JPS6222207B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a rectangular insulated wire, and more particularly to a method for manufacturing a rectangular insulated wire by rolling an insulated wire. Conventional rectangular insulated wires are manufactured by applying paint once or several times to a conductor with a rectangular cross section and baking it. is difficult to apply. Even if the paint could be applied, it would flow in the baking oven and it would be nearly impossible to apply the paint evenly to the edges. Therefore, as a method for uniformly insulating the edge portions, there is a method of rolling a round insulated wire into a rectangular shape, as described in, for example, Japanese Patent Publication No. 36-10130, Japanese Patent Publication No. 49-7428, and Japanese Patent Application Laid-open No. 47-16975. This method has been proposed, and the edges of rectangular insulated wires manufactured by such a method are coated in a very good condition. However, the coating undergoes processing deterioration due to rolling, and the electrical and mechanical properties of the coating generally deteriorate. Furthermore, in Japanese Patent Publication No. 47-7428, when the ratio of thickness to width is 1:5 or more, cracks often occur in the coating during rolling, and cracks occur in the coating during heat treatment after rolling. It is stated that it is difficult to obtain a rectangular insulated wire that can be put to practical use. In view of this, the inventors of the present invention have conducted intensive research on a new manufacturing method to obtain a product with a thickness to width ratio of 1:5 or more.
Even in the case of the above-mentioned ratio, we succeeded in producing a rectangular insulated wire with little processing deterioration due to rolling and with good edge coverage. That is, in the method of rolling an insulated wire into a rectangular insulated wire, the method of the present invention does not make the ratio of thickness and width to a ratio of 1:5 or more by rolling, but by rolling multiple times. A desired thickness-to-width ratio is obtained by rolling, and in this case, the rolled insulated wire is heat-treated at least once between the first rolling and the last rolling. The method of the present invention will be explained in more detail below. 1st
As shown in the figure, the insulated wire 2 fed out from the supply reel 1 is first rolled into a flat shape by a first rolling roller 3, and then passed through a heat treatment furnace 4.
It is rolled into a flat shape by the second rolling roller 5. For example, a round insulated wire is rolled by a first rolling roller to a thickness to width ratio of less than 1:5, and by a second rolling roller to a thickness to width ratio of 1:10. The insulated wire 2' rolled into a rectangular shape is then heat treated using a heat treatment furnace 6 and wound up by a winder 7. In the above, the first rolling process, the subsequent heat treatment process, and the final rolling process do not necessarily need to be performed in tandem as shown in Figure 1, but may be separated and performed as separate processes, and three times. In the case of the above rolling process, it is not necessarily necessary to include a heat treatment process after the first rolling process, and a heat treatment process may be provided between the rolling processes depending on the overall degree of rolling. The purpose of this heat treatment step is to soften the conductor that has been work-hardened by rolling, and the heat treatment temperature must be 200° C. or higher. In addition, in the present invention, after the final rolling, if necessary,
An insulating paint or a self-adhesive paint of the same type or different type as the rolled insulating film may be applied and baked.
In this case, the paint is applied and baked one or more times, but if it is applied more than once, the guide rollers 8, 9, 10, 11
is used. Note that 12 indicates a coating tank for coating the paint after the final rolling. In the present invention, by performing heat treatment during multiple rolling cycles as described above, it is possible to produce a rectangular insulated wire with no cracks in the film and with a good appearance. A thickness to width ratio of 1:5 can be achieved in one rolling process.
If an attempt is made to obtain a rectangular insulated wire with the above ratio, the coating cannot follow the deformation of the conductor, and the coating is likely to break during rolling. Even if the film can be rolled without breaking, cracks may occur in the film during the next heat treatment process. This is because when the insulated wire is rolled to a thickness-to-width ratio of 1:5 or more in one rolling process, the insulated wire is deformed, but the amount of deformation depends on the parts that are in strong contact with the roller and the parts that are in weak contact with the roller. It is thought that the large amount of deformation is due to cracks in the film caused by the heat treatment. Therefore, when obtaining the desired thickness and width ratio by rolling multiple times, the variation in the amount of deformation at each location due to one rolling is small, and the film follows the deformation of the conductor each time, causing cracks in the film. It is thought that the rolling process is carried out without any problems. Furthermore, as described in the present invention, if a heat treatment step is provided between the first and last rolling steps of multiple rolling, the conductor will be softened, and the next rolling will be possible with less stress, which will cause the film to deteriorate. This has the advantage of reducing processing deterioration. There is also the advantage that the residual stress in the film that has been subjected to rolling is greatly alleviated as a result of the heat treatment causing molecular movement in the film. By providing a heat treatment step between the rolling steps in this manner, it is possible to obtain a rectangular insulated power supply having a thickness to width ratio of 1:5 or more and of higher quality than conventional ones. In the rolling of metals, rolling is performed multiple times, or multiple times with a heat treatment step between the rolling steps as in the present invention. This method is used to obtain a metal shape with good dimensional accuracy by repeating the process or to roll a very hard metal material, and its purpose is completely different from that of the present invention. The number of times of rolling and the location of heat treatment vary depending on the material of the conductor used, especially its hardness and insulation coating. For example, when obtaining a rectangular insulated wire with a thickness to width ratio of 1:10, if the film has poor adhesion to the conductor, it is best to finish it by rolling 3 to 5 times, and the number of heat treatments is also 2 to 4 times. However, in the case of a film that has good adhesion to the conductor, it is sufficient to finish the film by rolling it twice, and therefore, heat treatment only needs to be done once. For example, polyesterimide wires and polyimide wires with poor adhesion should be rolled three or more times, and heat treated two or more times, whereas polyvinyl formal wires and polyamide-imide wires should be rolled two times or more. The heat treatment may be performed only once. Another factor that determines the number of rolling cycles is the conductor diameter. Generally, the larger the conductor diameter, the worse the adhesion with the film, so it is better to increase the number of rolling and heat treatment to reduce the ratio of width to thickness per rolling. In order to roll an insulated wire with a conductor diameter of 1.0 mm or more and achieve a thickness to width ratio of 1:5 or more, it must be rolled and heat treated three or more times.
It is best to apply it more than once. However, since there is also a relationship with the coating described above, it is desirable to determine the number of rolling times by taking into consideration the properties of the coating and the diameter of the conductor. Note that for conductors such as aluminum which are softer than copper, two rolling steps and one heat treatment may be sufficient even if the conductor diameter is 1.0 mm or more. According to the present invention as described above, the ratio of thickness to width is 1:
It has become possible to manufacture rectangular insulated wires with a ratio of up to about 15, and it has also become possible to obtain rectangular insulated wires of higher quality than conventional wires. Examples of the present invention will be described below in comparison with comparative examples. Comparative Example 1 A polyamide-imide insulated wire (conductor is copper) with two types of structure with a conductor diameter of 0.40 mm was rolled once to obtain a rectangular insulated wire with a finished thickness x width = 0.123 mm x 1.050 mm. For heat treatment, it was passed once through a heat treatment furnace (furnace length: 1.5 m, temperature: 530°C) at a linear speed of 25 m/min. Table 1 shows the properties of the obtained rectangular insulated wire. Comparative Example 2 A polyamide-imide insulated wire (conductor is copper) with two types of structure with a conductor diameter of 0.17 mm was wound at a wire speed of 70 m/min.
Then, it was rolled twice. A rectangular insulated wire with a finished thickness x width = 0.133 mm x 0.344 mm was obtained by the first rolling. In order to heat-treat this rectangular insulated wire, it is passed through a heat treatment furnace (furnace length 1.5m, temperature 470℃) at a linear speed of 30m/
Passed once at min. Table 1 shows the properties of the obtained rectangular insulated wire. Comparative Example 3 A polyamide-imide insulated wire (conductor is aluminum) having two types of structure with a conductor diameter of 0.36 mm was rolled once to obtain a rectangular insulated wire with a finished thickness x width = 0.103 mm x 0.960 mm. In order to heat-treat this rectangular insulated wire, a heat treatment furnace (furnace length 1.5m, temperature 500℃) was used.
It was passed through once at a linear speed of 27 m/min. Table 1 shows the properties of the obtained rectangular insulated wire. Comparative Example 4 A polyester imide insulated wire with a dual structure (conductor is copper) with a conductor diameter of 1.0 mm was rolled to obtain a rectangular insulated wire with a finished thickness x width = 0.52 mm x 1.53 mm, and then rolled further to obtain a finished wire. Thickness x width = 0.32mm x 2.01mm
A flat insulated wire was obtained. After a third round of rolling to obtain a rectangular insulated wire with a finished thickness x width = 0.21 mm x 2.50 mm, the wire was rolled in a heat treatment furnace (furnace length 3 m, temperature 400 mm).
℃) twice at a linear speed of 25 m/min. Table 1 shows the properties of the obtained rectangular insulated wire. Example 1 Everything is the same as Comparative Example 1 except as described below. After the insulated wire used in Comparative Example 1 was rolled for the first time to obtain a rectangular insulated wire with a thickness x width = 0.181 mm x 0.790 mm, it was placed in a heat treatment furnace (furnace length 1.5 m, temperature 530°C).
After the wire was heat-treated through the wire, it was rolled a second time to obtain a rectangular insulated wire with a finished thickness x width = 0.122 mm x 1.090 mm. Table 2 shows the wire characteristics after heat treatment. Example 2 Everything is the same as Comparative Example 2 except as described below. Using the insulated wire used in Comparative Example 2, after rolling it for the first time to make a rectangular insulated wire with a finished thickness x width = 0.130 mm x 0.370 mm, it was placed in a heat treatment furnace (furnace length 1.5 m, temperature
After heat treatment at 470°C), a second rolling was performed to obtain a rectangular insulated wire with a finished thickness x width = 0.038 mm x 0.520 mm. Table 2 shows the wire characteristics after heat treatment. Example 3 Everything is the same as Comparative Example 3 except as described below. The insulated wire used in Comparative Example 3 was rolled for the first time to form a rectangular insulated wire with a finished thickness x width = 0.182 mm x 0.680 mm, and then heated in a heat treatment furnace (furnace length 1.5 mm, temperature 470 mm).
℃), and then rolled a second time to obtain a rectangular insulated wire with a finished thickness x width = 0.105 mm x 1.090 mm. Table 2 shows the wire characteristics after heat treatment. Example 4 Everything is the same as Comparative Example 4 except as described below. The insulated wire used in Comparative Example 4 was rolled once to make a rectangular insulated wire with a finished thickness x width = 0.51 mm x 1.55 mm, and then placed in a heat treatment furnace (furnace length 1.5 m, temperature 500 m).
℃), and then rolled a second time to obtain a rectangular insulated wire with a finished thickness x width = 0.30 mm x 2.24 mm. Furthermore, a heat treatment furnace (furnace length 1.5m, temperature 500
℃), and then rolled a third time to obtain a rectangular insulated wire with a finished thickness x width = 0.205 mm x 2.70 mm. Finally, it was passed through a heat treatment furnace (furnace length: 3 m, furnace temperature: 400°C) twice. Table 2 shows the properties of the obtained rectangular insulated wire.

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【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the method for manufacturing a rectangular insulated wire according to the present invention. 1... Supply reel, 2... Round insulated wire, 2'... Flat insulated wire, 3... Rolling roller,
4...Heat treatment furnace, 5...Rolling roller, 6...Heat treatment furnace, 7...Take-up reel, 8, 9, 10, 11...
...Guide roll, 12...Paint application tank after final rolling.

Claims (1)

[Claims] 1. In a method for manufacturing a rectangular insulated wire having a thickness to width ratio of 1:5 or more, in which an insulated wire is rolled multiple times and then heat treated, the first rolling and the last rolling are A method for manufacturing a rectangular insulated wire, which comprises softening a work-hardened conductor by heat-treating it at least once at a temperature of 200°C or higher. 2. The method for manufacturing a rectangular insulated wire according to claim 1, wherein an insulating paint is applied and baked after the final rolling. 3. A method for manufacturing a rectangular insulated wire according to claim 1, which comprises applying and baking a self-adhesive paint after the final rolling.