JPH0230129B2 - DENRYOKUKAIHEISOCHI - Google Patents

Description

[Detailed Description of the Invention] This invention provides a power switching device that switches and closes current;
In particular, it relates to its arc extinguishing mechanism.

Main applicable switches of this invention include electromagnetic contactors, wiring switches, and disconnectors.

First, an example of a conventional electromagnetic contactor will be described with reference to FIG. Generally, an electromagnetic contactor is symmetrical, so FIG. 1 shows only one side of the contactor in cross section. In the figure, 1 is a mounting base, 2 is a fixed core laminated with silicon steel plates on this mount, 3 is a movable core installed opposite the fixed core 2 and also laminated with silicon steel plates, and 4 is the movable core 3 and the fixed core. 2 is an operating coil that applies a driving force to attract the magnets against a tripping spring (not shown), and 5 is a crossbar having a square window, the lower end of which holds the movable iron core 3.
6 is a movable contact inserted into the corner window of the cross bar 5 and held by a push spring 7, 6A is a movable contact provided on this movable contact 6, 6B is an end of the movable contact, and 8 is the above-mentioned movable contact. A fixed contact that is provided opposite to the movable contact 6 and conducts current flow, 8A.
is provided on this fixed contact 8, and the movable contact 6
It is a fixed contact that can be brought into contact with and separated from A. 9 is a terminal screw for connecting the electromagnetic contactor body to an external circuit; 10
1 is a base on which the fixed contact 8 is attached, 11 is an interphase barrier, and 11A is a cover that covers the upper surface of the contacts 6 and 8. Inside the cover is a cover for extinguishing an arc 12 that occurs between the fixed contact 8A and the movable contact 6A. A metal arc-extinguishing plate 13 made of a magnetic material is provided, and FIG. 2 shows the state in which the metal arc-extinguishing plate 13, the fixed contact 8, and the fixed contact 8A are attached. This metal arc-extinguishing plate 13 is configured as a U-shaped frame that covers the fixed contact 8A and is erected in parallel to the contact and separation direction of both contacts 6A and 8A, and is inserted into a portion close to the fixed contact 8. A notch 14 is provided for the purpose.

Next, the operation will be explained. When the operating coil 4 is demagnetized, the movable core 3 is separated from the fixed core 2 by a tripping spring (not shown), the crossbar 5 also assumes the state shown in FIG. 1, and the fixed contact 8A and the movable contact 6A are separated and both Arc 1 between contacts 6A and 8A
2 occurs, but this arc 12 is caused by the metal arc extinguishing plate 13
As a result, the arc is extinguished at the current zero point, and the current is briefly cut off.

The arc extinguishing process of the arc 12 in this conventional electromagnetic contactor will be explained in more detail with reference to FIG. 3, which shows a cross section of the arc extinguishing chamber.

The arc 12 generated between the movable contact 6A and the fixed contact 8A is attracted by the magnetic metal arc-extinguishing plate 13 and is elongated into an extended arc 12A.
When the arc is stretched like this extended arc 12A, the arc voltage increases, so the movable contact end 6B
and the metal arc-extinguishing plate 13, and the metal arc-extinguishing plate 13
Dielectric breakdown occurs between the fixed contact 8 and the arc 12A, and the arc 12A is analyzed into two arcs 12B, 12C, and at the zero current point, these two arcs 12B,
12C is extinguished.

In a conventional electromagnetic contactor where the arc is extinguished by such a process, the arc 12B is
When the arc 12B occurs at a position as shown in FIG. 4 in FIG.
Since it is driven in the direction of the surface facing B, no inconvenience will occur. However, if arc 12B occurs at the position shown in FIG.
Magnetic flux shown by the broken line is generated around 2B and arc 1
2B is driven toward the corner of the U-shaped metal arc-extinguishing plate 13. Therefore, the generation position of the arc 12C in FIG. 3 is as shown in FIG. 6, so the interphase barrier 11 shown in FIG. This has the disadvantage of causing a short circuit between phases.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and the metal arc extinguishing plate is composed of a trough-like curved surface or a multifaceted surface in which the angle between adjacent surfaces is an obtuse angle. The aim is to reduce damage to the interphase barrier due to arc heat by using a device in which the curved surface or multifaceted recess is arranged parallel to the contact/separation direction so as to face the end of the movable contact. There is.

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

In FIGS. 7 and 8, the metal arc-extinguishing plate 13 is gutter-shaped, and is composed of five surfaces such that the angles between adjacent surfaces are obtuse angles, and the contact points 6A and 8A are connected to each other in the direction of contact and separation. A concave portion (on the left side in this figure) formed by the five surfaces is arranged parallel to the movable contact end portion 6B.

In the device having the metal arc-extinguishing plate 13 configured and arranged in this manner, even if an arc 12B occurs at a location as shown in FIG. A magnetic flux shown by is generated, and the arc 12B is driven in the direction shown by the arrow. Therefore, the arc 12C is generated at a location away from the interphase barrier 11 as shown in FIG. 8, so that the heat loss of the interphase barrier 11 can be reduced, and the phenomenon of interphase short circuit caused by holes in the interphase barrier 11 can also be suppressed. can do.

FIG. 9 shows another embodiment of this invention,
In the figure, the metal arc-extinguishing plate 13 has a trough-like curved surface, and is arranged parallel to the direction of contact and separation of both contacts 6A and 6B, such that the recessed part of the curved surface faces the movable contact end 6B. .

In the device having the metal arc-extinguishing plate 13 configured and arranged in this manner, thermal damage to the interphase barrier 11 can be reduced, and interphase short circuits can also be suppressed, as in the above embodiment.

FIG. 10 shows another embodiment of the present invention, in which a portion of the movable contact end 6B facing surface 13A of the metal arc-extinguishing plate 13 shown in FIGS. 7 and 8 is adjacent to the fixed contact 8. A U-shaped protrusion 13B is formed on the
This U-shaped protrusion 13B is provided to protrude opposite to the separation space of the movable contact 6A. In the device configured in this manner, the heat loss of the interphase barrier 11 can be reduced and short circuits between the phases can be suppressed, as well as the arc 12 generated between the contacts 6A and 8A is caused by the U-shaped protrusion. 13B, and after being separated, the metal arc-extinguishing plate 13 is driven at high speed by the magnetic field created by the current flowing through the U-shaped protrusion 13B, and the arc can be extinguished quickly. It can exhibit excellent shrunken performance.

It goes without saying that the present invention can be expected to have similar effects on fixed contacts 8 having different shapes as shown in FIG.

Furthermore, when the fixed contact 8 is provided with the projection 8B as shown in FIG. 12, the distance between the metal arc-extinguishing plate 13 and the projection 8B of the fixed contact 8 is reduced. Since the distance is smaller than the distance between the protrusions and the non-protrusions, there is a high probability that the arc 12C will occur on the protrusions 8B of the fixed contact 8. That is, arc 12C
Since there is a high probability that this will occur at a location away from the interphase barrier 11, thermal damage to the interphase barrier 11 can be further reduced.

Note that the shape of the protrusion 8B does not have to be cylindrical as shown in FIG. 12, and may be, for example, prismatic or radial.

In addition, in the above explanation, contacts 6A and 8A
Although this invention is only described as an example of applying the present invention to a power switchgear that opens and closes using a magnet, that is, an electromagnetic contactor, this invention can also be applied to other power switchgear such as a wiring shield or a disconnector. is obvious.

As described above, according to the present invention, the metal arc-extinguishing plate is composed of a trough-like curved surface or multiple surfaces in which the angle between adjacent surfaces is an obtuse angle. Alternatively, since the multi-faceted recess is arranged so as to face the end of the movable contact, it is possible to reduce damage to the interphase barrier due to arc heat.

[Brief explanation of drawings]

Figure 1 is a partial sectional view of a conventional magnetic contactor, Figure 2 is a partial cross-sectional view of a conventional magnetic contactor.
The figure is an enlarged perspective view of the metal arc-extinguishing plate and fixed contact of the one shown in Fig. 1, Fig. 3 is an explanatory diagram for explaining the arc-extinguishing operation in a conventional electromagnetic contactor, and Fig.
5 and 6 are plan views and perspective views for explaining the drawbacks of conventional electromagnetic contactors, and FIGS. 7 and 8 are configurations of metal arc-extinguishing plates according to an embodiment of the present invention. FIG. 9 is a plan view and perspective view for explaining the structure and operation of a metal arc-extinguishing plate according to another embodiment of the present invention, and FIG.
FIG. 11 is a perspective view showing a metal arc-extinguishing plate and a fixed contact according to another embodiment of the present invention, and FIG.
The figure is a perspective view showing a fixed contact according to another embodiment of the invention. In the figure, 6 is a movable contact, 6A is a movable contact, 6B is a movable contact end, 8 is a fixed contact, 8
A is a fixed contact, 11 is an interphase barrier, 12, 12
A, 12B, and 12C are arcs, and 13 is a metal arc extinguishing plate. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A fixed contact, a fixed contact joined to this fixed contact, a movable contact provided opposite to the fixed contact, a movable contact joined to this movable contact and capable of coming into contact with and separating from the fixed contact, and a metal arc-extinguishing plate that extinguishes the arc generated between the two contacts, wherein the metal arc-extinguishing plate has a trough-like curved surface or a multifaceted surface in which the angle between adjacent surfaces is an obtuse angle. A power switchgear comprising: a curved or multifaceted concave portion disposed parallel to the contact/separation direction so as to face the end portion of the movable contact.