JP3117055B2 - Circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker such as a circuit breaker for a wiring or an earth leakage breaker.

[0002]

2. Description of the Related Art A circuit breaker for wiring has a structure in which an opening / closing mechanism and an overcurrent trip device are integrally incorporated in an insulating container including a case and a cover. In addition to the above, a leakage detection unit and a trip coil unit driven by the leakage detection unit are incorporated. In such wiring breakers and earth leakage breakers, the insulating containers are generally made in different sizes, but the earth leakage breaker has a leakage detection unit in addition to the components of the wiring breaker. This is because it was considered that the earth leakage breaker would be larger than the wiring breaker even with the same frame size.

[0003] However, if the insulating container is different between the circuit breaker for wiring and the earth leakage breaker, it is not possible to flexibly cope with a specification change due to the presence or absence of the earth leakage protection function, and the molding cost becomes high because the molding is separated. . Therefore, the present inventors have previously developed a circuit breaker that can unify the insulating container between the wiring breaker and the earth leakage breaker, and applied for a patent by the present applicant (Japanese Patent Application No. 4-83301). This is to form a spare space between the overcurrent trip device of the insulating container and the load side terminal, and use this spare space when adding a leakage leakage trip function or other functions to the circuit breaker for wiring. An earth leakage detection unit and the like are provided.

[0004]

On the other hand, in the above-described circuit breaker, when the current is interrupted, the internal pressure of the insulating container rises due to the generation of arc gas. Not even. Therefore, when the internal pressure rises in one of the right and left phases (R phase or T phase), especially when a large current is interrupted, the excessive internal pressure acts on one side wall of the insulating container, and there is a risk of damaging the concentrated internal pressure. is there. Therefore, if the offset of the increase in the internal pressure can be dispersed between the phases, it is advantageous in preventing breakage of the insulating container. In view of the above, the present invention provides a circuit breaker in which, when a spare space is provided on the load side of an insulating container, the internal pressure rise during current interruption is balanced between the phases to prevent damage to the insulating container due to excessive concentration of the internal pressure. The purpose is to provide.

[0005]

SUMMARY OF THE INVENTION The present invention achieves the above object by providing a ventilation hole in a partition plate between phases defining a spare space.

[0006]

Conventionally, the phases in the insulating container are completely closed. However, by providing a vent in the partition between the phases, the arc gas can flow between the phases through the vent. Even when the internal pressure rises in one of the phases, the arc gas can be released to the central phase or the other phase therebefore to equalize the internal pressure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a circuit breaker for wiring, and FIG. 2 is a plan view with a part of a cover thereof cut away. In these figures, an opening / closing mechanism 3, an overcurrent trip device 4, and the like are integrally incorporated in an insulating container including a case 1 and a cover 2 made of a molded resin. The current is supplied from the power source side terminal 5 to the fixed contact 6 integral therewith, the movable contact 7 contacting / separating therefrom, the fixed conductor 8 slidingly contacting the same, and the overcurrent tripping device 4 connected to this by a screw. After passing through the heater conductor 9 and the connection conductor 10 brazed to the heater conductor 9, the current flows to the load-side terminal 11 integrated therewith.

When the current flowing through the heater conductor 9 of the overcurrent trip device 4 is overloaded, the heat generated by the heater conductor 9 causes the bimetal 12 to bend leftward in FIG. Of the opening / closing mechanism 3
To unlock the movable contact 7. When a large current such as a short-circuit current flows through the heater conductor 9, the armature 13 of the overcurrent tripping device 4 is instantaneously attracted in the counterclockwise direction in FIG. 1, and the upper end thereof strikes the tripping portion 3a to move. The contact 7 is separated.

Here, a spare space 14 is formed between the overcurrent trip device 4 and the load terminal 11 in the container so as to cross each phase. As shown in FIG. 3, a notch 15 is provided at a portion of the case 1 that partitions the inside of the insulating container for each phase, at a portion that intersects with the spare space 14 of the phase space wall 1a. Spare space 1 in notch 15 as shown
A partition plate 16 made of an insulating material for partitioning 4 is detachably mounted using a groove 17. And this partition plate 16
Is provided with two vent holes 16a formed of round holes. The size, shape, position, number, and the like of the ventilation holes 16a are appropriately determined so as not to impair the insulation distance between the charged portions in the adjacent phases, and are not limited to the illustrated example. In the case where the circuit breaker is configured as an earth leakage breaker, the partition plate 16 is removed, and an earth leakage detection unit extending over each phase is installed in the spare space 14.

In the illustrated circuit breaker, when a current is interrupted, an arc gas is generated, and this arc gas flows through the internal space of the insulator container for each phase to the power supply side and the load side,
The air is exhausted from the exhaust holes of the shielding plates 18 (FIGS. 1 and 2) on each side. FIG. 4 shows, for example, the right phase (T
FIG. 7 is a plan view of a main part of the case 1 in which arrows indicate flows of arc gas to the load side when a particularly high internal pressure is generated in the phase 1).

In this case, if the phases are completely closed, the high internal pressure of the T phase acts on the case side wall 1b as it is, and when the internal pressure rises excessively, cracks may occur at the base of the case 1b. is there. On the contrary,
In the case of FIG. 4, a part of the T-phase arc gas moves to the middle phase (S phase) having a relatively low internal pressure through the vent hole 16a as shown by an arrow, and a part of the gas moves to the R phase. Therefore, the increase in the internal pressure in the T phase is alleviated, and the sidewall 1b is not damaged due to excessive internal pressure concentration. In addition, the arc gas is finally discharged to the outside from the shielding plate 18, but the discharge amount is also equalized between the phases, so that the discharge of the contained conductive component and the metal melt to the outside is accelerated. Withstand voltage performance is also improved. These actions are the same when a high internal pressure is generated in the R phase.

In the above-mentioned embodiment, the notch 15 is formed in the phase space 1a of the case 1 and the ventilation hole 16a is provided in the partition plate 16 in which the notch 15 is mounted. In this case, a chain line in FIG. As shown in the figure, it is possible to provide the ventilation hole 19 also in the phase space wall 2a of the cover 2 which intersects the spare space 14, and the notch is also formed in the phase space wall 2a of the cover 2, and the partition plate is formed in this notch. When the is installed, it is possible to provide a ventilation hole in this partition plate.

[0013]

According to the present invention, since the ventilation holes are provided in the inter-phase partition plates which define the spare space formed on the load side of the insulating container, the imbalance in the internal pressure rise at the time of current interruption is provided. , The damage of the insulating container due to excessive concentration of the internal pressure can be prevented, and the discharge of the arc gas to the outside of the container can be promoted to improve the withstand voltage performance after the interruption.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a circuit breaker showing an embodiment of the present invention.

FIG. 2 is a plan view in which a part of a cover of the circuit breaker of FIG. 1 is cut away.

FIG. 3 is a perspective view of a case of the circuit breaker of FIG. 1 and a partition attached to the case.

FIG. 4 is a plan view of a main part of a case for explaining a flow of arc gas in the circuit breaker of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 1a Phase spacing wall 1b Side wall 2 Cover 2a Phase spacing wall 3 Opening / closing mechanism 4 Overcurrent trip device 14 Spare space 15 Notch 16 Partition plate 16a Vent hole

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-59-203338 (JP, A) JP-A-5-2979 (JP, A) JP-A-5-250976 (JP, A) JP-A-56-203 162442 (JP, A) JP-A-2-121223 (JP, A) Japanese Utility Model Application Sho 51-58859 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 71/02 H01H 73 / 06

Claims (1)

(57) [Claims] An opening / closing mechanism, an overcurrent trip device and the like are integrally incorporated in an insulator container comprising a case and a cover.
A circuit breaker in which a spare space is formed between an overcurrent trip device of the insulating container and a load-side terminal, wherein a ventilation hole is provided in a partition plate between phases that divides the spare space. Circuit breaker.