JP6263744B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker.

  When a circuit breaker reaches a predetermined circuit state in a circuit in which a power source and a load are connected, the circuit breaker disconnects the contacts to interrupt the circuit (Patent Document 1).

  Examples of the circuit breaker include a circuit breaker, a leakage breaker, an overvoltage breaker, an undervoltage breaker, and the like. The circuit breaker interrupts the circuit when an abnormal current flows due to a short circuit or overload. The earth leakage breaker breaks the circuit when an earth leakage occurs. The overvoltage circuit breaker breaks the circuit when the voltage of the circuit is higher than a predetermined voltage. The undervoltage circuit breaker breaks the circuit when the voltage of the circuit is lower than a predetermined voltage. Moreover, the composite circuit breaker which combined said circuit breaker may be used.

  In such a circuit breaker, a movable contact having a movable contact can be rotated, and the movable contact is rotated so that the movable contact is brought into and out of contact with the fixed contact (contact and separation). Can be switched between closing and opening (breaking).

JP-A-5-159658

  The circuit breaker according to the embodiment of the present invention includes a fixed contact having a fixed contact, a movable contact having a movable contact that can be moved toward and away from the fixed contact by an opening / closing operation, and a commutation portion. The commutation part is disposed at a position where it does not interfere with the movable contact during the opening / closing operation, and is electrically connected between the fixed contact other than the fixed contact and the movable contact other than the movable contact at the time of opening. Intervene and allow arc current to pass through.

  With the above configuration, thermal damage due to the arc current between the fixed contact and the movable contact in the circuit breaker can be reduced.

FIG. 1 is a side view of a closed circuit in a circuit breaker according to an embodiment of the present invention. FIG. 2 is a side view of the circuit breaker of FIG. 1 in an open state. FIG. 3 is a side view of the circuit breaker of FIG. 1 in a trip state. 4 is a side view of an arc current bypass portion of the circuit breaker of FIG. FIG. 5 is a side view of an arc current bypass unit according to Modification 1 of the embodiment of the present invention. FIG. 6 is a side view of an arc current bypass unit according to Modification 2 of the embodiment of the present invention. FIG. 7 is a perspective view of a fixed contact in the arc current bypassing portion of FIG. FIG. 8 is a side view of an arc current bypass unit according to Modification 3 of the embodiment of the present invention. FIG. 9 is a side view of an arc current bypass unit according to Modification 4 of the embodiment of the present invention.

  Prior to the description of the present embodiment, problems in a conventional circuit breaker will be described.

  In the circuit breaker, when the fixed contact and the movable contact are separated from each other, the arc is stopped between the contacts, and there is a possibility that thermal damage is given to each contact. As a result, the resistance of the contact increases and the temperature rises easily. Furthermore, there is a possibility that the contacts are welded to each other when the contacts are brought into contact with each other to close the contacts.

  By this invention, the thermal damage by the arc between each contact in a circuit breaker can be reduced.

  A circuit breaker according to one embodiment of the present invention will be described with reference to the drawings. Note that each of the embodiments described below shows a preferred specific example. Accordingly, numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples and do not limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. In each figure, substantially the same structure is denoted by the same reference numeral, and redundant description is omitted or simplified.

(Embodiment)
Hereinafter, a circuit breaker 10 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a side view of a circuit breaker 10 in a closed state (ON state). FIG. 2 is a side view of the circuit breaker 10 in the open state (OFF state). FIG. 3 is a side view of the circuit breaker 10 in a trip state. FIG. 4 is a side view of the arc current bypass unit 100 of the circuit breaker 10.

  As shown in FIG. 1, the circuit breaker 10 includes a fixed contact 21 having a fixed contact 22, a movable contact 31 having a movable contact 32 that can be moved toward and away from the fixed contact 22 by an opening / closing operation, and a commutation. Part 61. The commutation portion 61 is disposed at a position where it does not interfere with the movable contact 31 during the opening / closing operation. The commutation part 61 is electrically interposed between the location of the stationary contact 21 other than the stationary contact 22 and the location of the movable contact 31 other than the movable contact 32 at the time of opening, and allows the arc current to pass therethrough. That is, the arc current bypass unit 100 that bypasses the arc current is configured by the fixed contact 21 other than the fixed contact 22 and the movable contact 31 other than the commutation unit 61 and the movable contact 32.

  Details of the circuit breaker 10 will be described below. The circuit breaker 10 includes a fixed contact 21, a movable contact 31, a driving member 41, and an opening / closing trip mechanism 51 in the housing 11.

  The casing 11 has a rectangular box shape that is long in one direction (left-right direction in FIG. 1), and has terminals 12 and 13 at both ends in the longitudinal direction. The casing 11 has a through hole 11a penetrating in the short direction on the side surface extending in the longitudinal direction on one side in the short direction (vertical direction in FIG. 1), and the handle 14 is connected to the through hole 11a. Configured to be exposed. The handle 14 is supported by a shaft 15 held by the housing 11. Various components are accommodated in the housing 11.

  The fixed contact 21 has a rectangular plate shape, has a fixed contact 22 at one end, and is electrically connected to the terminal 13 at the other end.

  As shown in FIG. 4, the fixed contact 22 is disposed on a surface 211 of the fixed contact 21 facing the movable contact 31, and is fixed to the fixed contact 21 by a rivet 22a. The rivet 22a is provided on the surface 211 opposite to the surface 211 on which the fixed contact 22 is arranged in the fixed contact 21. The stationary contact 21 is integrally formed with the terminal plate of the terminal 13. Thereby, the terminal 13 and the fixed contact 22 are electrically connected.

  As shown in FIG. 1, the movable contact 31 has a rectangular plate shape, has a movable contact 32 at one end, and is connected to the flexible lead wire 33 at the other end. The movable contact 31 is supported by a drive member 41 described later at a substantially intermediate portion.

  As shown in FIG. 4, the movable contact 32 is disposed on a surface 311 of the movable contact 31 that faces the fixed contact 21, and is fixed to the movable contact 31 by a rivet 32a. The rivet 32 a is provided on the surface 311 opposite to the surface 311 on which the movable contact 32 is disposed in the movable contact 31.

  As shown in FIGS. 1 and 2, the drive member 41 drives (rotates) the movable contact 31 in a manner in which the movable contact 32 is brought into and out of contact with the fixed contact 22. That is, by opening and closing the movable contact 31 by the drive member 41, the movable contact 32 can be brought into and out of contact with the fixed contact 22. The drive member 41 is pivotally supported by a shaft 16 fixed to the housing 11. By turning the drive member 41 about the shaft 16, it is possible to switch between an on operation (a closing operation) and an off operation (an opening operation). Specifically, in FIG. 1, the driving member 41 rotates clockwise about the shaft 16, thereby opening the movable contact 32 and the fixed contact 22. When the driving member 41 rotates counterclockwise about the shaft 16, a closing operation in which the movable contact 32 and the fixed contact 22 come into contact with each other is performed. The drive member 41 is biased in the opening direction (clockwise) by the opening spring 42.

  The open / close trip mechanism 51 drives the drive member 41 by operating the handle 14 to bring the movable contact 32 into and out of contact with the fixed contact 22 and forcibly opens the movable contact 32 from the fixed contact 22 when an abnormal current flows. .

  As shown in FIG. 1, the opening / closing trip mechanism 51 locks the link 52 having one end 52 a connected to the handle 14, the latch member 53 pivotally supported by the other end 52 b of the link 52, and the latch member 53. And a trip member 54.

  One end 52a of the link 52 is pivotally supported (not shown) on the handle 14 so as to be rotatable. The handle 14 rotates about the shaft 15. Since one end 52a of the link 52 is pivotally supported by the handle 14, the link 52 is lowered when the handle 14 is rotated clockwise, and the link 52 is raised when it is rotated counterclockwise.

  The intermediate portion 53 c of the latch member 53 is pivotally supported by the other end portion 52 b of the link 52. The trip member 54 is pivotally supported by a shaft 55 fixed to the housing 11. In the closed state, the first locking portion 53 a that is one end of the latch member 53 locks the pressing portion 41 a of the driving member 41. The second locking portion 53 b that is the other end of the latch member 53 is locked to one end 54 a of the trip member 54. The trip member 54 is urged by a spring 56 in a direction to be locked to the second locking portion 53b.

  The bimetal 57 is disposed to face the trip member 54. A base end portion 57 a of the bimetal 57 is held by the housing 11, and a tip end portion 57 b is close to the trip member 54. One end of a flexible lead wire 58 is connected to the distal end portion 57 b of the bimetal 57. The base end portion 57 a of the bimetal 57 is electrically connected to the terminal 12 and the flexible lead wire 58. Note that the other end of the flexible lead wire 58 is electrically connected to the terminal 12.

  As shown in FIGS. 1 and 4, the circuit breaker 10 has an extending portion 60 that is integrally formed with the housing 11 at a position that does not interfere with the rotation range of the movable contact 31 (movable contact 32).

  As shown in FIG. 4, the extending portion 60 is an L-shaped plate member having two straight portions. In the extending part 60, one linear part is a movable side extending part 60a extending toward the movable contact 31 side, and the other linear part is a fixed side extending part extending toward the fixed contact 21 side. 60b. The extending part 60 is composed of an insulating member. Further, a commutation portion 61 made of a magnetic material is fixedly provided on a surface opposite to the surface facing the movable contact 31 in the extending portion 60.

  As shown in FIG. 4, the commutation part 61 is an L-shaped plate-like member having two straight parts, like the extension part 60. One straight portion of the commutation portion 61 has a movable-side facing portion 61 a that faces the location of the movable contact 31 other than the movable contact 32, and the other straight portion is connected to the fixed contact 21 other than the fixed contact 22. It has the fixed side opposing part 61b which opposes. Specifically, the movable contact 32 is provided on one surface 311 of the plate-like movable contact 31. In the present embodiment, the movable-side facing portion 61a faces the one surface 311 of the movable contact 31 and the other surface 312 facing away from the other at the time of opening. The movable-side facing portion 61 a faces the rivet 32 a that projects on the other surface 312 of the movable contact 31. The fixed contact 22 is provided on one surface 211 of the plate-like fixed contact 21. The fixed-side facing portion 61 b faces the portion of the fixed contact 21 other than the fixed contact 21 on one surface 211 of the fixed contact 21.

[Closed state]
FIG. 1 shows a closed state of the circuit breaker 10. When the handle 14 falls to the upper surface of the housing 11, the link 52 is lowered. As a result, the drive member 41 that rotates about the shaft 16 rotates counterclockwise, and the movable contact 31 is closed. As a result, the movable contact 32 contacts the fixed contact 22. In this state, the driving member 41 is applied with a force that rotates clockwise from the opening spring 42. The second locking portion 53 b of the latch member 53 is locked by the trip member 54. The first locking portion 53 a of the latch member 53 presses the pressing portion 41 a of the driving member 41 against the opening spring 42.

  As shown in FIG. 1, when the link 52 is lowered, the position of the one end 52 a of the link 52 that is pivotally supported by the handle 14 is slightly left of the shaft 15 that pivotally supports the handle 14. ing. At this time, the handle 14 is urged clockwise by the spring force of the opening spring 42 and locked to the edge of the through hole 11a. Thereby, the terminals 12 and 13 are electrically connected through an electric circuit formed by the flexible lead wire 58, the bimetal 57, the flexible lead wire 33, the movable contact 31, and the fixed contact 21. A current flows in this electric circuit.

[Opened state]
FIG. 2 shows the open circuit state of the circuit breaker 10. When the handle 14 is moved from the collapsed state (ON state) to the upright state (OFF state), the handle 14 is biased counterclockwise by the spring force of the opening spring 42 when it exceeds a predetermined rotation position. And is locked to the edge of the through hole 11a. At this time, the latch member 53 is pulled up, and the drive member 41 rotates clockwise. For this reason, the movable contact 31 opens, and the movable contact 32 moves away from the fixed contact 22 to open the electric circuit. At this time, the arc current between the movable contact 31 and the fixed contact 21 is the fixed contact 21 (other than the fixed contact 22), the fixed-side facing portion 61b, the movable-side facing portion 61a, the rivet 32a, and the movable contact 31. It passes between (except for the movable contact 32). That is, since no arc current flows through the fixed contact 22 and the movable contact 32, thermal damage due to the arc current at the fixed contact 22 and the movable contact 32 is alleviated. The sum (L1 + L2) of the distance L1 between the movable contact 31 and the movable-side facing portion 61a at the time of opening and the distance L2 between the fixed contact 21 and the fixed-side facing portion 61b is as follows. It is shorter than the distance L3 between the movable contact 32 and the fixed contact 22. As shown in FIG. 4, the distance L1 between the movable contact 31 and the movable side facing portion 61a in the present embodiment is the distance between the tip of the rivet 32a (a part of the movable contact 31) and the movable side facing portion 61a. This is the distance from the facing surface of the movable contact 31. With this configuration, an arc current path through the commutation portion 61 is easily formed.

  When the handle 14 is tilted again after the opening operation, the driving member 41 rotates counterclockwise around the shaft 16 in the state shown in FIG. 1 and the movable contact 31 performs the closing operation.

[Trip state]
FIG. 3 shows a trip state of the circuit breaker 10. When an abnormal current, for example, an overcurrent flows through the electric circuit, the bimetal 57 is bent and the tip 57b of the bimetal 57 pushes the trip member 54. Then, the trip member 54 rotates clockwise about the shaft 55, and the second locking portion 53 b of the latch member 53 supported by the trip member 54 is separated from the trip member 54. Therefore, the driving member 41 receiving the spring force of the opening spring 42 rotates clockwise about the shaft 16, and the latch member 53 rotates clockwise about the other end 52 b of the link 52. . Since the drive member 41 rotates clockwise, the movable contact 31 performs an opening operation.

[reset]
The reset after the trip is performed by raising the handle 14 to the OFF side (turning to the OFF state) in a state where the bimetal 57 is cooled and stopped by the current stop and the trip member 54 is returned by the spring 56. When the handle 14 is raised, the link 52 is pulled up, and the first locking portion 53a of the latch member 53 rotates counterclockwise with the pressing portion 41a as a fulcrum. At the same time, the second locking portion 53 b is also rotated counterclockwise, pulled up, and locked to the trip member 54. As a result, the open state shown in FIG. 2 is obtained.

  Next, the effect of this embodiment will be described.

  (1) The commutation part 61 is disposed at a position where it does not interfere with the movable contact 31 during the opening / closing operation. The commutation part 61 can pass the arc current at the time of opening between the location of the stationary contact 21 other than the stationary contact 22 and the location of the movable contact 31 other than the movable contact 32. For this reason, the thermal damage by the arc current in the fixed contact 22 and the movable contact 32 can be reduced.

  (2) The movable-side facing portion 61a of the commutation portion 61 faces the surface 311 on the movable contact 31 where the movable contact 32 is disposed and the back surface 312 when the pole is opened. Therefore, it is possible to more reliably suppress the arc current from flowing to the movable contact 32.

  (3) Between the commutation part 61 and the stationary contact 21 and between the commutation part 61 and the movable contact 31, an insulating member is used except for the fixed side facing part 61 b and the movable side facing part 61 a. Extending portion 60. As a result, an arc is formed between the movable-side facing portion 61a and the fixed-side facing portion 61b of the commutation portion 61 and the location of the stationary contact 21 other than the stationary contact 22 and the location of the movable contact 31 other than the movable contact 32. It is possible to more reliably bypass the current. That is, deterioration due to the arc current of the fixed contact 22 and the movable contact 32 can be suppressed.

  (4) The commutation part 61 has a sum of a distance L1 between the movable contact 31 and the movable side facing part 61a and a distance L2 between the fixed contact 21 and the fixed side facing part 61b at the time of opening the pole. The distance between the movable contact 32 and the fixed contact 22 at the time of opening is shorter than the distance L3. With this configuration, the arc current can be bypassed via the commutation unit 61 more reliably. That is, it is possible to suppress an arc current from flowing between the fixed contact 22 and the movable contact 32.

  (5) The commutation part 61 is comprised with a magnetic body. Therefore, the arc current can be bypassed more reliably through the commutation unit 61. For this reason, it is possible to suppress an arc current from flowing between the fixed contact 22 and the movable contact 32.

  (6) The movable contact 31 has a movable protruding portion that protrudes toward the commutation portion 61. In the present embodiment, the movable protrusion is a rivet 32 a that is a fixed member that fixes the movable contact 32 to the movable contact 31. By projecting the rivet 32a toward the movable side facing portion 61a, the distance L1 between the movable contact 31 and the movable side facing portion 61a can be shortened. An arc current easily flows between the movable side facing portion 61a of the commutation portion 61 and the rivet 32a. With this configuration, it is possible to more reliably bypass the arc current via the commutation unit 61.

  In addition, you may change the said embodiment as follows.

(Modification 1)
An arc current bypass unit 101 according to Modification 1 of the embodiment of the present invention will be described with reference to FIG. FIG. 5 is a side view of the arc current bypass unit 101. The arc current bypassing part 101 is constituted by a part of the stationary contact 21 other than the stationary contact 22 and a part of the movable contact 31 other than the commutation part 61 and the movable contact 32. The arc current bypass unit 101 can be replaced with the arc current bypass unit 100 of the circuit breaker 10. The arc current bypassing part 101 is different from the arc current bypassing part 100 in that the fixed contact 21 has a fixed side protruding part 21a that protrudes toward the commutation part 61 (fixed side facing part 61b). The other configuration is the same as that of the arc current bypass unit 100. The distance L2 between the fixed-side facing portion 61b of the commutation portion 61 and the portion of the fixed contact 21 excluding the fixed contact 22 can be shortened by the fixed-side protruding portion 21a. As a result, the arc current can easily flow between the fixed-side protruding portion 21a and the fixed-side facing portion 61b, and the arc current can be bypassed more reliably through the commutation portion 61. Therefore, the thermal damage due to the arc in the fixed contact 22 and the movable contact 32 can be reduced. Note that the fixed protrusion 21 a may be a fixing member for fixing the fixed contact 21 to the housing 11.

(Modification 2)
An arc current bypass unit 102 according to Modification 2 of the embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 7 is a side view of the arc current bypass unit 102. FIG. 8 is a perspective view of the stationary contact 21 of the arc current bypass unit 102. The arc current bypassing portion 102 is configured by a location of the stationary contact 21 other than the stationary contact 22 and a location of the movable contact 31 other than the commutation portion 61 and the movable contact 32. The arc current bypass unit 102 can be replaced with the arc current bypass unit 100 of the circuit breaker 10. The arc current bypassing part 101 is different from the arc current bypassing part 100 in that it has an arc induction part that guides the arc current to the commutation part 61. The other configuration is the same as that of the arc current bypass unit 100.

  The stationary contact 21 has a substantially annular coil portion 21b as an arc induction portion. By energizing the coil portion 21b, a magnetic field by electromagnetic induction is generated around the coil portion 21b. An arc current can be induced in the commutation unit 61 by the generated magnetic field. Further, the arc current can be induced to the commutation part 61 by using a permanent magnet for the arc induction part.

(Modification 3)
An arc current bypass unit 103 according to Modification 3 of the embodiment of the present invention will be described with reference to FIG. FIG. 8 is a side view of the arc current bypass unit 103. The arc current bypassing portion 103 is configured by a location of the stationary contact 21 other than the stationary contact 22 and a location of the movable contact 31 other than the commutation portion 61 and the movable contact 32. The arc current bypass unit 103 can be replaced with the arc current bypass unit 100 of the circuit breaker 10. The arc current bypassing part 103 is different from the arc current bypassing part 100 in that the commutation part 61 has a cylindrical or linear shape. The other configuration is the same as that of the arc current bypass unit 100. Specifically, the commutation part 61 is comprised with the electric wire. The electric wire is covered with an insulating covering portion 62. That is, the covering portion 62 covers the periphery of the commutation portion 61 so as to expose both end portions of the commutation portion 61 and is made of an insulating material. One end of the commutation portion 61 is a movable-side facing portion 61a, and the other end is a fixed-side facing portion 61b.

(Modification 4)
An arc current bypass unit 104 according to Modification 4 of the embodiment of the present invention will be described with reference to FIG. FIG. 9 is a side view of the arc current bypass unit 104. The arc current bypassing part 104 is constituted by a part of the stationary contact 21 other than the stationary contact 22 and a part of the movable contact 31 other than the commutation part 61 and the movable contact 32. The arc current bypass unit 104 can be replaced with the arc current bypass unit 100 of the circuit breaker 10. The stationary contact 21 and the commutation unit 61 in the arc current bypass unit 100 are separated from each other. In the arc current bypassing part 104, the fixed contact 21 and the commutation part 61 are integrally formed and electrically connected. In this respect, the arc current bypass unit 104 is different from the arc current bypass unit 100 and the other configuration is the same. By setting it as such a structure, it becomes possible to fix the commutation part 61 more reliably and easily. Moreover, you may employ | adopt the structure which abuts the stationary contact 21 and the commutation part 61 only.

DESCRIPTION OF SYMBOLS 10 Circuit breaker 11 Case 14 Handle 21 Fixed contact 21a Fixed side protrusion 21b Coil part (arc induction part)
22 fixed contact 31 movable contact 32 movable contact 32a rivet (movable side protrusion and fixed member)
41 Drive member 51 Open / close trip mechanism 52 Link 53 Latch member 54 Trip member 57 Bimetal 60 Extension part (insulation part)
60a Movable side extension portion 60b Fixed side extension portion 61 Commutation portion 61a Movable side facing portion 61b Fixed side facing portion 62 Covering portion 100, 101, 102, 103, 104 Arc current bypassing portion

Claims (14)

A stationary contact having a stationary contact;
A movable contact having a movable contact that can be brought into and out of contact with the fixed contact by an opening and closing operation;
It is disposed at a position where it does not interfere with the movable contact during the opening / closing operation, and at the time of opening, between the position of the fixed contact other than the fixed contact and the position of the movable contact other than the movable contact e Bei electrically interposed, a commutation unit arc current is passed through, the,
The commutation portion is a fixed-side facing portion that faces a portion of the fixed contact other than the fixed contact;
A movable side facing portion that faces the position of the movable contact other than the movable contact;
The movable contact is plate-shaped, and the movable contact is provided on one surface of the movable contact,
The circuit breaker according to claim 1, wherein the movable-side facing portion opposes the other surface of the movable contact that faces away from the one surface during the opening. Furthermore, between the commutation part and the fixed contact and between the commutation part and the movable contact, an insulating member is provided at a place excluding the fixed side facing part and the movable side facing part.
The circuit breaker according to claim 1. The sum of the distance between the movable contact and the movable side facing portion at the time of opening and the distance between the fixed contact and the fixed side facing portion is the sum of the movable contact and the distance at the time of opening. Shorter than the distance between the fixed contacts
The circuit breaker according to claim 2. The commutation part is made of a magnetic material.
The circuit breaker as described in any one of Claims 1-3. The fixed contact has a fixed-side protruding portion that protrudes toward the commutation portion.
The circuit breaker as described in any one of Claims 1-4. The fixed side protrusion is a fixing member for fixing the fixed contact to the casing of the circuit breaker.
The circuit breaker according to claim 5. The movable contact has a movable protruding portion that protrudes toward the commutation portion.
The circuit breaker as described in any one of Claims 1-6. The circuit breaker according to claim 7, wherein the movable protrusion is a fixing member for fixing the movable contact to the movable contact . Furthermore, an arc induction part for inducing the arc current to the commutation part is provided.
The circuit breaker as described in any one of Claims 1-8. The arc induction part has a coil part for inducing an arc current to the commutation part by electromagnetic induction.
The circuit breaker according to claim 9. The arc induction part has a permanent magnet that induces an arc in the commutation part by a magnetic field.
The circuit breaker according to claim 9. The commutation part is cylindrical or linear,
The circuit breaker further includes a covering portion made of an insulating material that covers the periphery of the commutation portion so as to expose both ends of the commutation portion.
The circuit breaker as described in any one of Claims 1-11. The commutation part is an electric wire
The circuit breaker according to claim 12. The commutation part is integrally formed with the stationary contact.
The circuit breaker as described in any one of Claims 1-11.

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