JP5957715B2 - Circuit breaker for wiring - Google Patents

Description

  The present invention relates to a circuit breaker for wiring in which insulation deterioration of an intermediate case due to arc gas generated when a short circuit is interrupted is prevented.

The circuit breaker for wiring is a device that has a function of opening the contact and cutting off the current when it detects that a large current such as a short circuit current has flowed in the circuit. Arc discharge may occur and arc gas may be generated. The generated arc gas fills the space between the fixed contact and the movable contact at a high temperature, and moves from the space surrounded by the insulator toward the exhaust hole. For this reason, the arc gas causes the insulation deterioration of the insulating part to which the fixed contact is fixedly attached.

  Therefore, as shown in Patent Document 1, an arc extinguishing device is incorporated in the circuit breaker for wiring to extinguish the generated arc, or a protective member for protecting the insulator constituting the circuit breaker for wiring from the arc is provided. Things have been done.

  However, since the contact portion becomes very hot when the arc is generated, there is a possibility that even if the arc generated by disposing the arc extinguishing device is extinguished, insulation deterioration may occur in the intermediate case supporting the fixed contact.

  Further, when another protective member is incorporated around the fixed contact, the number of parts increases and the number of assembling steps also increases, leading to a problem of increasing costs.

JP 2003-297215 A

  Therefore, a main object of the present invention is to provide a circuit breaker for wiring which can solve the above-mentioned conventional problems and can protect an intermediate case around a fixed contact from arc gas to prevent insulation deterioration. Another object of the present invention is to provide a wiring breaker that can prevent insulation deterioration of the intermediate case without increasing the number of components.

The present invention has been made in order to solve the aforementioned problem, and an intermediate case solid Teise' probe is attached and fixed, in the left and right case and circuit breaker provided with a covering the intermediate case, the tip from the intermediate case in the space between the fixed contact which is formed by float and its vicinity of the intermediate case, the intermediate case protective member for protecting the intermediate casing from the arc gas, characterized in that provided by intermediate cases or al separated Is.

Incidentally, the intermediate case protective member, it is rather preferable are those projecting from the inner surface of the left and right of the case, it is preferable that the intermediate case protective member has a shape that covers the lower side of the fixed contact.

  The circuit breaker for wiring according to the present invention is provided with an intermediate case protection member for protecting the intermediate case from arc gas, separated from the intermediate case, in a space between the stationary contact and the intermediate case in the vicinity thereof. Thus, the creeping distance and the spatial distance between the fixed contact and the intermediate case can be increased, and the arc can be prevented from moving along the surface of the intermediate case.

  Further, since the intermediate case protection member is separated from the intermediate case, the arc does not continue through the intermediate case protection member, and insulation deterioration of the intermediate case can be prevented. Further, if the intermediate case protection member is provided so as to protrude from the inner surfaces of the left and right cases as in claim 2, there is no increase in the number of parts and the number of assembly steps.

It is a disassembled perspective view of the circuit breaker for wiring of embodiment. It is a perspective view of the state which opened the left case. It is a side view of the principal part. It is a perspective view of the right and left cases showing the shape of the intermediate case protection member. It is the perspective view of the principal part which abbreviate | omitted the intermediate | middle case protection member and the case on either side. It is a perspective view of the principal part which abbreviate | omitted the intermediate case protection member, the right and left cases, and the stationary contact. It is explanatory drawing which shows how to transmit the arc gas in this invention.

Embodiments of the present invention will be described below.
FIG. 1 is an exploded perspective view of a circuit breaker according to the present invention. As shown in this figure, the circuit breaker according to the present invention has an outer case formed by an intermediate case 1 and left and right cases 2. The structure incorporates an opening and closing mechanism. The left and right cases 2 are fixed to each other by screws 3. The intermediate case 1 and the left and right cases 2 are both formed of an insulating resin.

  The opening / closing mechanism is composed of a bimetal 4, a trigger lever 5, a handle 6, a cross bar 7, and the like. When an overcurrent is detected, the movable contact 8 is lifted from the fixed contact 9 and the movable contact 10 is pulled away from the fixed contact 11. The circuit is shut off as before. In addition, since the circuit breaker for wiring of this embodiment is a plug-in type, a plurality of plug portions 12 are provided on the power supply side, and are configured to be plug-in connected to a bus bar (not shown).

  As shown in FIGS. 2 and 3, a fixed contact 11 is formed on the top surface of the tip of the fixed contact 9, and a movable contact 10 is located above the fixed contact 11. The fixed contact 9 is fixed to the upper surface of the bottom of the intermediate case 1, but as shown in FIG. 3, the tip of the fixed contact 9 protrudes from the intermediate case 1 and is in a position raised from the upper surface of the bottom of the intermediate case 1. . As shown in FIGS. 5 and 6, it has a fixed contact holding portion 15 formed integrally with the intermediate case 1 that holds the fixed contact 11 of the fixed contact 9 so that the tip of the fixed contact 11 is floated. Forming.

  As shown in FIG. 2 and FIG. 4, an intermediate case protection member 14 projects horizontally from the inner surfaces of the left and right cases 2 toward the central partition wall 13 of the intermediate case 1. As shown in FIGS. 3 and 4, the intermediate case protection member 14 of this embodiment has a substantially crank-shaped cross-sectional shape in which upper and lower horizontal planes are connected by a vertical wall. 1 is a structure that is inserted into the space between the stationary contact 9 and the intermediate case 1 in the vicinity thereof when assembled to 1. The intermediate case protection member 14 is inserted into the space at a position separated from the intermediate case 1. When the left and right cases 2 are fixed to each other with screws 3, the front end surface of the intermediate case protection member 14 comes into contact with the central partition wall 13 of the intermediate case 1.

  The intermediate case protection member 14 is a member for protecting the intermediate case 1 from arc gas generated between the fixed contact 11 and the movable contact 10 when a large current is interrupted. The lower surface of the fixed contact 9 is covered with the horizontal plane and the vertical wall. This prevents an arc from flowing from the fixed contact 11 to the lower intermediate case 1.

  In addition, as shown in FIG. 7, the intermediate case 1 in the vicinity of the fixed contact 11 is formed with a plurality of concave and convex portions 16 in a rib shape to increase the creepage distance. These concavo-convex portions 16 also have an effect of reinforcing the vicinity of the fixed contact 11 against a gas generated when a large current is interrupted.

Next, the function and effect of the present invention will be described.
In a normal circuit breaker having no intermediate case protection member 14 according to the present invention, an arc generated between the fixed contact 11 and the movable contact 10 when a large current is interrupted will flow along the surface of the insulating material in the vicinity thereof. And However, the circuit breaker according to the present invention is provided with an intermediate case protection member 14 formed from the inner surfaces of the left and right cases 2 separated from the intermediate case 1 in the space between the stationary contact 9 and the intermediate case 1 in the vicinity thereof. Therefore, since the intermediate case protection member 14 and the intermediate case 1 are not in direct contact, the arc does not continue between the fixed contact 9 and the intermediate case 1 via the intermediate case protection member 14. If there is a direct contact, there is a problem that the insulation of the intermediate case 1 deteriorates due to the arc moving to the intermediate case 1 along the intermediate case protection member 14, so the intermediate case protection member 14 is fixed to the fixed contact 9 and the intermediate contact 1. It is formed separately from the case 1. Moreover, since the uneven part 16 is formed on the side of the fixed contact 9, the creeping distance becomes longer as shown in FIG.

  Further, the spatial distance between the stationary contact 9 and the intermediate case 1 in the vicinity thereof is also increased by the intermediate case protection member 14 existing between them. Thus, since the intermediate case protection member 14 increases the creepage distance and the spatial distance, it is possible to prevent the deterioration of the insulation of the surface of the intermediate case 1 by the arc gas moving in the direction of the exhaust hole from the space surrounded by the insulator. .

  As described above, in this embodiment, the intermediate case protection member 14 has a substantially crank-shaped cross section, but a vertical portion or the like is formed so as not to interfere with the movement of the movable contact 9 and the spatial distance is made longer. It is also possible.

  Further, since the intermediate case protection member 14 is projected from the inner surfaces of the left and right cases 2, it is only necessary to assemble the left and right cases 2 with screws 3 with respect to the intermediate case 1, and no separate parts are required. In addition, the assembly is simple and the number of parts does not increase, and the cost increase can be suppressed.

  As described above, according to the present invention, it is possible to protect the intermediate case 1 around the fixed contact 11 from arc gas and prevent insulation deterioration without increasing the number of parts. For this reason, there exists an advantage which can avoid the trouble accompanying the insulation deterioration of the intermediate case 1 at low cost.

DESCRIPTION OF SYMBOLS 1 Intermediate case 2 Right and left case 3 Screw 4 Bimetal 5 Trigger lever 6 Handle 7 Crossbar 8 Movable contact 9 Fixed contact 10 Movable contact 11 Fixed contact 12 Plug part 13 Central partition 14 Intermediate case protection member 15 Fixed contact holding part 16 Uneven part

Claims (3)

In a circuit breaker comprising an intermediate case with a fixed contact mounted and fixed, and left and right cases covering the intermediate case,
An intermediate case protection member for protecting the intermediate case from arc gas is provided separately from the intermediate case in the space between the stationary contact formed with the tip floating above the intermediate case and the intermediate case in the vicinity thereof. Characteristic circuit breaker.   2. The circuit breaker according to claim 1, wherein the intermediate case protection member is provided on the inner surfaces of the left and right cases. The circuit breaker according to claim 2, wherein the intermediate case protection member has a shape that covers a lower side of the fixed contact.

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