JPS5948501B2 - Molding core for arc extinguishing chamber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a molding core for an arc extinguishing chamber used in the manufacturing process of an arc extinguishing chamber such as an electromagnetic contactor or a magnetic breaker.

[Conventional technology]

Figures 1 to 5 show the configuration of a typical arc extinguishing chamber of this type. As shown in FIG. 1, every other grid plate 1 is inverted and arranged in parallel with a predetermined interval, so that the current passing through the V-shaped groove 1a is The arc path at the time of interruption is configured to be a zigzag path.

2 is a fixed contact, 3 is a movable contact, 4.5 is an arc horn, 6 is a side plate that supports the arc horns 4 and 5, 7 is a shield plate 8 that connects the side plate 6, the grid plate 1, the side plate 6, and the shield. 9 is a deflection plate that covers the upper part of the arc extinguishing chamber 8 and divides the arc; 10 is a magnetic pole plate that is fixed to the arc extinguishing chamber 8 in close proximity to the side of the grid plate 1; and 11 is a fixing metal fitting whose tip is hooked to the window 10a of the magnetic pole plate 10 and fixes the deflection plate 9 to the arc extinguishing chamber 8.

Next, a method for manufacturing the arc extinguishing chamber configured as described above will be explained with reference to FIGS. 6 and 7.

In the figure, 12 is an outer mold metal, 13 is a core made of foamed polystyrene resin, etc., 14 is a liquid arc-resistant material for forming the arc extinguishing chamber 8, such as a mixture of zircon sand, alumina cement, and water, 15 is liquid arc-resistant material 12
It is a container that accommodates.

FIG. 7 shows a perspective view of a conventional molding core 13 used in the manufacturing process of such an arc extinguishing chamber, in which 13a is a projection for forming the V-shaped groove 1a of the grid plate 1, and 13b is a projection for forming the V-shaped groove 1a of the grid plate 1. A spacing piece 13C for forming the interval between the grid plates 1 is a side surface that forms the shield plate 7 with the outer metal fitting 12.

The conventional molding core 13 configured as described above is placed at a predetermined position inside the outer mold 12 assembled on the lower mold metal (not shown), and is mounted on the upper mold metal (not shown). Cover,
Liquid arc-resistant material 14 in container 15 from a sprue (not shown)
inject.

Thereafter, after the liquid arc-resistant material 14 is hardened, the upper mold metal and the outer mold metal 12 are removed, and the molded product is fired in a furnace at about 1300°C.

Along with this, since the molding core 13 is made of foamed polystyrene resin, etc., it is vaporized by the heat during firing,
This means that the arc extinguishing chamber 8 can be obtained by removing it.

By the way, the conventional molding core 13 used in the manufacturing process of the arc extinguishing chamber is configured so that only the grid plate 1, side plate 6, and shield plate 7 of the arc extinguishing chamber can be molded. There was a problem in that the deflection plate 9 had to be manufactured separately and assembled.

Furthermore, since the spacing pieces 13b of the core 13 are connected only at the lower part of FIG. 7, the distance between the spacing pieces 13b may vary when the liquid arc-resistant material 14 is injected.
There was a risk that the thickness of the molded grid plate 1 would be uneven, which could adversely affect the stability of the arc breaking performance in the molded arc extinguishing chamber.

[Summary of the invention]

This invention was made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a molding core for an arc extinguishing chamber that can improve the dimensional accuracy of a molded grid plate and that can mold the arc extinguishing chamber at a low cost. The core is made of a combustible plastic material, and the plurality of spacing plates forming the intervals between the grid plates are connected to the upper parts of the spacing plates located on both sides from the center of the plurality of spacing plates. It is characterized by being composed of a pair of bridge plates.

[Embodiments of the invention]

Hereinafter, one embodiment of a molding core for an arc extinguishing chamber according to the present invention will be described with reference to FIGS. 8 and 9.

Figure 8 shows molding core 1 used in the manufacturing process of the arc extinguishing chamber.
6 is partially cut away, and in the figure, 16a is a projection for forming the V-shaped groove 1a of the grid plate 1;
b is a spacing plate 16 for forming the spacing between the grid plates 1;
C is a side surface of the core 16 for forming the shield plate 7 with the outer metal fitting 12, and 16d is a pair of bridge plates connecting the upper parts of the spacing plates 16b located on both sides from the center, respectively. As shown in the figure, the spacing plates 16b are divided into two groups and connected from the center.

When manufacturing the arc extinguishing chamber 17 as a molded product using the molding core 16 configured as described above, the core 1 used is
Since the manufacturing method is completely the same as the conventional one except for the shape of 6, the explanation will be omitted.

FIG. 9 is a perspective view showing the arc extinguishing chamber 17 manufactured using the core 6 according to the embodiment shown in FIG. 8 divided in the vertical direction. The same reference numerals as in the figures indicate the same or corresponding parts.

As shown in the figure, the side part of the grid plate 1 is formed integrally with the shield plate 7, and a guide plate 18 that divides and guides the arc ejected from the upper part of the grid plate 1 into left and right sides is formed integrally with the arc extinguishing chamber 17. Therefore, the deflection plate 9 unlike the conventional one is not required.

Further, since the cores 16 are used in which the spacer plates 16b are connected at predetermined intervals by the bridge plates 16d, the dimensional accuracy of the grid plate 1 can be improved.

〔Effect of the invention〕

As described above, the arc extinguishing chamber molding core according to the present invention includes a plurality of spacer plates and a pair of bridge plates that respectively connect the upper parts of the parts located on both sides from the center of the spacer plates. Therefore, there is no need to manufacture a separate deflection plate, the number of parts can be reduced, and the cost can be reduced. At the same time, it is possible to improve the dimensional accuracy of the molded grid plate of the arc extinguishing chamber. This has the effect of contributing to improving the arc breaking performance in the arc extinguishing chamber.

[Brief explanation of drawings]

Figures 1 to 5 are diagrams showing general arc extinguishing chambers.
The figure is a perspective view showing the arrangement of the grid plate, Figure 2 is a vertical sectional view of the arcing chamber, Figure 3 is a perspective view of the upper part of the arcing chamber, Figure 4 is a perspective view of the deflection plate, and Figure 5 is a fixed view. Fig. 6 is a perspective view of the metal fittings; Fig. 6 is a perspective view showing the injection state of liquid arc-resistant material into the molding core;
The figure is a perspective view of a conventional molding core used in the manufacturing process of an arc-extinguishing chamber, and FIG. 8 is a perspective view showing an embodiment of the molding core of the present invention used in the manufacturing process of an arc-extinguishing chamber. 9 are vertically divided perspective views of an arc extinguishing chamber manufactured using the core shown in FIG. 8. In the figures, the same reference numerals indicate the same or corresponding parts, 1
12 is a grid plate, 12 is an outer mold metal fitting, 14 is a liquid arc-resistant material, 16 is a core, 16b is a spacing plate, 16d is a bridge plate, and 17 is an arc extinguishing chamber.

Claims (1)

[Claims] 1. In a molding core for an arc extinguishing chamber used in the manufacturing process of an arc extinguishing chamber having grid plates arranged in parallel at a predetermined interval and extinguishing an arc during current interruption, the interval between the grid plates is formed. For molding an arc extinguishing chamber made of a combustible plastic material, which is composed of a plurality of spacer plates and a pair of bridge plates that connect the upper parts of the spacer plates located on both sides from the center of the plurality of spacer plates. Middle child.