JPH0479085B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to power switching devices such as electromagnetic contactors and molded circuit breakers, and particularly relates to improvements in commutating electrodes.

A conventional electromagnetic contactor is constructed as shown in FIGS. 1, 2, and 3 a and b.

In the figure, reference numeral 1 denotes an arc extinguishing arc box made of a heat-resistant material, in which a grid 2 and a commutating electrode 3 made of magnetic metal are arranged and fixed in accordance with the number of phases of the electrical circuit to be opened and closed. 4 is a cross bar, 5 is a movable contact, 6 is a movable contact attached to both ends of the movable contact 5, 7 is a movable contact holder, 8
9 is a contact spring, and 10 is a stopper. The contact spring 9 is a stopper 10
is compressed and fixed between the lower part of the presser spring support 8 and the lower end of the presser spring support 8. It is assembled in contact with the 12 is a terminal.

13 is a fixed contact, and 14 is a fixed contact. The movable contact 5 and the fixed contact 13 are provided facing each other, and the movable contact 6 and the fixed contact 14 can be moved toward and away from each other. 15 is an arc runner.

The movable contact is connected to a built-in well-known electromagnetic drive device via a movable contact spring 9.

Such a contact mechanism is provided symmetrically with respect to the A-A cross section, and is arranged in correspondence with the number of phases of the electric circuit that opens and closes in a direction perpendicular to the plane of the paper.

FIG. 2 is a perspective view schematically showing the commutation plate 3, movable contact 5, and movable contact 6, which are the main parts of FIG. When the part 15 is enlarged, it looks like Fig. 3 a and b. Second
In the figure, 31 to 34 indicate first to fourth surfaces, respectively.

In such an electromagnetic contactor, when the fixed contact 14 and the movable contact 6 are opened, one end of the arc generated between the two contacts 6 and 14 is transferred from the movable contact 6 to the commutating electrode 3, while the other end is Transfers from the fixed contact 14 to the arc runner 15. The other end of the transferred arc moves toward the end on the arc runner 15,
Eventually, the arc is extinguished between the vertical portion of the arc runner 15 and the commutating electrode 3 facing thereto.

By the way, the commutation electrode 3 in a conventional electromagnetic contactor had a shape as shown in FIG. When the legs of the arc 17 occur at the position indicated by point P in this commutation electrode, if the current components flowing from the commutation electrode 3 to the legs of the arc 17 are represented by i ₁ , i ₂ , i ₃ , the arc 17 is A driving force toward the fixed contact 13 is applied by the current component _i3 , and a driving force toward the grid 2 is weakened. For this reason, sufficient breaking performance could not be obtained.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above. It is an object of the present invention to provide a power switching device with excellent interrupting performance by providing a wide notch on the fourth surface that extends toward the boundary side and close to the boundary side.

An embodiment of the present invention will be described below.
FIG. 4 shows a commutating electrode according to an embodiment of the present invention, and in the figure, 3A indicates the fourth surface 34 and the third surface 34.
The boundary side forming the boundary with the surface 33, 16 is the fourth
This is a wide notch that extends from the side opposite to the boundary side 3A on the surface 34 toward the boundary side 3A and as far as the boundary side. Although not shown, the commutation electrode 3 has a predetermined thickness.

Now, when the contacts 6 and 14 of the power switchgear are opened, the arc 17 generated between the contacts 6 and 14 is transferred to the third surface 33 of the commutating electrode 3 and the arc runner 15. The arc 17 then moves over the third surface 33 and the arc runner 15 and finally reaches the fourth surface 34 of the commutating electrode 3, the grid 2 and the arc runner 1.
An arc 17 exists between the grid 2 of No. 5 and the opposing surface 15A. When one leg of the arc 17 is at a point P on the fourth surface 34 of the commutating electrode 3, the current components flowing into the arc 17 from the commutating electrode 3 are i ₁ and i ₂ , and the conventional The current component i ₃ in the example, that is, drives the arc 17 toward the fixed contact 13 side, and there is no component that weakens the driving force toward the grid 2 side, so the arc 17 is strongly driven toward the grid 2 side, resulting in excellent breaking performance. is obtained.

In addition, although the shape of the notch 16 was made rectangular in the said Example, it is not limited to this.

In addition, in an electromagnetic contactor without an arc runner 15, the arc leg generated at the fixed contact 14 is transferred to the fixed contact 13, and this arc leg is transferred to the fixed contact 13.
3. Run on top. However, the other leg of the arc is transferred from the movable contact 6 to the commutating electrode 3, and the situation in which the arc is driven is the same without the arc runner 15 as with the arc runner 15. Therefore,
It is obvious that the present invention is also effective for an electromagnetic contactor without an arc runner 15.

Note that the present invention is applicable not only to electromagnetic contactors but also to other power switching devices such as molded circuit breakers.

As described above, according to the present invention, the fourth surface facing the boundary side forming the boundary between the third surface and the fourth surface
Since the fourth surface is provided with a wide notch extending from the side of the surface toward the boundary side and close to the boundary side, it is possible to obtain a power switchgear with excellent interrupting performance.

[Brief explanation of drawings]

FIG. 1 is a side view partially showing a conventional electromagnetic contactor in cross section, FIG. FIG. 3a is an enlarged plan view of the arc runner and fixed contact shown in FIG. 1, and FIG.
FIG. 4 is a cross-sectional view showing section A, and a perspective view showing a commutating electrode according to an embodiment of the present invention. In the figure, 2 is a grid, 3 is a commutation electrode, and 5 is a grid.
1 is a movable contact, 6 is a movable contact, 13 is a fixed contact, 14 is a fixed contact, 33 to 34 are the first to fourth surfaces of the commutating electrode 3, respectively, and 3A is the fourth surface 34 and the third surface. Boundary sides forming a boundary with the surface 33 include a notch 16 and an arc 17. 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 the above. a grid provided parallel to the contact/separation direction of both contacts, a first surface opposite to the opposite contact joining surface of the movable contact, a second surface parallel to the contact/separation direction, and the movable contact. a third surface facing the contact joint surface of the movable contact and a fourth surface facing the grid; the second and third surfaces are provided with notches that do not hinder the contact and separation of the movable contact; 1. In a power switchgear comprising a commutator plate electrically connected to the second, third, and fourth surfaces in this order, on the boundary side forming the boundary between the third surface and the fourth surface. A power switchgear characterized in that the fourth surface is provided with a wide notch that extends from the opposite side of the fourth surface toward the boundary side and close to the boundary side.