CN114520131A

CN114520131A - Circuit breaker

Info

Publication number: CN114520131A
Application number: CN202111338133.6A
Authority: CN
Inventors: 相良雄大; 舛田真一; 藤原匠; 春名贤一; 阿部达广; 前田智也
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2020-11-18
Filing date: 2021-11-12
Publication date: 2022-05-20
Also published as: JP7446204B2; JP2022080514A

Abstract

The circuit breaker is provided with: a movable element (6) including a plurality of movable conductors (60); and a movable element holder (7) which rotatably holds the plurality of movable conductors (60) in a parallel arrangement state via a movable element pin (13). The movable element holder (7) has a pair of holder projections which are arranged around the movable element pin (13) and project toward both side surfaces (601, 602) of each of the plurality of movable conductors (60) in the direction in which the movable element pin (13) extends.

Description

Circuit breaker

Technical Field

The present invention relates to a circuit breaker including a movable element holder rotatably holding a plurality of movable conductors arranged in parallel.

Background

Conventionally, in a circuit breaker requiring a performance of closing a short circuit, when the short circuit is closed, a large current flows through a movable contact attached to the movable element at the moment when the movable contact comes into contact with a fixed contact. If a large current flows through the movable element, a large lorentz force is generated as a reaction force in the movable conductor, and therefore, a closing force exceeding the lorentz force is required in the circuit breaker.

In such a circuit breaker, in order to reduce the lorentz force generated in the movable conductor through which a large current flows, a technique is known in which a plurality of movable conductors constituting a movable element are arranged in parallel in each phase. For example, patent document 1 discloses a circuit breaker in which 3 movable conductors are rotatably held by a movable element holder in a state where the movable conductors are arranged in parallel in each phase.

In the circuit breaker described in patent document 1, in order to prevent the movable conductors from being inclined by a lorentz force generated in the movable conductors when a large current flows between the contacts, a spacer is inserted between the movable conductors. The contact between the movable conductors is suppressed by the spacer, and the friction generated by the Lorentz force is reduced.

Patent document 1: japanese laid-open patent publication No. 61-279026

However, in the technique described in patent document 1, the spacers are displaced along with the displacement of the movable conductors due to the lorentz force acting in the direction in which the movable conductors are arranged, and therefore the range of displacement of the movable conductors is increased. Therefore, if the movable contact attached to the movable conductor comes into contact with the fixed contact and a large current flows through the movable conductor, the movable conductor is greatly displaced, and the contact between the movable contact and the fixed contact becomes unstable during the closing operation. Further, if the contact between the movable contact and the fixed contact becomes unstable during the closing operation, an arc may be generated between the contacts, and a conduction failure may occur.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circuit breaker capable of stabilizing contact between a movable contact and a fixed contact during a closing operation.

In order to solve the above problems and achieve the object, a circuit breaker according to the present invention includes: a movable member including a plurality of movable conductors; and a movable element holder that rotatably holds the plurality of movable conductors arranged in parallel via a movable element pin. The movable element holder has a pair of holder projections which are arranged around the movable element pin and project toward both side surfaces of each of the plurality of movable conductors in an extending direction of the movable element pin.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the contact between the movable contact and the fixed contact can be stabilized during the closing operation.

Drawings

Fig. 1 is a side view of the inside of the circuit breaker according to embodiment 1 when separated.

Fig. 2 is a side view of the inside of the circuit breaker according to embodiment 1 when closed.

Fig. 3 is a diagram showing an example of the structure of a movable element and a movable element holder in the circuit breaker according to embodiment 1.

Fig. 4 is a diagram showing a state in which the movable contact attached to the movable conductor is rotated after contacting the fixed contact in the circuit breaker according to embodiment 1.

Fig. 5 is a diagram showing the direction of the lorentz force acting on the movable conductor when a large current flows between the movable contact and the fixed contact of the circuit breaker according to embodiment 1.

Fig. 6 is a perspective view showing the direction of the lorentz force acting on the movable conductor when a large current flows between the movable contact and the fixed contact of the circuit breaker according to embodiment 1.

Fig. 7 is a front view of the movable element holder according to embodiment 1.

Fig. 8 is a front view of the movable element holder according to embodiment 1 in a state where a plurality of movable conductors are held.

Fig. 9 is a diagram showing an example of the shape of the projection according to embodiment 1.

Fig. 10 is a diagram showing another example of the shape of the projecting portion according to embodiment 1.

Fig. 11 is a diagram showing another example of the shape of the projection according to embodiment 1.

Fig. 12 is a front view of the movable element holder according to embodiment 2 in a state where a plurality of movable conductors are held.

Fig. 13 is a diagram showing an example of a plurality of protective covers in a state in which corresponding movable conductors among a plurality of movable conductors according to embodiment 2 are attached to each other.

Fig. 14 is a diagram showing another example of a plurality of protection covers in a state where corresponding movable conductors among a plurality of movable conductors according to embodiment 2 are mounted.

Detailed Description

Hereinafter, a circuit breaker according to an embodiment will be described in detail with reference to the drawings.

Embodiment 1.

The circuit breaker according to embodiment 1 is an air circuit breaker that opens and closes an electric circuit such as a low-voltage distribution line, and detects at least one of overcurrent and electric leakage to open the electric circuit. The circuit breaker according to embodiment 1 may be a circuit breaker other than an air circuit breaker. For convenience of explanation, the positive Z-axis direction is set to the upper side, and the negative Z-axis direction is set to the lower side.

Fig. 1 is a side view of the inside of the circuit breaker according to embodiment 1 when separated. Fig. 2 is a side view of the inside of the circuit breaker according to embodiment 1 when closed. As shown in fig. 1, a circuit breaker 1 according to embodiment 1 includes: a frame 2 formed of an insulating member; a power source side terminal 3 and a load side terminal 4 each attached to the housing 2; and a flexible conductor 5 having one end connected to the load side terminal 4 inside the housing 2.

In addition, the circuit breaker 1 includes: a movable element 6 having one end connected to the other end of the flexible conductor 5; a movable element holder 7 having one end rotatably attached to the housing 2 inside the housing 2; and a pressure contact spring 8 having one end and the other end attached to the other end of the movable element holder 7 and the other end of the movable element 6. The power supply side terminal 3 is connected to a power supply side conductor, not shown, outside the housing 2, and the load side terminal 4 is connected to a load side conductor, not shown, outside the housing 2. Inside the housing 2, a fixed contact 10 is attached to the power source side terminal 3, and a movable contact 11 is attached to the other end of the movable element 6.

Fig. 3 is a diagram showing an example of the structure of a movable element and a movable element holder in the circuit breaker according to embodiment 1. As shown in fig. 3, the movable element 6 has 5 movable conductors 60. The movable element holder 7 rotatably holds 5 movable conductors 60 arranged in parallel via a movable element pin 13.

The movable element holder 7 has a plurality of partition plates 72, and the plurality of partition plates 72 are arranged in the extending direction of the movable element pin 13 to form a plurality of receiving portions 71 for receiving the corresponding movable conductors among the plurality of movable conductors 60. Each receiving portion 71 is a space surrounded by 2 adjacent partition plates 72.

The movable pin 13 is fixed to the movable holder 7. Each movable conductor 60 is formed with a through hole 61 described later through which the movable element pin 13 is inserted, and each movable conductor 60 is rotatable with respect to the movable element pin 13. A movable contact 11a is attached to each movable conductor 60. The movable contact 11 shown in fig. 1 and 2 is constituted by the movable contacts 11a of the plurality of movable conductors 60. The number of the movable conductors 60 is not limited to 5, and may be 2 or more and less than 4, or 6 or more. The receiving portions 71 and the partition plates 72 are provided in the number corresponding to the number of the movable conductors 60.

Returning to fig. 1, the description of the circuit breaker 1 is continued. The flexible conductor 5 is a flexible conductor and electrically connects the load side terminal 4 and the movable element 6. In the circuit breaker 1 in the separated state shown in fig. 1, the movable contact 11 is not in contact with the fixed contact 10, and the power source side terminal 3 and the load side terminal 4 are not electrically connected as the circuit breaker 1. The movable element holder 7 has one end rotatably attached to the housing 2 around a holder shaft 12 as a rotation center, and has the movable element 6 rotatably attached to an intermediate portion via a movable element pin 13.

In addition, the circuit breaker 1 includes: an electromagnetic actuator 20 disposed inside the housing 2 as a closing actuator of the circuit breaker 1; and a transmission mechanism 30 for transmitting the driving force of the electromagnetic actuator 20 to the movable element 6 to bring the movable contact 11 into and out of contact with the fixed contacts 10. In addition, the circuit breaker 1 includes: a separation spring 39 having one end and the other end attached to the transmission mechanism 30 and the frame 2; a trip mechanism 40 that maintains the closed state and releases the closed state; and a drive circuit 45 that drives the electromagnetic actuator 20.

When the exciting coil 21 is energized by the drive circuit 45, the electromagnetic actuator 20 moves the shaft 25 upward. The transmission mechanism 30 includes: a coupling link 31 having one end rotatably coupled to the shaft 25 of the electromagnetic actuator 20 by a coupling pin 34; a main shaft 32 rotatably coupled to the other end of the coupling link 31 by a coupling pin 35; and a link 33 rotatably coupled to one end of the main shaft 32.

The spindle 32 is rotatably attached to a rotating shaft 36 fixed in absolute position to the housing 2 around the rotating shaft 36. The link 33 has one end rotatably connected to one end of the main shaft 32 by a connecting pin 38, and the other end rotatably attached to one end of the movable element 6 and an intermediate portion of the movable element holder 7 by the movable element pin 13.

When the circuit breaker 1 is in the open state, if the electromagnetic actuator 20 is energized, the shaft 25 of the electromagnetic actuator 20 moves upward in the driving direction. The main shaft 32 rotates about the rotation shaft 36 by the upward movement of the shaft 25, and the movable element 6 is moved forward by the transmission mechanism 30, so that the fixed contacts 10 and the movable contacts 11 contact each other and the circuit breaker 1 is in a closed state as shown in fig. 2. The movable contact 11 is in contact with the fixed contact 10, whereby the circuit breaker 1 is electrically connected to the power source side terminal 3 and the load side terminal 4.

The circuit breaker 1 is a circuit breaker that opens and closes a 3-phase circuit, and has a power source side terminal 3, a load side terminal 4, a flexible conductor 5, a movable element 6, a movable element holder 7, a link 33, and the like for each phase, and opens and closes the circuit by rotating a main shaft 32.

Fig. 4 is a diagram showing a state in which the movable contact attached to the movable conductor is rotated after contacting the fixed contact in the circuit breaker according to embodiment 1. As shown in the left-hand diagram of fig. 4, when the movable contact 11a attached to the movable conductor 60 comes into contact with the fixed contact 10, the short circuit is closed and a large current flows instantaneously.

In the state of the left-hand diagram in fig. 4, the circuit breaker 1 does not reach the final closed state, i.e., the closed state, and the transmission mechanism 30 further pushes the movable pin 13 in the right direction in fig. 4, thereby bringing the circuit breaker into the closed state as shown in the right-hand diagram in fig. 4. As described above, after a large current flows, the movable pin 13 needs to be further pushed in the right direction in fig. 4, but a large current flows through the movable conductor 60 and the flexible conductor 5, and a lorentz force acts on the movable conductor 60 and the flexible conductor 5.

Fig. 5 is a diagram showing the direction of the lorentz force acting on the movable conductor when a large current flows between the movable contact and the fixed contact of the circuit breaker according to embodiment 1. Fig. 6 is a perspective view showing the direction of the lorentz force acting on the movable conductor when a large current flows between the movable contact and the fixed contact of the circuit breaker according to embodiment 1.

As shown in fig. 5 and 6, a lorentz force of the movable conductor 60 toward the center of the plurality of movable conductors 60 in the extending direction of the movable pin 13 acts on the plurality of movable conductors 60. Therefore, the lorentz force acts as a force for pressing the plurality of movable conductors 60 against the plurality of partition plates 72 in the movable element holder 7. Further, the circuit breaker 1 causes a lorentz force to act in the left-right direction in fig. 5 on the movable elements 6 provided for each phase, and this lorentz force also acts as a force that presses the plurality of movable conductors 60 against the plurality of partition plates 72.

The force pressing the movable conductor 60 against the partition plate 72 serves as a vertical resisting force, and a frictional torque is generated between the partition plate 72 and the movable conductor 60. Therefore, although the contact pressure of the movable contact 11a with respect to the fixed contact 10 is reduced, the pair of projecting portions 75 that project toward both side surfaces 601 and 602 of each movable conductor 60 in the extending direction of the movable pin 13 are disposed around the movable pin 13 in the movable holder 7 as shown in fig. 5. One of the pair of projections 75 is provided to one of the 2 partition plates 72 adjacent to each other, and the other is provided to the other of the 2 partition plates 72 adjacent to each other.

When a pressing force to the partition plate 72 acts on the movable conductor 60, the movable conductor 60 contacts at least 1 of the pair of projections 75, and the projections 75 are formed in the pair. Therefore, in the circuit breaker 1, the friction torque between the movable element holder 7 and the movable conductor 60 can be reduced as compared with the case where the protruding portion 75 is not disposed in the partition plate 72 and the movable conductor 60 is in contact with the flat portion 74 of the partition plate 72. Further, the contact portion of the movable conductor 60 to the partition plate 72 is defined as the convex portion 75, so that the fluctuation of the friction torque can be reduced. Thus, the circuit breaker 1 can prevent an increase in reaction force due to friction when closing the short circuit, and stabilize the contact between the movable contact 11a and the fixed contact 10, thereby stably closing the short circuit.

In the circuit breaker 1, the movable conductor 60 is restrained from moving in the left-right direction shown in fig. 5 by the projection 75, and thus the range in which the movable conductor 60 is displaced by the lorentz force acting on the movable conductor 60 can be reduced. Therefore, in a state where a large current flows between the movable contact 11a and the fixed contact 10, the range in which the movable contact 11a can be displaced in the left-right direction shown in fig. 5 while sliding on the fixed contact 10 is reduced, and thus, the contact between the movable contact 11a and the fixed contact 10 can be stabilized.

Next, the structure of the movable element holder 7 will be described in more detail. Fig. 7 is a front view of the movable element holder according to embodiment 1, and fig. 8 is a front view of the movable element holder according to embodiment 1 in a state where a plurality of movable conductors are held.

The movable element holder 7 shown in fig. 7 includes a plurality of receiving portions 71, a plurality of partition plates 72, and a support portion 73 that supports the plurality of partition plates 72 and is rotatably supported by the holder shaft 12. Each partition plate 72 has a

flat portion

74 and 1 or more convex portions 75. At the projection 75, there is a projection 75₁And a projection 75₂. The adjacent 2 partition plates 72 have a pair of projections 75 opposed in the left-right direction in fig. 7₁And a pair of projections 75 opposed in the left-right direction in fig. 7₂。

As shown in fig. 8, when the movable element holder 7 is attached with the plurality of movable conductors 60 via the movable element pins 13, the pair of projections 75 are provided₁And a pair of projections 75₂The movable conductor 60 is disposed therebetween. Due to the fact thatIn this way, in the circuit breaker 1 according to embodiment 1, the range of displacement of the plurality of movable conductors 60 in the left-right direction in fig. 8 can be reduced as compared with the case where the projection 75 is not provided. Thus, in the circuit breaker 1, since the contact between the movable contact 11a and the fixed contact 10 can be stabilized while preventing an increase in the reaction force due to friction when closing the short circuit, the short circuit can be closed stably.

In addition, as shown in fig. 8, a pair of projections 75₁A pair of projections 75 are disposed at positions closer to the movable element pin 13 than one end of the movable conductor 60 in the extending direction of the movable conductor 60, that is, in the vertical direction in fig. 8₂The movable conductor 60 is disposed at a position closer to the movable pin 13 than the other end portion in the vertical direction in fig. 8. Thus, with a pair of projections 75₁And a pair of projections 75₂In the case where the movable element pin 13 is disposed at a position closer to the end of the movable conductor 60 in the vertical direction in fig. 8, the frictional torque between the movable element holder 7 and the movable conductor 60 can be reduced, and the contact between the movable contact 11a and the fixed contact 10 can be further stabilized.

In the example shown in fig. 8, a pair of projections 75₁In the vertical direction in fig. 8, the movable conductor 60 is in contact with the lower side of the movable contact 11 a. In addition, a pair of projections 75₂Spaced from the movable member pin 13 by a pair of projections 75₁The distance from the mover pin 13 is equal to or less than this. Thus, as compared to the pair of projections 75₁In the case where the movable contact 11a is arranged above the vertical direction in fig. 8, the frictional torque between the movable holder 7 and the plurality of movable conductors 60 can be reduced, and the contact between the movable contact 11a and the fixed contacts 10 can be further stabilized.

Fig. 9 is a diagram showing an example of the shape of the projection according to embodiment 1. The partition plate 72 shown in fig. 9 is a partition plate that is continuous with the support section 73 in the vertical direction in fig. 9, among the plurality of partition plates 72.

As shown in fig. 9, the projection 75₁And a projection 75₂Extending in a direction orthogonal to the extending direction of the mover pin 13Having extended regions opposite to each other. The extending region may be a linearly extending region or an arcuately extending region centered on the movable element pin 13.

In the above example, the movable element holder 7 has the projection 75 on the movable element holder 7₁And a projection 75₂But may be without the projection 75₂The structure of (1). In this case, the projection 75₁For example, the movable element pin 13 is formed to have an annular region surrounding the movable element. Fig. 10 is a diagram showing another example of the shape of the projection according to embodiment 1, and fig. 11 is a diagram showing another example of the shape of the projection according to embodiment 1. The partition plate 72 shown in fig. 10 and 11 is a partition plate that is continuous with the support portion 73 in the vertical direction in fig. 10 and 11, among the plurality of partition plates 72.

In the example shown in fig. 10, the projection 75₁The ring shape surrounds the mover pin 13 inserted through the through hole 76 formed in the partition plate 72. The annular region surrounding the mover pin 13 inserted through the through hole 76 is formed at the edge of the through hole 76 through which the mover pin 13 is inserted, but may be formed around the edge of the through hole 76. In addition, in the example shown in fig. 11, the convex portion 75₁The through-hole 76 is formed in a shape including an annular region surrounding the through-hole and an extended region extending in the left direction in fig. 11 from the annular region.

As described above, the circuit breaker 1 according to embodiment 1 includes: a movable element 6 including a plurality of movable conductors 60; and a movable element holder 7 that rotatably holds the plurality of movable conductors 60 arranged in parallel via a movable element pin 13. The movable element holder 7 includes a pair of projecting portions 75, and the pair of projecting portions 75 are disposed around the movable element pin 13 and project toward both side surfaces 601 and 602 of each of the plurality of movable conductors 60 in the extending direction of the movable element pin 13. The pair of projections 75 is an example of a pair of holder projections. This stabilizes the contact between the movable contact 11 and the fixed contact 10 during the closing operation of the circuit breaker 1.

The movable element holder 7 has a plurality of partition plates 72, and the plurality of partition plates 72 are arranged in the extending direction of the movable element pin 13 to form a plurality of receiving portions 71 for receiving corresponding ones of the plurality of movable conductors 60. The pair of projections 75 project from the adjacent pair of partition plates 72 among the plurality of partition plates 72 in the extending direction of the movable piece pin 13. Thus, in the circuit breaker 1, the pair of projections 75 can be easily formed on the movable element holder 7.

In addition, the movable element holder 7 has a plurality of pairs of projections 75 for each of the plurality of movable conductors 60₁、75₂. A plurality of a pair of projections 75₁、75₂Are formed at positions facing each other across the movable pin 13 in a direction orthogonal to the extending direction of the movable pin 13. This makes it possible to stabilize the contact between the movable contact 11 and the fixed contact 10 during the closing operation of the circuit breaker 1.

In addition, a plurality of a pair of projections 75₁、75₂Extending in a direction orthogonal to the extending direction of the mover pin 13 when viewed from the extending direction of the mover pin 13, have extending regions opposed to each other. This makes it possible to stabilize the contact between the movable contact 11 and the fixed contact 10 during the closing operation of the circuit breaker 1.

In addition, each of the pair of projections 75 has an annular region that surrounds the periphery of the mover pin 13 when viewed from the extending direction of the mover pin 13. This makes it possible to stabilize the contact between the movable contact 11 and the fixed contact 10 during the closing operation of the circuit breaker 1.

Embodiment 2.

The circuit breaker according to embodiment 2 is different from the circuit breaker 1 according to embodiment 1 in that a plurality of protection covers are further provided, each of which covers a different one of the plurality of movable conductors 60 and forms a protruding portion protruding toward an adjacent protection cover. Hereinafter, the same reference numerals are used to designate components having the same functions as those of embodiment 1, and the description thereof will be omitted, and the differences from the breaker 1 of embodiment 1 will be mainly described.

Fig. 12 is a front view of the movable element holder according to embodiment 2 in a state where a plurality of movable conductors are held. As shown in fig. 12, the circuit breaker according to embodiment 2 is different from the circuit breaker 1 according to embodiment 1 in that it includes a movable element 6, a movable element holder 7, and

protective covers

9A, 9B, and 9C that cover 3 movable conductors 60 out of 5 movable conductors 60 constituting the movable element 6. Hereinafter, the

protective covers

9A, 9B, and 9C may be referred to as the protective cover 9 when they are not individually shown.

Fig. 13 is a diagram showing an example of a plurality of protective covers in a state in which corresponding movable conductors among a plurality of movable conductors according to embodiment 2 are attached to each other. As shown in fig. 13, the protective cover 9A includes a 1 st side wall 91A, a 2 nd side wall 92A, and a coupling portion 93A that couples the 1 st side wall 91A and the 2 nd side wall 92A.

The projecting

portions

94, 95 projecting in the left direction in fig. 12 are provided at the 1 st side wall 91A, and the projecting

portions

94, 95 projecting in the right direction in fig. 12 are provided at the 2 nd side wall 92A. In the example shown in fig. 12, the top surfaces of the projecting

portions

94 and 95 are flat surfaces having a square shape, but may have other shapes.

The protective cover 9B includes a 1 st side wall 91B, a 2 nd side wall 92B, and a connecting portion 93B connecting the 1 st side wall 91B and the 2 nd side wall 92B. The 1 st side wall 91B is provided with the projecting

portions

94, 95 projecting in the left direction in fig. 12, but the 2 nd side wall 92B is not provided with the projecting

portions

94, 95, but is formed in a flat shape.

The protective cover 9C has a 1 st side wall 91C, a 2 nd side wall 92C, and a connecting portion 93C connecting the 1 st side wall 91C and the 2 nd side wall 92C. The projecting

portions

94, 95 are not provided at the 1 st side wall 91C, but formed in a flat shape, but projecting

portions

94, 95 projecting in the right direction in fig. 12 are provided at the 2 nd side wall 92C.

In the up-down direction in fig. 12, the projecting portion 94 and the projecting portion 95 are formed at positions sandwiching the movable piece pin 13. The protrusion 94 and the protrusion 75 provided on the partition plate 72₁The projection 95 is formed at a position farther from the movable piece pin 13 than the projection 75 provided to the partition plate 72₂As compared to a position away from the movable piece pin 13.

As shown in fig. 12, the projecting

portions

94, 95 of the 1 st side wall 91A in the shield case 9A are opposed to the 2 nd side wall 92B of the shield case 9B, and the projecting

portions

94, 95 of the 2 nd side wall 92A in the shield case 9A are opposed to the 1 st side wall 91C of the shield case 9C. In addition, the projecting

portions

94, 95 of the 1 st side wall 91B in the protection cover 9B are opposed to the movable conductor 60 of the protection cover 9B opposed to the 1 st side wall 91B. In addition, the projecting

portions

94, 95 of the 2 nd side wall 92C in the protection cover 9C are opposed to the movable conductor 60 of the protection cover 9C opposed to the 2 nd side wall 92C.

If a lorentz force acts on the plurality of movable conductors 60 shown in fig. 12, the adjacent boots 9 contact each other or the adjacent boots 9 and movable conductors 60, and the boots 9 contact the projections 75 of the movable element holder 7, so that the frictional torque generated in the movable conductors 60 is dispersed. Since the displacements of the protective cover 9 and the movable conductor 60 in the depth direction in fig. 12 are the same, the friction torques generated at the projecting

portions

94 and 95 of the

protective covers

9A, 9B, and 9C cancel each other out, and therefore the friction torques generated at the projecting

portions

94 and 95 of the

protective covers

9A, 9B, and 9C are considerably smaller than the friction torque generated at the projecting portion 75. Therefore, the circuit breaker described in embodiment 2 can further suppress an increase in the reaction force due to the friction torque when closing the short circuit, compared to the circuit breaker 1 described in embodiment 1, and can stabilize the contact between the fixed contacts 10 and the movable contacts 11 a. The depth direction in fig. 12 is the left-right direction in fig. 2.

Further, since the range of displacement of the movable conductor 60 in the left-right direction in fig. 2 can be further reduced by the projecting

portions

94 and 95 of the protective cover 9, the contact between the fixed contact 10 and the movable contact 11a can be further stabilized when a large current flows during the closing operation for closing the short circuit.

Fig. 14 is a diagram showing another example of a plurality of protection covers in a state where corresponding movable conductors among a plurality of movable conductors according to embodiment 2 are mounted. In the protective cover 9A shown in fig. 14, a projecting portion 94 projecting in the left direction in fig. 12 is provided at the 1 st side wall 91A, and a projecting portion 94 projecting in the right direction in fig. 12 is provided at the 2 nd side wall 92A.

The projection 94 is provided on the 1 st side wall 91B of the protective cover 9B and the 2 nd side wall 92C of the protective cover 9C, but the projection 94 is not provided on the 2 nd side wall 92B of the protective cover 9B and the 1 st side wall 91C of the protective cover 9C, and is formed in a flat shape. The projecting portion 94 shown in fig. 14 is cylindrical, and the top surface of the projecting portion 94 is an annular flat surface. The projecting portion 94 is disposed at a position surrounding the through hole 61 of the movable conductor 60 through which the movable element pin 13 is inserted, when viewed in the left-right direction of fig. 12.

In the above example, the

projections

94 and 95 or the projection 94 are provided on the protective cover 9, but the

projections

94 and 95 may be provided on the movable conductor 60 without providing the protective cover 9. In this case, if a lorentz force acts on the plurality of movable conductors 60, the movable conductors 60 come into contact with each other, and therefore the frictional torques of the movable conductors 60 cancel each other out. Therefore, the reaction force generated by the friction torque when closing the short circuit can be reduced, and the short circuit can be closed stably. In the circuit breaker according to embodiment 2, the protection cover 9 and the movable conductor 60 may be provided with the

projections

94 and 95, respectively.

As described above, the circuit breaker according to embodiment 2 includes the plurality of protection covers 9, and the plurality of protection covers 9 cover the movable conductors 60 different from each other among the plurality of movable conductors 60. Each of the plurality of boots 9 has a projecting

portion

94, 95 projecting in the extending direction of the movable piece pin 13 so as to be opposed to the adjacent boot 9 or the movable conductor 60.

Projections

94, 95 are one example of a plurality of cover projections. The plurality of

projections

94, 95 are disposed around the movable piece pin 13. Thus, the circuit breaker according to embodiment 2 can prevent an increase in reaction force due to friction torque when closing the short circuit, and can stably close the short circuit.

In addition, the

projections

94, 95 are formed on the pair of projections 75₁、75₂Further away from the position of the movable member pin 13. As a result, the circuit breaker according to embodiment 2 can avoid the end portions of the plurality of movable conductors 60 from contacting each other with higher accuracy, and can stabilize the contact between the movable contacts 11 and the fixed contacts 10 during the closing operation.

At least a part of the plurality of movable conductors 60 has a movable conductor projecting portion which projects in the extending direction of the mover pin 13 and faces the adjacent movable conductor 60. This allows the circuit breaker 1 to avoid the end portions of the plurality of movable conductors 60 from coming into contact with each other with higher accuracy, and to stabilize the contact between the movable contacts 11 and the fixed contacts 10 during the closing operation.

For example, by adjusting the positions and heights of the projecting

portions

94 and 95 of the protection covers 9A, 9B, and 9C, the shapes of the protection covers 9 are made the same, and the same effect can be expected even when the protection covers 9 are attached to at least 2 movable conductors 60 and at most all of the movable conductors 60. Further, the number of types of shapes of the protective cover 9 is reduced, so that the number of components can be reduced, and the cost can be reduced.

The configurations described in the above embodiments are merely examples, and may be combined with other known techniques, or the embodiments may be combined with each other, and a part of the configurations may be omitted or modified without departing from the scope of the invention.

Description of the reference numerals

1 circuit breaker, 2 frame, 3 power source side terminal, 4 load side terminal, 5 flexible conductor, 6 movable piece, 7 movable piece holder, 8 pressure contact spring, 9A, 9B, 9C protective cover, 10 fixed contact, 11a movable contact, 12 holder shaft, 13 movable piece pin, 20 electromagnetic actuator, 21 excitation coil, 25 shaft, 30 transmission mechanism, 31 connecting link, 32 main shaft, 33 link, 34, 35, 38 connecting pin, 36 rotation shaft, 39 separation spring, 40 trip mechanism, 45 drive circuit, 60 movable conductor, 61, 76 through hole, 71 containing part, 72 division plate, 73 supporting part, 74 flat part, 75₁、75₂The

convex portions

94 and 95, the 1

st side walls

91A, 91B and 91C, the 2

nd side walls

92A, 92B and 92C, and the

connection portions

93A, 93B and 93C, the side surfaces 601 and 602.

Claims

1. A circuit breaker, comprising:

a movable member including a plurality of movable conductors; and

a movable element holder for rotatably holding the plurality of movable conductors in a parallel arrangement via a movable element pin,

the movable element holder has a pair of holder projections which are arranged around the movable element pin and project toward both side surfaces of each of the plurality of movable conductors in an extending direction of the movable element pin.

2. The circuit breaker of claim 1,

the movable element holder has a plurality of partition plates arranged in an extending direction of the movable element pin to form a plurality of receiving portions for receiving the respective movable conductors among the plurality of movable conductors,

the pair of holder projections project from an adjacent pair of the plurality of partition plates in an extending direction of the movable piece pin.

3. The circuit breaker according to claim 1 or 2,

the movable element holder has a plurality of the pair of holder projections with respect to the plurality of movable conductors,

the pair of holder projections are formed at positions facing each other with the movable pin therebetween in a direction orthogonal to an extending direction of the movable pin.

4. The circuit breaker of claim 3,

the pair of holder projections have extension regions that extend in a direction orthogonal to the extending direction of the movable pin when viewed from the extending direction of the movable pin and face each other with the movable pin interposed therebetween.

5. The circuit breaker according to claim 1 or 2,

the pair of holder projections each have an annular region that surrounds the periphery of the movable element pin when viewed from the extending direction of the movable element pin.

6. The circuit breaker according to any of claims 3 to 5,

has a plurality of protective covers for covering mutually different movable conductors among the plurality of movable conductors,

each of the plurality of protective covers has a cover projecting portion projecting in an extending direction of the movable pin so as to oppose an adjacent protective cover or the movable conductor,

the cover projection is disposed around the movable piece pin.

7. The circuit breaker of claim 6,

the cover projection is formed at a position farther from the movable piece pin than the pair of holder projections.

8. The circuit breaker according to any of claims 3 to 5,

at least a part of the plurality of movable conductors has a movable conductor projecting portion that projects in the extending direction of the movable pin and faces an adjacent movable conductor.