JPH07141977A - Arc-extinguishing device of circuit breaker - Google Patents

Abstract

PURPOSE:To prevent noise emission by securing a grid inserted in a groove provided at a case so that the grid does not vibrate with the electromagnetic force. CONSTITUTION:Facing upward, a claw 4a is formed in a single piece at the top of each lateral member of a grid 4 which is inserted in a groove 3 provided at a case 1, and the tip of this claw 4a protruding from the oversurface 1c of the case 1 when a cover 5 is fitted, is left biting into the joining surface of cover 5 with the case 1. Thereby the grid 4 does not make rattles even though a play across the width of the groove 3 exists relative to the plate thickness of the grid 4, and no noises will be generated caused by vibration with the electromagnetic force effected from the internal conductor of a circuit breaker.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deion ion grid type arc extinguishing device in a circuit breaker such as a circuit breaker for wiring or an earth leakage breaker.

[0002]

2. Description of the Related Art As is well known, the arc extinguishing device is composed of several grids made of a magnetic plate having a V-shaped cutout, and drives the arc generated when the current is cut off to the back of the cutout to divide it. It is cooled together with it and the arc voltage is increased to promote extinction. FIG. 4 shows a conventional structure of a case of a circuit breaker having such an arc extinguishing device and a grid attached to the case. In the figure, the inside of a case 1 made of mold resin is divided into a three-phase conduction path space 2 by a side wall 1a and a partition wall 1b, and is perpendicular to a facing wall surface of the side wall 1a and the partition wall 1b from a mating surface 1c with a cover (not shown). A plurality of grooves 3 provided in parallel with each other are provided, and a grid 4 is inserted into these grooves 3. The upper end surface of the grid 4 is at substantially the same height as the surface 1c of the case 1, and is prevented from coming off by the cover attached to the case 1.

[0003]

In the illustrated configuration, the groove 3 is provided with a certain margin in width with respect to the plate thickness in consideration of the insertion of the grid 4. There is a problem in that there is play in the holding of the grid 4 and the grid 4 vibrates under the influence of the magnetic field generated from the internal conductor of the circuit breaker when a current is applied to generate noise. As a countermeasure, it is conceivable to make the gap between the groove 3 and the grid 4 tight and to press the grid 4 into the groove 3, but in order to do so, the width of the groove 3 and the thickness of the grid 4 should be controlled. It is necessary to perform it precisely, resulting in an increase in cost, and a problem that the work of inserting the grid 4 becomes troublesome. Therefore, an object of the present invention is to provide an arc extinguishing device for a circuit breaker in which a grid is firmly fixed without causing such a new problem and noise due to vibration of the grid is prevented. is there.

[0004]

According to the present invention, a claw is integrally formed vertically on the upper end or the lower end of both sides of a grid inserted in a groove of a case, and the claw is bited into the cover or the case. By doing so, the above object is achieved.

[0005]

The vertical claws are integrally formed on the upper or lower ends of both sides of the grid, and the claws are pressed into the cover or the case by the pressing force when the cover is mounted on the case to fix the grid.

[0006]

1 is a right pole (T phase) showing an embodiment of the present invention.
It is a front view of the arc-extinguishing device part. In the figure, case 1
Of the grid 4 to be inserted into the groove 3 of the side wall 1a and the phase-separation wall 1b are provided with sawtooth-shaped protrusions 4a on the upper ends thereof, and the height of both sides including the protrusion 4a is larger than the depth of the groove 3. Has become. Therefore, when the grid 4 is simply inserted in the groove 3, the tips of the protrusions 4a project from the upper surface of the case 1, that is, the mating surface 1c with the cover 5. Therefore, when the cover 5 is mounted on the case 1, the pressing force causes the claw 4a to bite and be fixed to the lower surface of the cover 5, that is, the mating surface with the case 1. As a result, even if there is a play between the width of the groove 3 and the plate thickness of the grid 4, the grid 4 will not rattle, and will not vibrate even when receiving an electromagnetic force.

FIG. 2 shows an embodiment in which the claw 4a is provided at the lower end of the grid 4. In this case, grid 4
The upper ends of both sides project from the surface 1c of the case 12 in a state where it is simply inserted into the groove 3, but the claw 4a bites into the bottom surface of the groove 3 when the grid 4 is pushed by mounting the cover 5 and is fixed. To be done. The claws 4a may be provided at both upper and lower ends of both sides of the grid 4.

FIG. 3 is a vertical cross-sectional view showing a closed state of the circuit breaker to which the grid 4 is fixed as described above. Current flows from the power supply side terminal 6 to the fixed contactor 7 integrated with the terminal 6, and It flows through the movable contactor 8, the lead wire 9, the connecting conductor 10, the heater conductor 12 of the overcurrent trip device 11 and the connecting conductor 13 which are in contact with each other, and then to the load side terminal 14 integrated therewith. When the operation handle 15 is tilted to the right in the figure from the closed state shown in the figure, or when the overcurrent trip device 11 acts on the trip mechanism 17 in the overcurrent state, the opening / closing mechanism 16 operates and the movable contact 8 opens. To do. At that time, an arc is generated between the fixed and movable contacts 7 and 8, and this arc is drawn into the arc extinguishing device composed of the grid 4, divided, cooled, and extinguished.

[0009]

According to the present invention, the claws at the upper end or the lower end of the grid are made to bite into the cover or the case by the pressing force when the cover is attached to the case, so that the grid is played in the groove of the case. Even if there is, the grid is securely fixed and does not vibrate and emit noise even when subjected to electromagnetic force. Further, since the grid can be inserted into the groove as in the conventional case, the assembling property is not impaired, and the simple construction of simply forming the claws integrally with the grid does not require a separate part, so that the grid can be implemented at low cost.

[Brief description of drawings]

FIG. 1 is a front view of an arc extinguishing device portion showing an embodiment of the present invention.

FIG. 2 is a front view of an arc extinguishing device portion showing another embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a circuit breaker including the arc extinguishing device of FIG. 1 or 2.

FIG. 4 is a perspective view of a case of a circuit breaker having a conventional arc extinguishing device.

[Explanation of reference numerals] 1 case 1a side wall 1b partition wall 1c mating surface with cover 2 current-carrying path space 3 groove 4 grid 4a claw 5 cover

Claims (1)

[Claims] 1. A plurality of grooves are provided in parallel to each other in a vertical direction from a mating surface with a cover on a side wall of a case and a wall surface of a partition wall which face each other and define a conduction path space of each phase, and these grooves are V-shaped notches. In a circuit breaker arc extinguishing device in which grids each consisting of a magnetic plate with a grid are inserted, upper and lower edges of both sides of the grid inserted into the groove of the case are integrally formed with vertical claws, and these claws are An arc extinguishing device for a circuit breaker, characterized in that it is designed to bite into the cover or the case.