JPH06283091A - Circuit breaker - Google Patents

Abstract

PURPOSE:To improve an arc guiding effect with an arc runner, and realize the improvement of circuit breaking performance, in spite of the use of a different member for the arc runner to guide an arc to an arc-extinguishing device and for a fixed terminal. CONSTITUTION:A ceramic spacer member 21 positioned between a fixed terminal 12 and the inner bottom of a molded case 11, is U-shaped with the upper side open, and a pair of riser pieces 25 having such form as coupled to the notch sections 24 of the terminal 12 at both ends are integrated with both sides of the member 21. An arc runner 26 having such form as allowing the passage of the terminal 12 at a position between the pieces 25 and having the forward end directed to an arc-extinguishing device 19 is integrated with the bottom of the member 21. According to this construction, when an arc is generated, a magnetic path to allow a flow of magnetic flux due to breaking current is formed between the upper ends of the pieces 25, and the arc is guided toward the arc runner 26, due to an electromagnetic force acting between the magnetic flux and the arc.

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 an arc runner for guiding an arc generated when a circuit is cut off to the arc extinguishing device side.

[0002]

2. Description of the Related Art Generally, in a circuit breaker, the shape of a fixed terminal differs depending on the size of its breaking capacity. That is, as shown in FIG. 5, for example, the fixed terminal 2 provided in the molded case 1 has a large breaking capacity, and the fixed terminal 2 is made of a conductive plate piece, and the tip side (right side in the figure) is U-shaped. It is bent back to the top and the contact point 4 is
Is provided. Further, in this case, the arc runner 3a is integrally formed by extending the tip end portion of the folded-back portion 3 obliquely upward toward the arc extinguishing device 5, and the contact 4 on the fixed side and the movable arm 6 side at the time of circuit interruption. The arc generated between the contact 7 and the contact 7 of the arc runner 3a.
This leads to the arc extinguishing device 5 side.

In the circuit breaker having such a structure,
When an excessive fault current such as a short-circuit current flows, currents in opposite directions respectively flow in the folded portion 3 of the fixed terminal 2 and the movable arm 6 in the opposing state, and an extremely large magnetic repulsive force is generated between them. Therefore, the movable arm 6 can be swung quickly in the circuit breaking direction based on the magnetic repulsive force as described above, without waiting for the start of operation of the overcurrent trip device (not shown).

On the other hand, in the case of a circuit breaker having a small breaking capacity, the circuit breaking operation due to the magnetic repulsive force as described above is not particularly required. Therefore, for example, as shown in FIG. As the terminal 8, a simple terminal having no U-shaped bent portion on the tip side is used. In this case, it is impossible to integrally form the arc runner on the fixed terminal 8, and when the mold case 1 is used as a common component, a gap is generated between the fixed terminal 8 and the inner bottom surface of the mold case 1. Therefore, the spacer 9 integrally having the arc runner 9a is arranged between the fixed terminal 8 and the inner bottom surface of the molded case 1. still,
The arc runner 9a is in a state of penetrating a hole (not shown) formed in the fixed terminal 8.

[0005]

In the circuit breaker constructed as shown in FIG. 6, since the arc runner 9a and the fixed terminal 8 which is the location of the arc are separate members, the arc generated during the circuit breaking operation. However, there is a problem that the arc extinguishing performance, and thus the current interruption performance, deteriorates because the foot portion of the above is difficult to transfer to the arc runner 9a.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an arc guiding effect by the arc runner, although the arc runner for guiding the arc to the arc extinguishing device and the fixed terminal are separate members. Another object of the present invention is to provide a circuit breaker that can improve the breaking performance and can improve the breaking performance.

[0007]

In order to achieve the above object, the present invention provides a fixed terminal disposed in a mold case, a movable arm which is brought into contact with and separated from the fixed terminal, and above the fixed terminal. In a circuit breaker having an arc extinguishing device arranged so as to correspond to a moving locus of a movable arm, a spacer member made of a magnetic material is provided between the fixed terminal and an inner bottom surface of the mold case. In addition, a pair of rising pieces that are formed so as to rise integrally from both sides of the spacer member and whose upper ends are projected upward from both side edge portions of the fixed terminal are provided. And an arc runner having a tip directed toward the arc-extinguishing device, the arc runner being formed in such a shape that it rises up and penetrates the fixed terminal at a position sandwiched by the pair of rising pieces. It is obtained by the. in this case,
It is desirable that the arc runner be oriented in the same direction as the movable arm.

[0008]

The magnetic spacer member located between the fixed terminal and the inner bottom surface of the molded case has a structure in which the magnetic member is integrally erected from both sides and the upper end is projected upward from both side edge portions of the fixed terminal. Since a pair of rising pieces is provided, the magnetic flux generated by the above current is generated in the magnetic path formed by the spacer member and each rising piece when a current accompanied by an arc flows during the breaking operation. Become. In this case, each rising piece is positioned so that the upper end thereof projects upward from both side edge portions of the fixed terminal and sandwiches the fixed terminal and the arc runner from both sides.
The magnetic flux passing through the magnetic path formed between the upper ends of these rising pieces will link with the foot portion of the arc generated between the fixed terminal and the movable arm. For this reason, the electromagnetic force due to the magnetic flux acts on the arc, and the arc moves in the direction of the arc runner, so that the arc voltage increasing function of the arc extinguishing device can be rapidly exhibited. The arc is extinguished earlier, and as a result, the breaking performance is improved.

When the arc runner is oriented in the same direction as the movable arm, when the arc is transferred to the arc runner, the direction of the current flowing through the arc runner and the direction of the current flowing through the movable arm are opposite. Therefore, the electromagnetic repulsive force acts between the arc runner and the movable arm, and the opening speed of the movable arm is increased, which also improves the breaking performance.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, the mold case 11
The fixed terminal 12 provided inside has a left end side in the figure protruding outside the mold case 11, and the protruding portion is
A terminal screw 13 is provided and configured to function as a power bus connecting portion. A contact 14 is attached to the upper surface on the right end side of the fixed terminal 12.

The movable arm 15 provided in the mold case 11 so as to correspond to the fixed terminal 12 is rotatably supported at its base end side (right end side in the figure) by the support shaft 16, and A contact 17 facing the contact 14 is attached to the lower surface on the tip end side, and is configured to come into contact with and separate from the fixed terminal 12 according to the rotation thereof. In this case, although not shown, the movable arm 15 is adapted to be rotated through a toggle link mechanism in accordance with the operation of the knob.
When the knob is operated to the ON position, it is rotated downward to maintain the closed state where the contacts 14 and 17 are in contact with each other, and when the knob is operated to the OFF position, and the tripping device having a well-known configuration. When it is operated, it is rotated upward to switch to the open circuit state. The base end side of the movable arm 15 is connected to a main circuit conductor (not shown) via a flexible conductor 18.

A fixed terminal 12 is provided in the mold case 11.
A well-known deer ion arc extinguishing device 19 supporting a plurality of magnetic grid plates 19a having V-shaped notches so as to be located above, is fixed to the lowermost grid plate 19a. An insulating plate 20 is provided between the terminal 12 and the terminal 12.

Now, the fixed terminal 12 and the molded case 11
A spacer member 21 made of a magnetic material is arranged between the inner bottom surface and the inner bottom surface. The spacer member 21 and the fixed terminal 12 will be described below with reference to FIGS. 2 to 4.

The fixed terminal 12 is formed by bending a conductive metal plate into a shape as shown in FIG. 3, and has the screw 1 at the left end in the figure.
Screw holes 22 for 3 are formed, a through hole 23 is formed at a position adjacent to the contact 14 from the screw hole 22 side, and a pair of notches 24 are formed on both side edges of the contact 14.
24 is formed.

On the other hand, the spacer member 21 is formed by bending the conductive metal plate upward and bending the width dimension Ws (see FIG. 4) into a U-shape substantially equal to the width dimension Wt (see FIG. 2) of the fixed terminal 12. It has been configured. Then, the fixed terminal 1 rises from both sides of the spacer member 21.
A pair of rising pieces 25, 25 having a shape that can be fitted into the two notches 24 are integrally formed, and an arc runner 26 having a shape that can stand up from the bottom and penetrate the through hole 23 is integrally formed. In particular, the arc runner 26 is formed in a substantially doglegged shape in which the tip is directed toward the arc extinguishing device 19 (that is, the same direction as the movable arm 15) while being penetrated by the through hole 23. There is.

As a result of such a configuration, the spacer member 21
In the state where the fixed pieces are integrated with the lower surface of the fixed terminal 12, the respective rising pieces 25 are fitted into the notches 24 and are positioned so as to project upward from both side edge portions of the fixed terminal 12, and the arc runner is arranged. 26 is penetrated through the through hole 23 so that its tip is positioned in the direction of the arc extinguishing device 19. The pair of rising pieces 2
5 is configured such that the contact 14 and the arc runner 26 are sandwiched from both sides when the spacer member 21 and the fixed terminal 12 are integrated.

According to the above structure, when the contacts 14 and 17 are separated according to the overcurrent tripping operation,
An arc corresponding to the magnitude of the breaking current is generated between them. When the breaking current flows in this way, magnetic flux due to the above current is generated in the magnetic path (shown by the broken line F in FIG. 4) formed by the spacer member 21 and each rising piece 25. At this time, each of the rising pieces 25
Has an upper end protruding upward from both side edges of the fixed terminal 12,
Moreover, since the contact 14 and the arc runner 26 are located so as to sandwich the contact runner 26 from both sides, the magnetic path F formed in response to the generation of the breaking current includes the space between the upper ends of the rising pieces 25, that is, the contact 14. Since it passes through the space above the fixed terminal 12 and the portion corresponding to the arc runner 26, the foot portion of the arc generated between the contacts 14 and 17 interlinks with the magnetic flux passing through the space between the upper ends of the rising pieces 25. Will be done. Therefore, the electromagnetic force by the magnetic flux acts on the arc, and the arc is transferred to the arc runner 26 direction.
The function of increasing the arc voltage by 9 is promptly exhibited, the arc is extinguished early, and as a result, the breaking performance is improved.

When the arc is transferred to the arc runner 26, the direction of the current flowing through the arc runner 26 and the direction of the current flowing through the movable arm 15 are opposite to each other, so that an electromagnetic repulsive force acts between the arc runner 26 and the movable arm 15. Come to do. As a result, the opening speed of the movable arm 15 is increased, and improvement of the breaking performance can be expected from this aspect as well.

[0019]

As is apparent from the above description, according to the circuit breaker of claim 1, when an arc is generated during the breaking operation, the electromagnetic force by the magnetic flux generated by the breaking current at that time is generated. Since it is configured to transfer the arc in the direction of the arc runner, the arc runner for guiding the arc to the arc extinguishing device and the fixed terminal can enhance the arc guiding effect by the arc runner. As a result, it has an excellent effect that the breaking performance can be improved.

According to the circuit breaker of the second aspect, the arc runner is directed in the same direction as the movable arm, so that when the breaking current flows, the arc runner is placed between the arc runner and the movable arm. Since the electromagnetic repulsive force is applied, the opening speed of the movable arm is increased, and the breaking performance can be further improved.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing a state in which a fixed terminal and a spacer member are combined.

[Fig. 3] Side view in the same state

FIG. 4 is a front view of the same state.

FIG. 5 is a view corresponding to FIG. 1 showing a conventional example.

FIG. 6 is a view corresponding to FIG. 1 showing a different conventional example.

[Explanation of symbols]

In the drawings, 11 is a molded case, 12 is a fixed terminal, and 14 is a fixed terminal.
Is a contact point, 15 is a movable arm, 17 is a contact point, 19 is an arc extinguishing device, 21 is a spacer member, 25 is a rising piece, and 26 is an arc runner.

Claims (2)

[Claims] 1. A fixed terminal arranged in a molded case, a movable arm which is brought into contact with and separated from the fixed terminal, and an arc extinguishing arranged above the fixed terminal so as to correspond to a movement locus of the movable arm. In a circuit breaker including a device, a spacer member made of a magnetic material is provided between the fixed terminal and the inner bottom surface of the mold case, and the spacer member is formed so as to stand up from both sides of the spacer member integrally. A pair of rising pieces positioned with their upper ends projecting upward from both side edges of the fixed terminal, and rising up integrally from the spacer member and penetrating the fixed terminal at a position sandwiched by the pair of rising pieces. An arc runner having a shape and a tip directed to the arc extinguishing device. 2. The circuit breaker according to claim 1, wherein the arc runner is oriented in the same direction as the movable arm.