JP2012089416A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker in which an arc generated between a fixed contact and the movable contact element of a movable contact maintains the movable contact element in open pole state after commutation to suppress restrike phenomenon when the main circuit is interrupted.SOLUTION: A movable contact 5 provided in a movable contact element 6 supported rotatably by a movable element holder 9 is separated from a fixed contact 3, the movable contact element 6 performs rotational movement, and maintains the open pole state by an electromagnetic repulsion force at a position where the direction of a current flowing through the flexible conductor 15 of a commutation traveling conductor 14 is opposite from the direction of a current flowing to the other end 6b side of the movable contact element thus suppressing restrike.

Description

  The present invention relates to a circuit breaker such as a circuit breaker for wiring and an earth leakage breaker, and particularly relates to a circuit breaker having a configuration in which re-ignition after arc commutation is suppressed.

  In recent years, due to the increase in capacity and space saving of low-voltage wiring facilities, wiring breakers, earth leakage circuit breakers, etc. are required to be reduced in outer dimensions. One of the issues in miniaturization is the improvement of current limiting performance that suppresses overcurrent. When an overcurrent is interrupted during an accident, etc., the electromagnetic force generated between the energized conductors is used to open the movable contact with the movable contact at high speed, thereby extending the arc length and limiting the arc resistance. It is important that the arc generated between the contacts or the arc generated between the contacts is drawn into the arc extinguishing plate, which is an arc extinguishing device, and the arc voltage is increased by limiting the current by generating an electrode drop voltage and cooling the arc. . Improved current-limiting performance enables the arc energy to be processed in the arc-extinguishing chamber of the circuit breaker to be reduced, reducing the thermal and electromagnetic load on the components that make up the circuit breaker and enabling downsizing. .

  In a conventional circuit breaker, an arc runner arranged almost in parallel is arranged on one side of the arc extinguishing device from the periphery of the tip where the movable contact is maximized. A technique is disclosed in which the electric potential is connected to the same potential and the arc spot on the movable contact is commutated to the arc runner (for example, Patent Document 1).

JP 02-265142 A

  However, in the conventional circuit breaker disclosed in Patent Document 1, when an arc is generated between the contacts and the movable contact is part of the energization path, the current flowing through the arc and the movable contact are Since the flowing current forms an angle close to a right angle, Lorentz force acts on the conductor around the arc spot on the movable contact side, and a driving force is generated in a direction to open the movable contact. This is a resistance against the driving force that the movable contact is constantly receiving in the closing (ON) direction by the contact pressure spring. Therefore, when the arc completely commutates to the arc runner, the movable contact becomes only the driving force in the closing direction, and the closing operation is started to shorten the distance between the contacts. As a result, the insulation resistance between the contacts decreases, the arc that has entered the arc-extinguishing device re-ignites, and the arc-extinguishing effect disappears, further reducing the arc length. Therefore, there is a problem that the current limiting performance is lowered and the breaking performance of the circuit breaker is lowered.

  The present invention has been made to solve the above-described problems. A circuit breaker capable of maintaining the movable contact in an open state after arc commutation and suppressing re-ignition phenomenon. The purpose is to provide.

  The circuit breaker according to the present invention is provided with a fixed contact, a movable contact, and a commutation running conductor. The fixed contact has a fixed contact at one end and an input terminal at the other end. A movable contact is supported by the movable element holder so that it can rotate. A movable contact is connected to one end of the movable element. A flexible contact is provided to the other end of the commutating conductor. The movable contact is connected to the output terminal via the movable element holder. When an overcurrent flows through the main circuit, the movable contact of the movable contact is separated from the fixed contact of the fixed contact, the movable contact rotates, and an arc generated between the movable contact and the fixed contact is generated. The open circuit state of the main circuit is maintained at a position where the direction of the current commutated to the commutation running conductor and flowing to the flexible conductor is opposite to the direction of the current flowing to the other end of the movable contact. is there.

  According to the present invention, since the circuit breaker adopts the above-described configuration, it is possible to maintain the movable contact that is to be closed after the arc is commutated to the commutation running conductor in the open state. For this reason, it is possible to obtain a high breaking performance in which the re-ignition phenomenon due to the shortening of the distance between the movable contact and the fixed contact is suppressed.

It is a side view which shows the closing state of the circuit breaker of Embodiment 1. It is a side view which shows the open circuit state of the circuit breaker of Embodiment 1. It is the side view which shows the state after the commutation of the circuit breaker of Embodiment 1, and the schematic diagram which shows the electricity supply path | route after a commutation. FIG. 3 is a top view showing the movable contact according to the first embodiment. It is a side view which shows the closing state of the circuit breaker of Embodiment 2. It is a side view which shows the open circuit state of the circuit breaker of Embodiment 2. It is the side view which shows the state after the commutation of the circuit breaker of Embodiment 2, and the schematic diagram which shows the electricity supply path | route after a commutation. FIG. 6 is a top view showing a commutation running conductor according to a second embodiment. It is a side view which shows the closing state of the circuit breaker of Embodiment 3. It is the side view which shows the state after the commutation of the circuit breaker of Embodiment 3, and the schematic diagram which shows the electricity supply path | route after a commutation. It is a side view which shows the closing state of the circuit breaker of Embodiment 4. It is the side view which shows the state after the commutation of the circuit breaker of Embodiment 4, and the schematic diagram which shows the electricity supply path | route after a commutation. FIG. 10 is a top view showing a commutation running conductor according to a fourth embodiment.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described with reference to FIGS.
1 to 3 (a) are side views of the arc-extinguishing chamber 50 which is a part of the circuit breaker 100. Although not shown in the figure, a relay section that detects an abnormal current and outputs an opening command is shown. A drive mechanism for performing ON / OFF operation of the circuit breaker 100 is disposed at the transmission destination of the commander, and the arc extinguishing chamber 50 is integrally housed in the circuit breaker 100 together with these. FIG. 1 shows a closed state (contact ON state), and FIGS. 2 and 3A show an open state (contact OFF state). The arc extinguishing chamber 50 is divided into three phases in parallel by a base 1 made of an insulating material, a cover 2, and the like, and is housed in the circuit breaker 100. In the arc extinguishing chamber 50, a fixed contact 4 having a fixed contact 3 fixed to one end and a movable contact 6 having a movable contact 5 fixed to one end 6a of the movable contact are disposed. The other end of the fixed contact 4 where the fixed contact 3 is not fixed is an input terminal 7 connected to an external conductor. The movable contact 6 has a U-shape and is arranged in a reverse shape with respect to a commutation running conductor 14 described later in FIGS. 1 to 3A. A rotating shaft 8 is provided near the top of the mold. The other end 6 b of the movable contact is connected to a flexible conductor 15 provided on the commutation running conductor 14. Further, as shown in FIG. 4 in which the movable contactor 6 is viewed from above, the periphery of the rotary shaft 8 is sandwiched and supported by the movable element holder 9, and the movable element holder 9 is movable contactable. It is in sliding contact with the child 6 and is electrically connected. Although not shown in FIGS. 1 to 3A, the movable contact 6 is provided with a contact pressure spring that applies a driving force in the closing direction.

  The movable contact 6 is surrounded by a crossbar 10 made of an insulator that is linked to a drive mechanism unit (not shown) that performs ON / OFF operation of the circuit breaker 100 described above to open and close the movable contact 6. It is supported. As shown in FIG. 1, an arc extinguishing plate made of a magnetic material that takes in and divides and cools an arc generated between the fixed contact 3 and the movable contact 5 when the movable contact 6 is opened above the fixed contact 4. An arc extinguishing device 12 in which a plurality of 11 are stacked is arranged. On the right side of the arc extinguishing device 12, there is an exhaust port 13 for discharging the hot gas of the arc 16 shown in FIG. 2, which is generated when the base 1 and the cover 2 are opened and shut off. The exhaust port 13 is closed and the inside of the circuit breaker 100 is closed. When the arc 16 is generated inside the arc extinguishing when interrupted, the barrier material is released by the generated pressure and discharges the internal hot gas. A commutating traveling conductor 14 is disposed above the movable contact 6 and the arc extinguishing device 12, and the flexible conductor 15 is connected to the other end 6b of the movable contact to which the movable contact 5 of the movable contact is not fixed. Has been. In FIG. 1 to FIG. 3A, the arrows in the drawings indicate energization paths. FIG. 3B shows only the energization path as a schematic diagram.

  In the arc-extinguishing chamber 50, when an overcurrent flows through the arc-extinguishing chamber 50 in the state of FIG. 1, the direction of the current flowing through the movable contact 6 and the direction of the current of the stationary contact 4 facing this is opposite. Therefore, an electromagnetic repulsive force depending on the value of the flowing current is generated, and the movable contact 6 generates a driving force in the opening direction. When the driving force exceeds the biasing force of the contact pressure spring (not shown), the movable contact 6 starts to open, and the fixed contact 3 and the movable contact 5 are separated, and an arc 16 is formed between the contacts as shown in FIG. Will occur. In this case, the energization path is fixed contact 4 → arc 16 → movable contact 6 → movable element holder 9. When the opening of the movable contact 6 advances and approaches the commutation running conductor 14, the flow of hot gas in the direction of the exhaust port 13 due to the pressure gradient around the arc 16, the current flowing through the fixed contact 4 and the movable contact 6. The electromagnetic driving force acts on the arc 16 to generate a rightward driving force. As a result, the arc spot on the movable contact 6 side is commutated to the commutation running conductor 14 having the same potential as the movable contact 6.

  This is the state of the arc 16 shown in FIG. 3, the arc length is further extended, the arc resistance is increased, and the current limiting effect against the overcurrent is increased. The energization path changes before and after commutation, and after commutation, as indicated by the arrow in FIG. 3, the stationary contact 4 → arc 16 → commutation running conductor 14 → flexible conductor 15 → the other end 6b side of the movable contact. → The mover holder 9 is obtained. Further, the arc 16 has a driving force due to a pressure gradient, an electromagnetic driving force from an overcurrent flowing through the stationary contact 4 and the commutating traveling conductor 14, and a magnetic attraction of the arc extinguishing plate 11 that is a magnetic body constituting the arc extinguishing device 12. A force or the like acts and is taken into the arc-extinguishing device 12 to form a cutting arc 16a. As a result, the arc voltage increases due to the generation of the electrode drop voltage and the cooling effect of the arc extinguishing plate 11, and the current limiting performance for limiting the overcurrent to a low level is enhanced.

  As shown in FIG. 3, when the arc commutates to the commutation running conductor 14, the energization path from the movable contact 5 to the rotor holder 9 disappears, and the fixed contact 4 and the movable contact that have become the opening driving force are moved. The electromagnetic repulsion between the children 6 disappears. In the conventional configuration, the movable contact 6 is rotated in the closing direction by the biasing force of the contact pressure spring, and the separation distance is shortened, and the insulation between the fixed contact 4 and the movable contact 6 is reduced. The proof stress is lowered and the arc returns again between the fixed contact 3 and the movable contact 5, the arc length is shortened and the dividing effect at the arc extinguishing plate 11 is lost, and the current limiting performance is lowered.

According to the first embodiment, in the energization path after commutation, as shown in FIG. 3 (b), the movable element holder 9 is formed from the current component 19 of the flexible conductor 15 and the other end 6b of the movable contact. Since the current component 20 up to this point has the opposite energization direction, an electromagnetic repulsive force F _(19-20) 21 is generated in both conductors. For this reason, since a downward driving force is applied to the conductor portion of the current component 20, an upward driving force is generated on the one end 6a side of the movable contact to which the movable contact 5 is fixed. Therefore, even after the arc 16 moves, the opening driving force continuously acts on the reverse-shaped movable contact 6 having the rotating shaft 8 as a fulcrum, and the opening distance is not shortened. An electromagnetic repulsive force F _(20-22) 23 is generated in both conductors between the current component 20 on the other end 6b side of the movable contact and the current component 22 of the movable member holder 9, but the flexible contact is flexible. The angle θ1 formed between the conductor 15 and the other end 6b of the movable contact is a sharper angle than the angle θ2 formed between the other end 6b of the movable contact and the mover holder 9, that is, θ1 <θ2. Therefore, the influence of the electromagnetic repulsive force F _(20-22) 23 is not dominant.
With the above operation, even after the arc of the movable contact 6 moves to the commutation running conductor 14, the distance between the contacts is not shortened, so that re-ignition is suppressed, and as a result, the current limiting performance is interrupted without deteriorating. The performance can be improved stably. Furthermore, the electromagnetic load is reduced and the apparatus can be downsized.

Embodiment 2. FIG.
A second embodiment will be described with reference to FIGS.
5 to 7A are side views of the arc-extinguishing chamber 50 portion of the circuit breaker 100 as shown in FIGS. FIG. 5 shows a closed state (contact ON state), and FIGS. 6 and 7A show an open state (contact OFF state). Except for the following description, the second embodiment is the same as the first embodiment.
In the second embodiment, an opening 14a is provided at the center in the width direction perpendicular to the figure of the commutation running conductor 14, and when the movable contact 6 opens and approaches the OFF state, the movable contact One end 6a of the movable contact including the six movable contacts 5 is inserted and surrounded by the opening 14a. FIG. 8 shows the movable contact 6 and the commutation running conductor 14 as viewed from above. The periphery of the rotary shaft 8 is supported by being sandwiched by the mover holder 9 and is in sliding contact with the movable contact 6. It is connected. Furthermore, one end 6a of the movable contact is surrounded by the opening 14a. In FIG. 5 to FIG. 7A, arrows in the drawings indicate energization paths. FIG. 7B shows a schematic diagram of the energization path.
In the arc-extinguishing chamber 50, when an overcurrent flows through the arc-extinguishing chamber 50 in the state of FIG. 5, the movable contact 6 starts the opening operation as in the first embodiment described above and is shown in FIG. Thus, the fixed contact 3 and the movable contact 5 are separated, and an arc 16 is generated between the contacts. In this case, the energization path is fixed contact 4 → arc 16 → movable contact 6 → movable element holder 9. The opening of the movable contact 6 progresses, the proximity of the commutation running conductor 14, and the surrounding of the arc spot on the movable contact 6 side is surrounded by the opening 14 a. The opening 14a is surrounded to the height of the arc spot, so that the commutation traveling conductor 14 is commutated. This is the state of the arc 16 shown in FIG.
As shown in FIG. 7A, when the arc 16 commutates to the commutation running conductor 14, the energization path from the movable contact 5 to the movable element holder 9 disappears, and the fixed contact that has become the opening driving force. The electromagnetic repulsion between 4 and the movable contact 6 disappears.

According to the second embodiment, in the energization path after commutation, as shown in FIG. 7B, the current component 19 of the flexible conductor 15 and the other end 6b of the movable contact to the movable holder 9 Since the current component 20 has the opposite energization direction, an electromagnetic repulsive force F _(19-20) 21 is generated in both conductors. For this reason, since a downward driving force is applied to the conductor portion of the current component 20, an upward driving force is generated on the one end 6a side of the movable contact to which the movable contact 5 of the movable contact is fixed. To do. Therefore, even after the arc 16 moves to the commutation running conductor 14, the opening driving force is continuously applied, and the separation distance is not shortened. An electromagnetic repulsive force F _(20-22) 23 is generated in both conductors between the current component 20 of the movable contact 6 and the current component 22 of the movable holder 9. Since the angle θ1 formed with the other end 6b of the movable contact is more acute than the angle θ2 formed with the other end 6b of the movable contact and the movable holder 9, the electromagnetic repulsive force F _{(20 -22)} The influence of 23 is not dominant.
By the above operation, the distance between the contacts is not shortened even after the arc (not shown) of the movable contact 6 moves to the commutation running conductor 14, thereby suppressing the occurrence of re-ignition and reducing the current limiting performance. It is possible to stably improve the blocking performance.

Embodiment 3 FIG.
The third embodiment will be described with reference to FIGS. 9 and 10A.
9 and 10A are side views of the arc extinguishing chamber 50 portion of the circuit breaker 100, as shown in FIGS. FIG. 9 shows a closed state (contact ON state), and FIG. 10 shows an open state (contact OFF state). Except for the following description, the second embodiment is the same as the first embodiment.
In the third embodiment, the mover holder 9 that is in sliding contact with the periphery of the rotary shaft 8 of the movable contact 6 is disposed on the left side of the arc extinguishing chamber 50 from the rotary shaft 8 of the movable contact 6. 10 (a) is maintained above the movable contact 6 in the open state.
In the arc-extinguishing chamber 50, when an overcurrent flows through the arc-extinguishing chamber 50 in the state of FIG. 9, the movable contact 6 is separated, and an arc (not shown) is commutated as shown in FIG. When commutating to the running conductor 14, the energization path from the periphery of the movable contact 5 to the rotating shaft 8 disappears, and the electromagnetic repulsive force between the fixed contact 4 and the movable contact 6 that has been the opening driving force disappears. .

According to the third embodiment, in the energization path after commutation, as shown in FIG. 10B, the current component 19 of the flexible conductor 15 and the current component 20 on the other end 6b side of the movable contact are in the energization direction. Therefore, the electromagnetic repulsive force F _(19-20) 21 is generated in both conductors. For this reason, since a downward driving force is applied to the other end 6b side of the movable contact to which the current component 20 is energized, the upper end is directed to the one end 6a side of the movable contact to which the movable contact 5 is fixed. The driving force is generated. Further, between the current component 20 on the other end 6b side of the movable contact and the current component 26 flowing through the movable holder 9, an electromagnetic repulsive force F _(19-26) 27 is generated in both conductors. For this reason, since a downward driving force is applied to the other end 6b side of the movable contact to which the current component 20 is energized, the upper end is directed to the one end 6a side of the movable contact to which the movable contact 5 is fixed. The driving force is generated. Therefore, even after the arc moves to the commutation running conductor 14, the opening driving force is continuously applied, and the separation distance is not shortened.
By the above operation, even after the arc (not shown) of the movable contact 6 moves to the commutation running conductor 14, the distance between the contacts is not shortened, thereby suppressing the occurrence of re-ignition, resulting in a decrease in current limiting performance. It is possible to stably improve the shut-off performance without causing it. In the third embodiment, the commutation running conductor 14 can realize the same effect of improving the breaking performance even in the structure shown in the second embodiment.

Embodiment 4 FIG.
A fourth embodiment will be described with reference to FIGS.
FIGS. 11 and 12A are side views of the arc extinguishing chamber 50 of the circuit breaker 100. FIG. Except for the following description, the second embodiment is the same as the first embodiment. FIG. 11 shows a closed state (contact ON state), and FIG. 12A shows an open state (contact OFF state). In the fourth embodiment, as shown in FIG. 13, the left end which is one end of the commutation running conductor 28 is a branch conductor 28a which is in a sliding contact state with the other end 6b of the movable contact being sandwiched therebetween. It is a feature. The branch conductor 28a is formed by providing an opening 28b in the commutation running conductor 28.
In the arc-extinguishing chamber 50, when an overcurrent flows through the arc-extinguishing chamber 50 in the state shown in FIG. 11, the movable contact 6 advances, and an arc (not shown) is commutated as shown in FIG. When commutated to the running conductor 28, the energization path from the periphery of the movable contact 5 to the rotating shaft 8 disappears, and the electromagnetic repulsive force between the fixed contact 4 and the movable contact 6 that has been the opening driving force disappears. .

According to the fourth embodiment, in the energization path after commutation, as shown in the schematic diagram of the energization path in FIG. 12B, the current component 29 of the branch conductor 28a and the other end 6b of the movable contact Between the current components 20, an electromagnetic repulsive force F _(29a-20) 30 is generated in both conductors. For this reason, since a downward driving force is applied to the other end 6b side of the movable contact, an upward driving force is generated on the one end 6a side of the movable contact to which the movable contact 5 is fixed. Therefore, even after the arc (not shown) moves to the commutation running conductor 14, the opening driving force continuously acts, and the opening distance is not shortened. Note that the relationship of the electromagnetic repulsion force by the energization path shown in FIG. 12B is the same as that in FIG.
By the above operation, even after the arc (not shown) of the movable contact 6 commutates to the commutation running conductor 28, the distance between the contacts is not shortened, so that re-ignition is suppressed, resulting in a decrease in current limiting performance. It is possible to stably improve the shut-off performance without causing it.
In the fourth embodiment, the same breaking performance improvement effect is realized even in the structure shown in the second embodiment for the commutation running conductor 14 and in the structure shown in the third embodiment for the mover holder 9. it can.

3 fixed contact, 4 fixed contact, 5 movable contact, 6 movable contact, 7 input terminal,
9 mover holder, 14 commutation running conductor, 14a opening, 15 flexible conductor,
28 commutation running conductor, 28a branching conductor, 28b opening, 100 circuit breaker.

Claims (6)

A circuit breaker that opens and closes the main circuit,
The circuit breaker is provided with a fixed contact, a movable contact, and a commutation running conductor, the fixed contact is provided with a fixed contact at one end and an input terminal at the other end, and the movable contact is A movable contact is supported by the movable element holder so as to be rotatable, and a movable contact is connected to one end and a flexible conductor provided to the commutation running conductor is connected to the other end, and the movable contact is output via the movable element holder. When the overcurrent flows through the main circuit, the movable contact of the movable contact is separated from the fixed contact of the fixed contact, and the movable contact rotates and moves with the movable contact. In the position where the direction of the current flowing through the flexible conductor and the direction of the current flowing through the other end of the movable contact are opposite to each other, the arc generated between the fixed contacts commutates to the commutation running conductor. The main circuit is kept open. Circuit breaker to. A circuit breaker that opens and closes the main circuit,
The circuit breaker is provided with a fixed contact, a movable contact, and a commutation running conductor, the fixed contact is provided with a fixed contact at one end and an input terminal at the other end, and the movable contact is The movable contact is supported so as to be rotatable, and a movable contact is extended at one end, and the other end is inserted into an opening provided to form a branch conductor at one end of the commutation running conductor, and the movable contact The child is connected to the output terminal via the mover holder, and when an overcurrent flows through the main circuit, the movable contact of the movable contact is separated from the fixed contact of the fixed contact. Rotating and moving, an arc generated between the movable contact and the fixed contact is commutated to the commutation running conductor and flows through the branch conductor, and a current flows through the other end of the movable contact. In the opposite direction, Circuit breaker, characterized in that the open state of the main circuit is maintained. The movable contact is formed and arranged in a reverse letter shape with respect to the commutation running conductor, and is rotatably supported by the mover holder near the vertex of the reverse letter shape. The circuit breaker according to claim 1, wherein the circuit breaker is provided. The commutation running conductor is provided with an opening, and when the movable contact of the movable contact is separated from the fixed contact of the fixed contact, one end portion of the movable contact including the movable contact is The circuit breaker according to claim 1, wherein the movable contact is rotated so as to be inserted into the opening. The open circuit state of the main circuit is maintained by setting an angle between the flexible conductor of the commutation running conductor and the other end of the movable contact to θ1, and the other end of the movable contact and the movable 2. The circuit breaker according to claim 1, wherein the circuit breaker is formed by a relationship of θ <b> 1 <θ <b> 2 when an angle formed with the holder is θ <b> 2. The main circuit is maintained in an open state in that the angle between the branch conductor formed at one end of the commutation running conductor and the other end of the movable contact is θ1, and the other end of the movable contact is 3. The circuit breaker according to claim 2, wherein the circuit breaker has a relationship of θ <b> 1 <θ <b> 2, where θ <b> 2 is an angle formed with the movable element holder.

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