A local painting process for flat enameled wire

Abstract

The present invention provides a local painting process for flat enameled wires, belonging to the technical field of enameled wire processing. The flat enameled wire includes a painted surface and a scraped surface, and the painting process comprises the following steps: A. Wax the wire in a state of covering the painted surface, so that the scraped surface is coated with a wax layer; B. Pass the waxed wire through paint; C. After the paint is dried and solidified, remove the wax layer on the wire to obtain a flat enameled wire with a self-adhesive layer only on the scraped surface. The present invention has the advantages of high wire quality and no need for scraping paint, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of enameled wire processing and relates to a local painting process for flat enameled wires. Background Art

[0002] Enameled wire consists of two parts: a conductor and an insulation layer. Larger-diameter raw wire is repeatedly drawn and annealed to a specified size, then painted and baked multiple times. Ordinary enameled wire has a circular cross-section, but this suffers from disadvantages such as a low slot fill rate and a small cross-section after winding. Simply put, circular-cross-section enameled wire has a low space utilization rate after winding, making it difficult to meet the technological development requirements for flattened, lightweight, low-power, and high-performance components. This is particularly true in the windings of various electrical equipment such as new energy vehicles, telecommunications equipment, transformers, motors, and generators. Flat-cross-section enameled wire offers improved impact resistance, higher space utilization, and significantly improved "skin effect" (when alternating current flows through a conductor, the current concentrates on the surface of the conductor), reducing losses in high-frequency electromagnetic coils.

[0003] Flat enameled wire is divided into four surfaces from the transverse cross section, generally two opposite straight surfaces and two opposite curved surfaces. Some flat enameled wires have four straight surfaces, and the adjacent straight surfaces are smoothly transitioned by small curved surfaces. In the winding process of flat enameled wire, only two of the straight surfaces are used as planes for mutual adhesion, and the other two surfaces (whether curved or flat) do not bear the role of adhesion. As we all know, in addition to the insulating paint (polyurethane layer), the enameled wire also needs to be coated with a polyamide self-adhesive layer for the winding wires to adhere to each other. In order to maximize the utilization of the accommodation space, the wire positions that do not bear the adhesion role do not need to be coated with a polyamide self-adhesive layer, such as Figure 4 As shown, of course, there is also a need to improve heat dissipation. Therefore, in the existing technology, the processing process of flat enameled wire is relatively complicated. It is necessary to coat the entire wire with a polyamide self-adhesive layer and then scrape the part (the wire passes through the paint scraping die, and the die mouth is provided with a paint scraping edge for the scraping surface). Since the painting is repeated many times, but the paint scraping is generally not completed in one go after the last painting, this will affect the quality of the wire due to the large scraping thickness, especially the risk of scratching and copper leakage will increase. Therefore, scraping the polyamide self-adhesive layer at the position that does not need to be coated needs to be performed many times, and the workload is large. However, there is a risk of damage to the wire in any scraping process. In addition, the flat enameled wire itself has certain difficulties in straight pulling, resulting in a high probability of damage to the wire during the scraping of the polyamide self-adhesive layer. Summary of the Invention

[0004] The object of the present invention is to provide a local painting process for flat enameled wires in view of the above problems existing in the prior art. The technical problem to be solved by the present invention is how to avoid wire damage caused by scraping paint.

[0005] The object of the present invention can be achieved by the following technical solutions: A local painting process for flat enameled wires, the flat enameled wire includes a painted surface and a scraped surface, and is characterized in that it includes the following steps: A. Wax the wire in a state of covering the painted surface so that the scraped surface is coated with a wax layer; B. Pass the waxed wire through the paint; C. After the paint dries and solidifies, remove the wax layer on the wire to obtain a flat enameled wire with an adhesive layer only on the scraped surface.

[0006] This solution is a local painting process that does not require scraping paint. The wax layer is used to protect the scraped surface, separating the paint liquid from the wire through the wax layer. Its significant advantage is not only that it can save the usage of polyamide self-adhesive, but also that it can avoid wire damage caused by scraping paint.

[0007] Further, after step B, the wire is dried and solidified at room temperature, and then step B is repeated multiple times to achieve multiple painting. After multiple painting is completed, the wax layer is removed.

[0008] Room temperature curing can maintain the existence of the wax layer, and only one waxing is required during the multiple painting process.

[0009] Further, the material for waxing to form the wax layer is paraffin wax.

[0010] Paraffin wax is incompatible with polyamide self-adhesive paint, which can avoid the adhesion of the paint liquid during the painting process and save the paint usage.

[0011] Further, the method for removing the wax layer is to wash it through a liquid of paraffin wax solution.

[0012] Of course, the wax layer can be removed by heating, but it will cause problems of incomplete removal and the problem that paraffin wax flows and adheres to the painted surface during the removal process. Therefore, the method of overnight cleaning can greatly improve the protection effect of the painted surface.

[0013] Further, step A is realized by a waxing device. The waxing device includes a frame and two sets of synchronously traction transmission and shielding mechanisms. The transmission and shielding mechanism includes two traction rollers rotatably connected to the frame and a wire clamping belt connected between the two traction rollers. The wire clamping surface of the wire clamping belt has a wire clamping groove, and the depth of the wire clamping groove is less than half of the wire thickness, so that after the two wire clamping belts clamp the wire, a waxing groove is respectively formed on the two thickness sides of the wire clamping belt. Two wax boxes are fixedly arranged on the frame respectively at the positions of the waxing grooves.

[0014] Further, the wax box is conical, and the small-diameter end of the wax box faces the wire outlet direction.

[0015] Regarding the waxing method, there are actually many optional means. The paraffin can be roller-coated on the scraped paint surface by means of a wire wheel contacting the scraped paint surface, which is similar to roller painting. However, paraffin may remain on the painted surface. In this solution, taking advantage of the lubricating property of paraffin, the resistance between the wax box and the wire clamping belt is small, and the wax box can be abutted against the wire clamping belt to avoid uncontrolled contamination of the wire clamping belt by paraffin.

[0016] Based on the wire capacity rate requirement of the flat enameled wire, when the scraped paint surface of the flat enameled wire is a curved surface, it is only necessary to ensure that a very small position on the scraped paint surface is not painted. That is to say, the waxing position only needs to be at the midline position of the scraped paint surface, and it is not required to wax the entire area of the scraped paint surface. This also provides convenience for the precise control of wax and is conducive to the precise coating of wax.

[0017] Furthermore, the paraffin solution can be one of gasoline and ether.

[0018] Both ether and gasoline are volatile and are not compatible with the main components of the polyamide self-adhesive paint. It is more convenient and thorough to clean the residues after removing the wax layer, and it will not contaminate the paint film. Description of the Drawings

[0019] Figure 1 is a schematic diagram of an optional painting process for flat enameled wire.

[0020] Figure 2 is a schematic structural diagram of a waxing device.

[0021] Figure 3 is a side view of the waxing device.

[0022] Figure 4 is a schematic diagram of winding flat enameled wire.

[0023] Figure 5 is a schematic diagram of the position of the wire clamping belt and the wax box.

[0024] Figure 6 is a schematic diagram of the wire clamping belt clamping the wire.

[0025] In the figure, 1, traction roller; 2, wire clamping belt; 3, wire clamping groove; 4, wax box; a, painted surface; b, scraped paint surface. Detailed Embodiments

[0026] The following are specific embodiments of the present invention and in combination with the drawings, the technical solutions of the present invention will be further described, but the present invention is not limited to these embodiments.

[0027] Such as Figure 1As shown in the figure, the partial painting process of the flat enameled wire includes the following steps: A. Wax the wire while covering the painting surface a, so that the scraping surface b is coated with a wax layer; B. Pass the waxed wire through the paint. The wire is dried at room temperature for the paint film to solidify, and then step B is repeated multiple times to achieve multiple paint coatings; C. After the paint is solidified, remove the wax layer on the wire to obtain a flat enameled wire with a self-adhesive layer only on the scraping surface b. This solution is a partial painting process that does not require scraping the paint. The wax layer is used to protect the scraping surface b, separating the paint liquid from the wire through the wax layer. Its significant advantage is not only that it can save the amount of polyamide self-adhesive used, but also that it can avoid damage to the wire caused by scraping the paint.

[0028] Room temperature curing can maintain the existence of the wax layer. Only one waxing is required during the multiple painting process.

[0029] The material for waxing to form the wax layer is paraffin wax. Paraffin wax is incompatible with the polyamide self-adhesive paint, which can avoid the adhesion of the paint liquid during the painting process and save the amount of paint used.

[0030] The method for removing the wax layer is to wash it with a paraffin-soluble solution. Of course, the wax layer can be removed by heating, but this will cause problems such as incomplete removal and the problem that the paraffin flows and adheres to the painting surface a during the removal process. Therefore, using the method of overnight cleaning can greatly improve the protection effect of the painting surface a.

[0031] Step A is realized by a waxing device, such as Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the waxing device includes a frame and two sets of synchronously traction transmission and shielding mechanisms. The transmission and shielding mechanism includes two traction rollers 1 rotatably connected to the frame and a wire clamping belt 2 connected between the two traction rollers 1. The wire clamping surface of the wire clamping belt 2 has a wire clamping groove 3. The depth of the wire clamping groove 3 is less than half of the thickness of the wire, so that after the two wire clamping belts 2 clamp the wire, a waxing groove is formed on each of the two thickness sides of the wire clamping belt 2. Two wax boxes 4 are fixedly arranged on the frame at the positions of the waxing grooves respectively.

[0032] The wax box 4 is conical, and the small-diameter end of the wax box 4 faces the wire outlet direction. Regarding the waxing method, there are actually many optional means. The paraffin wax can be roller-coated on the scraping surface b by means of a guide wire wheel contacting the scraping surface b, similar to roller painting, but the paraffin wax may remain on the painting surface a. In this solution, taking advantage of the lubricating property of the paraffin wax, the resistance between the wax box 4 and the wire clamping belt 2 is small, and the wax box 4 can be abutted against the wire clamping belt 2 to avoid the uncontrolled pollution of the wire clamping belt 2 by the paraffin wax.

[0033] Based on the requirement of the wire capacitance rate of the flat enameled wire, when the scraping surface b of the flat enameled wire is a curved surface, it is only necessary to ensure that the position with a very small scraping surface b is not painted. That is to say, the waxing position only needs to be at the midline position of the scraping surface b, and it is not required to wax the entire area of the scraping surface b. This also provides convenience for the precise control of wax and is conducive to the precise coating of wax.

[0034] The paraffin solution can be one of gasoline and ether. Both ether and gasoline are volatile and are not compatible with the main components of the polyamide self-adhesive paint. It is more convenient and thorough to clean the residue after removing the wax layer and will not contaminate the paint film.

[0035] The specific embodiments described in this article are only illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A local painting process for flat enameled wire. The flat enameled wire includes a painted surface (a) and a scraped surface (b), characterized in that The method includes the following steps: A. Wax the wire in a state where the painted surface (a) is blocked, so that the scratched paint surface (b) is coated with a wax layer; B. Pass the waxed wire through the paint. C. After the paint dries, remove the wax layer on the wire to obtain a flat enameled wire with an adhesive layer only on the scratched paint surface (b).

2. The local painting process of a flat enameled wire according to claim 1, characterized in that After step B, the wire is dried at room temperature for the paint film to solidify, and then step B is repeated multiple times to achieve multiple coatings. After multiple coatings are completed, the wax layer is removed.

3. The local painting process for a flat enameled wire according to claim 1, characterized in that, The material for forming the wax layer by waxing is paraffin wax.

4. The local painting process of a flat enameled wire according to claim 1, characterized in that, The method for removing the wax layer is to wash it with a solution of paraffin that can be dissolved.

5. A local painting process for flat enameled wire according to any one of claims 1-4, characterized in that, Step A is implemented by a waxing device. The waxing device includes a frame and two sets of synchronously traction conveyor blocking mechanisms. The conveyor blocking mechanism includes two traction rollers (1) rotatably connected to the frame and a wire clamping belt (2) connected between the two traction rollers (1). The wire clamping surface of the wire clamping belt (2) has a wire clamping groove (3). The depth of the wire clamping groove (3) is less than half of the thickness of the wire, so that after the two wire clamping belts (2) clamp the wire, a waxing groove is formed on each of the two thickness sides of the wire clamping belt (2). Two wax boxes (4) are fixedly arranged on the frame at the positions of the waxing grooves respectively.

6. The partial painting process of a flat enameled wire according to claim 5, characterized in that, The wax box (4) is conical, and the small-diameter end of the wax box (4) faces the wire outlet direction.

7. A local painting process for flat enameled wire according to any one of claims 1-4, characterized in that, The paraffin soluble solution is one of gasoline and ether.

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