avoiding insulation defects caused by poor wrapping. During the wrapping process, strict control of the tape overlap rate and number of layers further improves the performance of the insulation layer. This series of fine operations not only improves production efficiency, but also ensures the high quality of the insulation layer, laying a solid foundation for the long-term safe operation of motors and other equipment.

[0046] Among them, the preparation of the impregnation paint includes mixing the epoxy resin, anhydride curing agent and accelerator in a weight ratio of 100:90:1 to make the impregnation paint, and preheating the impregnation paint to about 50°C, keeping the temperature stable and stirring evenly. The impregnation operation includes placing the preheated stator wire rods into the tank truck of the impregnation tank. The bottom of the tank truck should be provided with drainage holes to facilitate paint dripping. The door of the impregnation tank is closed and the vacuum pump is started. The impregnation tank is evacuated to below 10Pa. The pressure difference between the paint storage tank and the impregnation tank is used to evenly inject the impregnation paint into the impregnation tank from the bottom to fully impregnate the wire rods. The impregnation time is determined according to the wire rod size and the performance of the impregnation paint, and is controlled to be 5-10 minutes.

[0047] By accurately proportioning and preheating the impregnation varnish, its good fluidity and permeability are ensured. During the impregnation process, a vacuum pump is used to create a low-pressure environment, which allows the impregnation varnish to evenly penetrate into the interior of the wire rod, effectively filling the pores and enhancing the insulation effect. Precise control of the impregnation time ensures that the wire rod is fully impregnated, improves the overall performance of the insulation layer, and provides reliable protection for the stable operation of equipment such as motors.

[0048] Among them, the pressurized impregnation includes closing the impregnation paint input valve after the impregnation is completed, starting the air compressor to pressurize the impregnation tank to 0.6Mpa, and maintaining the pressure and continuing to impregnate for 3 hours to ensure that the impregnation paint fully penetrates the insulation layer. During the pressurized impregnation process, the pressure and temperature in the impregnation tank are regularly checked to ensure the stability of the process parameters. The paint dripping treatment includes discharging the air in the impregnation tank to the atmosphere through a circulation device after the pressurized impregnation is completed, reducing the pressure in the tank to close to atmospheric pressure, and placing the wire rod in a tank truck in a free state in the impregnation tank for 10 minutes for paint dripping treatment to remove excess paint liquid.

[0049] Pressurized impregnation increases pressure, forcing the impregnation paint to penetrate the insulation layer more deeply, significantly improving the density and electrical performance of the insulation layer. At the same time, regular monitoring of pressure and temperature ensures the stability and controllability of process parameters. The dripping paint treatment effectively removes excess paint liquid, avoids surface defects of the insulation layer, and further improves the overall quality of the insulation layer. These two steps together provide a solid guarantee for the long-term stable operation of equipment such as motors.

[0050] Among them, the preparation of the molding die includes checking the cleanliness and integrity of the molding die, ensuring that there are no impurities and damage, and applying an appropriate amount of mold release agent in the mold for demolding. The curing operation includes placing the impregnated stator wire rod into the molding die, ensuring that the straight section and the end of the wire rod are close to the mold, adjusting the position of the movable side iron and the upper pressure iron to fix the wire rod firmly, starting the heating system to start heating, and heating from 70°C to 145°C at a temperature rise rate of 1 to 2°C / min. When the temperature rises to 80°C, a pressure of 3MPa is applied and maintained until the curing is completed. The temperature is kept at 145°C for 10 hours to ensure that the insulation layer is completely cured. Cooling and demolding include natural cooling to room temperature after curing is completed and forced cooling to accelerate the cooling speed. After cooling, the mold is removed and the wire rod is taken out for subsequent processing.

[0051] Cleaning the mold and applying the release agent ensures the smooth curing process and demoulding of the product. During the curing operation, the uniform curing and high-strength formation of the insulation layer are ensured by precisely controlling the temperature rise rate and pressure. The cooling and demoulding steps further consolidate the performance of the insulation layer and facilitate subsequent processing. This series of fine operations jointly improves the insulation quality and production efficiency of the stator bars.

[0052] Among them, the cleaning work includes using cleaning agents to clean the surface of the wire rod to remove excess glue and impurities and paying attention to protecting the surface of the wire rod to avoid scratches or damage during the cleaning process. The inspection work includes measuring the size and appearance of the wire rod to ensure that there are no defects such as deformation and cracks, and conducting insulation performance tests including insulation resistance and dielectric strength index tests to ensure that they meet the design requirements.

[0053] Through meticulous cleaning, excess glue and impurities are removed, and the surface finish of the wire rod is maintained. The strict testing process comprehensively evaluates the dimensional accuracy, appearance quality and insulation performance of the wire rod, ensuring that it has no defects such as deformation and cracks, and meets the insulation resistance and dielectric strength indicators required by the design. This link is of great significance to improving product quality and ensuring the safe and stable operation of equipment.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A stator wire rod less glue insulation whole impregnation process, comprising the following steps: S1: Preliminary preparation; S2: stator bar pretreatment; S3: Wrap with less-glue mica tape; S4: immersion treatment; S5: curing treatment; S6: Cleaning and testing; The preliminary preparation includes material selection and equipment inspection and debugging, the stator wire rod pretreatment includes cleaning and preheating, the wrapping of low-glue mica tape includes parameter setting and wrapping operation, the impregnation treatment includes impregnation paint treatment, impregnation operation, pressurized impregnation and dripping paint treatment, the curing treatment includes molding mold preparation and curing operation as well as cooling and demolding, and the cleaning and inspection include cleaning work and inspection work.

2. The stator wire rod less-rubber insulation whole-impregnation process according to claim 1 is characterized by: The material selection includes selecting high-quality low-glue mica tape with a mica content of ≥70% and a glue content of 5%±2%, using epoxy resin-based solvent-free impregnating varnish, mixing at a weight ratio of epoxy resin: anhydride curing agent: accelerator = 100:90:1, and selecting acetone, toluene and other cleaning agents, release agents, and insulating pads as auxiliary materials. The equipment inspection and debugging includes the integrity and operating status of CNC taping machines, impregnation tanks, molding molds, air compressors, and vacuum pumps, and adjusting the corresponding control systems.

3. The stator wire rod less-rubber insulation whole-impregnation process according to claim 1 is characterized by: The cleaning includes using organic solvents such as acetone and toluene to clean the surface of the stator wire rod to remove oil, impurities and old insulation layer, and then drying it naturally or blowing it with a hot air gun to ensure that there is no residual solvent on the surface. The preheating includes placing the cleaned stator wire rod in an oven or a preheating furnace, preheating it to 80°C±5°C, and keeping it for a period of time to remove internal moisture.

4. The stator wire rod less-rubber insulation whole-impregnation process according to claim 1 is characterized in that: The parameter setting includes setting the speed of the CNC taping machine, which is adjusted according to the wire rod diameter and the mica tape width and controlled at about 15m / min, and performing tension control to ensure that the mica tape is tightly and evenly wrapped. The tension size needs to be determined through experiments based on the mica tape material and the wire rod size. The wrapping operation includes fixing the preheated stator wire rod on the CNC taping machine, ensuring that the straight section of the wire rod is parallel to the axis of the taping machine, starting the taping machine, and performing the wrapping operation according to the preset parameters. Pay attention to controlling the tape overlap rate and the number of wrapping layers. After the wrapping is completed, check the wrapping quality to ensure that there is no missing bag, uneven overlap or looseness.

5. The stator wire bar less-rubber insulation whole-impregnation process according to claim 1 is characterized in that: The preparation of the impregnation varnish includes uniformly mixing epoxy resin, anhydride curing agent and accelerator in a weight ratio of 100:90:1 to prepare the impregnation varnish, and preheating the impregnation varnish to about 50°C, keeping the temperature stable and stirring evenly. The impregnation operation includes placing the preheated stator wire rod into a tank car of the impregnation tank, and a drainage hole should be provided at the bottom of the tank car to facilitate paint dripping. The door of the impregnation tank is closed and the vacuum pump is started to evacuate the inside of the impregnation tank to below 10Pa. The pressure difference between the paint storage tank and the impregnation tank is utilized to uniformly inject the impregnation varnish into the impregnation tank from the bottom to fully impregnate the wire rod. The impregnation time is determined according to the wire rod size and the performance of the impregnation varnish and is controlled to be 5-10 minutes.

6. The stator wire bar less-rubber insulation whole-impregnation process according to claim 1 is characterized by: The pressurized impregnation includes closing the impregnation paint input valve after the impregnation is completed, starting the air compressor to pressurize the impregnation tank to 0.6Mpa, and maintaining the pressure and continuing the impregnation for 3 hours to ensure that the impregnation paint fully penetrates the insulating layer. During the pressurized impregnation process, the pressure and temperature in the impregnation tank are regularly checked to ensure that the process parameters are stable. The paint dripping treatment includes discharging the air in the impregnation tank to the atmosphere through a circulation device after the pressurized impregnation is completed, reducing the pressure in the tank to near atmospheric pressure, and placing the wire rod in a tank truck in a free state in the impregnation tank for 10 minutes for paint dripping treatment to remove excess paint liquid.

7. The stator wire bar less-rubber insulation whole-impregnation process according to claim 1 is characterized by: The molding die preparation includes checking the cleanliness and integrity of the molding die, ensuring that there are no impurities and damage, and applying an appropriate amount of mold release agent in the mold for demolding. The curing operation includes placing the impregnated stator wire rod into the molding die, ensuring that the straight section and the end of the wire rod are close to the mold, adjusting the position of the movable side iron and the upper pressure iron to fix the wire rod firmly, starting the heating system to start heating, and heating from 70°C to 145°C at a temperature rise rate of 1 to 2°C / min. When the temperature rises to 80°C, a pressure of 3MPa is applied and maintained until the curing is completed, and the temperature and pressure are maintained at 145°C for 10 hours to ensure that the insulation layer is completely cured. The cooling and demolding include naturally cooling to room temperature after curing is completed and using forced cooling to accelerate the cooling rate. After cooling, the mold is removed and the wire rod is taken out for subsequent processing.

8. The stator wire rod less-rubber insulation whole-impregnation process according to claim 1 is characterized by: The cleaning work includes using a cleaning agent to clean the surface of the wire rod to remove excess glue and impurities and protecting the surface of the wire rod to avoid scratches or damage during the cleaning process. The inspection work includes measuring the size and appearance of the wire rod to ensure that there are no defects such as deformation and cracks, and conducting insulation performance tests including insulation resistance and dielectric strength index tests to ensure that they meet the design requirements.

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