JPS5938689B2 - Arc extinguishing chamber of hardwire circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention forms an inner box 3 and an outer box 4 with a gap serving as an arc extinguishing gas bypass path 2 in a molded circuit breaker 1, and a rear part 5 of the inner box 3 has an arc extinguishing The arc plate 6 is stored, and the rear end surface 7 of the inner box 3 and outer box 4 is
For wiring, a partition plate 8 is installed between them to block the arc extinguishing gas bypass path 2, and arc extinguishing gas vent holes 9 are bored on both sides of the partition plate 8 on the rear end surfaces 7 of the inner box 3 and outer box 4. This relates to the arc extinguishing chamber of the circuit breaker, and although its purpose is to smoothly discharge arc extinguishing gas and ensure arc extinguishing,
To provide an arc extinguishing chamber for a molded circuit breaker in which an arc is not short-circuited between arc extinguishing gas vent holes outside an inner box, causing a drop in arc voltage and causing a significant decrease in current limiting effect.

The present invention will be described in detail below according to examples.

When an overcurrent flows in the molded circuit breaker 1, the internal solenoid 1
3 works, the lever 14 is irreversibly driven and the movable contact 10 and the fixed contact 11 are separated, but at this time an arc discharge occurs between the movable contact 10 and the fixed contact 11, This arc discharge is extinguished by an arc extinguishing device 15 shown in FIG.

This arc extinguishing device 15 is composed of an inner box 3, an outer box 4, and an arc extinguishing section 16 in which arc extinguishing plates 8 are laminated at regular intervals.

An outer box 4 is provided outside the inner box 3 with a gap serving as an arc-extinguishing gas bypass path 2 interposed therebetween.

An arc extinguisher 16 is housed in the rear half of the inner box 3, and a movable contact 10 and a fixed contact 11 are installed in the front half.

A partition plate 8 is installed vertically between the opposing rear end surfaces 1 of the outer box 4 and the inner box 3 [7, the arc extinguishing gas bypass path 2 is blocked from the left and right by the partition plate 8.

Arc extinguishing gas vent holes 9 communicating with the arc extinguishing gas bypass path 2 are bored on both sides of the partition plate 8 on the rear end surface 7 of the outer box 4 and the inner box 3.

The arc-extinguishing gas vent hole 9a of the outer box 4 has a small diameter, and the arc-extinguishing gas vent hole 9b of the inner box 3 has a large diameter, so that the arc-extinguishing gas can be easily discharged from the inner box 3.

However, when an overcurrent flows through the molded circuit breaker 1, the movable contact 10 separates from the fixed contact 11, but at this time an arc 12 is generated between the movable contact 10 and the fixed contact 11. The arc 12 is magnetically driven in the direction of the arc extinguishing plate 6, and is extinguished by the arc extinguishing plate 6.

Then, the arc extinguishing gas generated when the arc 12 is extinguished is exhausted to the arc extinguishing gas bypass path 2 through the arc extinguishing gas vent hole 9 of the inner box 3 on the rear side of the arc extinguishing plate 6, and a part of it is exhausted from the outer box 4
The arc-extinguishing gas is exhausted to the outside through the arc-extinguishing gas vent hole 9, and the other gas is exhausted to the outside through the arc-extinguishing gas bypass path 2.

In this case, the arc extinguishing gas vent hole 9a of the inner box 3 has a large diameter, but since the partition plate 8 is provided between the left and right arc extinguishing gas vent holes 9a, there is no short circuit between the arc extinguishing gas vent holes 9a, and a drop in arc voltage is prevented. The arc is smoothly extinguished without impairing the current limiting effect.

In the present invention, an inner box and an outer box are formed through a gap that is an arc-extinguishing gas bypass path, an arc-extinguishing plate is housed in the rear half of the inner box, and a Since the arc extinguishing gas vent hole is drilled, the arc extinguishing gas coming out of the arc extinguishing gas vent hole in the inner box is separated into the arc extinguishing gas bypass path and the arc extinguishing gas vent hole in the outer box, and is discharged into the inner box. The arc-extinguishing gas is smoothly discharged, and the arc is guided toward the arc-extinguishing plate and extinguished by the magnetic drive in the direction of the arc-extinguishing plate, and the high-temperature arc-extinguishing gas forms an arc-extinguishing gas bypass path. Since the arc-extinguishing gas is separated and discharged through the arc-extinguishing gas vent hole in the outer box, the only part of the high-temperature arc-extinguishing gas that directly waves out of the outer box is the arc-extinguishing gas discharged from the arc-extinguishing gas vent hole in the outer box. This has the advantage of reducing the amount of high-temperature arc-extinguishing gas discharged directly to the outside, and is effective in preventing deterioration of the insulation of the cord wired to the molded circuit breaker and preventing flashover. A partition plate is installed between the rear end faces to block the arc extinguishing gas bypass path,
Arc extinguishing gas vent holes are drilled on both sides of the partition plates on the rear end faces of the inner and outer boxes, so even if arc extinguishing gas is discharged from the arc extinguishing gas vent holes in the inner box, the left and right arc extinguishing gas vent holes can be removed. Since it is partitioned by a partition plate, it is possible to prevent a short circuit due to an arc between the left and right arc extinguishing gas vent holes, and there is an effect that it is possible to prevent a decrease in the arc voltage and a significant decrease in the current limiting effect.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of an embodiment of the arc extinguishing chamber of the present invention; Fig. 2 is a longitudinal sectional view of an embodiment of the molded case circuit breaker of the above; and Fig. 3 is an embodiment of the arc extinguishing chamber of the above. 4 is an exploded perspective view of one embodiment of the same as above, 1 is a molded circuit breaker, 2 is an arc extinguishing gas bypass path, 3 is an inner box, 4 is an outer box, 5 is a rear half, 6 is an arc extinguishing plate, 7 is a rear end surface, 8 is a partition plate, and 9 is an arc extinguishing gas vent hole.

Claims (1)

[Claims] 1 An inner box and an outer box are formed through a gap that is an arc-extinguishing gas bypass path in a molded circuit breaker, and an arc-extinguishing plate is stored in the rear half of the inner box, and between the rear end surfaces of the inner box and the outer box. The arc extinguishing chamber of a molded circuit breaker is constructed by constructing a partition plate to block the arc extinguishing gas bypass path, and drilling arc extinguishing gas vent holes on both sides of the partition plate on the rear end faces of the inner and outer boxes.