JPS59108216A - 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 mechanism.

For example, in a switch used as an electromagnetic contactor or a molded circuit breaker, how to improve the breaking performance of the switch is a matter of greatest interest to those skilled in the art.

FIG. 1 shows an example of an electromagnetic contactor as a conventional switch. The contactor shown in the figure has a mounting base 10. Fixed iron core 12, movable iron core 14, operating coil 16, cross spar 18, movable contact 20 to which movable contact 20A is joined, 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 of the cross par 18 by a retaining screw 22, and the cross par 1
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), thereby bringing the movable contact 20A and the fixed contact 24A into contact.

Here, when the power to the operating coil 16 is cut off, the movable contact 2OA and the fixed contact 24A are separated by the action of the separation spring. At this time, an arc 32 occurs between both contacts 20A and 24A, but this arc 32 is caused by the metal arc extinguishing plate 3.
The arc is extinguished by 4.36, thereby cutting off the current.

FIG. 2 shows a portion near the fixed contact 24A, and FIG. 3 shows a process in which an arc 32 generated between both contacts 20A and 24A is extinguished. Here, the arc 32 generated between the two contacts 20A and 24A is attracted to the first metal arc extinguishing plate 34 made of a magnetic material and is stretched as shown by the reference numeral 32A. If the shear arc 32 is U-shaped as shown in the figure, the arc 32 is driven by the magnetic field created by the current flowing through the fixed contact 24, thereby stretching the shear arc 32 further. 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 34 and between the first metal arc extinguishing plate 34 and the movable contact 20A, and the arc 32A is divided into two arcs 32B and 320. One of the divided arcs 32C is attracted to the second metal arc extinguishing plate 36 and is driven by the magnetic field created by the current flowing through the fixed contact 24. , as shown at 32D. When this arc 32D is stretched and the arc voltage increases, the arc 32D becomes two arcs 32E and 32
It is divided into F. The arc 32 is finally divided into three arcs 32B, 32F, and 32'F, extinguished at the current zero point, and the current is interrupted.

In conventional switches, arc extinguishing is performed as described above, but since the distance between the first metal arc extinguishing plate 34 and the fixed contact 240 is small, the first metal arc extinguishing plate 34 and the fixed contact 240 are not in contact with each other. The width of the arc 32DG between the children 24 was not large, making it difficult for the useless arc 32D to be divided into two arcs 32E and 32F. And for this reason, the arc 32 is the first
The tip of the metal arc-extinguishing plate 34 and the fixed contact 240 tended to stick together. As a result, electric field concentration tends to occur at one end of the arc 32D, and the electric field concentration occurs at the tip of the first metal arc-extinguishing plate 34, which has poor heat conduction. was occurring.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to improve interrupting performance by preventing one end of the arc from concentrating on the tip of the arc extinguishing plate, which has poor heat conduction. The object of the present invention is to provide a switch that can

In order to achieve the above object, the present invention includes a fixed contact joined to a fixed contact, a fixed contact joined to a movable contact, and a commutating electrode provided on the back side of the movable contact.
It is characterized by comprising a U-shaped metal arc-extinguishing plate having a surface facing the commutating electrode, a surface facing the fixed contact, and a surface facing the side surface of the movable contact.

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

FIG. 4 and FIG. 5 show an embodiment of a main part of a switch according to the present invention. The switch, a part of which is shown in the figure, differs from the conventional switch described above in that a commutation electrode 40 is newly provided and a metal arc-extinguishing plate 38 is formed in a U-shape. do. The negative side of the metal arc-extinguishing plate 40 faces the fixed contact 24, and the commutation electrode 40 is provided on the opposite side thereof.

Here, the arc 32 generated between the movable contact 20A and the fixed contact 24A is attracted to a metal arc-extinguishing plate 38 made of a magnetic material, and is elongated as shown by the reference numeral 32A. When the fixed contact 24 is formed in a U-shape with three sides as shown in FIG. Stretched. As the arc 32 is stretched, the arc voltage increases, so dielectric breakdown occurs between the fixed contact 24 and the metal arc-extinguishing plate 38, and between the metal arc-extinguishing plate 38 and the movable contact 20, and the arc 32A becomes two arcs. 32
It is divided into B and 320.

One of the divided arcs 32C is driven by the magnetic field created by the current flowing through the metal arc-extinguishing plate 38, and is elongated as shown at 32D. When this arc 32D is stretched and the arc voltage increases, dielectric breakdown occurs between the metal arc extinguishing plate 38 and the commutating electrode 40, and the arc 32D becomes an arc'
・It becomes like 32G.

As a result, the two arcs 32B and 32M are extinguished at the current zero point, and the current is interrupted.

As described above, in the switch of this invention, two arcs 3
Both ends of 2C and 32G reach a current zero point and extinguish the arc at three flat parts where electric field concentration is difficult to occur and which have good heat conduction, that is, the flat parts of the commutation electrode 40, the metal arc-extinguishing plate 38, and the fixed contact 24. As a result, excellent interrupting performance can be obtained.

Although the fixed contact 24 has a U-shape in the embodiment, it is needless to say that the shape is not limited to this.

As described above, the switch according to the present invention extinguishes the arc by reaching the current zero point on a flat surface where electric field concentration is less likely to occur and which has good heat conduction, so the breaking performance is significantly improved compared to the conventional one. can be done.

[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. FIG. 5, which is a perspective view of the main parts of the embodiment, is an explanatory diagram of the operation of Hisaaki's embodiment. 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 32G are arcs, 38 is a metal arc extinguishing plate, 40 is a commutation electrode. Agent: Patent attorney Shin Kuzuno - (Ooka or one person) Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) A fixed contact joined to a fixed contact, a movable contact joined to a movable contact, a commutation electrode provided on the back side of the movable contact, and a fixed contact with the surface facing the commutation electrode. A switch comprising a U-shaped metal arc-extinguishing plate having a surface facing the contact and a surface facing the side surface of the movable contact.