JPS628421A - Arc extinguisher - 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 [Industrial Application Field] The present invention relates to an arc extinguishing device used in a circuit breaker or the like, and particularly to its gas circulation structure.

[Conventional technology]

FIG. 3 shows a conventional arc extinguishing device disclosed in Japanese Unexamined Patent Publication No. 55-46487. When the movable contact (2) separates from the fixed contact (4) due to the breaking operation, both contacts (2
) (4) An arc occurs between. This arc moves between the arc traveling plates 16) (8), is magnetically attracted to the grid Ql, and is divided. The generated gas is discharged through the exhaust plate 00 hole (
(to) to the exhaust port (2). Arc running plate (6)
A reflux side plate α4 is provided on the side of (8), and has the following effect. For explanation, a plan sectional view of the vicinity of the reflux side plate α4 is shown in FIG. Arc (3
) moves toward the grid plate Qd, the gas pressure at the forward point (P2), where the arc flash advances, changes to the backward point (P2).
Therefore, the arc flash cannot move quickly, and the travel time to the grid plate αO is delayed, reducing the current limiting effect. Therefore, the reflux side plate α
A gap is provided to allow the gas at point (P2) to circulate through the back side of the reflux side plate α4 as indicated by arrow αG. Therefore, the gas pressure at the point (P2) decreases and the gas pressure at the point (Pl) increases, making it easier for the arc flash to move toward the grid plate Qf).

[Problem that the invention seeks to solve]

However, when the current is large and the amount of arc gas generated is large, sufficient circulation is not achieved. Therefore, the gas pressure at point (P2) increases, and the arc (3) does not move quickly toward the grid plate αG, resulting in a problem that the current limiting performance deteriorates.

In order to solve this problem, a method has been adopted in which the distance between the reflux side plates α is widened to reduce the gas pressure at point (P2). However, when the distance between the reflux side plates α4 is widened in this manner, there is a problem in that sufficient reflux cannot be achieved when the current is small and the amount of arc gas generated is small.

An object of the present invention is to solve the above-mentioned problems and to obtain an arc extinguishing device that has stable current-limiting performance regardless of the magnitude of the current.

[Means for Solving the Problems] In the arc extinguishing device according to the present invention, the reflux side plates are held by elastic means so that the mutual spacing changes depending on the gas pressure.

[Effect]

- When the flow is large and the gas pressure is high, the gas pressure causes the reflux side plates to move away from each other.

Therefore, even in the case of a large current, the gas pressure in front of the arc does not increase, and the arc moves quickly.

Further, when the current is small and the gas pressure is low, the return side plates move toward each other due to the action of the elastic means.

Therefore, even in the case of a small current, sufficient circulation is carried out. In other words, the arc moves quickly.

〔Example〕

An embodiment of this invention is shown in FIG. Arc running plate (8
) is provided with a one-piece book side selection α4.

The circulation side plate α4 is held on the casing angle of the breaker by an elastic body (2) which is elastic means.

The arc gas causes a point (P2) in front of the arc (3)
When the pressure at is increased, the arc gas is circulated as indicated by arrow αG. As a result, the pressure at point (P2) decreases and the pressure at point (Pl) increases, allowing the arc (3) to travel quickly.

Furthermore, when the current is large, the pressure of the arc gas becomes high, and the amperage body supporting the reflux side plate α flexes. Therefore, as shown in Figure 2, the reflux side plate a4
The distance between them increases, and the pressure at point (P2) is prevented from becoming abnormally high. In other words, the arc (3) travels quickly.

As described above, as the arc (3) travels quickly and is quickly divided by the grid plate frame, the current is quickly limited.

〔Effect of the invention〕

In this invention, since the circulation side plate is held by elastic means, stable circulation is always performed regardless of the magnitude of the current. That is, an arc extinguishing device having excellent current limiting characteristics can be obtained.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing a case where the distance between the circulation side plates is widened at the time of large current, Fig. 3 is a diagram showing a conventional arc extinguishing device, and Fig. 4 is a diagram showing an example of the present invention. The figure is a plan sectional view showing the vicinity of the circulation side plate of a conventional arc extinguishing device. (6) (8) is the arc traveling plate, aO is the grid plate, α
This is the reflux side plate. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A pair of arc running plates that run the arc fired at the contact point, a grid that is placed between the arc running plates and divides and extinguishes the running arc, and a gas pressure An arc extinguishing device comprising: a reflux side plate held by elastic means so that the mutual spacing changes according to the reflux side plate.