A production process of fine enameled square wire

Abstract

The invention relates to the technical field of enameled wire production, and discloses a manufacturing process of a fine enameled square wire, comprising wire laying, wire drawing, cleaning, annealing, first painting, first baking, first cooling, calendering, combined calendering, second painting, second baking, second cooling, lubrication and wire taking-up; the invention directly uses round wires for the first painting treatment and the first baking treatment, and since the round wires have good consistency and the size of the paint film is controllable, the debugging time is effectively reduced, and then the round wires after the first painting treatment are used for calendering treatment, and in the process of the round wires becoming flat wires, most of the paint film will be squeezed to the narrow side by a pressing roller, so that when the combined calendering is performed, the "bone shape" on the wires will be significantly improved, so that the angle of the cross-sectional R angle of the wires is increased, the film forming rate is increased, and the performance of the wires is also improved.

Description

Technical Field

[0001] The invention relates to the technical field of enameled wire production, in particular to a manufacturing process of a fine enameled square wire. Background Art

[0002] The existing enameled square wire is composed of paint film and square conductor, and is widely used in various inductors, electrical appliances, motors, voice coils, car multimedia and other products. In particular, in recent years, 5G mobile phones, 5G equipment, artificial intelligence machines, new energy and intelligent electrical appliances and automobiles have grown rapidly and demand has increased. These high-end products have extremely high added value, bringing a broader application field and bright prospects for enameled wires. As a result, higher and more stringent requirements are put forward for enameled wires.

[0003] In the production process of enameled square wire, when the width-to-thickness ratio of the enameled square wire is greater than 5 times, it is generally necessary to perform two calendering processes. After the first calendering, painting and baking, since the size of the wide and narrow side paint films of the flat wire is uncontrollable, during the second calendering after baking, the wide side paint film will be squeezed by the roller and extended to both ends, which will press the two ends of the conductor into a "bone shape". The larger the wide side paint film, the more obvious the "bone shape". In order to reduce the size of the "bone shape", the amount of paint applied in the first coating can only be continuously reduced, and the shape can be judged by grinding the cross section to see whether it meets the production requirements. The debugging time is long and it is not convenient for production. In addition, the formation of the "bone shape" will lead to unstable performance of the enameled square wire. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a production process for fine enameled square wire which can improve the "bone-shaped" formation condition, has high production efficiency and good product quality.

[0005] In order to solve the above technical problems, the present invention provides a process for manufacturing a fine enameled square wire, comprising the following steps:

[0006] S1: The semi-finished conductor is led out from the wire-laying device, and then drawn into a round wire by the wire-drawing device;

[0007] S2: After cleaning the wire, annealing is performed;

[0008] S3: Use high-pressure closed spray method to carry out the first painting treatment on the annealed wire;

[0009] S4: performing a first baking treatment on the wire after the first painting treatment, and then performing a first cooling treatment;

[0010] S5: performing calendering treatment on the wire after the first cooling treatment;

[0011] S6: performing combined calendering on the calendered wire to shape the wire into a square;

[0012] S7: Use high pressure and closed spray method to carry out second painting treatment on the wire after combined calendering treatment;

[0013] S8: performing a second baking treatment on the wire after the second painting treatment, and then performing a second cooling treatment;

[0014] S9: performing surface lubrication treatment on the wire after the second cooling treatment, and finally winding the wire to obtain the finished wire.

[0015] As a preferred embodiment of the present invention, in S4, the paint in the first painting process is PAI, and in S7, the paint in the second painting process is PI.

[0016] As a preferred embodiment of the present invention, in S6, the combined calendering treatment is carried out by a combined calendering device, which includes a plurality of roller devices arranged along the conveying direction of the wire, and the roller device includes four roller assemblies, and the four roller assemblies are arranged in the same plane, and the plane is perpendicular to the conveying direction of the wire. The roller assembly performs multiple rolling and shaping on the wire in all directions, and the deformation amount of each rolling and shaping is 10-15%.

[0017] As a preferred embodiment of the present invention, after S8, if self-adhesive paint coating is not required, the process proceeds to S9; if self-adhesive paint coating is required, after the self-adhesive paint coating is completed, the wire is subjected to a third baking treatment and a third cooling treatment in sequence, and then proceeds to S9.

[0018] As a preferred embodiment of the present invention, the paint used for the self-adhesive paint coating is one of HB, SB and SV.

[0019] As a preferred embodiment of the present invention, in S1, the semi-finished conductor is one of copper, silver, aluminum, alloy, copper-clad aluminum and tinned copper.

[0020] As a preferred embodiment of the present invention, in S2, the annealing temperature of the wire is: copper: 400-600°C; silver: 500-750°C; aluminum: 350-450°C; alloy: 500-750°C; copper-clad aluminum: 300-400°C; tinned copper: 600-700°C.

[0021] As a preferred solution of the present invention, in S9, the finished wires are subjected to performance inspection and finished product inspection, and are packaged and stored after they are qualified.

[0022] The present invention discloses a process for producing a fine enameled square wire. Compared with the prior art, the present invention has the following beneficial effects: the present invention directly uses round wire for the first painting treatment and the first baking treatment. Since the round wire has good consistency, the size of the paint film is controllable (can be measured and controlled by a handheld laser instrument), which effectively reduces the debugging time. The round wire after the first painting treatment is then subjected to calendering treatment. In the process of the round wire being converted into a flat wire, most of its paint film will be squeezed to the narrow side by the pressing roller. In this way, when the combined calendering is performed, the "bone shape" on the wire will be significantly improved, so that the angle of the cross-sectional R angle of the wire is increased, the film-forming rate is increased, and the performance of the wire is also improved. DETAILED DESCRIPTION

[0023] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0024] A manufacturing process of a fine enameled square wire according to a preferred embodiment of the present invention comprises the following steps:

[0025] S1: The semi-finished conductor is led out from the wire-laying device, and then drawn into a round wire by a wire drawing device. During the wire drawing process, a round wire die is used to ensure that the cross-section of the drawn wire is round. The semi-finished conductor is one of copper, silver, aluminum, alloy, copper-clad aluminum and tinned copper. The above materials are commonly used types in the market, but are not limited to the above materials.

[0026] S2: After the wire is cleaned, it is annealed. Ultrasonic cleaning equipment is generally used for cleaning to clean copper powder, oil and other dirt on the surface of the wire, so that the wire tube has better reading and stronger adhesion. Annealing can soften the wire at high temperature, rearrange the molecular lattice to restore the softness required by the process, and make the R angle of the wire more rounded and smooth. In addition, annealing can also eliminate certain structural defects and internal stress caused by the previous process, and remove lubricants, oil and other residual on the surface of the wire during the stretching process, so that the wire is easy to paint.

[0027] S3: Use a high-pressure closed spray method to apply the first paint treatment to the wire after annealing. The high-pressure closed spray method can be used for one or more multi-pass coatings. The single-sided paint film can achieve 0.3-6μm, and the thickness of the paint film can be accurately controlled. It has the advantages of simple operation, uniform painting, stable and efficient. Among them, the annealing temperature of the wire is: copper: 400-600℃; silver: 500-750℃; aluminum: 350-450℃; alloy: 500-750℃; copper-clad aluminum: 300-400℃; tinned copper: 600-700℃.

[0028] S4: The wire after the first painting treatment is subjected to the first baking treatment, and then the first cooling treatment is carried out. Generally, the baking treatment is carried out in a baking furnace. The wire is heated in the furnace and then cured and air-dried. The purpose of baking is to evaporate the solvent in the coating, so that the paint base is cured into a film to form a solidified insulating layer. After the solvent evaporates, it is catalyzed by a catalyst and converted into carbon dioxide and water, while releasing a large amount of heat. The cured paint layer can be repeatedly coated to facilitate subsequent processes. In order to ensure that the wire shrinks evenly during the cooling process, the cooling can be carried out in a gradient manner. The cooling is usually carried out by immersion in water, and the temperature of the water decreases in a gradient manner along the wire feeding direction. In addition, air cooling can also be used for cooling.

[0029] S5: The wire after the first cooling treatment is rolled to preliminarily reshape the wire. The wire is flat and its R angle is shaped to be close to a semicircle, which is beneficial to the next process. The overall processing volume of the wire is evenly and sufficiently distributed, the force is stable, and it is not easy to break.

[0030] S6: Performing combined calendering on the calendered wires to shape them into a square shape without the need for a mold. The wires have strong applicability, save mold opening time, and can be flexibly adjusted in size. The combined calendering is performed by a combined calendering device, which includes a plurality of roller devices arranged along the conveying direction of the wires. The roller device includes four roller assemblies, and the four roller assemblies are arranged in the same plane. The plane is perpendicular to the conveying direction of the wires. The roller assemblies perform multiple rolling shaping on the wires on all sides, and the deformation amount of each rolling shaping is 10-15%.

[0031] S7: The wire material after the combined calendering treatment is subjected to a second painting treatment by a high-pressure closed spray method. The operation is basically the same as that of the first painting treatment, but the paint used in the second painting treatment is different from that used in the first painting treatment.

[0032] S8: The wire after the second painting treatment is subjected to a second baking treatment, and then subjected to a second cooling treatment, and the operation is similar to that in S4; thereafter, yes can be selected according to the needs of the customer.

[0033] S9: The surface of the wire after the second cooling treatment is lubricated, and finally the wire is taken up to obtain the finished wire. The lubrication treatment can reduce the friction of the wire during winding, which is convenient for the wire taking-up operation. After that, the finished wire can be subjected to performance inspection and finished product inspection, and it will be packaged and stored after passing the inspection.

[0034] The principle of this embodiment is: when processing enameled square wires with a width-to-thickness ratio greater than 5 times, the first painting and baking treatments are directly performed with round wires. Since the round wires have good consistency and the size of their paint films is controllable (can be measured and controlled by a handheld laser instrument), the debugging time is effectively reduced. Afterwards, the round wires after the first painting treatment are subjected to calendering treatment. In the process of the round wires becoming flat wires, most of their paint films will be squeezed to the narrow sides by the pressing rollers. In this way, when combined calendering is performed, the "bone shape" on the wires will be significantly improved, so that the cross-sectional R angle of the wires is increased, the film-forming rate is increased, and the performance of the wires is also improved. The present invention can effectively improve the situation where the wires produce a "bone shape" during calendering and shaping, thereby ensuring high production efficiency and good product quality.

[0035] Exemplarily, in S4, the paint in the first painting process is PAI, and in S7, the paint in the second painting process is PI. Since PI-based materials are expensive, coating uniformity is difficult, storage conditions are harsh and the shelf life is short, a combination of PAI and PI is used in this embodiment. After processing, the insulation layer of the finished wire is a combination of PAI and PI. The product paint film coating has high uniformity and small deviation. The cost of this product is lower than that of simply coating PI insulating material, and the product is more competitive. The finished wire is resistant to high temperature and high pressure, has excellent mechanical properties and heat resistance, has inherent flame retardancy and good dielectric properties, and the softening breakdown test by the temperature rise method reaches above 500°C. The product can withstand higher temperature and high pressure and harsh operating conditions.

[0036] For example, after S8, it can be selected whether to apply self-adhesive paint according to the needs. If it is not necessary to apply self-adhesive paint, enter S9; if it is necessary to apply self-adhesive paint, then it is necessary to perform a third baking treatment and a third cooling treatment on the wire in sequence after the self-adhesive paint is applied, and then enter S9. In this embodiment, the paint for the self-adhesive paint is one of HB, SB and SV, and the self-adhesive paint can be applied in multiple layers.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A process for producing fine enameled square wire, characterized in that: The following steps are involved: S1: The semi-finished conductor is led out from the wire-laying device, and then drawn into a round wire by the wire-drawing device; S2: After cleaning the wire, annealing is performed; S3: Use high-pressure closed spray method to carry out the first painting treatment on the annealed wire; S4: performing a first baking treatment on the wire after the first painting treatment, and then performing a first cooling treatment, wherein the paint in the first painting treatment is PAI; S5: performing a calendering treatment on the wire after the first cooling treatment; S6: performing combined calendering on the calendered wire to shape the wire into a square; S7: using a high-pressure closed spray method to perform a second painting treatment on the wire after the combined calendering treatment, wherein the paint in the second painting treatment is PI; S8: performing a second baking treatment on the wire after the second painting treatment, and then performing a second cooling treatment; S9: performing surface lubrication treatment on the wire after the second cooling treatment, and finally winding the wire to obtain the finished wire; In S6, the combined calendering treatment is performed by a combined calendering device, which includes a plurality of roller devices arranged along the conveying direction of the wire rod, the roller device includes four roller assemblies, and the four roller assemblies are arranged in the same plane, and the plane is perpendicular to the conveying direction of the wire rod. The roller assembly performs multiple rolling shaping on the wire rod on all sides, and the deformation amount of each rolling shaping is 10-15%.

2. The process for producing fine enameled square wire according to claim 1, characterized in that: After S8, if self-adhesive paint coating is not required, the process proceeds to S9; if self-adhesive paint coating is required, after the self-adhesive paint coating is completed, the wire is subjected to a third baking treatment and a third cooling treatment in sequence, and then proceeds to S9.

3. The process for producing fine enameled square wire according to claim 2, characterized in that: The paint used for the self-adhesive paint is one of HB, SB and SV.

4. The process for producing fine enameled square wire according to claim 1, characterized in that: In S1, the semi-finished conductor is one of copper, silver, aluminum, alloy, copper-clad aluminum and tinned copper.

5. The process for producing fine enameled square wire according to claim 1, characterized in that: In S2, the annealing temperature of the wire is: copper: 400-600°C; Silver: 500-750°C; Aluminum: 350-450°C; Alloy: 500~750℃; Copper clad aluminum: 300~400℃; Tinned copper: 600~700℃.

6. The process for producing fine enameled square wire according to claim 1, characterized in that: In S9, the finished wires are subjected to performance inspection and finished product inspection, and are packaged and stored after they pass the inspection.