JPS6256650B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding die for manufacturing a resin insulator for a capacitor having a lead wire, and more particularly, a molding die for manufacturing a resin insulator for a capacitor having a lead wire, and more specifically, a The present invention relates to a mold for forming an insulator for a capacitor, in which a pin-like member for forming a hole for passing the lead wire is provided in the cavity.

As shown in FIG. 10A, in this kind of conventional general molding die, the pin-like member 07 is fixed to one die 01, and the other die 02 has a mold. A recess 02a is formed into which the pin-like member 07 fits externally with an appropriate gap formed between it and the top of the tip when tightening, or as shown in FIG. 10B, the pin-like member 0
There are some models in which the pin-like member 07 is fixed to one of the molds 01 in a state where the tip of the pin-like member 07 is very close to the other mold 02 during mold clamping, but in all of these cases, the opening end of the hole 06 is closed during molding. Although these were designed with the intention of preventing burrs from forming on the parts, the following drawbacks occurred in each case.

That is, during mold clamping, if the tip of the pin-like member 07 comes into contact with the recess 02a or the inner surface of the other mold 02 due to a slight deviation in dimensional accuracy, the pin-like member 07 may be deformed or damaged. As mentioned above, a gap is provided between the tip of the pin-like member 07 and the recess 02a or the inner surface of the other mold 02, although it is small. Typically, molds are designed and manufactured. Therefore, when the molten resin is injected into the cavity 05, a part of the molten resin infiltrates into the small gap and unintentionally forms a thin film-like burr (molding Pira) 08
appears on the insulator 04. In the former case, this burr largely protrudes on the outer surface of the insulator 04, and in the latter case, although it is flush with the insulator 04, it is in the form of a thin film, so it is easy to partially peel off and protrude to the outside. . As a result, in any case, when insulators are supplied to the insulator feeding device of an automatic capacitor manufacturing machine, the protruding burrs make the feeding and posture of the insulators slippery, uncertain, and uneven, resulting in poor product yield. It causes. Therefore, as a means for improving yield, a step of polishing the protruding burrs after molding is required. Furthermore, with this polishing, the insulator is charged with static electricity, making it easier for dust to adhere to it, and if the insulator is fed as is to the insulator feeding device, the feeding becomes even more uncertain due to the influence of the dust that has fallen and accumulated. However, in order to avoid this deterioration of product performance, a process is also required to clean and remove the adhering dust, which requires a large number of processes to manufacture the insulator as a whole, which is reflected in the increased cost of the product. It is.

An object of the present invention is to provide a mold for forming an insulator for a capacitor, which can improve the above-mentioned drawbacks of the prior art while providing advantageous mold design and manufacture.

In order to achieve the above object, the mold for forming an insulator for a capacitor according to the present invention includes a mold for forming a capacitor insulator at a tip portion of the pin-like member at a position corresponding to the opening end of the hole at one end side in the penetrating direction of the insertion hole. It is characterized by a structure in which one of each of the male and female fitting parts is formed to form a bottomed cylindrical molding space that communicates with the cavity from the inside to the outer position of the cavity. As a result, we have come to expect the following actions and effects.

In other words, a bottomed cylindrical burr is formed at the tip of the pin-like member and protrudes outward with the root located slightly inside the opening end of the lead wire insertion hole as the molten resin is injected into the cavity. By configuring the mold so that it is formed actively and intentionally, it is easier to design and manufacture the mold than when designing and manufacturing the mold with the intention of preventing the formation of burrs, as in the past. The manufacturing cost of the mold itself can be reduced by increasing the tolerance range and lowering the design and manufacturing accuracy. Moreover, the burrs formed protrudingly through molding are relatively large and their bases are located inside the hole, so even if the burrs are to be removed after molding, special mechanical equipment such as polishing must be used. This eliminates the need for time-consuming and labor-intensive operations, and by simply wiping, any remaining residue is located within the hole and an insulator with no outward burr protrusion can be obtained.

Therefore, while automatically transporting insulators after molding, the insulators can be fed smoothly when assembling capacitors, maintain their posture reliably, and significantly improve product yield by using the minimum number of insulators required. Manufactured using this process, it is possible to reduce product costs, and
The design and production of the mold itself has also become cost-effective.

An embodiment of the present invention will be described below in detail with reference to the drawings.

1 and 2, 1 and 2 are male and female molds for forming a large number of insulator molding cavities 5 in parallel, and these molds 2 and 1 are connected to the fixed platen 9 of the molding machine. Each of the molds 1 and 2 has a cavity 5 fixed to each side of the movable plate 10, which is fixed to a mold clamping ram 11 that is movable in the distance direction with respect to the fixed plate 9. One of each pin-like member 7, 7' having the same diameter is embedded and fixed at approximately the center position within the capacitor 3 to form an insertion hole 6 for the lead wire 3a of the capacitor 3. The end portion 7'A of the one pin-like member 7' on the side of the cavity 5 is shaped like a cylinder with a bottom, and its open end 7'a is formed so as to protrude slightly into the cavity 5. The tip portion 7A of the other pin-like member 7 constitutes a mating portion.
is formed in a stepped small diameter part (male fitting part) so as to fit inside the bottomed cylindrical end part 7'A of the former pin-like member 7', and this stepped small diameter tip part 7A and By fitting with the bottomed cylindrical end portion 7'A, it protrudes outward from the cavity 5 at one end side in the penetration direction of the lead wire insertion hole 6 from slightly inside the position corresponding to the opening end of the hole 6. A bottomed cylindrical burr forming space 5A is formed in communication with the cavity 5 over the position. This burr forming space 5A
is a thin film bottomed cylindrical burr 8 formed thereby.
The clearance of the portion corresponding to the root portion is configured to be the minimum so that the wall thickness of the root portion 8a is the smallest.

Then, the male and female molds 1 and 2 are moved to the hydraulic ram 11.
A first step of clamping the mold in a state where the cavity 5 and the burr molding space 5A are formed in communication through the cavity 5, and a step of injecting molten rubber, which is an example of a resin constituting the insulator, into the cavity 5, and pouring a portion of the molten rubber into the cavity 5. The burr is flowed into the burr forming space 5A, and as shown in FIG. In the second step of molding the semi-finished product A as shown in FIG. By removing the outward protruding portion of the burr 8 by wiping it off, the root portion 8a of the burr 8 remains at a position slightly inside the opening end of the insertion hole 6, as shown clearly in FIG. The third step is to manufacture capacitor insulators.

By inserting the capacitor lead wire 3a into the insertion hole 6 of the insulator 4 manufactured in this way, the outer circumferential surface of the insertion lead wire 3a can be attached to the inside of the hole 6, as shown in FIG. Residual burr root 8a
As a result, a product is obtained in which the liquid in the capacitor 3 is not transmitted to the lead wire 3a and leaked because the capacitors are in close elastic contact with each other.

Another embodiment will be described below.

[] As shown in FIG. 7, in order to configure the burr molding space 5A, a recess 7 corresponding to the bottomed cylindrical end portion 7'A is formed on the surface of one of the molds 2 on the side facing the cavity 5. 'A may also be formed.

[] Rubber is the most suitable constituent resin, but
Any other resin may be used as long as it has excellent elasticity, electrical insulation, corrosion resistance, etc.

[] To configure the burr forming space 5A, as shown in FIG. The fitting portion 7A is formed into a truncated conical shape, and a minute gap is formed between the conical peripheral surface of the tip portion 7A and the inner peripheral edge of the opening 7'a of the bottomed cylindrical end portion 7'A. Alternatively, as shown in FIG. 9, the truncated conical tip portion 7A of the one pin-like member 7 fits into the other pin-like member 7'.
The inner circumferential surface of the bottomed cylindrical end portion 7'A may also be formed into a conical surface having the same or almost the same slope as the tip portion 7A, and in either case, the conical portion may be a male or female. This has the advantage that it exhibits a fitting guide effect when the molds 1 and 2 are clamped, and facilitates mold matching.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a mold showing one embodiment of the present invention, FIG. 3 is a partially cutaway perspective view of a semi-finished product, and FIGS. 4 and 5 are enlarged vertical cross-sections of essential parts, respectively. Fig. 6 is a vertical sectional view of the finished product, Fig. 7 is an enlarged sectional view of the main part of the mold showing another embodiment, and Figs. 8 and 9 are also respectively showing another embodiment of the mold. FIGS. 10A and 10B are enlarged sectional views of essential parts of a conventional mold, and FIGS. 11A and 11B are enlarged longitudinal sectional views of essential parts of a conventional product. 1, 2... Mold, 3... Capacitor, 3a...
... Lead wire, 4 ... Insulator, 5 ... Cavity, 5A ... Bottomed cylindrical molding space, 6 ... Insertion hole, 7 ... Pin-like member, 7A, 7'A ... Male and female fitting Part 8... Thin film bottomed cylindrical burr, 8a... Root part of burr.

Claims (1)

[Scope of Claims] 1. A hole 6 for inserting the lead wire 3a is formed between the male and female molds 1 and 2 in a cavity 5 for molding the resin insulator 4 of the capacitor 3 having the lead wire 3a. In a mold for forming an insulator for a capacitor, which is provided with a pin-like member 7 for forming the pin-like member 7, the opening end of the hole 6 is placed at the tip of the pin-like member 7 on one end side in the penetrating direction of the insertion hole 6. A male and female fitting part 7 forming a bottomed cylindrical molding space 5A that communicates with the cavity 5 from a position slightly inside the corresponding position to a position outside the cavity 5.
A mold for forming an insulator for a capacitor, characterized in that one of each of A and 7'A is formed. 2. The mold for forming an insulator for a capacitor according to claim 1, wherein the constituent resin of the insulator 4 is rubber.