JP2012043565A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker that increases driving power for an arc to arc-extinguishing chambers even after arcs move to arc runners.SOLUTION: In the circuit breaker which includes a first fixed contact 1 and a second fixed contact 2, a movable contact 3 bridging them, arc-extinguishing chambers 5, 5 which extinguish arcs generated between contact points, and arc runners 1b, 2b formed at the first fixed contact 1 and second fixed contact 2 respectively, the arc runners 1b, 2b are provided with channel-shaped magnetic materials 1c, 2c adapted to drive arcs on sides of the fixed contact points 1a, 2a to the arc-extinguishing chambers 5, 5.

Description

  The present invention relates to a circuit breaker including, for each phase, a current interrupting unit including a pair of fixed contacts facing each other and a movable contact that bridges between them.

As this type of circuit breaker, a configuration disclosed in Patent Document 1 is known. FIG. 7 is a side view of a current interrupting part of a circuit breaker showing a conventional example.
In the figure, the current breaker of the circuit breaker includes a first fixed contact 1 having a U-shape having a first fixed contact 1a and a second L-shaped having a second fixed contact 2a. It consists of a stationary contact 2, a movable contact 3 having movable contacts 3a and 3a that contact the fixed contacts 1a and 2a at both ends, and an arc extinguishing chamber 5 having a plurality of grids 4 made of a U-shaped magnetic body. The movable contact 3 is pressed against the first and second fixed contacts 1 and 2 by a contact spring 6.

  An arc runner 1b is formed at the tip of the first fixed contact 1a of the first fixed contact 1, and an arc runner 2b is formed at the tip of the second fixed contact 2a of the second fixed contact 2. Has been.

  An arc commutation plate 7 is disposed between the arc extinguishing chambers 5, 5 so as to straddle between the arc extinguishing chambers 5, 5. It has become. Further, a pair of front and rear U-shaped magnetic bodies 8 are arranged on the anti-fixed contacts 1 and 2 side of the movable contact 3, and the tips of both legs of the U-shaped magnetic body 8 are movable in a closed state. The contact 3 is sandwiched from both sides via a gap.

  In the configuration described above, the current flows from the power supply side terminal (not shown) to the load terminal (not shown) via the first fixed contact 1, the movable contact 3, the second fixed contact 2, and the overcurrent tripping device (not shown). Flowing.

  In such a circuit breaker, when a large current such as a short circuit current flows through the energization path, the movable contact 3 is brought into contact spring by the electromagnetic repulsion force acting between the parallel conductors of the fixed contacts 1 and 2 and the movable contact 3. 6, and an arc is generated between the contacts 1a and 3a and between the contacts 2a and 3a. This arc is stretched toward the arc extinguishing chamber 5 by the electromagnetic force generated by the current flowing through the arc itself and the action of the grid 4. At that time, the legs of the arc fixed contacts 1 and 2 are driven to the arc runners 1 b and 2 b, and then driven toward the arc extinguishing chamber 5. In addition, the legs of the arc on the movable contact 3 side are driven toward the arc extinguishing chamber 5 after being commutated to the arc commutation plate 7. The arc is divided by the grid 4 and extinguished.

  Further, a U-shaped magnetic body 8 is provided in the vicinity of the movable contact 3a, and when a large current flows, the magnetic flux of the current flowing through the movable contact 3 is focused on the U-shaped magnetic body 8. Thereby, the opening speed of the movable contact 3 can be increased and the interruption performance can be improved.

Japanese Patent No. 2965025

  By the way, in the conventional circuit breaker, in order to improve the breaking performance, it is necessary to drive the arc generated between the contacts to the arc extinguishing chamber faster. For this purpose, it is effective to increase the driving force of the arc toward the arc extinguishing chamber by using the electromagnetic force of the arc itself. In the conventional circuit breaker, an arc runner is provided at the tips of the first and second stationary contacts, and the arc is moved to the arc extinguishing chamber side by moving the arc foot on the stationary contact side generated between the contacts to the arc runner. I try to drive it.

  However, after the foot of the arc on the fixed contact side has moved to the arc runner, the driving force of the arc to the arc extinguishing chamber side is reduced only by the electromagnetic force by the arc itself, thereby reducing the interruption performance. There were drawbacks.

  Then, the subject of this invention is providing the circuit breaker which can raise the drive force of the arc to the arc-extinguishing chamber side, even after an arc moves to an arc runner.

  In order to achieve the above object, according to the present invention, a first fixed contact having a first fixed contact, a second fixed contact having a second fixed contact, and the first and second A movable contact that has movable contacts at both ends that respectively contact the fixed contact; and an arc generated between the first and second fixed contacts and the movable contact disposed at both ends of the movable contact. In the circuit breaker comprising an arc extinguishing chamber and arc runners formed respectively on the first and second fixed contacts, the arc runner drives an arc on the fixed contact side to the arc extinguishing chamber side. A letter-shaped magnetic material is provided.

  In the circuit breaker, the magnetic body is preferably formed integrally with the arc runner. In addition, the U-shaped magnetic body may be disposed on the anti-movable contact side of the arc runner. Furthermore, an insulating cover may be provided on the magnetic body.

  According to the present invention, since the arc runner is provided with the U-shaped magnetic body for driving the arc on the fixed contact side to the arc extinguishing chamber side, the driving force of the arc can be increased even after the arc moves to the arc runner. It is possible to improve the blocking performance.

Sectional drawing which shows the principal part which shows the OFF state of the circuit breaker which shows the 1st Embodiment of this invention The perspective view of the electric current interruption part shown in FIG. FIG. 2 is a perspective view around the contact portion shown in FIG. Sectional drawing which shows the principal part which shows the OFF state of the circuit breaker which shows the 2nd Embodiment of this invention The perspective view of the electric current interruption part shown in FIG. FIG. 5 is a perspective view around the contact portion shown in FIG. Side view of current interrupter of circuit breaker showing conventional example

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.
1 is a cross-sectional view of a main part showing an off state of a circuit breaker showing a first embodiment of the present invention, FIG. 2 is a perspective view of a current interrupting unit shown in FIG. 1, and FIG. 3 is shown in FIG. It is a perspective view of a contact part periphery. In addition, in the figure of an Example, the same code | symbol is attached | subjected and demonstrated to the member corresponding to FIG.

In the figure, the current interrupting part of the circuit breaker according to the present embodiment has a U-shaped first fixed contact 1 having a first fixed contact 1a and a U-shaped having a second fixed contact 2a. The second fixed contact 2 is composed of a movable contact 3 having movable contacts 3a and 3a that are in contact with the fixed contacts 1a and 2a at both ends, and an arc extinguishing chamber 5 that extinguishes an arc generated between the contacts. Has been.
The current interrupting unit is housed for each phase in a main body case including a case 12a and a cover 12b.

  The first fixed contact 1 and the second fixed contact 2 are arranged opposite to each other in the front-rear direction, and the movable contact 3 is formed in a strip shape with both ends bent into a square shape, and in a closed state. The first and second stationary contacts 1 and 2 are pressed by a contact spring (not shown) to bridge between them. At the time of opening, the movable contact 3 is pushed down against the contact spring by an opening / closing mechanism through a holder or the like (not shown).

  Further, arc runners 1b and 2b made of a magnetic material are formed at the tip of the first fixed contact 1a of the first fixed contact 1 and the tip of the second fixed contact 2a of the second fixed contact 2. By moving the legs of the arc on the fixed contacts 1a, 2a generated between the contacts from the fixed contacts 1a, 2a to the arc runners 1b, 2b, damage to the fixed contacts 1a, 2a due to a large current is prevented.

The first fixed contact 1 is connected to a power supply side terminal (not shown), and the second fixed contact 2 is connected to a load side terminal (not shown) via an overcurrent tripping device (not shown).
As shown in FIG. 2, the arc extinguishing chamber 5 is disposed at both ends of the movable contact 3, and includes a plurality of grids 4 made of a U-shaped magnetic body, and a U-shape that supports the grid 4. It is comprised from the support body 5a which consists of this insulator.

  Further, an arc commutation plate 7 is provided between the arc extinguishing chambers 5 and 5 so as to straddle between the arc extinguishing chambers 5 and 5, and the arc on the movable contact 3 a side generated between the contacts is arranged. By causing the foot to commutate to the arc commutation plate 7, damage to the movable contact 3 and the movable contact 3a due to a large current is prevented.

  Here, in this embodiment, the arc-shaped runner 1b formed at the tip of the first fixed contact 1a of the first fixed contact 1 drives the arc on the fixed contact 1a side to the arc extinguishing chamber 5 side. A magnetic body 1c is provided. The arc runner 2b formed at the tip of the second fixed contact 2a of the second fixed contact 2 also has a U-shaped magnetic body 2c that drives the arc on the fixed contact 2a side to the arc extinguishing chamber 5 side. Is provided.

  In this embodiment, the U-shaped magnetic body 1c is formed integrally with the arc runner 1b, and as shown in FIG. 3, a pair of flat plate portions 1d, 1d projecting from both ends of the arc runner 1b toward the movable contact 3 side. have. Similarly, the U-shaped magnetic body 2c is formed integrally with the arc runner 2b, and as shown in FIG. 3, a pair of flat plate portions 2d and 2d projecting from both ends of the arc runner 2b to the movable contact 3 side. have.

  The flat plate portions 1d and 2d of the U-shaped magnetic bodies 1c and 2c are arranged over the entire area of the arc runners 1b and 2b, that is, fixed contacts, so that the arc moved to the arc runners 1b and 2b can be driven to the arc extinguishing chambers 5 and 5 side. It is formed from the portion where 1a and 2a are provided to the tip of arc runners 1b and 2b.

Next, the operation of the present invention will be described.
In the configuration described above, when a large current such as a short-circuit current flows through the energization path, an electromagnetic repulsive force is generated between the first and second fixed contacts 1 and 2 and the movable contact 3, which is shown in FIG. As described above, the movable contact 3 opens from the first and second fixed contacts 1 and 2, and the first fixed contact 1a and the movable contact 3a, the second fixed contact 2a and the movable contact 3a An arc 11 is generated between them.

  In the arc 11 generated between the first fixed contact 1a and the movable contact 3a, the arc foot on the fixed contact side moves from the fixed contact 1a to the arc runner 1b, and the arc foot on the movable contact 3a side moves to the movable contact 3a. To the arc commutation plate 7 via the tip of the movable contact 3. Similarly, the arc 11 generated between the second fixed contact 2a and the movable contact 3a also moves the arc foot on the fixed contact side from the fixed contact 2a to the arc runner 2b, and the arc foot on the movable contact 3a side is It commutates from the movable contact 3 a to the arc commutation plate 7 via the tip of the movable contact 3. In this way, the commutated current flows through the arc commutation plate 7 while the arc continues.

  Here, the arc runners 1b and 2b are provided with U-shaped magnetic bodies 1c and 2c, and the magnetic flux generated by the current flowing through the arc runners 1b and 2b is converged on the U-shaped magnetic bodies 1c and 2c. The arc that has moved to the arc runners 1b and 2b is driven to the arc extinguishing chambers 5 and 5 by the action of the U-shaped magnetic bodies 1c and 2c.

Then, the arc 11 driven to the arc extinguishing chambers 5 and 5 is divided by the grid 4 and extinguished.
Thus, according to this embodiment, since the arc-shaped runners 1b and 2b are provided with the U-shaped magnetic bodies 1c and 2c, the electromagnetic force acting on the arc moved to the arc runners 1b and 2b can be increased. Thereby, an arc can be driven to the arc-extinguishing chamber side at high speed, and the interruption | blocking performance improves.

  If the flat plate portions 1d and 1d of the magnetic body 1c and the flat plate portions 2d and 2d of the magnetic body 2c are covered with an insulating cover, the arc on the fixed contact side generated between the contacts is the flat plate portion of the magnetic bodies 1c and 2c. Can be prevented, and the arc on the fixed contact side can be more reliably moved to the arc runner.

Next, a second embodiment of the present invention will be described with reference to FIGS.
4 is a cross-sectional view of an essential part showing an OFF state of a circuit breaker showing a second embodiment of the present invention, FIG. 5 is a perspective view of the current interrupting part shown in FIG. 4, and FIG. 6 is shown in FIG. It is a perspective view of a contact part periphery.

In the first embodiment, the magnetic body is formed integrally with the arc runner. However, in the second embodiment, the U-shaped magnetic body is formed by a separate member from the arc runner.
Since other configurations are the same as those of the first embodiment, the same reference numerals are given and detailed description thereof is omitted.

  In the figure, 9 is a U-shaped magnetic body having flat plate portions 9a, 9a at both ends. The U-shaped magnetic body 9 is inserted between the U-shaped first fixed contact 1 and the anti-moving contact of the arc runner 1b so that the flat plate portions 9a and 9a protrude toward the movable contact 3 side. It is arranged on the child 3 side. Similarly, a U-shaped magnetic body 9 is also inserted between the U-shaped second fixed contact 2 so that the flat plate portions 9a and 9a protrude toward the movable contact 3 side. A U-shaped magnetic body 9 is disposed on the counter movable contact 3 side of the arc runner 2b.

The U-shaped magnetic body 9 can be fixed to the arc runners 1b and 2b by fixing means such as caulking, welding, and screwing.
According to the above-described configuration, since the U-shaped magnetic body 9 is provided in the arc runners 1b and 2b as in the first embodiment, the electromagnetic force acting on the arc moved to the arc runners 1b and 2b is U-shaped. It can be increased by the magnetic body 9 having a shape. Thereby, an arc can be driven to the arc-extinguishing chamber side at high speed, and the interruption | blocking performance improves.

  Similarly to the first embodiment, if the flat plate portions 9a, 9a of the U-shaped magnetic body 9 are covered with an insulating cover, the arc on the fixed contact side generated between the contacts is a flat plate of the magnetic body 9. It is possible to prevent the portion from being ignited and to move the arc on the fixed contact side to the arc runner more reliably.

DESCRIPTION OF SYMBOLS 1 1st fixed contact 1a 1st fixed contact 1b Arc lanna 1c Magnetic body 2 2nd fixed contact 2a 2nd fixed contact 2b Arc lanna 2c Magnetic body 3 Movable contact 3a Movable contact 5 Arc extinguishing chamber Magnetic material 11 arc

Claims (4)

A first fixed contact having a first fixed contact, a second fixed contact having a second fixed contact, and a movable contact having both ends contacting each of the first and second fixed contacts. A contact, an arc extinguishing chamber disposed at both ends of the movable contact, for extinguishing an arc generated between the first and second fixed contacts and the movable contact; and the first and second fixed In a circuit breaker having an arc runner formed on each contact,
A circuit breaker, wherein the arc runner is provided with a U-shaped magnetic body for driving an arc on the fixed contact side toward the arc extinguishing chamber.   The circuit breaker according to claim 1, wherein the magnetic body is formed integrally with the arc runner.   2. The circuit breaker according to claim 1, wherein the U-shaped magnetic body is disposed on a non-movable contact side of the arc runner.   The circuit breaker according to claim 2 or 3, wherein an insulating cover is provided on the magnetic body.