JPH05225887A - Circuit breaker - Google Patents

Abstract

PURPOSE:To enhance the reliability of the circuit breaker by preventing a movable contact piece from becoming unable to be closed again due to deformation thereof at the time of breaking a large current, or preventing the opening/ closing of the movable contact piece from becoming difficult for the same reason. CONSTITUTION:Non-magnetic material reinforcement plates 9a, 9b for preventing deformation of a movable contact piece 4 due to electromagnetic repulsive force acting between each phase movable contact piece 4 are mounted to the side surfaces thereof, respectively, over the entire length thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker having a plurality of fixed contacts and a plurality of movable contacts.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a main portion of a conventional circuit breaker similar to that shown in, for example, "Switchboard / Control Board Handbook" (6.7.2 wiring breaker). 8 is a sectional view taken along the line VIII-VIII in FIG.

In the figure, 1 is a case, 2 is a fixed contact fixed in the case 1, 3 is a fixed contact fixed to the tip of the fixed contact 2, and 4 is rotatable in the case 1. The movable contacts 5 provided at the movable contacts 5 are fixed to the tip of the movable contact 4.
Is brought into contact with or separated from the fixed contact 3 by the rotation of the movable contactor 4.
Reference numeral 6 denotes an operation mechanism portion of the movable contactor 4 provided in the case 1, and illustration of the inside is omitted. An arc extinguishing device 7 is provided around the movable contact 5.

Next, the operation will be described. In the state where the rated power is supplied to the load from the power source (not shown) through the fixed contact 2, the fixed contact 3, the movable contact 5, and the movable contact 4, in order to secure the reliability of energization, The movable contact 5 is pressed against the fixed contact 3 by the contact pressure. From this state, when a short circuit accident occurs in the load side circuit and a large current flows, the movable contactor 4 is rotated by the operation mechanism portion 6 and the movable contact 5 is separated from the fixed contact 3.

However, in the case of a short circuit accident, the fixed contact 3
Since a current several to several tens of times the rated current passes through the contact surface of the movable contact 5, the electromagnetic repulsive force on this contact surface becomes equal to or higher than the contact pressure of the movable contact 5. Therefore, in the case of a short-circuit accident or the like, the movable contactor 4 normally rotates without waiting for the operation of the operation mechanism section 6.

In the conventional circuit breaker configured as described above, the electromagnetic repulsive force also acts between the movable contacts 4 of each phase when a large current is interrupted. On the other hand, the movable contact 4
Is made of copper or a copper alloy having a relatively low strength and is annealed when the movable contact 5 is brazed to lower its strength. Therefore, as shown in FIG. The electromagnetic repulsive force causes the movable contactor 4 to be laterally deformed.
As a result, the movable contactor 4 comes into contact with the arc extinguishing device 7 and cannot be reclosed, and it becomes difficult to bring the movable contact 5 into contact with the fixed contact 3 to close the contact.

[0007] In order to solve this problem, for example
There is a movable contactor as shown in Japanese Patent Publication No. 2-5543. The basic configuration of this movable contact is shown in FIGS.
Shown in 1. In this configuration, the movable pressure reflector 8 made of a high resistance material having a higher electrical resistivity than the movable contact 4 is attached to the movable contact 4 so as to surround the outer periphery of the movable contact 5. Other parts are the same as those in FIG. 7.

Next, the operation of this circuit breaker will be described. When a large current flows such as in the case of a short circuit accident, the movable contact 4 is rotated by the operation mechanism portion 6 and the movable contact 5 is separated from the fixed contact 3, as in the case of FIG. 7. The same applies to the fact that the electromagnetic repulsive force acts between the movable contacts 4 of each phase. However, in this rotation breaker, even if the movable contactor 4 receives an electromagnetic repulsive force, the movable side pressure reflector 8 is arranged around the movable contact 5, so that the movable side pressure reflector 8 is arranged. In the range of the movement, the movable contact 4 itself is prevented from being deformed by the electromagnetic repulsive force.

[0009]

10 and 1 described above.
In the conventional circuit breaker as shown in FIG. 1, since the movable side pressure reflector 8 is provided only in a part of the movable contactor 4, as shown in FIG. The movable contactor 4 is deformed at a portion not provided,
There is a problem in that the movable contactor 4 and the movable side pressure reflector 8 may come into contact with the arc extinguishing device 7 and become inoperable again. When a magnetic material is used for the movable side pressure reflector 8, the arc A (FIG. 11) generated when the movable contact 5 and the fixed contact 3 are separated from each other is extinguished by the movable side pressure reflector 8. The movement to the 7 side is hindered, and the movable contact 5 and the fixed contact 3 are stagnant. Therefore, there is a problem that the arc A is not cooled and a predetermined current interruption performance cannot be obtained.

The present invention has been made to solve the above problems, and it is possible to prevent the movable contact from being deformed by the electromagnetic repulsive force, which makes the opening / closing operation difficult. It is an object of the present invention to provide a circuit breaker that can prevent the electric current from being generated, and that does not prevent the arc from moving to the arc extinguishing device side and that can obtain a predetermined current interruption performance.

[0011]

A circuit breaker according to a first aspect of the present invention is provided with an upper surface, both side surfaces and a lower surface of each movable contact.
A reinforcing member made of a non-magnetic material is attached along at least one of the surfaces.

A circuit breaker according to a second aspect of the present invention is the circuit breaker according to the first aspect of the present invention in which ribs are provided.

[0013]

According to the present invention, the movable contactor is reinforced by attaching the reinforcing member to the movable contactor, and the movable contactor is prevented from being deformed by the electromagnetic repulsive force acting between the movable contactors. Further, by using a non-magnetic material for the reinforcing member, it is possible to prevent the arc from moving to the arc extinguishing device side.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. Example 1. 1 is a block diagram showing a main part of a circuit breaker according to a first embodiment of the invention of claim 1, and FIG.
The same or corresponding parts as those in 2 are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 9a and 9b are reinforcing plates as reinforcing members which are attached to both side surfaces of each movable contactor 4 over the entire length as shown in FIG. 2, and these reinforcing plates 9a and 9b are not Magnetic material such as stainless steel (S
US304 etc.) and is attached to the movable contactor 4 by brazing, for example.

Although such a circuit breaker operates in the same manner as in the prior art, since the entire length of the movable contactor 4 is reinforced by the reinforcing plates 9a and 9b made of non-magnetic material, each phase is interrupted when a large current is cut off. The movable contactor 4 is prevented from being deformed by the electromagnetic repulsive force generated between the movable contactors 4. Therefore, when the large current is cut off, the movable contact 4 is not deformed and the opening and closing operation becomes difficult.

Further, since the reinforcing plates 9a and 9b are made of a non-magnetic material, the arc is not prevented from moving to the arc extinguishing device 7 side, so that a predetermined current interruption performance is obtained. be able to.

Example 2. In the above embodiment, the reinforcing plate 9
Although a and 9b are attached to both side surfaces of the movable contactor 4, if the deformation due to the electromagnetic repulsive force can be prevented, for example, as shown in FIG. 3, the reinforcing plate 9 as a reinforcing member may be attached to only one side surface. ..

Example 3. Further, for example, as shown in FIG. 4, the reinforcing plate 9 may be attached along the upper surface of the movable contactor 4 (the surface opposite to the fixed surface of the movable contact 5). Further, although not shown, a reinforcing plate may be attached along the lower surface of the movable contactor 4 excluding the movable contact 5, and the attaching method is not limited to brazing.

Example 4. Further, although the reinforcing plates 9, 9a, 9b are shown as the reinforcing members in the above-mentioned embodiment, the shape of the reinforcing member is not limited to this, and for example, as shown in FIG. Also, a reinforcing member 10 having a U-shaped cross section that covers the upper surface may be used, and attachment to the movable contact 4 is easy.

Embodiment 5. Next, FIG. 6 is a perspective view showing a main part of a circuit breaker according to an embodiment of the present invention.
As shown in this figure, the movable member 4 is provided with a reinforcing member 11 having a rib 11a along the lower end of a U-shaped cross section.
In this case, the same strength can be obtained with a thinner plate thickness than the reinforcing member 10 of FIG.

[0022]

As described above, the circuit breaker according to the first aspect of the present invention is made of a non-magnetic material for preventing the movable contacts from being deformed by the electromagnetic repulsive force acting between the movable contacts. Since the reinforcing member is attached to the movable contactor, it is possible to prevent the movable contactor from being re-closed due to the deformation of the movable contactor or the opening / closing operation becoming difficult when a large current is interrupted.
An effect that reliability can be improved is exhibited.
Further, since the non-magnetic material is used for the reinforcing member, there is an effect that a predetermined current interruption performance can be obtained without hindering the arc from moving to the arc extinguishing device side.

Further, in the circuit breaker of the second aspect of the invention, since the reinforcing member is provided with the ribs, in addition to the effect of the first aspect of the invention, the plate thickness of the reinforcing member can be reduced without lowering the strength. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a main part of a circuit breaker according to a first embodiment of the invention of claim 1.

FIG. 2 is a perspective view of an essential part of FIG.

FIG. 3 is a main part perspective view showing a second embodiment of the invention of claim 1;

FIG. 4 is a perspective view of an essential part showing a third embodiment of the invention according to claim 1;

FIG. 5 is a perspective view of a main part showing a fourth embodiment of the invention of claim 1.

FIG. 6 is a perspective view of an essential part showing an embodiment of the invention of claim 2;

FIG. 7 is a configuration diagram showing a main part of an example of a conventional circuit breaker.

8 is a sectional view taken along the line VIII-VIII in FIG.

9 is a configuration diagram showing a state in which the movable contactor in FIG. 7 is deformed by an electromagnetic repulsive force.

FIG. 10 is a configuration diagram showing a main part of another example of a conventional circuit breaker.

11 is a sectional view taken along the line XI-XI of FIG.

12 is a configuration diagram showing a state in which the movable contactor in FIG. 10 is deformed by an electromagnetic repulsive force.

[Explanation of symbols]

 2 Fixed Contact 3 Fixed Contact 4 Movable Contact 5 Moving Contact 9 Reinforcing Plate (Reinforcing Member) 9a Reinforcing Plate (Reinforcing Member) 9b Reinforcing Plate (Reinforcing Member) 10 Reinforcing Member 11 Reinforcing Member 11a Rib

Claims (2)

[Claims] 1. A plurality of fixed contacts each having a fixed contact, a plurality of movable contacts each having a movable contact that contacts and separates from the fixed contact, and an upper surface of these movable contacts. A reinforcing member made of a non-magnetic material, which is attached along at least one of the four surfaces of both side surfaces and the lower surface, and which prevents the movable contacts from being deformed by an electromagnetic repulsive force acting between the movable contacts. A circuit breaker characterized by being provided. 2. A plurality of fixed contacts each having a fixed contact, a plurality of movable contacts each having a movable contact that contacts and separates from the fixed contact, and upper surfaces of these movable contacts. A rib is attached along at least one of the four surfaces of both side surfaces and the lower surface, and a rib is provided to prevent deformation of the movable contact due to electromagnetic repulsive force acting between the movable contacts. A circuit breaker, comprising: a reinforcing member made of a magnetic material.