JP2003151423A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker capable of satisfying breaking capability in breaking current in a small current region, large current, and DC current. SOLUTION: Pressure generated based on an arc 21 generated when a movable contact 1 is dissociated from a fixed contact 4, or magnetic flux generated around the fixed contact 4 based on current running through the fixed contact 4 moves an arc-extinguisher 60 in a separating direction from the opening/ closing position of the movable contact 1 and the fixed contact 4. An arc runner 18 is rotatably formed so that the magnetic flux generated around the fixed contact 4 based on the current running through the fixed contact 4 rotates the other end 18b of the arc runner 18 in the separating direction from the opening/closing position of the movable contact 1 and the fixed contact 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for turning on / off a current flowing in an electric circuit, and more particularly to improving the current breaking performance.

[0002]

2. Description of the Related Art FIG. 8 shows, for example, Japanese Patent Laid-Open No. 2001-1959.
Fig. 65 is a vertical sectional view showing a conventional circuit breaker, Fig. 9 is an enlarged sectional view of an essential part when the circuit breaker of Fig. 8 is opened, and Fig. 10 is an arc extinguishing state of the circuit breaker of Fig. 8. FIG. 1A is a plan view of the apparatus alone, and FIG.

In the figure, 1 is a movable contactor formed of a good conductor such as copper, 2 is a movable contact fixed to one end of the movable contactor 3, and 3 is movable when the movable contactor 1 is rotated. The fixed contacts 4 that come into contact with and separate from the contact 2 are fixed to the fixed contact 3 and fixed contacts that are fixed to the base 12 described later are provided at the other end of the fixed contact 4 to connect the electric wires of the electric path. It is the terminal part.

Numeral 6 is an arc 21 to be extinguished by extending an arc 21, which will be described later, generated when the movable contact 2 and the fixed contact 3 are separated from each other, in a direction away from the open / close position of the movable contact 2 and the fixed contact 3 to cool the arc 21. In the arc extinguishing device, the magnetic flux is magnetized by the arc current of the arc 21 generated when the movable contact 2 is separated from the fixed contact 3 by being laminated and arranged with a gap therebetween. And a plurality of arc extinguishing plates 6a, and an arc extinguishing side plate 6b formed of an insulator holding the arc extinguishing plate 6a at both ends. Reference numeral 7 is a mechanism unit for opening and closing the movable contact 1, 8 is a handle for manually operating the mechanism unit 7, and 9 is a trip device for detecting when an overcurrent flows through the circuit breaker and tripping the mechanism unit 7. 10,
Is the other terminal part to which the electric wire of the electric circuit is connected.

Reference numeral 11 is a cover, and 12 is a base, which constitutes a casing 13 for accommodating the above-mentioned components. Reference numeral 14 is a crossbar that is interlocked with the mechanism portion 7, and is formed of, for example, a resin molded product. The crossbar 14 and the movable contact 1 are rotatably held by a shaft 15 penetrating them. Reference numeral 21 is an arc generated between the movable contact 2 and the fixed contact 3 when the movable contact 2 is separated from the fixed contact 3.

Next, the operation of the conventional circuit breaker configured as described above will be described. When the terminal portion 5 is connected to a power source, the terminal portion 10 is connected to a load, and the handle 8 is operated, the mechanism portion 7 operates to rotate the movable contactor 1 and bring the movable contact 2 and the fixed contact 3 into contact with each other. Power is supplied from the power supply to the load.

When the circuit breaker exceeds the rated current and an overcurrent flows, the trip device 9 detects the overcurrent, operates the mechanism portion 7, and moves the movable contact 1 with the shaft 15 as a fulcrum in the direction of arrow A. The movable contact 2 and the fixed contact 3 are separated by rotating the movable contact 2 and the arc 21, and an arc 21 is generated between the movable contact 2 and the fixed contact 3. However, the energy of the arc 21 in the small current region is small,
The arc 21 is relatively easily extinguished by being stretched in the direction of the arc extinguishing plate 6a of the arc extinguishing device 6 and cooled by the electromagnetic force generated by the magnetic flux and arc current generated in the arc extinguishing plate 6a. The current is cut off.

On the other hand, when a short circuit accident occurs on the load side of the circuit breaker and a large current such as a short circuit current flows through the circuit breaker (large current region), the contact surface between the movable contact 2 and the fixed contact 3 is Electromagnetic repulsion, fixed contact 4 and movable contact 1
The electromagnetic repulsive force between the movable contact 1 and the movable contact 1 is rotated in the direction of arrow A without waiting for the tripping operation by the tripping device 9 and the mechanism portion 7, and the movable contact 2 and the fixed contact 3 are separated. Although separated, the arc 21 due to the large current generated between the movable contact 2 and the fixed contact 3 causes the arc extinguishing plate 6 of the arc extinguishing device 6 to generate a strong electromagnetic force due to the magnetic flux generated in the arc extinguishing plate 6a and the arc current.
It is stretched in the direction of part a and cooled.

When the arc 21 is cooled, the arc resistance increases and a current limiting action is generated to reduce the arc current to a small extent, and the arc 21 is extinguished at the zero cross point of the current to complete the current interruption. The surrounding energy such as the cover 11, the base 12 and the arc extinguishing plate 6a is melted and gasified by the arc energy of the arc 21 generated at the time of interruption, thereby instantaneously increasing the pressure inside the circuit breaker.

[0010]

The conventional circuit breaker is constructed as described above, and the circuit breaker extends from a small current region close to the rated current to a large current region such as a short circuit current.
It is necessary to have a breaking performance of quickly extinguishing the arc generated between the movable contact 2 and the fixed contact 3, but the performance greatly depends on the structure of the arc extinguishing device 6 and the arrangement position of the arc extinguishing device 6.

In the current interruption operation in the small current region close to the rated current, the diameter of the arc 21 generated between the movable contact 2 and the fixed contact 3 is small, and the magnetic flux generated in the arc extinguishing plate 6a and the electromagnetic force due to the arc current are also generated. Since the generated arc 21 remains small in the vicinity of the contact without moving toward the arc extinguishing plate 6a of the arc extinguishing device 6, the arc 21 is extinguished for a long time, but the energy of the arc 21 is small. ,
There is little adverse effect such as wear of the movable contact 2 and the fixed contact 3.

However, in the breaking operation of a large current such as a short-circuit current, although a strong electromagnetic force is generated by the magnetic flux and arc current generated in the arc extinguishing plate 6a, the arc diameter is large and the arc 21 and the arc extinguishing are extinguished. When the plate 6a is close to the arc extinguishing plate 6a, the arc is stagnated at the end (left side of FIG. 9) of the arc extinguishing plate 6a and the arc 21 is moved to the terminal portion 5 side of the arc extinguishing plate 6a (right side of FIG. 9).
Is difficult to extend, the current limiting effect of narrowing down the arc current is not sufficiently obtained, it becomes impossible to cut off, and the heat of the arc 21 melts the movable contact 2, the fixed contact 3 and the resin molded product in the vicinity thereof. There was a problem.

Furthermore, when the current flowing in the electric path is a direct current having no zero cross point, there is a problem that the arc is continuously interrupted and the current cannot be interrupted. There is a problem in that the breaking operation that satisfies all of the DC current interruption cannot be performed.

The present invention has been made in order to solve the above problems, and is a circuit breaker capable of satisfying the breaking performance in breaking a current in a small current region, breaking a large current, and breaking a direct current. The purpose is to provide a vessel.

[0015]

A circuit breaker according to the present invention includes a housing, a fixed contact fixed to the housing, and a movable contact for connecting and disconnecting the load current to and from the fixed contact. In a circuit breaker including a child and an arc extinguishing device that extinguishes an arc generated when the movable contact separates from the fixed contact, the arc extinguishing device generates based on the arc. The arc extinguishing device is provided with a pressure receiving plate for receiving a pressure and moving the arc extinguishing device in a direction away from the opening / closing positions of the movable contact and the fixed contact when the pressure exceeds a predetermined pressure.

Further, the housing, the fixed contact fixed to the housing, the movable contact for connecting and disconnecting the load current to and from the fixed contact, and the movable contact from the fixed contact. In a circuit breaker equipped with an arc extinguishing device for extinguishing an arc generated when opening and closing, the arc extinguishing device is a magnetic flux generated around the fixed contactor based on a current flowing through the fixed contactor. Is provided with a magnetic plate that is attracted when the amount of magnetic flux is greater than or equal to a predetermined magnetic flux amount and moves the arc extinguishing device in a direction away from the opening / closing positions of the movable contact and the fixed contact.

Further, the arc extinguishing device is provided with an elastic member for urging the movable contact and the fixed contact toward the open / close position side.

Further, it is provided with a magnetic conducting ring which is wound around the fixed contactor and which guides the magnetic flux generated based on the current flowing through the fixed contactor to attract the magnetic plate.

Further, the casing, the fixed contact fixed to the casing, the movable contact for connecting and disconnecting the load current to and from the fixed contact, and the movable contact from the fixed contact. An arc extinguishing device that extinguishes the arc generated when opening and closing,
It is electrically connected to the fixed contact and extends from the vicinity of the opening / closing position of the movable contact and the fixed contact to the vicinity of the arc extinguishing device to open / close the arc of the movable contact and the fixed contact. In a circuit breaker having an arc runner that shifts in a direction away from a position, the arc runner has one end rotatably held by the fixed contact, and the other end of the arc runner of the movable contact and the fixed contact. The movable contact and the fixed contact are rotated so as to move away from the opened / closed position against a pressing member that is biased toward the open / closed position, and the fixed contact is generated based on an electric current flowing through the fixed contact. The other end of the arc runner rotates in a direction away from the open / close position of the movable contactor and the fixed contactor when the magnetic flux generated around the child exceeds a predetermined magnetic flux amount.

Further, it is provided with a magnetic conducting ring which is wound around the fixed contactor and which guides the magnetic flux generated based on the current flowing through the fixed contactor to attract the arc runner.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a vertical cross-sectional view showing a circuit breaker according to a first embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of an essential part when the circuit breaker of FIG. 1 is opened, and FIG. 3 is a circuit breaker of FIG. 1A is a plan view and FIG. 1B is a right side view of a single arc extinguishing device.

In the figure, 1 is a movable contactor made of a good conductor such as copper, 2 is a movable contact fixed to one end of the movable contactor 3, and 3 is movable as the movable contactor 1 rotates. The fixed contacts 4 that come into contact with and separate from the contacts 2 are fixed contacts to which the fixed contact 3 is fixed and are fixed to the base 12 described later, and the fixed contacts 5 are provided at the other end of the fixed contact 4 to which the electric wires of the electric path are connected. It is the terminal part.

Reference numeral 7 denotes a mechanism portion for opening and closing the movable contactor 1, and 8
Is a handle for manually operating the mechanical section 7, 9 is a trip device that detects when an overcurrent flows through the circuit breaker and trips the mechanical section 7, and 10 is the other one to which the electric wire of the electric circuit is connected. It is a terminal part.

Reference numeral 11 is a cover formed of, for example, a resin molded product, and 12 is a base formed of, for example, a resin molded product, and a housing 13 for housing the above-mentioned components of the circuit breaker.
Are configured. Reference numeral 14 is a crossbar that is interlocked with the mechanism portion 7, and is formed of, for example, a resin molded product. The crossbar 14 and the movable contact 1 are rotatably held by a shaft 15 penetrating them. 16 is a leaf spring which is an elastic member,
For example, it is formed of a stainless plate, one end of which is fixed to the base 12 by a fixing member 16a, and the arc extinguishing device 60 described later is provided at the other end of the movable contact 2 and the fixed contact 3 at the open / close position side (left side in FIG. 2). Is urged to. 21 is a movable contact 2
Is an arc generated between the movable contact 2 and the fixed contact 3 when the contact is separated from the fixed contact 3.

The reference numeral 60 cools the arc 21, which is generated when the movable contact 2 is separated from the fixed contact 3, by extending it in a direction away from the open / close positions of the movable contact 2 and the fixed contact 3 to cool the arc 21. In the arc-extinguishing device, a plurality of magnetic bodies, such as steel plates, which are magnetically induced by the arc current of the arc generated when the movable contact 2 is separated from the fixed contact 3 are stacked and arranged with a gap therebetween. The arc extinguishing plate 61, the arc extinguishing side plate 62 formed of an insulator holding the arc extinguishing plate 61 at both ends, and the pressure of the arc 21 generated when the movable contact 2 separates from the fixed contact 3 are received. The pressure receiving plate 63 is made of an insulating material. Reference numeral 64 denotes a support shaft which is fitted into the arc extinguishing device 60 and whose both ends are held by the cover 11 or the base 12 to rotatably support the arc extinguishing device 60.

Next, the operation of the circuit breaker according to the first embodiment of the present invention configured as described above will be described. When the terminal portion 5 is connected to a power source, the terminal portion 10 is connected to a load, and the handle 8 is operated, the mechanism portion 7 operates to rotate the movable contactor 1 and bring the movable contact 2 and the fixed contact 3 into contact with each other. Power is supplied from the power supply to the load.

When the circuit breaker exceeds the rated current and an overcurrent flows, the trip device 9 detects the overcurrent, operates the mechanism portion 7, and moves the movable contact 1 in the direction of arrow B with the shaft 15 as a fulcrum. The movable contact 2 and the fixed contact 3 are separated by rotating the movable contact 2 and the arc 21, and an arc 21 is generated between the movable contact 2 and the fixed contact 3. However, the energy of the arc 21 in the small current region is small,
The arc 21 is relatively easily extinguished by the magnetic flux generated in the arc extinguishing plate 61 and the electromagnetic force caused by the arc current being extended to the arc extinguishing plate 61 portion of the arc extinguishing device 60 and being cooled, whereby the current is reduced. Be cut off.

At this time, the movable contact 2 and the fixed contact 3
The position of the arc extinguishing device 60 relative to the opening / closing position of the arc extinguishing plate 6 is
The arc 21 is extended to the arc extinguishing plate 61 of the arc extinguishing device 60 by the electromagnetic force generated by the magnetic flux and the arc current generated in No. 1 and is arranged close to a position where it is sufficiently cooled.

When a short circuit accident occurs on the load side of the circuit breaker and a large current such as a short circuit current flows through the circuit breaker, electromagnetic repulsive force on the contact surface between the movable contact 2 and the fixed contact 3 or fixed contact. The electromagnetic repulsive force between the child 4 and the movable contactor 1 becomes very strong, and the movable contactor 1 moves in the direction of arrow B without waiting for the tripping operation by the tripping device 9 and the mechanism portion 7 to move. The contact 2 is separated from the fixed contact 3.

When the movable contact 2 is separated from the fixed contact 3, an arc 21 is generated between the movable contact 2 and the fixed contact 3, and the arc energy generated by the arc 21 causes the cover 11, the base 12, the crossbar 14, etc. The resin molded product around is melted and gasified to instantaneously increase the pressure inside the circuit breaker. The pressure receiving plate 63 constituting the arc extinguishing device 60 receives this pressure, and the arc extinguishing device 60 resists the biasing force of the leaf spring 16 and the support shaft 64 serves as a fulcrum in the direction of arrow C (see FIG. 2).
(Shown in step 1). At this time, the arc extinguishing device 60 is rotated in proportion to the pressure generated inside the circuit breaker, and is configured so that it can be rotated to an angle required to extend and extinguish the arc 21. There is.

As a result, the arc 21 is extinguished by the magnetic force generated by the arc extinguishing plate 61 and the electromagnetic force generated by the arc current.
Of the arc extinguishing plate 61 and the action of the arc extinguishing plate 61 of the arc extinguishing device 60 moving away from the open / close positions of the movable contact 2 and the fixed contact 3 to expand the arc 21 and thereby extend the arc 21. Therefore, the end portion 6 of the arc extinguishing plate 61
The arc 21 is not stagnant in 1a and is sufficiently cooled,
The arc resistance rises, a current limiting action occurs in which the arc current is narrowed down, and the arc 21 is extinguished at the zero cross point of the current to complete the current interruption.

The above-described arc extinguishing action is the same when the DC current, which is difficult to cut off, is cut off.
By moving 1 in the direction away from the open / close position of the movable contact 2 and the fixed contact 3, the arc 21 is stretched and sufficiently cooled, the arc resistance is increased, and a current limiting action of narrowing the arc current is generated. Can be extinguished.

In the above embodiment, the fixed contact 3 is fixed to the fixed contact 4 and the movable contact 2 is attached to the movable contact 1.
The current is turned on and off between the fixed contact 3 and the movable contact 2 by fixing the fixed contact 3 to the movable contact 2. However, for example, in the case of a circuit breaker having a small capacity (a small amount of the supplied current), it is directly fixed to the movable contact 1. The energizing current may be turned on / off by the contactor 4.

Although the leaf spring 16 is used as the elastic member for urging the arc extinguishing device 60, a compression spring, a twist spring, or the like may be used. Furthermore, the arc extinguishing device 60 is rotated about the support shaft 64 as a fulcrum to move the arc extinguishing plate 61 away from the arc 21 against the biasing force of the leaf spring 16. The arc extinguishing plate 61 may be moved away from the arc 21 by sliding it to the right.

As described above, according to the circuit breaker according to the first embodiment of the present invention, when the large current flows, the arc extinguishing device 60 is moved to the movable contact 2 (or the movable contactor if the movable contact 2 is not provided). The arc extinguishing plate 61 of the arc extinguishing device 60 is configured so as to move in a direction away from the open / close position of 1) and the fixed contact 3 (the fixed contact 4 when the fixed contact 3 is not provided).
The arc 21 does not stagnate at the end portion 61a of the arc, and the arc 21 is stretched and sufficiently cooled by the electromagnetic force generated by the magnetic flux and the arc current generated in the arc extinguishing plate 61, the arc resistance increases, and the arc current is reduced to a small limit. Since the flow action occurs and the arc 21 is extinguished at a high speed, the breaking performance of the circuit breaker can be improved.

Embodiment 2. 4 is a vertical sectional view showing a circuit breaker according to a second embodiment of the present invention, and FIG. 5 is an enlarged view of a main part when the circuit breaker of FIG. 4 is opened. In the figure, 17 is a magnetic guide ring wound around the fixed contact 4 and guiding a magnetic flux generated based on the current flowing through the fixed contact 4, for example, a magnetic guide ring formed of a magnetic material such as a steel plate, and 65 is a magnetic guide ring 17. A magnetic plate disposed in the vicinity and fixed to the arc extinguishing device 60, and is formed of a magnetic material such as a steel plate.
1 to 5, 7 to 16, 21, 60 to 62 and 64 are the same as those shown in the above-described first embodiment, and the same reference numerals are given and the description thereof is omitted.

Next, the operation of the circuit breaker according to the second embodiment of the present invention configured as described above will be described. The operation when the overcurrent flows in the circuit breaker in the small current region in excess of the rated current is the same as in the above-described first embodiment. The open / close positions of the movable contact 2 and the fixed contact 3 and the relational position of the arc extinguishing device 60 are the same as those in the first embodiment.

When a short circuit accident occurs on the load side of the circuit breaker and a large current such as a short circuit current flows through the circuit breaker, electromagnetic repulsive force on the contact surface between the movable contact 2 and the fixed contact 3 or fixed contact The electromagnetic repulsive force between the child 4 and the movable contact 1 becomes very strong, and the movable contact 1 moves in the direction of arrow D without waiting for the tripping operation by the tripping device 9 and the mechanism portion 7 to move. The contact 2 is separated from the fixed contact 3.

At the same time when the movable contact 2 starts to separate from the fixed contact 3, or at an earlier time, a magnetic flux is generated around the fixed contact 4 according to the right-hand screw law based on the current flowing through the fixed contact 4. To do. This magnetic flux concentrates on the magnetic guide ring 17 and magnetizes the magnetic guide ring 17, whereby the magnetic plate 65 is attracted, and the arc extinguishing device 60 resists the biasing force of the plate spring 16 and uses the support shaft 64 as a fulcrum. Rotate in the direction of arrow E. In addition,
At this time, the arc extinguishing device 60 is rotated in proportion to the amount of the magnetic flux generated around the fixed contactor 4, and can be rotated to an angle necessary to extend and extinguish the arc 21. Has been done.

As a result, the arc 21 is extinguished by the arc 21 by the electromagnetic force generated by the magnetic flux and arc current generated in the arc extinguishing plate 61.
Of the arc extinguishing plate 61 and the action of the arc extinguishing plate 61 of the arc extinguishing device 60 moving away from the open / close positions of the movable contact 2 and the fixed contact 3 to expand the arc 21 and thereby extend the arc 21. Therefore, the end portion 6 of the arc extinguishing plate 61
The arc 21 is not stagnant in 1a and is sufficiently cooled,
The arc resistance rises, a current limiting action occurs in which the arc current is narrowed down, and the arc 21 is extinguished at the zero cross point of the current to complete the current interruption.

The above-described arc extinguishing action is the same when the DC current which is difficult to interrupt is interrupted.
By moving 1 in the direction away from the open / close position of the movable contact 2 and the fixed contact 3, the arc 21 is stretched and sufficiently cooled, the arc resistance is increased, and a current limiting action of narrowing the arc current is generated. Can be extinguished.

In the embodiment described above, the magnetic conducting ring 17 wound around the fixed contact 4 and the magnetic plate 65 fixed to the arc extinguishing device 60 are used to generate a current based on the current flowing through the fixed contact 4. The magnetic flux that is generated around the fixed contact 4
The magnetic plate 65 is attracted to the magnetic conducting ring 17 when a large amount of current is applied by magnetizing the magnetic conducting ring 17 by concentrating the magnetic conducting ring 17 on the magnetic poles. The magnetic plate 65 may be directly attracted by the magnetic flux generated in the surroundings.

As described above, according to the circuit breaker according to the second embodiment of the present invention, when a large current flows, the arc extinguishing device 60 moves in a direction away from the open / close positions of the movable contact 2 and the fixed contact 3. With this configuration, the arc 21 does not stay at the end 61a of the arc extinguishing plate 61 of the arc extinguishing device 60, and the arc 21 is extended by the electromagnetic force generated by the magnetic flux and the arc current generated in the arc extinguishing plate 61. And the arc 21 is cooled sufficiently, the arc resistance is increased, the current limiting action of narrowing the arc current is generated, and the arc 21 is extinguished at a high speed, so that the breaking performance of the circuit breaker can be improved.

Embodiment 3. 6 is a vertical sectional view showing a circuit breaker according to a third embodiment of the present invention, and FIG. 7 is an enlarged view of a main part when the circuit breaker of FIG. 6 is opened. In the figure, 17 is wound around the fixed contactor 4, a magnetic conducting ring formed of a magnetic material such as a steel plate, and 18 is formed of a magnetic material such as a steel plate, and one end 18a is attached to the fixed contactor 4. It is rotatably held by the runner shaft 19, and the other end 1
Reference numeral 8b is an arc runner that rotates so as to move away from the open / close position of the movable contact 2 and the fixed contact 3 against the twist spring 20 which is a pressing member that urges the movable contact 2 and the fixed contact 3 toward the open / closed position. 1 to 15 and 21 are the same as those shown in the above-mentioned conventional technique, and the same reference numerals are given to omit the description.

Next, the operation of the circuit breaker according to the third embodiment of the present invention configured as described above will be described. When an overcurrent flows in the circuit breaker in excess of the rated current, the trip device 9 detects the overcurrent, operates the mechanism section 7, and rotates the movable contact 1 in the arrow F direction with the shaft 15 as a fulcrum. By doing so, the movable contact 2 and the fixed contact 3 are separated from each other, and an arc 21 is generated between the movable contact 2 and the fixed contact 3. However, the arc 21 in the small current region has small energy and moves on the upper surface of the arc runner 18. The arc 21 is extinguished relatively easily by the magnetic flux generated in the arc extinguishing plate 61 and the electromagnetic force generated by the arc current, so that the arc 21 is extended and cooled, and the current is interrupted.

When a short circuit accident occurs on the load side of the circuit breaker and a large current such as a short circuit current flows through the circuit breaker, electromagnetic repulsive force on the contact surface between the movable contact 2 and the fixed contact 3 or fixed contact The electromagnetic repulsive force between the child 4 and the movable contactor 1 becomes very strong, and the movable contactor 1 rotates in the direction of arrow F without waiting for the tripping operation by the tripping device 9 and the mechanism portion 7 to move. The contact 2 is separated from the fixed contact 3.

At the same time as the movable contact 2 starts to separate from the fixed contact 3 or earlier, magnetic flux is generated around the fixed contact 4 according to the right-hand screw rule based on the current flowing through the fixed contact 4. . This magnetic flux concentrates on the magnetic conducting ring 17 and magnetizes the magnetic conducting ring 17, whereby the arc runner 18 is attracted, and the arc runner 18 resists the biasing force of the twist spring 20 and the runner shaft 19 serves as a fulcrum in the direction of arrow G. Turn to.

The arc 21 moves on the upper surface of the arc runner 18 while being stretched by the electromagnetic force generated by the magnetic flux generated in the arc extinguishing plate 6a and the arc current. By rotating the other end 18b of the arc runner 18 in the direction of arrow G, the arc 21 further moves in the direction of arrow H, is extended and cooled, the arc resistance is increased, and the current limiting action of narrowing down the arc current occurs. Arc 2 at the zero cross point of the current
1 is extinguished and the current interruption is completed.

As described above, according to the circuit breaker according to the third embodiment of the present invention, when a large current flows, the arc 2
1 rapidly moves toward the arc extinguishing plate 6a of the arc extinguishing device 6 through the upper surface of the arc runner 18 while being stretched by the magnetic force generated in the arc extinguishing plate 61 and the electromagnetic force of the arc current, and at the same time, the other end 18b of the arc runner 18 When the arc 21 is rotated, the arc 21 is further moved in a direction away from the open / close positions of the movable contact 2 and the fixed contact 3.
Is stretched and cooled sufficiently, the arc resistance increases,
Since the current limiting action of narrowing down the arc current occurs and the arc 21 is extinguished at a high speed, the breaking performance of the circuit breaker can be improved.

In the above embodiment, the magnetic conducting ring 17 wound around the fixed contact 4 is used to generate a magnetic flux around the fixed contact 4 based on the current flowing through the fixed contact 4. The arc runner 18 is rotated when a large current is applied by concentrating the magnetic flux into the magnetic conducting ring 17 and magnetizing the magnetic conducting ring 17. The arc runner 18 may be directly rotated by the magnetic flux generated in the surroundings.

In the first to third embodiments, the configurations of the examples have been described individually.
It is also possible to implement them in combination, and by implementing them in combination, it is possible to further improve the breaking performance of the circuit breaker.

【The invention's effect】

As described above, according to the circuit breaker of the present invention, the arc extinguishing device receives the pressure generated based on the arc, and when the pressure is equal to or higher than the predetermined pressure, the arc extinguishing device has a movable contact (movable contact). Since it moves so as to move away from the open / close position of the contact) and the fixed contact (fixed contact), the arc is sufficiently stretched and cooled, and the arc is extinguished at high speed. The breaking performance of the circuit breaker can be satisfied not only in breaking the current but also in breaking the current in the large current region.

The magnetic plate fixed to the arc-extinguishing device is attracted by the magnetic flux generated around the fixed contactor based on the current flowing through the fixed contactor, and the arc-extinguishing device is fixed to the movable contact (movable contactor). Since the contact (fixed contact) is moved away from the open / close position, the arc is sufficiently stretched and cooled not only when the current is cut off in the small current region but also when the current is cut off in the large current region. Since the arc is extinguished at a high speed, the breaking performance of the circuit breaker can be satisfied.

Further, the arc extinguishing device is provided with a movable contact (movable contact).
Since the arc-extinguishing device is equipped with an elastic member that urges the fixed contact (fixed contact) to the open / close position side, the arc extinguishing device can operate around the fixed contact based on the pressure generated by the arc or the current flowing through the fixed contact. It moves in proportion to the magnitude of the attractive force due to the magnetic flux generated in the circuit, and ensures the circuit breaking performance.

Further, since a magnetic conducting ring wound around the fixed contactor is provided to guide the magnetic flux generated based on the current flowing through the fixed contactor, the magnetic plate fixed to the arc extinguishing device is surely attracted. Thus, the arc can be reliably transferred in the direction away from the open / close position of the movable contact (movable contact) and the fixed contact (fixed contact).

Further, one end is rotatably held by the fixed contact, and the other end resists a pressing member that urges the movable contact (movable contact) and the fixed contact (fixed contact) to the open / close position side. And movable contact (movable contact) and fixed contact (fixed contact)
Since the arc runner that turns away from the open / close position of the fixed contact is provided, the arc moves by moving when the magnetic flux generated around the fixed contact based on the current flowing through the fixed contact exceeds a predetermined magnetic flux amount. The contact (movable contact) and the fixed contact (fixed contact) move away from the arc-extinguishing plate to extend and cool the arc, so the arc is extinguished at a high speed and the current in a small current region It is possible to satisfy the breaking performance of the circuit breaker not only for breaking the current but also for breaking the current in the large current region.

Further, since the magnetic flux is wound around the fixed contactor to guide the magnetic flux generated based on the current flowing through the fixed contactor, the arc runner is surely attracted to move the arc to the movable contact (movable contact). Contact) and fixed contact (fixed contact)
It is possible to reliably shift the opening away from the open / close position.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a circuit breaker according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of essential parts when the circuit breaker of FIG. 1 opens.

3A and 3B are unit diagrams of the arc extinguishing device for the circuit breaker shown in FIG. 1, where FIG. 3A is a plan view and FIG. 3B is a right side view.

FIG. 4 is a vertical sectional view showing a circuit breaker according to a second embodiment of the present invention.

5 is an enlarged view of a main part when the circuit breaker of FIG. 4 opens.

FIG. 6 is a vertical sectional view showing a circuit breaker according to a third embodiment of the present invention.

7 is an enlarged view of an essential part when the circuit breaker of FIG. 6 is opened.

FIG. 8 is a vertical sectional view showing a conventional circuit breaker.

9 is an enlarged cross-sectional view of a main part when the circuit breaker of FIG. 8 is opened.

10 (a) is a plan view and FIG. 10 (b) is a right side view of the arc extinguishing device for the circuit breaker of FIG.

[Explanation of symbols]

1 movable contactor, 2 movable contact, 3 fixed contact, 4 fixed contactor, 6,60 arc extinguishing device, 6a, 61 arc extinguishing plate,
6b, 62 arc-extinguishing side plate, 13 housing, 16 elastic member (leaf spring), 17 magnetic ring, 18 arc runner, 18
a one end, 18b other end, 20 pressing member (twist spring), 21 arc, 63 pressure receiving plate, 65 magnetic plate.

Claims (6)

[Claims] 1. A housing, a fixed contact fixed to the housing, a movable contact for connecting and disconnecting a load current to and from the fixed contact, and the movable contact from the fixed contact. In a circuit breaker equipped with an arc extinguishing device that extinguishes an arc generated when opening and closing, the arc extinguishing device receives a pressure generated based on the arc and when the pressure is equal to or higher than a predetermined pressure. A circuit breaker comprising a pressure receiving plate for moving the arc extinguishing device in a direction away from the open / close positions of the movable contact and the fixed contact. 2. A housing, a fixed contact fixed to the housing, a movable contact for connecting and disconnecting a load current to and from the fixed contact, and the movable contact from the fixed contact. In a circuit breaker equipped with an arc extinguishing device for extinguishing an arc generated when opening and closing, the arc extinguishing device is a magnetic flux generated around the fixed contactor based on a current flowing through the fixed contactor. Is provided with a magnetic flux greater than a predetermined magnetic flux, the circuit breaker is equipped with a magnetic plate that moves the arc extinguishing device in a direction away from the open / close positions of the movable contact and the fixed contact. 3. The circuit breaker according to claim 1, further comprising an elastic member for urging the arc extinguishing device toward the open / close position side of the movable contact and the fixed contact. 4. The circuit according to claim 2, further comprising a magnetic conducting ring wound around the fixed contactor to guide a magnetic flux generated based on a current flowing through the fixed contactor to attract the magnetic plate. Circuit breaker. 5. A housing, a fixed contact fixed to the housing, a movable contact for connecting and disconnecting a load current to and from the fixed contact, and the movable contact from the fixed contact. An arc-extinguishing device for extinguishing the arc generated when opening and closing is electrically connected to the fixed contact, and extends from the vicinity of the open / close position of the movable contact and the fixed contact to the vicinity of the arc-extinguishing device. A circuit breaker provided with an arc runner that moves the arc in a direction away from the open / close position of the movable contact and the fixed contact, wherein the arc runner has one end rotatably attached to the fixed contact. The other end is held, and the other end of the arc runner rotates so as to move away from the open / close position of the movable contact and the fixed contact against a pressing member that biases the arc runner toward the open / close position of the movable contact and the fixed contact. And above When the magnetic flux generated around the fixed contact based on the current flowing through the fixed contact exceeds a predetermined magnetic flux amount, the other end of the arc runner moves away from the open / close position of the movable contact and the fixed contact. A circuit breaker characterized by rotating. 6. The circuit breaker according to claim 5, further comprising a magnetism ring wound around the fixed contactor to guide a magnetic flux generated based on a current flowing through the fixed contactor to attract the arc runner. vessel.