JPS59225914A - Casting mold device - Google Patents

Abstract

PURPOSE:To ease stress to be generated around insert metals when synthetic resin hardens and shrinks by using a magnetic material for a part of the supporting pin of the insert metals. CONSTITUTION:An insert metal supporting pin 2 for a casting mold device consists of a central side part 2a and a peripheral side part 2b, and the central side part 2a is made of a magnetic material. When insert metals 4 are put in the device, the insert metals 4 are attracted by the magnetic force of the magnetic material 2a of the supporting pins 2 and an aperture is formed on the peripheral side by as much as the clearance between the insert metal 4 and the insert metal supporting pin 2. The aperture is determined by the formula (whole length of cast insulator X hardening contraction of cast insulator in relation to molds/2). Therefore, when synthetic resin 3 hardens and shrinks toward the direction of center, the insert metals 4 also can move by as much as the aperture according to the shrinkage of synthetic resin, and thereby stress to be generated around the insert metals 4 when synthetic resin hardens and shrinks is eased. The occurrence of cracks in the surrounding of the insert metals 4 can thus be prevented and cast insulators having excellent mechanical strength can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a casting mold device in which synthetic resin is injected for producing insulators.

Conventionally, as this type of casting mold apparatus, those shown in FIGS. 1 to 3 have been used.

That is, l is the mold, /a is the mold body, /b is the flat mold, /c is the injection port where the synthetic resin is injected, and ko is the filler support pin attached to the mold body /a. 3 is a synthetic resin, DA is a filler metal that is embedded in the synthetic resin 3 while being fitted into the support pin 2, and 5 is a filler metal to prevent the synthetic resin from flowing between the filler support pin and the filler hole. It is a placed patchkin.

In order to mold a cast insulator with a filler metal using the casting mold apparatus described above, the filler l is inserted into the filler support pin, and then a flat metal nib is covered. When the mold assembly is completed in this manner, the synthetic resin 3 is injected through the injection port IC, and after curing, the mold is released, thereby obtaining a cast insulator with a solid filling.

However, since the conventional casting mold apparatus is configured as described above, the filler metal q is completely fixed under pressure by the filler support pin. Either the synthetic resin 3 tends to shrink toward the center due to curing shrinkage, or because the filler metal t is completely fixed by the filler support pins, a large stress is generated around the filler metal 1a, and when it hardens. Another disadvantage is that cracks occur in the female part.

Further, even if no cracks occur, residual stress around the filler metal causes a decrease in the mechanical strength of the cast insulator.

This invention was made in order to eliminate the drawbacks of the conventional casting mold apparatus as described above, and by using a magnetic material for a part of the filling support pin, hardening of the synthetic resin is achieved. This is designed to relieve the stress generated around the filler metal during shrinkage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to drawings showing embodiments thereof.

In Fig. 7, /a is the metal body, /b is a flat plate mold, C is a filler support pin, 3 is a synthetic resin, G is a filler metal, S is a packing, and the filler support pin is on the center side. It consists of a partial core a and an outer peripheral side portion 2b, with the central partial core a made of a magnetic material.

If the part core a on the center side of the filler supporting pin is made of magnetic material, as in the above-mentioned casting mold device, when the filler is inserted, On the circumferential side, the remaining fill is attracted by the magnetic force of the magnetic material part λa of the filler support bin, and a gap is created on the outer circumferential side only outside the gap between the filler l and the filler support bin.

This will result in

This gap is λ It is determined by a formula like .

Therefore, when the synthetic resin 3 shrinks toward the center due to curing shrinkage, the filler metal q can also move along with the shrinkage of the synthetic resin only outside the above-mentioned gap. Stress generated in the surrounding area can be alleviated.

Therefore, it is possible to prevent the occurrence of cracks around the filler metal L during curing or demolding, and to produce a cast insulator with excellent mechanical strength, with almost no residual stress remaining around the filler metal Q. It becomes possible to do so.

In particular, the potting machine with the above configuration is highly effective when used to manufacture cast insulators using synthetic resin with a large curing shrinkage rate, or cast insulators with large dimensions. be done.

As described above, according to the present invention, in a casting mold device in which synthetic resin is injected to manufacture an insulator, a part of the support pin that supports the embedded metal is formed of a magnetic material. Therefore, a remarkable effect can be obtained in alleviating the stress generated around the filler metal due to curing shrinkage of the synthetic resin.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional casting mold device, Fig. 2 is a vertical sectional view, Fig. 3 is an enlarged sectional view of main parts, and Fig. 1 is a casting mold showing an embodiment of the present invention. FIG. 3 is a vertical cross-sectional view of the main part of the molding device. L...Mold, C...Filled metal support pin, 3...Synthetic resin, q
...Filling metal, S...packet, core a...magnetic material part forming part of the support pin. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Masu Oiwa 1 coin, 3 coins, 4 coins

Claims (1)

[Claims] (1) In a mold into which synthetic resin is injected to manufacture an insulator, a filler support is used to create a gap between the filler embedded in the synthetic resin and the support pin that supports it. A casting mold device characterized in that a portion of the pin is formed of a magnetic material. (g) The casting mold device according to claim 1, wherein the filler support pin is composed of a center side portion and an outer peripheral side portion, and the center side portion is made of a magnetic material.