JPS6317326B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a resin insulator provided with a hole for inserting a lead wire of a capacitor.

Conventionally, as shown in FIG. 6, the resin insulator was manufactured through the following steps (a) and (b).

(a) A cavity 6 for molding an insulator is formed between the two, and a pin-like member 20 for forming a hole for passing a lead wire, and a slight gap at the tip of the pin-like member 20 when the mold is clamped. In this state, both the male and female molds 9 and 10, which are provided with recesses 21 for external fitting, are clamped together.

(b) Inject molten resin into the cavities 6 in both the molds 9 and 10.

This conventional manufacturing method had the following drawbacks.

That is, during mold clamping, the pin-like member 20
If the tip of the pin-like member 20 comes into contact with one of the molds 9, the pin-like member 20 will be deformed and damaged, which will lead to poor product accuracy.
The molten resin is injected with a small gap formed between the tip of the mold 9 and the recess 21 of one of the molds 9. Therefore, it is inevitable that a portion of the injected molten resin will enter the gap and form a thin film-like burr (molded fly) that protrudes greatly outside the insulator. If the insulator is fed to the insulator feeding device of an automatic capacitor manufacturing machine with protruding burrs, the protruding burrs will make the feeding and posture of the insulator uncertain, easily leading to capacitor manufacturing errors, and reducing product yield. Then came the shortcomings.

An object of the present invention is to improve the fundamental defects during molding that cause a decrease in yield in the entire manufacturing process as described above.

The characteristics of the method for manufacturing a capacitor insulator according to the present invention, which has been made to achieve the above object, are as follows:
It is manufactured through the following steps (a) and (b).

(b) Both male and female molds are clamped, each having a cavity for molding an insulator between them, and a pair of pin-like members that are very close to each other at a position corresponding to the middle of the insertion hole when the molds are clamped. .

(b) Injecting molten resin into the cavities in both of the molds.

The effects of the above feature method are as follows.

In other words, when the mold is clamped, a gap is formed between the opposing ends of both the pin-like members to avoid deformation and damage to both of them, and at the same time, a thin film that is generated as the molten resin is injected in this state. Since a shaped burr is formed in the middle part of the insertion hole, even if a part of the burr breaks off, it will not protrude to the outer surface of the insulator.

The effects of the above action are as follows.

Therefore, even if the insulator after molding is fed as is to the insulator feeding device of an automatic capacitor manufacturing machine, the burrs will not have a negative effect on the feeding and feeding posture of the insulator, thereby minimizing capacitor manufacturing errors. However, we were able to significantly improve the yield in the entire manufacturing process.

Hereinafter, embodiments of the method of the present invention will be described based on the drawings.

A rubber insulator 2 having insertion holes 2a, 2a for the lead wires 1a, 1a of the capacitor 1 shown in FIGS. 4 and 5 is manufactured through the following steps (a) to (e).

(a) A large number of insulators are arranged in parallel between the fixed platen 3 of the injection molding machine and the movable platen 5 fixed to the mold clamping ram 4, which is movable in the direction of distance from the fixed platen 3. A male and female mold 9 is provided with a cavity 6 for simultaneous molding in the state, and a pair of pin-like members 7, 8 that are very close to each other at a position corresponding to the middle of the insertion hole 2a when the mold is clamped. , 10 are installed. (See Fig. 1) (b) The ram 4 is extended and both molds 9 and 10 are clamped. (See Fig. 2) (c) Molten rubber is injected into the cavity 6 in both the molds 9 and 10, and as shown in Fig. 3, a semi-finished product A in which a large number of insulators 2 are integrated is molded. .

(d) Both molds 9 and 10 are moved by contracting the ram 4.
Release the mold clamping and take out the semi-finished product A from the cavity 6.

(e) Punch out insulator 2 from semi-finished product A.

In the insertion hole 2a of the insulator 2 formed by such a manufacturing method, the pin-like members 7,
An annular barrier is created by the rubber that has entered the gap between the
is formed, but since this barrier is located at the center of the insertion hole 2a and does not protrude to the outside,
This makes it possible to eliminate the need for special finishing treatment for the insulator 2.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view before mold clamping, showing the method for manufacturing a capacitor insulator of the present invention, Fig. 2 is a cross-sectional view during mold clamping, Fig. 3 is a perspective view of a molded semi-finished product, and Fig. 4. 5 is a sectional view of the insulator, FIG. 5 is a perspective view of the capacitor, and FIG. 6 is a sectional view of the conventional manufacturing method during mold clamping. 1... Capacitor, 1a... Lead wire, 2...
... Resin insulator, 2a ... Insertion hole, 6 ... Cavity, 7, 8 ... Pin-like member, 9, 10 ... Mold.

Claims (1)

[Scope of Claims] 1. An insulation for a capacitor, characterized in that a resin insulator 2 having an insertion hole 2a for the lead wire 1a of the capacitor 1 is manufactured through the following steps (a) and (b). How the body is manufactured. (a) A male and female mold having an insulator molding cavity 6 formed therebetween, and a pair of pin-like members 7 and 8 that are very close to each other at a position corresponding to the middle of the insertion hole 2a when the mold is clamped. Clamp molds 9 and 10. (b) Inject molten resin into the cavities 6 in both the molds 9 and 10. 2. The method of manufacturing an insulator for a capacitor according to claim 1, wherein the constituent resin of the insulator 2 is rubber.