Local lacquering process for flat enameled wire

Abstract

The invention provides a local varnishing process for a flat enameled wire, and belongs to the technical field of enameled wire processing. The flat enameled wire comprises a varnishing surface and a paint scraping surface, and the varnishing process comprises the following steps: A, waxing a wire rod in a state of shielding the varnishing surface, so that the paint scraping surface is coated with a wax layer; b, painting the waxed wire rod; and C, after the paint is dried and solidified, removing the wax layer on the wire rod to prepare the flat enameled wire with the self-adhesive layer only on the paint scraping surface. The method has the advantages of high wire quality, no paint scraping and the like.

Description

Technical Field

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

[0002] Enameled wire consists of two parts: conductor and insulation layer. The original wire with larger diameter is repeatedly drawn and annealed to the specified size, and then painted and baked for many times. The cross section of ordinary enameled wire is circular, but the circular enameled wire has the disadvantages of low slot fill rate and small cross section after winding. In short, the space utilization rate of circular cross-section enameled wire after winding is low, which is difficult to meet the requirements of technological development for flattening, lightweight, low power consumption and high performance of components. Especially in the windings of various electrical equipment such as new energy vehicles, telecommunications equipment, transformers, motors and generators, flat cross-section enameled wire has better impact resistance and higher space utilization rate. At the same time, it can also greatly improve the "skin effect" (when alternating current passes through the conductor, the current will be concentrated on the surface of the conductor) and reduce the loss of high-frequency electromagnetic coils.

[0003] From the perspective of the transverse section, the flat enameled wire is divided into four surfaces, 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 through a small curved surface. During the winding process of the 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) of the enameled wire, it is also necessary to coat the 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 the polyamide self-adhesive layer, such as Figure 4 As shown, of course, there is also a need to improve heat dissipation. Therefore, in the prior art, the processing process of flat enameled wire is relatively complicated, and it is necessary to coat the entire wire with a polyamide self-adhesive layer and then scrape the wire partially (the wire passes through a paint scraping mold, and a paint scraping edge is provided at the mold mouth for the scraping surface). Since the painting is repeated many times, but the paint scraping is generally not completed at one time 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, which results in a high probability of damage to the wire during the scraping of the polyamide self-adhesive layer. Summary of the invention

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

[0005] The object of the present invention can be achieved by the following technical scheme: a local painting process for a flat enameled wire, the flat enameled wire includes a painted surface and a scraped paint surface, characterized in that it includes the following steps: A, waxing the wire while covering the painted surface, so that the scraped paint surface is covered with a wax layer; B, painting the waxed wire; C, removing the wax layer on the wire after the paint is dried, so as to obtain a flat enameled wire with a self-adhesive layer only on the scraped paint surface.

[0006] This solution is a local painting process that does not require paint scraping. The wax layer is used to protect the scraped paint surface so that the paint liquid and the wire are separated by the wax layer. Its significant advantage is that it not only saves the amount of polyamide self-adhesive, but also avoids wire damage caused by paint scraping.

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

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

[0009] Furthermore, the material used to form the wax layer during waxing is paraffin.

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

[0011] Furthermore, the wax layer is removed by washing with a paraffin-soluble solution.

[0012] Of course, the wax layer can be removed by heat, but this will cause problems such as incomplete removal and the paraffin adhering to the painted surface during the removal process. Therefore, overnight cleaning can greatly improve the protective effect of the painted surface.

[0013] Furthermore, step A is implemented by a waxing device, which includes a frame and two sets of synchronously pulled conveying and shielding mechanisms, wherein the conveying and shielding mechanisms include two traction rollers rotatably connected to the frame and a wire clamping belt connected between the two traction rollers, wherein the wire clamping belt has a wire clamping groove on its wire clamping surface, and the depth of the wire clamping groove is less than half of the thickness of the wire material so that after the two wire clamping belts clamp the wire material, a waxing groove is formed on the two thickness sides of the wire clamping belt, respectively, and two wax boxes are fixedly provided on the frame, respectively located at the waxing grooves.

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

[0015] Regarding the waxing method, there are actually many optional means. The paraffin roller can be applied to the scraped paint surface by contacting the paint scraping surface with the wire wheel, which is similar to roller painting. However, the paraffin may remain on the painted surface. In this solution, the lubricating properties of the paraffin wax are used to reduce the resistance between the wax box and the wire clamping belt. The wax box can be placed against the wire clamping belt to prevent the uncontrolled contamination of the paraffin wax on the wire clamping belt.

[0016] Based on the requirements of the wire capacity rate of flat enameled wire, when the paint-scraped surface of the flat enameled wire is a curved surface, it is only necessary to ensure that a very small position on the paint-scraped surface is not painted. In other words, the waxing position only needs to be at the center line of the paint-scraped surface, and it is not required to wax the entire area of ​​the paint-scraped surface. This also facilitates the precise control of the wax and is conducive to the precise coating of the wax.

[0017] Furthermore, the paraffin wax can be dissolved in one of gasoline and ether.

[0018] Both ether and gasoline are volatile and incompatible with the main components of polyamide self-adhesive paint. They are convenient and thorough in cleaning the residues after removing the wax layer and will not contaminate the paint film. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

[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 DESCRIPTION

[0026] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0027] like Figure 1As shown, the local painting process of flat enameled wire includes the following steps: A. Waxing the wire while covering the painted surface a, so that the scraped paint surface b is covered with a wax layer; B. Painting the waxed wire. The wire is dried at room temperature, and then step B is repeated multiple times to achieve multiple painting; C. After the paint is dried, the wax layer on the wire is removed to obtain a flat enameled wire with only a self-adhesive layer on the scraped paint surface b. This scheme is a local painting process that does not require scraping paint. The wax layer is used to protect the scraped paint surface b, so that the paint liquid and the wire are separated by the wax layer. Its significant advantage is that it can not only save the amount of polyamide self-adhesive, but also avoid wire damage caused by scraping paint.

[0028] Room temperature curing can maintain the existence of the wax layer, and only one waxing is required during multiple painting processes.

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

[0030] The wax layer can be removed by washing 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 paraffin wax adhering to the painted surface a during the removal process. Therefore, overnight cleaning can greatly improve the protective effect of the painted surface a.

[0031] Step A is achieved 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 pulled conveying and shielding mechanisms, the conveying and shielding mechanisms include 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 is provided with a wire clamping groove 3, the depth of the wire clamping groove 3 is less than half of the thickness of the wire material so that after the two wire clamping belts 2 clamp the wire material, a waxing groove is formed on the two thickness sides of the wire clamping belt 2 respectively, and two wax boxes 4 are fixedly arranged on the frame and are respectively located at the waxing grooves.

[0032] The wax box 4 is tapered, and the small diameter end of the wax box 4 faces the outlet direction of the wire. Regarding the waxing method, there are actually many optional means. The paraffin wax roller can be applied to the paint scraping surface b by the way that the wire wheel contacts the paint scraping surface b, which is similar to roller painting, but the paraffin wax may remain on the painted surface a. In this solution, the lubricating properties of the paraffin wax are used to reduce the resistance between the wax box 4 and the clamping belt 2, and the wax box 4 can be pressed against the clamping belt 2 to avoid the uncontrolled contamination of the clamping belt 2 by the paraffin wax.

[0033] Based on the requirements of the wire capacity rate of flat enameled wire, when the paint scraping surface b of the flat enameled wire is a curved surface, it is only necessary to ensure that a very small position of the paint scraping surface b is not painted. In other words, the waxing position only needs to be at the center line of the paint scraping surface b, and it is not required to wax the entire area of ​​the paint scraping surface b. This also provides convenience for the precise control of the wax and is conducive to the precise coating of the wax.

[0034] The paraffin wax can be dissolved in one of gasoline and ether. Both ether and gasoline are volatile and incompatible with the main component of polyamide self-adhesive paint. It is convenient and thorough to clean the residue after removing the wax layer, and it will not pollute the paint film.

[0035] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A process for partial painting of a flat enameled wire, the flat enameled wire comprising a painted surface (a) and a scraped paint surface (b), characterized in that: The method comprises the following steps: A. waxing the wire material while covering the painted surface (a) so that the scraped paint surface (b) is covered with a wax layer; B. painting the waxed wire material; C. After the paint is dry, remove the wax layer on the wire to obtain a flat enameled wire with a self-adhesive layer only on the scraped paint surface (b).

2. A process for partial painting of flat enameled wire according to claim 1, characterized in that: After step B, the wire is dried at room temperature, and then step B is repeated multiple times to achieve multiple painting. After the multiple painting is completed, the wax layer is removed.

3. A process for partial painting of flat enameled wire according to claim 1, characterized in that: The material used to form the wax layer during waxing is paraffin.

4. A process for partial painting of flat enameled wire according to claim 1, characterized in that: The wax layer can be removed by washing with a paraffin-soluble liquid.

5. A process for partial painting of flat enameled wire according to any one of claims 1 to 4, characterized in that: Step A is implemented by a waxing device, which comprises a frame and two sets of synchronously pulled transmission shielding mechanisms, wherein the transmission shielding mechanisms comprise two pulling rollers (1) rotatably connected to the frame and a wire clamping belt (2) connected between the two pulling rollers (1), wherein the wire clamping surface of the wire clamping belt (2) is provided with a wire clamping groove (3), wherein the depth of the wire clamping groove (3) is less than half the thickness of the wire material so that after the two wire clamping belts (2) clamp the wire material, a waxing groove is formed on two thickness sides of the wire clamping belt (2), and two wax boxes (4) are fixedly arranged on the frame and are respectively located at the waxing grooves.

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

7. A process for partial painting of flat enameled wire according to any one of claims 1 to 4, characterized in that: Paraffin wax is soluble in gasoline or ether.

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