JPS59108215A - Switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switch that switches on and off current, and particularly to an improvement in its arc-extinguishing function.

For example, with regard to switches used as electromagnetic contactors and molded circuit breakers, how to improve the breaking performance of the switches has become a major concern for manufacturers.

FIG. 1 shows an example of an electromagnetic contactor as a conventional switch. The contactor shown in the figure includes a mounting base 10, a fixed core 12, a movable core 14, an operating coil 16, a crossbar 18, a movable contact 20 to which a movable contact 20A is joined, a presser spring 22,
It is composed of a fixed contact 24 to which a fixed contact 24A is joined, a terminal screw 26, a base 28, a cover 30, and the like.

The movable contactor 20 is pressed against the lower edge surface of the square window 9 of the cross par 18 by a retaining screw 22, and
8 is connected to a movable iron core 14.

When the operating coil 16 is energized, the movable core 14 is magnetically attracted to the fixed core 12 against a separation spring (not shown), and the movable contact 20A and the fixed contact 24A come into contact with each other. There is.

Here, when the power to the operating coil 16 is cut off, the movable contact 20A and the fixed contact 24A are connected to each other by the action of the above-mentioned separation spring.
and are separated. At this time, both contacts 2OA, 24A
An arc 32 is generated in between, but this arc 32 is extinguished by metal arc extinguishing plates 34, 36, thereby interrupting the stain flow.

Figure 2 shows the metal arc-extinguishing plate 34, 36 and the fixed contact 24.
The state near A is shown. Still, Figure 3 shows both contacts 20A,
24A shows a process in which the arc 32 generated between 24A and 24A is extinguished.

Here, the arc 32 generated between both contacts 20A and 124A is attracted by the first metal arc-extinguishing plate 34 exerted by the magnetic material and is elongated as shown by the reference numeral 32A. In this case, if the fixed contact 24 is U-shaped as shown in FIG.
The arc 32 is driven by the magnetic field created by the current flowing through the fixed contact 24, thereby further elongating the p-arc 32. When the arc 32 is stretched, the arc voltage increases, so dielectric breakdown occurs between the fixed contact 24 and the first metal arc extinguishing plate 34 and between the first metal arc extinguishing plate 34 and the movable contact 2OA. , arc 32A connects two arcs 32B and 3
It is divided into 20 parts. One of the divided arcs 32C is attracted to the second metal arc extinguishing plate 36, and the fixed contact 24
is driven by a magnetic field created by a current flowing through it, which causes it to be stretched as shown by the sign. When this arc 32D is stretched and the arc voltage increases, the arc 32D
is divided into two arcs 32E and 32F. The arc 32 is finally divided into three arcs 32B, 32F, and 32F, extinguished at the current zero point, and the electric juice is cut off.

By the way, in the conventional switch, since the distance between the first metal arc-extinguishing plate 34 and the fixed contact 24 is small, the length of the arc 32D between the first metal arc-extinguishing plate 34 and the fixed contact 24 is small. was not large, and as a result, it was difficult for this arc 32D to be divided into two arcs 32F and 32F. As a result, the arc 32 was likely to be stuck between the tip of the first metal arc-extinguishing plate 34 and the fixed contact 24. Accordingly, one end of the arc 32D is concentrated at the tip of the first metal arc extinguishing plate 34 where electric field concentration is likely to occur and where heat conduction is poor.
This caused the problem that the interrupting performance was extremely degraded.

This invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a switch that can reliably prevent the deterioration of interrupting performance due to arc concentrating on the tip of the first metal arc-extinguishing plate. It is in.

In order to achieve the above object, the present invention includes a fixed contact to which a fixed contact is joined, a movable contact to which a movable contact is joined, and a vertical shape from the upper side of the fixed contact to the height of the movable contact joint. a first metal arc-extinguishing plate made of a magnetic material and provided on the opposite side of the movable contact with respect to the first metal arc-extinguishing plate and made of a magnetic material abutted against the fixed contact; 2 metal arc-extinguishing plates.

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

FIG. 4 shows an embodiment of a main part of a switch according to the present invention. The switch whose essential parts are shown in the figure is the same as the conventional switch described above, except for the second metal arc-extinguishing plate 36. The switch according to the embodiment of the present invention is different from the conventional switch in that the second metal arc-extinguishing plate 36 is held in contact with the fixed contact 24, as shown in FIG.

Here, to explain the arc extinguishing process of the arc 32 in the switch of this invention using FIG. 4, first, both contacts 20A,
24A is attracted to the first metal arc-extinguishing plate 34 made of a magnetic material and is elongated as shown by the reference numeral 32A.

If the fixed contact 24 is U-shaped as shown in FIG. 3, the arc 32 is driven by the magnetic field created by the current flowing through the fixed contact 24, and the arc 32 is further elongated.

As the arc 32 is stretched, the arc voltage increases, so dielectric breakdown occurs between the fixed contact 24 and the first metal arc extinguishing plate 340 and between the first metal arc extinguishing plate 34 and the movable contact 20A. As a result, the arc 32A is divided into two arcs 32B and 3
It is divided into 20 parts. One of the divided arcs 32C is attracted to the second metal arc extinguishing plate 36, and the fixed contact 24
It is driven by the magnetic field created by the current flowing through the
It is stretched as shown in . When this arc 32D is stretched and the arc voltage increases, dielectric breakdown occurs between the first metal arc-extinguishing plate 34 and the second metal arc-extinguishing plate 36, the arc 32D becomes like the arc 32G, and the second Driven by the magnetic field created by the current flowing through the metal arc-extinguishing plate 36,
The two arcs 32B and 32H are extinguished at the current zero point, and the current is interrupted.

The arc is extinguished as described above, but since one end of the arc 32D is generated on the flat part of the first metal arc extinguishing plate 34 where electric field concentration is difficult to occur and where heat conduction is good, that is, the arc 32D is Since the arc is extinguished after reaching 32H, excellent interrupting performance can be obtained.

In the above embodiments, the fixed contact 24 has a U-shape, but it goes without saying that similar effects can be obtained with other shapes.

As described above, the switch according to the present invention has an extremely simple structure in which the second metal arc-extinguishing plate is brought into contact with the fixed contact, and can greatly improve the breaking performance compared to the conventional switch.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a conventional switch, Fig. 2 is an enlarged view of the main part of the switch shown in Fig. 1, Fig. 3 is an explanatory diagram of the operation of the switch shown in Fig. 1, and Fig. 4 is an example of the present invention. It is a figure explaining an example and its operation. The same members in each figure are given the same reference numerals, 20 is a movable contact, 20A is a movable contact, 24 is a fixed contact, 24A is a fixed contact, 32.32A to 32H are arcs, and 34 is a first metal extinguisher. The arc plate 36 is a second metal arc extinguishing plate. Agent Patent attorney Shin Kuzuno - (1 other person) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (11) A fixed contactor to which a fixed contact is joined, a movable contactor to which a movable contact is joined, and a magnetic body provided vertically from the upper side of the fixed contact to the height of the movable contact joint. A second metal arc-extinguishing plate made of a magnetic material and provided on the side opposite to the movable contact with respect to the first metal arc-extinguishing plate and in contact with the fixed contact. A switch characterized by: