JPH01186514A - Die for coating enamel wire - Google Patents

Abstract

PURPOSE:To suppress the occurrence of defective eccentricity and improve the electric insulation performance by providing an approach angle with a specific angle on a tip section and exerting an excellent centering action. CONSTITUTION:A die tip section 3 is formed on the long guide passage 2a of the body section of a die 1. The right end of the passage 2a is in touch with the approach section of the tip section 3 via a bell mouth section. The approach section 3b has a small approach angle alpha. When this approach angle alphais set to the range of 1-10 deg., an excellent centering action is exerted, the occurrence of defective eccentricity can be suppressed. An enamel wire with uniform film thickness can be easily manufactured in coating and baking processes by the horizontal enamel wire coating method, the electric insulation performance is improved. The film thickness can be made further thinner, the material cost can be saved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in a die for coating enameled wire, and more particularly to a die for coating suitable for use in a horizontal enameled wire coating system.

[Prior Art and Problems] It is well known that the coating methods for enameled wire can be roughly divided into vertical coating methods and horizontal coating methods. Regardless of which method is used, it is unavoidable that vibrations of the wire rod cause wobbling during the painting process, and this wobbling causes uneven thickness of the coating film.

In the vertical coating method, the wire rod runs vertically and excess paint can be squeezed out using a floating die. Therefore, even if the wire rod undergoes vibration during coating, the pressure of the paint will cause the wire rod to run in a vertical direction and squeeze out excess paint using a floating die. It has the advantage that it floats in accordance with the vibration and is corrected accordingly, and centering is performed automatically to prevent uneven thickness coating, but the entire device tends to be large.

Although the horizontal coating method is economical because the entire device can be made compact and compact, it is difficult to mount the floating die because the wire runs in a horizontal direction.

For this reason, when vibration occurs in the wire being coated, it is not possible to automatically correct the centering using the floating die as in the vertical method described above, and this is done depending on the shape of the die to minimize uneven thickness. Attempts are being made to stop it.

FIG. 3 is a longitudinal sectional view showing the configuration of such a conventional horizontal painting die 1°. A body part 2 having a long guide passage 2-a is provided in front of the die chip part 3' which squeezes the paint and ultimately determines the coating thickness. The purpose of this method is to generate internal pressure in the paint that accompanies the movement of the wire rod, and to press the area around the wire rod with the internal pressure, thereby suppressing the occurrence of eccentricity due to vibration of the wire rod.

However, the result of applying enamel using a die configured as shown in Fig. 3 shows that although it is more effective than when the guide passage 2-a is not installed, contrary to initial expectations, there was unexpectedly uneven thickness. It was found that the occurrence of

The inventors conducted extensive research to find out the cause, investigated the flow of paint within the die in detail using fluid-dynamic analysis, and analyzed in detail the mechanism of internal pressure generation. As a result, it was found that although the centering effect on the wire also exists in the guide passage, the centering effect on the wire rod is in the approach portion 3-b of the tip portion 3'.

[Purpose of the Invention] The present invention has been made in view of the above-mentioned actual circumstances, and is capable of being used in a horizontal enamel coating furnace to significantly suppress the occurrence of uneven thickness defects, and has excellent continuous workability. The present invention aims to provide a die for coating enameled wire.

[Summary of the invention] That is, the gist of the present invention is that the approach angle at the tip portion is set at an extremely small angle of 1 to 10 degrees, and by providing such a small angle, fluid dynamics can be improved. Therefore, it is possible to generate extremely stable internal pressure and to achieve an extremely excellent centering effect on the wire.

[Example] The present invention will be explained below based on examples.

FIG. 4 shows an enlarged sectional view of the die tip portion 3' of the conventional die 1'. As shown in the figure, the conventional die tip section 3- consists of a bell mouth section 3-a, an approach section 3-b, and a bearing section 3-c. The bell mouth part 3-a is an introduction part, and the bearing part 3-C is a coating film forming part.

The approach part 3-b is a part that provides preliminary forming to the bearing part 3"C, and as a result of fluid dynamic analysis, the pressure of the paint flowing through this approach part greatly contributes to the centering effect on the wire. I understand.

The approach angle α- of the conventional die tip 3' is 20 to 1
As large as 20 degrees, such a large approach angle α'' creates turbulence in the flow of paint flowing through the approach portion 3-b from a fluid dynamics perspective, inhibits the above-mentioned centering action, and causes uneven thickness coating. That's what I found out.

Based on the above findings, the inventors manufactured die chips in which the diameter Di of the approach part inlet, the diameter DO of the approach part exit, and the diameter d of the wire rod passed through the approach part and applied were varied. , the flow of paint and its centering effect on the wire were investigated. As a result, the value of (Di-d) is 2 of the value of (Do-d)
It has been found that there is a point where the centering effect on the wire is greatest at a point where it is ~3 times as large.

The thickness of the enamel coating film is approximately fixed, and for wire diameters that are subject to horizontal coating, the thickness is usually about 0.02 to 0.045 ntm. Furthermore, since the length of the approach section is usually about 0.5 to 1.5 degrees, if this is converted into an approach angle, it is 1 to 10 degrees, which is a small approach angle that breaks the conventional idea. We were able to reach the conclusion that it is valid.

FIG. 1 is a longitudinal sectional view showing the configuration of a die 1 according to the present invention manufactured based on the above conclusion. There is a die chip 3 at the back of the long guide passage 2a of the body part 2, as in the conventional example, and the die chip 3 according to the present invention is the same as the conventional example, as shown in FIG. 2, which is an enlarged cross-sectional view. Next to the bell mouth portion 3a, there is an approach portion 3b having an extremely small approach angle α, and then a bearing portion 3C is formed. In the present invention, this approach angle α is set in the range of 1 to 10°.

As a result, it exhibits a centering effect that is far superior to that of conventional examples, and enables enamel coating with extremely low occurrence of uneven thickness defects.

The diameter of the large diameter part of the example body part is 5.7 m, and the diameter of the small diameter part is 4.0 mm.
, the inner diameter of the guide passage is 1.5 mm, and the total length of the body is 20.
A die according to the present invention is manufactured by fixing a die chip according to the present invention made of sapphire to a body portion made of aluminum having a thickness of 0 mm. The outer diameter of the die tip at this time is 2.5
mm, the length is 2.5 nm, the length of the bell mouth part is 0.50, the bell mouth angle is 100°, the length of the approach part is 1.0 mm, the approach angle is 4°, and the length of the bearing part. 1. It was onw.

When an enameled wire was manufactured by a horizontal enamel coating method using the die according to the present invention, the ratio of maximum film thickness/minimum film thickness was 20% smaller than when a conventional enameled wire coating die was used. The excellent effectiveness of the dice according to the invention has been demonstrated.

[Effects of the Invention] As described above, according to the enameled wire coating die according to the present invention, it is easy to manufacture an enameled wire having a uniform coating thickness in coating and baking using the horizontal enameled wire coating method, and the die for enameled wire coating according to the present invention can be easily manufactured using the conventional die. Not only can the electrical insulation performance be further improved compared to products using the same electrical insulation performance, but if the same electrical insulation performance is expected, the coating thickness can be made thinner, thereby reducing the amount of paint used. It has great industrial value, as it can contribute to reducing the cost of finished materials.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a die according to the present invention, and FIG.
FIG. 3 is a longitudinal sectional view of a conventional die, and FIG. 4 is an enlarged sectional view of the chip portion shown in FIG. 1: Dice, 2: Body part, 2a Mini guide path, 3: Chip part, 3b Near pro tip part. Agent Patent Attorney Fujio Sato 1: Riis 2 OJDen 32 1. March 180, 1985 2. Title of the invention: Dice for coating enamel wire 3. Relationship with the case of the person making the amendment Patent application Colonel's Office Tokyo 2-1 Marunouchi, Chiyoda-ku, Miyako
Number 2 Name (512) Representative of Hitachi Cable Co., Ltd.
Hiroharu Hashimoto 4, Agent 3165, Subject of amendment (1) Column 6 of detailed explanation of the invention in the specification, Contents of amendment (1) Page 6, line 1 of the specification “Thickness of enameled wire difference"
Correct it to read, "The value of r (DO-d)." (2) The following shall be inserted below the bottom line of page 7 of the specification. Table 1 shows the enamel coatings for Examples 1 to 6 having the dimensions shown in the Examples above and various approach angles within the scope of the invention, and Comparative Examples 1 and 2 having larger approach angles beyond that. This shows the results of measuring the degree of thickness deviation after that, and it is clearly seen that the degree of thickness deviation in the examples is extremely small compared to the comparative example.

Claims (1)

[Claims] (1) In a die consisting of a guide passage formed in the body of the die and a die tip installed at the back of the guide passage, the approach angle of the die tip is set to 1 to 1.
Enamel wire painting die configured in a 10° range.