JPS5832726B2 - Manufacturing method of flat insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a rectangular insulated wire, and particularly to a method of manufacturing a wide rectangular insulated wire with a width-to-thickness ratio of 5 or more.

Compared to round wires, rectangular wires have a better occupancy rate in a given space, so they have the advantage of allowing equipment to be made smaller.

However, if the film on the edges is thin, the breakdown voltage will be low.
This reduces the reliability of the coil, which in turn shortens the life of the device and reduces the reliability of the entire device.

Conventional rectangular insulated wires are manufactured by coating a rectangular conductor with paint once or several times and baking it, but with this manufacturing method, the edges of the rectangular conductor have a uniform coating thickness similar to that of the flat surface. Hard to get.

That is, even if the paint can be applied to the edge portions, the fluidity of the paint sometimes increases as the temperature of the paint increases, and after baking, only a thin coating film adheres to the edge portions.

For this reason, much attention has been paid to the curvature of the edges of rectangular conductors, the properties of paint, and the method of baking.

However, rectangular wires, especially muntin rectangular wires or ultra-fine rectangular wires used in coils for audio equipment, are foil-like insulated wires, and the edges of such thin rectangular conductors can be made uniform just like a flat surface. It is almost impossible to cover it with a film.

As a method to solve these problems, the present inventors
A method has been developed for manufacturing a rectangular insulated wire with good edge coverage by rolling a round insulated wire with a circular cross section into a rectangular insulated wire with a rectangular cross section.

However, it is difficult to obtain a wide range of products using this method.

The present invention has been made in view of these points, and it is an object of the present invention to provide a method for manufacturing a rectangular insulated wire with good edge coverage and a wide width.

That is, the present invention is characterized in that a rectangular insulated wire in which an insulating paint is coated and baked on a rectangular conductor is rolled into a rectangular shape, and then heat treated.

Hereinafter, the present invention will be explained in detail using illustrative drawings.

In the present invention, as shown in FIG. 1, a rectangular insulated wire 2, which is a rectangular conductor coated with an insulating paint and baked, is fed out from a supply reel 1 and rolled by a rolling mill 3 into a wide rectangular insulated wire. The electric wire 2' is passed through a heat treatment furnace 4 and wound up on a winding roll 5.

FIG. 2 is a sectional view of the rectangular insulated wire before rolling, and FIG. 3 is a sectional view of the rectangular insulated wire after being rolled.

Now, as shown in Fig. 2, the edge portion 9 of a rectangular insulated wire made of a rectangular conductor coated with paint and baked is extremely thin compared to the flat surface 7 and the thickness surface 8; The area around the part is finished thickly.

Note that 6 in the figure is a conductor. When such a rectangular insulated wire is rolled, surprisingly, the edge portion 9 in FIG.
It was discovered that the thickness surface 8 of FIG. 2 moves to the flat surface 11 of the figure and further moves to the edge portion 13 of FIG. 3, leading to the present invention.

According to the method of the present invention, as shown in FIG. 3, the edge portion 13 is coated in approximately the same good condition as the flat surface 11 and the thickness surface 12.

This is thought to be because the coating film applied and baked on the thick side of the conductor forms a new edge portion by rolling, resulting in a well-coated edge portion.

The edge portion of the rectangular insulated wire before rolling becomes a part of the flat surface of the rectangular insulated wire after rolling.

As a result, a thin part of the film is formed on a part of the flat surface, but since the thick part of the adjacent film moves toward the thin part due to plastic deformation due to rolling, the film on the edge part 9 shown in FIG. The film is not thin, and the film thickness is sufficient for practical use.

When an insulated wire is rolled, the conductor is required to undergo heat treatment in order to harden under pressure, as described in Japanese Patent Publication No. 49-7428.

In addition, since the film also deteriorates during processing, it is desirable to perform an appropriate heat treatment process after rolling.

That is, by rolling, the tensile strength is increased to 30 to 40 kV/
vt? Since the elongation increases at ti and decreases at about 1 to 7 l, a heat treatment process is required to soften the conductor.

Regarding softening after rolling, as stated in the above-mentioned Japanese Patent Publication No. 44-7428, insulated wires coated with insulation paint for heat resistance and baked may undergo heat shock and cracks during heat treatment. Therefore, the insulating film must be one that does not cause heat shock during heat treatment.

For example, coatings of polyimide, polyamideimide, polyhydantoin, and polyesterimide are desirable.

Alternatively, a double structure film may be used in which the above film with good heat resistance is used as the upper layer and polyester, polyvinyl formal, polyurethane, etc. is used as the lower layer.

Further, a double structure film may be used in which the above film is used as a lower layer and a linear polymer resistant to heat shock, such as nylon 66, nylon 6, or terephthalic acid polyester, is used as an upper layer.

The rectangular insulated wire used here preferably has a thickness to width ratio of 1 to less than 5 before rolling.

By the method described above, it was possible to obtain a wide rectangular insulated wire with a thickness to width ratio of up to 1:15 and with good edge coverage.

However, the present invention is by no means limited to such numerical values and can be widely used in the production of rectangular insulated wires.

Examples of the present invention are shown below.

Example (]) A rectangular insulated wire (film thickness 0.010 rtrm) made by baking a polyamide-imide insulating paint onto a rectangular conductor with a conductor size of 0.07mm x 0.22mm was rolled at a line speed of 25 m/min to a conductor size of 0.04mm x A rectangular insulated wire of O.32rrvn was obtained.

This rectangular insulated wire was heated in a heat treatment furnace (
The furnace length was 1.5 mb and the furnace temperature was 500°C.

Table 1 shows the properties of the obtained rectangular insulated wire.

Example (2) A rectangular insulated wire (film thickness 0.010 rrart) made by baking a polyimide insulating paint onto a rectangular conductor with a conductor size of 0.09 m x 0.25 mm was rolled at a line speed of 30 m/min to a conductor size of 0.05 mm x 0. A rectangular insulated wire of .40rrrm was obtained.

This rectangular insulated wire was heated in a heat treatment furnace (
Furnace length: 1.5 m, furnace temperature: 500°C).

Table 1 shows the properties of the obtained rectangular insulated wire.

Example (3) A rectangular insulated wire (conductor size 0.11 mm x 0.298 rectangular conductor with polyester imide insulating paint baked on)
film thickness 0.011 mm) at a linear speed of 30 m/mi
Rolled with n, conductor size 0.048y++mX O,60
A sn flat insulated wire was obtained.

This rectangular insulated wire was passed through a heat treatment furnace (furnace length: 1.5 m, furnace temperature: 500° C.) at a linear speed of 30 m/minO.

Table 1 shows the properties of the obtained rectangular insulated wire.

Example (4) A rectangular conductor with a conductor size of 0.14 tone x 0.50 rMt,
A rectangular insulated wire ('F coating thickness: 0.012, line coating thickness: 0.003 mm) coated and baked with polyester insulating paint as an f coating and then coated and baked with polyamide-imide insulating paint as a top coating at a linear speed of 25 m/min. A rectangular insulated wire with a conductor size of 0.08 m×O, 7FII771 was obtained.

This rectangular insulated wire was heated in a heat treatment furnace (
Furnace length: 1.5 m, furnace temperature: 500°C).

Table 1 shows the properties of the obtained rectangular insulated wire.

*0 Example (5) A rectangular conductor with a conductor size of 0.16 mm x O, 70 mm was coated with polyesterimide insulating paint as an f coating and baked, and then overcoated with an insulating coating material made by dissolving nylon 66 in m-cresol. Flat insulated wire coated and baked as
) was rolled at a linear speed of 30 m/min to a conductor size of 0.09 m.
A rectangular insulated wire of m×1.11 mm was obtained.

This rectangular insulated wire was heated in a heat treatment furnace (
Furnace length: 1.5 rn% Furnace temperature: 500°C).

Table 1 shows the properties of the obtained rectangular insulated wire.

(Note) Measurement of breakdown voltage: sample 10 in saturated salt glycerin
cm was immersed and measured at a pressure increase rate of 70 V/sec.

Measurement of pinhole: According to JISC3003.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the method for manufacturing a rectangular insulated wire of the present invention, and FIG. 2 is a cross-sectional view of the rectangular insulated wire before rolling in the manufacturing method of the present invention (only the portion near the rolled edge portion). FIG. 3 illustrates a cross-sectional view (only the portion near the comb edge portion) of a rectangular insulated wire after rolling in the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1... Supply reel, 2... Rectangular insulated wire after rolling, 2'-... Rectangular insulated wire after rolling, 3... Rolling roll, 4... Heat treatment furnace, 5... Winding Lilly, 6.
... flat conductor before rolling, 7 ... flat surface of flat insulated wire before rolling, 8 ... thickness surface of flat insulated wire before rolling, 9 ... edge part of flat insulated wire before rolling, 10...
- Rectangular conductor after rolling, 11... Flat surface of the rectangular insulated wire after rolling, 12... Thickness surface of the rectangular insulated wire after rolling, 13... Edge portion of the rectangular insulated wire after rolling.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a rectangular insulated wire, which comprises rolling a rectangular insulated wire into a rectangular shape by coating and baking an insulating paint on a rectangular conductor, and then heat-treating the wire. 2. The method for manufacturing a rectangular insulated wire according to claim 1, wherein the rectangular insulated wire has a width to thickness ratio of 5 or more and 151 after rolling.