JPS5821412B2 - Coil control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies an insulating material by molding to the outer surface of a coil formed by winding a wire around the outer circumferential surface of a cylindrical bobbin.

The present invention relates to a method of forming a coil having a coating portion made of a material.

For example, the flyback transformer 2 of a television receiver.
High-voltage coils such as the next coil have moldings on their outer surfaces to prevent corona discharge.

A covering portion is provided with an insulating material.

The mold used to provide this covering part by molding directly contacts a part of the side end surface of the interlayer paper, which has a wider winding than the winding of the conventional coil, thereby positioning the coil. Ta.

Therefore, a covering portion is not formed on a part of the side end portion of the interlayer paper that directly contacts the mold described in 2 above, and as a result, the withstand voltage of this coil is low.The present invention was made to correct this problem. The mold used for the above molding is provided with a tapered protrusion, and this protrusion is inserted into the bobbin and abuts against the end of the inner peripheral surface of the bobbin, thereby connecting the mold and the coil. It is designed to regulate the relative positional relationship with the

Therefore, according to the present invention, the coating is completely formed not only on the outer circumferential surface of the coil but also on the side ends, so that the pressure resistance of the coil is improved, and a preferable coil can be provided.

An embodiment in which the present invention is applied to a method of forming a secondary coil of a flyback transformer for a television receiver will be described below with reference to the drawings.

As shown in FIG. 1, the secondary coil 10 of this flyback transformer has a wire 12 on the outer peripheral surface of a cylindrical bobbin 11.
For example, interlayer paper 13 made of polyester film is wound so as to be alternately laminated.

The bobbin 11 is made of an insulating material, for example Bakelite.

A notch 14 is provided at the side end of the bobbin 11.

This notch 14 is formed by pulling out the winding start portion of the wire rod 12 several times and winding it to form a lead wire 15.
It is meant to lead you inside.

During the winding of the interlayer paper 130, the wire rod 120 is slightly wider, and there are spaces for this purpose at both ends of the interlayer paper 13 in the width direction.

Furthermore, the wire rod 12 is slightly narrower than the width of the bobbin 11.
It is wound around the outer circumference of 1.

Next, the process of providing a covering portion with an insulating material by molding on the outer surface of the coil 10 thus formed will be explained with particular reference to FIG. 2.

A pair of molds 16 and 17 for forming this covering portion has a mold dividing surface 18 at the center in the width direction of the coil.

Projections 19 and 20, each having a tapered peripheral surface, are formed in the center portions of the pair of molds 16 and 17 so as to face each other.

The tapered circumferential surfaces of these protrusions 19 and 20 abut on the left and right ends 11a and 11b of the inner circumferential surface of the bobbin 11, respectively, thereby causing the molds 16 and 17 to contact the coil 10 in the width direction and radial direction. The tapered peripheral surfaces of the protrusions 19 and 20 of the molds 16 and 17 are also in contact with the left and right ends 13a and 13b of the inner peripheral surface of the interlayer paper 13.

Therefore, when FC'1M dynamic insulation material is injected,
This insulating material does not flow inside the left and right ends 13a and 13b of the inner peripheral surface of the interlayer paper 13.

That is, the tapered peripheral surfaces of the protrusions 19 and 20 of the mold 16 and 17 are connected to the left and right ends 13a and 1 of the inner peripheral surface of the interlayer paper 13.
3b and are not in contact with each other, even if the protrusions 19 and 20
The tapered peripheral surface of the left and right ends 1 of the inner peripheral surface of the bobbin 11
1a and llb, the insulating material will flow into the inside of the bobbin 11 through the notch 14 formed in the bobbin 11 to guide the lead wire 15.

In order to form this lead wire 15 on the bobbin 11,
Another notch is symmetrical to the notch 14 and the axis of the bobbin 11.

In some cases, a cutout is additionally provided, and in such a case, the fluid insulating material also flows into the inside of the bobbin 11, which is even more undesirable.

It is also possible to make the protruding parts 19 and 20 of the molds 16 and 170 into a cylindrical shape instead of having a tapered shape, and to fit this cylindrical protruding part to the inner circumferential surface of the bobbin 11, but this method In this case, the coil 10 is not positioned in its width direction, and therefore the coil 10 is moved by the injection pressure of the insulating material, which is a drawback.

Furthermore, a stepped portion is provided on the protruding portions 19 and 20 of the molds 16 and 17, and this stepped portion is fitted into a stepped portion formed by the end of the inner circumferential surface of the interlayer paper 13 and the side end of the bobbin 11. and mold 16,
There are three possible methods for regulating the position of the mold 17, but this method has the disadvantage that the ends of the interlayer paper are bent and damaged when the molds 16 and 17 are inserted, and furthermore, the mold 16 in the radial direction of the coil 100 is , 17 interlayer paper 1 with flexible position regulation
There is a disadvantage that it is not accurate because it is performed using the inner circumferential surface of No. 3.

However, according to the present embodiment described above, the mold 16.1
7 is extremely preferable because it allows the position of the coil 10 to be properly regulated in the radial and width directions thereof, and also prevents the insulating material from flowing into the inside of the bobbin 11.

When an insulating material such as polyethylene, silicone rubber, unsaturated polyester, etc. is injected into the space surrounded by the molds 16 and 17 and the outer peripheral surface and both side surfaces of the coil 10 and solidified, the outer peripheral surface of the coil 1o and Covering part 2 on both sides
1 is formed.

The coil 10 with the covering portion formed in this manner is shown in FIG.

In this figure, the outer peripheral surface and protrusion 22 can be seen,
This protrusion 22 is produced because the high-voltage side terminal provided on the outer periphery of the coil 10 and the rectifying diode connected to this terminal are integrally molded with the coil 10.

, Coil 10 formed in this way, bobbin 11
A primary coil 23 is fitted inside as shown in FIG.

The bobbin 24 of this primary coil 23 has this bobbin 24
A ring 25 is formed integrally with the flange 25, and an annular groove 26 formed in the flange 25 is fitted into an annular projection 27 formed integrally with the covering portion 21.

A terminal block 29 is provided on the side opposite to the seven langes 25.

This terminal block is equipped with an annular leg 30, and this leg 30
is held between another annular projection 31 formed on the covering portion 21 and the outer peripheral surface of the primary coil 23 .

Further, inside the bobbin 24 of the primary coil 23, a pair of U-shaped cores 28 are disposed facing each other.

The terminal block 29 is formed with a recess 32 and a through hole 33 for allowing the core 28 to escape.

As a result, the terminal block 29 is combined with the core 28 and the coils 10 and 23, thereby forming a flyback transformer 35.

This terminal block 29 has many input and output terminals 3.
4 have been planted.

A predetermined voltage is supplied to the flyback transformer 35 through these terminals 34, or a desired voltage is taken out from the flyback transformer 35.

Although the present invention has been described above with reference to the embodiments, the present invention is such that the mold is provided with a tapered protrusion, the protrusion is inserted into the bobbin, and is brought into contact with the end of the inner circumferential surface of the bobbin. The relative positional relationship with the coil is regulated.

Therefore, the outer circumferential surface and both side surfaces of the coil do not come into contact with the mold at all, so that not only the outer circumferential surface of the coil but also both side surfaces are completely covered.

Therefore, the pressure resistance of the coil is significantly improved.

Furthermore, since the mold does not directly contact the wire rod, interlayer paper, etc. provided on the outer surface of the coil, damage to the wire rod, interlayer paper, etc. is eliminated.

Further, since the position of the mold with respect to the coil is accurately regulated in both the width direction and the radial direction of the coil, a covering portion having a desired shape can be accurately formed.

[Brief explanation of drawings]

The drawings show an embodiment in which the present invention is applied to a method of forming a secondary coil of a flyback transformer for a television receiver, and FIG. 1 is a longitudinal cross-sectional view of the coil before forming a covering part; Fig. 2 is a vertical cross-sectional view showing the state in which the coating is formed on the coil using a mold, Fig. 3 is a perspective view of the secondary coil with the coating formed, and Fig. 4 is a perspective view of the secondary coil. FIG. 2 is a longitudinal cross-sectional view of a flyback transformer using a In the same reference numerals used in the drawings, 10 is a coil, 11 is a bobbin, 11a and llb are ends of the inner circumferential surface, 12 is a wire, and 13 is an interlayer paper, 13a. 13b is the end of the inner peripheral surface, 16 is the mold, 17 is the mold, 1
9 is a protruding portion, 20 is a protruding portion, and 21 is a covering portion.

Claims (1)

[Claims] 1. In a method of forming a coil in which a wire is wound around the outer circumferential surface of a cylindrical bobbin, and a coating is formed with an insulating material on the outer surface of the coil, the forming die used for the above forming is tapered. A shaped protrusion is provided, and the protrusion is inserted into the bobbin and brought into contact with the end of the inner circumferential surface of the bobbin, thereby regulating the relative positional relationship between the forming die and the coil. A method of forming a coil characterized by.