CN111226301B - Circuit breaker - Google Patents

Abstract

A circuit breaker (1) is provided with: a transmission mechanism (30) which moves the movable element (6) in accordance with the movement of the plunger (23) of the electromagnetic solenoid (20) and changes the breaker (1) from an open state to a closed state; and a trip mechanism (50). The plunger (23) reaches the 1 st position where the movement of the plunger (23) is restricted, before a toggle mechanism composed of a rod (32) of the transmission mechanism (30) and an insulating rod (33) comes to a dead center. The trip mechanism (50) is engaged with the transmission mechanism (30) to maintain a closing state in a state that the plunger (23) retreats after reaching the 1 st position and is located at the 2 nd position.

Description

Circuit breaker

Technical Field

The present invention relates to a structure of a circuit breaker in which a movable contact is brought into contact with a fixed contact or separated from the fixed contact.

Background

Conventionally, as a circuit breaker using an electromagnetic solenoid as a closing mechanism, a circuit breaker of a type in which a current is applied to the electromagnetic solenoid after closing is completed to hold a closed state has been mainly developed. However, in a circuit breaker in which current is applied to an electromagnetic solenoid even in a closed state, there are problems such as difficulty in energy saving and deterioration of a closing coil that constitutes the electromagnetic solenoid due to continuous current flow in the closing coil.

Therefore, in the circuit breaker described in patent document 1, a circuit breaker has been developed in which a closed state is held by a trip mechanism after completion of closing, and the trip mechanism is operated to open the circuit breaker and release the closed state at the time of breaking.

Patent document 1: japanese laid-open patent publication No. 6-84433

Disclosure of Invention

However, the circuit breaker described in patent document 1 includes many components constituting a link mechanism that operates when the circuit breaker is opened. Therefore, a large number of components operate in a correlated manner to show a complicated behavior, and the components may be damaged or the mechanical characteristics may change over time due to the continuous use for a long period of time, thereby degrading the reliability of the circuit breaker.

In addition, the circuit breaker described in patent document 1 has a characteristic that the mechanical load rises obliquely rightward from the breaking state to the closing state, and the mechanical load in the closing state is the largest. Therefore, it is necessary to arrange a plurality of links to increase the reduction gear ratio, alleviate the trip load, and

a complicated mechanism for increasing the reduction ratio needs to be accommodated in a limited arrangement region, and the assembling property is also deteriorated.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a circuit breaker capable of reducing a load on a trip mechanism and achieving a reduction in size and an improvement in assemblability of the trip mechanism.

In order to solve the above problems and achieve the object, a circuit breaker according to the present invention includes: a frame body; a fixed terminal to which a fixed contact is attached and which is fixed to the housing; a movable element holder rotatably coupled to the frame about a 1 st axis fixed to the frame; a movable element rotatably coupled to the movable element holder and having a movable contact mounted thereon; a pressure contact spring that applies pressure to the fixed contact and the movable contact when the fixed contact and the movable contact are in contact; an electromagnetic solenoid having a plunger that moves linearly; a transmission mechanism for moving the movable element with the movement of the plunger so as to change from a disconnected state in which the movable contact is separated from the fixed contact to a closed state in which the movable contact is in contact with the fixed contact and is energized; and a trip mechanism which is engaged with the transmission mechanism to maintain the closing state, and releases the engagement with the transmission mechanism to release the maintenance of the closing state. The transmission mechanism includes: a rod which rotates around a 2 nd axis fixed to the frame body in accordance with the movement of the plunger; and an insulating rod having one end rotatably coupled to one end of the rod and the other end rotatably coupled to the movable element. The plunger of the electromagnetic solenoid reaches the 1 st position where the movement of the plunger is restricted before a toggle mechanism constituted by a rod and an insulating rod becomes a dead point. The trip mechanism is engaged with the transmission mechanism to maintain a closing state in a state where the plunger retreats after reaching a 1 st position and is located at a 2 nd position.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the load on the trip mechanism can be reduced, and the size reduction and the assembly of the trip mechanism can be improved.

Drawings

Fig. 1 is a sectional view showing a configuration example of a circuit breaker according to embodiment 1.

Fig. 2 is an enlarged view of the trip mechanism shown in fig. 1.

Fig. 3 is a configuration diagram showing a circuit breaking state of the circuit breaker according to embodiment 1.

Fig. 4 is an enlarged view of the trip mechanism shown in fig. 3.

Fig. 5 is a configuration diagram showing a state at the moment of contact start of the circuit breaker according to embodiment 1.

Fig. 6 is an enlarged view of the trip mechanism shown in fig. 5.

Fig. 7 is a configuration diagram showing a state in which the circuit breaker according to embodiment 1 reaches the maximum closing position.

Fig. 8 is an enlarged view of the trip mechanism shown in fig. 7.

Fig. 9 is an enlarged view of the trip mechanism after the trip lever is rotated from the state shown in fig. 7.

Fig. 10 is a configuration diagram showing a state in which the circuit breaker according to embodiment 1 reaches a closing completion position.

Fig. 11 is an enlarged view of the trip mechanism shown in fig. 10.

Fig. 12 is a diagram showing a relationship between a movement position of a core plunger and a load applied to an electromagnetic solenoid according to embodiment 1.

Fig. 13 is a configuration diagram showing a broken state of the circuit breaker according to embodiment 2.

Fig. 14 is an enlarged view of the trip mechanism shown in fig. 13.

Fig. 15 is a configuration diagram showing a state of the trip mechanism in a state at the moment when the contacts of the circuit breaker according to embodiment 2 start to make contact.

Fig. 16 is a configuration diagram showing a state of a trip mechanism in a case where the circuit breaker according to embodiment 2 reaches the maximum closing position.

Fig. 17 is a configuration diagram showing a state of a trip mechanism in a case where the circuit breaker according to embodiment 2 reaches the maximum closing position.

Fig. 18 is a configuration diagram showing a state of a trip mechanism in a case where the circuit breaker according to embodiment 2 reaches a closing completion position.

Detailed Description

Hereinafter, a circuit breaker according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the present embodiment.

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. For convenience of explanation, the Z-axis positive direction is set to the upper side, the Z-axis negative direction is set to the lower side, the X-axis positive direction is set to the right side, the X-axis negative direction is set to the left side, the Y-axis positive direction is set to the front side, and the Y-axis negative direction is set to the rear side. In the following, clockwise and counterclockwise indicate clockwise and counterclockwise in the drawings described later.

Fig. 1 is a diagram showing a configuration example of a circuit breaker according to embodiment 1 of the present invention. 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 which are respectively attached to the housing 2 by penetrating the wall portion 2a of the housing 2; and a flexible conductor 5 having one end 5a 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 6a connected to the other end 5b of the flexible conductor 5; a movable element holder 7 having one end 7a 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 7b of the movable element holder 7 and the other end 6b 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. The power source side terminal 3 is electrically connected to the fixed contact 10 inside the housing 2, and the other end 6b of the movable element 6 is electrically connected to the movable contact 11. The power source side terminal 3 and the load side terminal 4 are fixed separately from each other. In the example shown in fig. 1, the power supply side terminal 3 is disposed above the load side terminal 4, but the load side terminal 4 may be disposed above the power supply side terminal 3.

The flexible conductor 5 is a flexible conductor, and has one end 5a connected to the load side terminal 4 and the other end 5b connected to the movable element 6. The load side terminal 4 and the movable element 6 are electrically connected by the flexible conductor 5. As described above, the movable contact 11 is electrically connected to the movable element 6, and the movable contact 11 is brought into contact with the fixed contact 10, whereby the circuit breaker 1 is brought into a closed state in which the power source side terminal 3 and the load side terminal 4 are electrically connected and energized. The movable contact 11 is separated from the fixed contact 10, and the circuit breaker 1 is thereby brought into a disconnecting state in which the power source side terminal 3 and the load side terminal 4 are electrically disconnected.

One end portion 7a of the movable element holder 7 is rotatably attached to the housing 2 via a holder shaft 12 around a holder axial center 12 a. Further, the middle portion 7c of the mover holder 7 is rotatably attached to the one end portion 6a of the mover 6 by a coupling pin 13. A movable element stopper 9 is provided in the movable element holder 7.

The movable element stopper 9 restricts the angle of rotation of the movable element 6 with respect to the movable element holder 7 around the connecting pin 13. In the state shown in fig. 1, the one end 6a of the movable element 6 abuts on the movable element stopper 9. Therefore, the rotation of the other end portion 6b of the movable element 6 in the direction separating from the other end portion 7b of the movable element holder 7 is restricted by the movable element stopper 9, but the other end portion 6b of the movable element 6 can rotate in the direction approaching the other end portion 7b of the movable element holder 7.

The pressure contact spring 8 is a spring for pressure contacting the movable contact 11 to the fixed contact 10. In the state shown in fig. 1, the pressure contact spring 8 is shorter than the natural length and is in an energy storage state, and has a predetermined initial contact pressure in advance. Therefore, when the other end portion 6b of the movable element 6 is rotated in the direction approaching the other end portion 7b of the movable element holder 7, the distance between the other end portion 6b of the movable element 6 and the other end portion 7b of the movable element holder 7 becomes smaller, and the pressure contact spring 8 further accumulates energy.

Further, the circuit breaker 1 includes: an electromagnetic solenoid 20 disposed inside the housing 2 as a closing actuator of the circuit breaker 1; a transmission mechanism 30 for transmitting the driving force of the electromagnetic solenoid 20 to the movable element 6 to bring and separate the movable contact 11 into and from the fixed contact 10; an opening spring (40) having one end and the other end attached to the transmission mechanism 30 and the frame 2; and a trip mechanism 50 that maintains the closed state and releases the closed state.

The electromagnetic solenoid 20 has: a yoke 21 formed of a magnet; a closing coil 22 wound around a Bobbin (Bobbin), not shown, and fixed to the inside of the yoke 21; a core plunger 23 that is linearly reciprocated in the vertical direction; and a projection 24 formed on an upper portion of the core plunger 23. At least one of the electromagnetic solenoid 20 and the housing 2 is provided with a guide portion, not shown, for guiding the moving direction of the core plunger 23 in the vertical direction, and the core plunger 23 can be displaced only in the vertical direction by the guide portion. Further, the core plunger 23 and the projection 24 may be fixed, and the fixing method of the core plunger 23 and the projection 24 is not limited.

By energization of the closing coil 22, an electromagnetic attraction force is generated in the electromagnetic solenoid 20. The generation of the electromagnetic attraction force causes the core plunger 23 to move upward, and when the gap 25 between the core plunger 23 and the inside of the closing coil 22 disappears, the movement of the core plunger 23 is restricted and the core plunger 23 physically stops. As described above, the position at which the core plunger 23 is stopped is the position at which the core plunger 23 is positioned at the uppermost position, and is hereinafter referred to as the maximum on position or the maximum movement position. The structure for stopping the core plunger 23 is not limited to the above example. For example, a protrusion may be provided at a lower portion of the core plunger 23 to engage with the yoke 21 or the bobbin of the closing coil 22, thereby physically stopping the core plunger 23.

After a predetermined time has elapsed since the position of the core plunger 23 reached the maximum closing position, the electromagnetic solenoid 20 stops the generation of the electromagnetic attraction force due to the energization to the closing coil 22 being stopped. The electromagnetic attraction force of the electromagnetic solenoid 20 disappears, and the plunger 23 is urged downward from the maximum closing position by, for example, the own weight of the plunger 23 and the opening force of the opening spring 40.

The transmission mechanism 30 includes: a coupling link 31 having one end 31a rotatably coupled to the projection 24 of the electromagnetic solenoid 20; a lever 32 rotatably coupled to the other end 31b of the coupling link 31; and an insulating rod 33 rotatably coupled to one end portion 32a of the rod 32.

One end 31a of the connecting link 31 is rotatably connected to the boss 24 of the electromagnetic solenoid 20 by a connecting pin 34, and the other end 31b of the connecting link 31 is rotatably connected to the rod 32 by a connecting pin 35.

The lever 32 is rotatably attached to a lever shaft 37 about a lever shaft center 36 fixed in absolute position to the housing 2. The lever 32 is coupled to the other end 31b of the coupling link 31 via a coupling pin 35 in a region closer to the trip mechanism 50 than the lever shaft 37. The transmission mechanism 30 of the circuit breaker 1 includes an engagement pin 51, and the engagement pin 51 is fixed to the other end 32b of the lever 32.

One end 33a of the insulating rod 33 is rotatably coupled to one end 32a of the rod 32 by a coupling pin 38, and the other end 33b is rotatably attached to one end 6a of the movable element 6 by a coupling pin 13. The insulating rod 33 is made of a material having high electrical insulation, such as resin. Therefore, when the circuit breaker 1 is in the energized state, the current flowing between the power source side terminal 3 and the load side terminal 4 does not leak through the rod 32. The insulating rod 33 does not need to be entirely made of an insulating material, and may be partially made of a conductor as long as it is in an insulating state between the coupling pin 13 and the coupling pin 38.

The rod 32 and the insulating rod 33 constitute a toggle link mechanism in a 4-link having a rod axis 36 and a holder axis 12a as fixed rotation centers. Therefore, the transmission mechanism 30 can be driven with a smaller force as it approaches the dead point where the lever axial center 36, the coupling pin 38, and the coupling pin 13 are linearly arranged. The projection 24, the connecting link 31, the rod 32, the insulating rod 33, the movable element 6, and the movable element holder 7 constitute a link structure.

As described above, the opening spring 40 has one end and the other end attached to the rod 32 and the housing 2, and the transmission mechanism 30 is biased in a direction of being displaced toward the open-state position described later by the elastic restoring force of the opening spring 40.

As described above, the trip mechanism 50 has a function of maintaining the closed state and releasing the closed state. Fig. 2 is an enlarged view of the trip mechanism shown in fig. 1. In fig. 2, the housing 2 of the circuit breaker 1 is indicated by a broken line.

As shown in fig. 2, the trip mechanism 50 has: a trip lever 52 that engages with an engagement pin 51 fixed to the other end 32b of the lever 32; and a 1 st return spring 53 having one end and the other end attached to the trip lever 52 and the frame 2. Further, the trip mechanism 50 includes: a trip bar 54 rotated by a driving force of an actuator not shown; and a 2 nd return spring 55 having one end and the other end attached to the trip bar 54 and the housing 2.

The engagement pin 51 projects from the lever 32 to the right orthogonal to the extending direction of the lever 32. The trip lever 52 has an arc portion 56 having an arc surface, which is in contact with the engagement pin 51 during closing, formed at one end portion 52a, and is attached so that the other end portion 52b is rotatable around a trip lever shaft center 60 fixed to the frame body 2. Further, a recess 52c recessed rearward is formed in the middle of the trip lever 52. An engagement surface 57 that engages with the engagement pin 51 in the closed state is formed in the recess 52 c. An engagement portion 59 that engages with the trip bar 54 is provided in a front region of the other end portion 52b of the trip lever 52.

The one end 54a of the trip bar 54 is rotatably attached to the housing 2 about a trip bar axis 61, and has a semicircular portion 58 about the trip bar axis 61. The semicircular portion 58 is formed of a circular arc portion 58a having a circular arc surface and a flat portion 58b having a flat surface.

The semicircular portion 58 is rotated about the trip bar axial center 61 by a driving force of an actuator not shown, and the arc portion 58a of the semicircular portion 58 is engaged with the engagement portion 59 formed at the one end portion 52a of the trip lever 52, whereby the rotation of the other end portion 52b of the trip lever 52 in the forward direction is restricted.

The 2 nd return spring 55 biases the trip bar 54 in a direction in which the other end portion 54b of the trip bar 54 facing upward rotates in a forward direction about the trip bar axial center 61. That is, the 2 nd return spring 55 biases the trip bar 54 clockwise.

The operation of the breaker 1 configured as described above will be specifically described. Fig. 3 is a configuration diagram showing a circuit breaking state of the circuit breaker according to embodiment 1, and fig. 4 is an enlarged view of the trip mechanism shown in fig. 3. Fig. 5 is a configuration diagram showing a state at the moment when contact of the contacts of the circuit breaker according to embodiment 1 starts, and fig. 6 is an enlarged view of the trip mechanism shown in fig. 5. Fig. 7 is a configuration diagram showing a state where the circuit breaker according to embodiment 1 reaches the maximum closing position, fig. 8 is an enlarged view of the trip mechanism shown in fig. 7, and fig. 9 is an enlarged view showing the trip mechanism after the trip lever is rotated from the state shown in fig. 7. Fig. 10 is a configuration diagram illustrating a state in which the circuit breaker according to embodiment 1 reaches a closing completion position, and fig. 11 is an enlarged view of the trip mechanism shown in fig. 10. In fig. 3 to 11, the housing 2 is indicated by a broken line.

As shown in fig. 3, when the circuit breaker 1 is in the open state, the core plunger 23 constituting the electromagnetic solenoid 20 reaches the lowermost portion by the opening spring 40 and physically contacts the housing 2, and cannot be further lowered downward. At this time, the size of the gap 25 becomes maximum.

When the core plunger 23 is positioned at the lowermost portion, the other end portion 32b of the rod 32 is positioned below the one end portion 32a and is positioned to face the one end portion 52a of the trip lever 52 in the left-right direction. Further, the one end portion 52a of the trip lever 52 is given a rearward tension by the elastic restoring force of the 1 st return spring 53. Therefore, the engagement pin 51 attached to the other end portion 32b of the lever 32 is in a state of being in contact with the arc portion 56 formed at the one end portion 52a of the trip lever 52.

When the circuit breaker 1 is in the disconnecting state, the rotation of the movable element 6 in the direction in which the other end portion 6b of the movable element 6 is separated from the other end portion 7b of the movable element holder 7, that is, the clockwise rotation of the movable element 6 is restricted by the movable element stopper 9 of the movable element holder 7. Since the pressure contact spring 8 has a predetermined initial contact pressure as described above, the one end portion 6a of the movable element 6 is not separated from the movable element stopper 9 as long as the pressing reaction force from the fixed contact 10 to the movable contact 11 does not exceed the initial contact pressure.

As shown in fig. 3, when the circuit breaker 1 is in the open state, the physical shortest distance between the movable contact 11 and the fixed contact 10 of the movable element 6, that is, the separation distance, is maximized. In the state shown in fig. 3, as shown in fig. 4, the flat portion 58b of the semicircular portion 58 of the trip bar 54 contacts the corner portion of the engaging portion 59 formed at the one end portion 52a of the trip lever 52 by the elastic restoring force generated by the 2 nd return spring 55 trying to rotate the trip bar 54 clockwise. Therefore, the rotation of the trip lever 52 is restricted, and the state shown in fig. 4 is maintained.

Further, the one end portion 52a of the trip lever 52 is brought into contact with the engagement pin 51 of the lever 32 at the arc portion 56 by the elastic restoring force of the 1 st return spring 53 which attempts to rotate the trip lever 52 clockwise so that the one end portion 52a of the trip lever 52 faces rearward. This restricts clockwise rotation of the trip lever 52, and the state shown in fig. 4 is maintained.

When the circuit breaker 1 is in the open state, if the closing coil 22 of the electromagnetic solenoid 20 is energized, the plunger 23 moves upward as shown in fig. 5. By the upward movement of the core plunger 23, the rod 32 rotates about the rod axis 36, and the connection angle between the rod 32 and the insulating rod 33 decreases. The connection angle is an angle formed by the extending direction of the rod 32 and the extending direction of the insulating rod 33, and the connection angle of the circuit breaker 1 decreases as it changes from the state shown in fig. 3 to the state shown in fig. 5.

As the connection angle decreases, the movable element 6 moves forward, and the fixed contacts 10 and the movable contacts 11 come into contact with each other. The state at the moment when movable contact 11 and fixed contact 10 start to contact is the contact start state. At this time, the power source side terminal 3 and the load side terminal 4 are in a current-carrying state via the fixed contact 10, the movable contact 11, and the flexible conductor 5.

As shown in fig. 4 and 6, the engagement pin 51 attached to the tip end of the lever 32 that is rotatable about the lever axis 36 slides on the arc portion 56 formed on the other end 52b of the trip lever 52 as the connection angle decreases, while maintaining contact with the trip lever 52 to which the elastic restoring force is applied by the 2 nd return spring 55.

The arc portion 56 of the trip lever 52 is formed of an arc centered on the lever axis 36 of the lever 32. Therefore, even if the engagement pin 51 moves during the period from the state shown in fig. 4 to the state shown in fig. 6, the position of the trip lever 52 does not change.

When the circuit breaker 1 reaches the contact start state, the clockwise rotation of the mover 6 is restricted by the mover stopper 9 provided in the mover holder 7, but the counterclockwise rotation is enabled. If the core plunger 23 further advances from the contact start state shown in fig. 6, the contact reaction force from the fixed contact 10 increases with respect to the movable contact 11 attached to the other end portion 6b of the movable element 6, and therefore the other end portion 6b of the movable element 6 rotates counterclockwise about the coupling pin 13 and approaches the other end portion 7b of the movable element holder 7. Therefore, the pressure contact spring 8 further stores energy from the state shown in fig. 5.

As shown in fig. 7, if the position of the core plunger 23 becomes the maximum on position by the upward movement of the core plunger 23, the angle of rotation of the movable element 6 with respect to the movable element holder 7 becomes maximum due to the contact reaction force from the fixed contact 10 against the movable contact 11, and the energy stored in the pressure contact spring 8 also becomes maximum.

Further, if the position of the core plunger 23 is the maximum on position, as shown in fig. 8, the engagement pin 51 sliding on the arc portion 56 of the trip lever 52 passes through the arc portion 56 of the trip lever 52 and reaches the upper portion of the engagement surface 57 of the trip lever 52. Therefore, the engagement pin 51 and the release lever 52 are in a non-contact state instantaneously.

The release lever 52 whose clockwise rotation is restricted by the engagement pin 51 releases the restriction of the clockwise rotation if the relationship with the engagement pin 51 is changed to a non-contact state. Therefore, as shown in fig. 9, the concave portion 52c of the trip lever 52 rotates clockwise by the elastic restoring force of the 1 st return spring 53, and comes into contact with the engagement pin 51. The engagement pin 51 contacts the concave portion 52c of the trip lever 52, and thereby the clockwise rotation of the trip lever 52 is restricted.

Further, if the engaging pin 51 reaches the upper portion of the engaging surface 57 of the trip lever 52 and the trip lever 52 rotates, the trip rod 54 whose clockwise rotation is restricted by the trip lever 52 rotates clockwise by the elastic restoring force of the 2 nd return spring 55, and the arc portion 58a of the semicircular portion 58 is wound above the engaging portion 59 and stopped as shown in fig. 8 and 9. The circuit breaker 1 is provided with a stopper, not shown, that restricts rotation of the trip bar 54, and rotation of the trip bar 54 is restricted in the state shown in fig. 8 and 9.

When the position of the plunger 23 reaches the maximum opening position, the energization of the electromagnetic solenoid 20 is terminated. If the energization to the electromagnetic solenoid 20 is terminated, the drive to the transmission mechanism 30 by the electromagnetic solenoid 20 is released.

Therefore, the reaction force generated by the stored energy of the pressure contact spring 8 acts between the fixed contact 10 and the movable contact 11, and a force trying to push back the core plunger 23 of the electromagnetic solenoid 20 in a direction moving from the maximum on position to the off-state position is generated via the transmission mechanism 30. Further, due to the own weight of the core plunger 23 and the opening force of the opening spring 40, a force in a direction to move the core plunger 23 from the maximum opening position to the open state position is simultaneously applied. Thereby, the core plunger 23 starts to move downward from the maximum closing position shown in fig. 7.

When the core plunger 23 moves downward from the maximum switching position, the lever 32 rotates counterclockwise about the lever axis 36. When the lever 32 rotates counterclockwise, the engagement pin 51 rotates counterclockwise about the lever axis 36, and as shown in fig. 10 and 11, comes into contact with the engagement surface 57 of the trip lever 52, and reaches the closing completion position of the core plunger 23, thereby completing the closing operation of the circuit breaker 1.

When the trip lever 52 is at the closing completion position of the core plunger 23, the arc portion 58a of the semicircular portion 58 engages with the flat portion of the engagement portion 59 formed at the one end 52a of the trip lever 52, and the rotation of the other end 52b of the trip lever 52 in the forward direction is restricted.

Therefore, although a force based on the reaction force of the pressure contact spring 8 that attempts to rotate in the counterclockwise direction with respect to the trip lever axial center 60 acts on the trip lever 52 via the engagement pin 51, the trip lever 52 does not rotate due to the rotation restriction by the arc portion 58a of the semicircular portion 58 as shown in fig. 11.

As described above, when the circuit breaker 1 is in the disconnecting state, a constant initial contact pressure is applied to the pressure contact spring 8 in advance, and the contact pressure of the movable contact 11 with respect to the fixed contact 10 is set to be increased from the moment when the movable contact 11 starts to contact with the fixed contact 10. Therefore, when the circuit breaker 1 is in the energized state, it is possible to prevent the contacts from being separated from each other due to electromagnetic repulsive force generated between the movable contact 11 and the fixed contact 10, and to increase the opening speed, which is the separation speed of the movable contact 11 and the fixed contact 10 after a trip command described later is issued.

Next, a trip operation of the circuit breaker 1 will be described. When the circuit breaker 1 is in the state of the closing completion position shown in fig. 10, if a trip command is given to the circuit breaker 1 from the outside, the trip bar 54 is driven to rotate counterclockwise by an actuator, not shown, provided in the circuit breaker 1.

By the counterclockwise rotation of the trip bar 54, the arc portion 58a of the semicircular portion 58 of the trip bar 54 is separated from the engagement portion 59 of the trip lever 52, and the engagement between the arc portion 58a and the engagement portion 59 is released. Therefore, the trip lever 52 rotates counterclockwise about the trip lever axial center 60 by the force based on the reaction force of the pressure contact spring 8, and the core plunger 23 returns to the open state position of fig. 3 through the state shown in fig. 5. Thereby, the trip of the circuit breaker 1 is completed.

Here, a relationship between the moving position of the core plunger 23 and the load amount applied to the electromagnetic solenoid 20 will be described. Fig. 12 is a diagram showing a relationship between a moving position of a core plunger and an amount of load applied to an electromagnetic solenoid according to embodiment 1. The core plunger 23 moves in a range from the position shown in fig. 3 to the maximum switching position shown in fig. 7.

Hereinafter, the upward movement of the core plunger 23 is referred to as forward movement, and the downward movement of the core plunger 23 is referred to as backward movement. The moving position of the core plunger 23 when it moves forward is referred to as the forward position, and the moving position of the core plunger 23 when it moves backward is referred to as the backward position. The load applied to the electromagnetic solenoid 20 when the core plunger 23 moves forward is referred to as forward movement load, and the load applied to the electromagnetic solenoid 20 when the core plunger 23 moves backward is referred to as backward movement load.

As shown in fig. 12, when the core plunger 23 is moved from the open state position to the open state position where it reaches the contact start position, the transmission mechanism 30 is driven in a state where the fixed contacts 10 and the movable contacts 11 are not in contact with each other. Therefore, when the forward position of the core plunger 23 is the open state position, the load applied to the electromagnetic solenoid 20 is relatively small. Then, if the forward position of the core plunger 23 is the contact abutment start position, the contact of the movable contact 11 with the fixed contacts 10 is started. Therefore, the lever 32 receives the reaction force from the pressure contact spring 8 via the connecting pins 13 and 38, and the closing load applied to the electromagnetic solenoid 20 increases rapidly as a counterclockwise load torque about the lever axis 36.

Further, if the core plunger 23 further advances, the component of the reaction force from the pressure contact spring 8 applied to the connection pin 38, which is the point of action, in the direction perpendicular to the straight line connecting the rod axis 36 and the connection pin 38 becomes rapidly smaller. Therefore, the counterclockwise load torque centered on the spindle axis 36 starts to decrease. In accordance with this reduction in load torque, the closing load of the electromagnetic solenoid 20 required to rotate the lever 32 also turns to be reduced.

In the mechanical state of the circuit breaker 1 in which the core plunger 23 further advances and the advanced position first reaches the maximum closing position after the start of the closing operation, the rod 32 and the insulating rod 33 are in a state close to a straight line, and the toggle mechanism constituted by the rod 32 and the insulating rod 33 is closest to the dead point. Therefore, the component of the reaction force from the pressure contact spring 8 applied to the connecting pin 38 in the direction perpendicular to the straight line connecting the lever axis 36 and the connecting pin 38 approaches zero, and the closing load of the electromagnetic solenoid 20 required for rotating the lever 32 also rapidly approaches zero. That is, the load force acting distance, which is the distance by which the plunger 23 of the electromagnetic solenoid 20 advances to apply the load torque to the rod 32, is configured to be small in accordance with the switching force of the electromagnetic solenoid 20, which increases by the displacement from the open-state position to the closed-state position. Therefore, not only the electromagnetic attraction force of the electromagnetic solenoid 20 can be efficiently used at the time of the closing operation of the circuit breaker 1, but also the electromagnetic solenoid 20 having a size that matches the change in the load force acting distance necessary for the closing operation of the circuit breaker 1 can be used, and the electromagnetic solenoid 20 can be reduced in size and cost. In the circuit breaker 1 according to embodiment 1, the core plunger 23 is configured to stop moving forward before the toggle mechanism described above goes over dead center, and the core plunger does not go over dead center when switching from the closed state to the open state, so that the configuration of the trip mechanism 50 can be prevented from being complicated.

In a state after contact of the breaker 1, if a contact pressure receiving a reaction force from the pressure contact spring 8 is generated by contact of the movable contact 11 and the fixed contact 10, a pressing force in the front-rear direction is generated on the rod shaft 37 via the insulating rod 33 and the rod 32. If the pressing force against the lever shaft 37 is generated, a frictional torque against the lever shaft 37 is generated, and the sliding frictional loads in the vertical direction of the electromagnetic solenoid 20 related to the components in the front-rear direction of the load transmitted to the electromagnetic solenoid 20 via the connecting link 31 are combined, and the closing load of the electromagnetic solenoid 20 is increased as an irrespective frictional force.

When the moving direction of the core plunger 23 is changed to the backward direction after the core plunger 23 reaches the maximum on position, the direction of the frictional force received by the entire transmission mechanism 30 is also changed. Therefore, the load on the trip mechanism 50 in the closed state can be reduced by the effect of reducing the trip load by the frictional force.

As described above, since the load on the trip mechanism 50 in the closed state can be reduced, the structure of the trip mechanism 50 can be simplified. Therefore, the trip mechanism 50 can be miniaturized, or the circuit breaker 1 can be miniaturized, and the reliability in terms of the durability of the trip mechanism 50 can be improved by reducing the number of components of the trip mechanism 50.

Until the movable contact 11 comes into contact with the fixed contact 10, friction force is mainly generated according to the rotation of the respective rotating portions of the connecting pins 13 and 38, the lever shaft 37, and the connecting pins 34 and 35. Therefore, until the movable contact 11 comes into contact with the fixed contact 10, the friction torque on the lever shaft 37 and the sliding friction load in the vertical direction of the electromagnetic solenoid 20 are smaller than those in a state where the contact pressure is generated by the reaction force from the pressure contact spring 8 after the movable contact 11 comes into contact with the fixed contact 10. Therefore, as shown in fig. 12, the difference between the closing loads at the forward and backward directions caused by the frictional force before the contact point makes contact is smaller than the difference between the closing loads caused by the frictional force after the contact point makes contact.

Regarding a series of closing operations and closing loads of the circuit breaker 1, a load characteristic required for closing the electromagnetic solenoid 20 in the circuit breaker 1 can be formulated. For example, by formulating load characteristics required for closing the electromagnetic solenoid 20 in each of the states of fig. 3, 5, 7, and 10, the mechanism load at the time of tripping is significantly reduced by mechanism friction, and thus the design of the circuit breaker 1 having hysteresis in the closing load characteristics of the electromagnetic solenoid 20 can be realized.

As described above, the circuit breaker 1 according to embodiment 1 includes the housing 2, the power source side terminal 3, the movable element holder 7, the movable element 6, the pressure contact spring 8, the electromagnetic solenoid 20, the transmission mechanism 30, and the trip mechanism 50. The power source side terminal 3 is an example of a fixed terminal, and is fixed to the housing 2 by attaching a fixed contact 10. The movable element holder 7 is coupled to the housing 2 so as to be rotatable around a holder axial center 12a fixed to the housing 2. The holder axial center 12a is an example of the 1 st axial center. The mover 6 is rotatably coupled to the mover holder 7, and a movable contact 11 is attached. The pressure contact spring 8 applies pressure to the fixed contact 10 and the movable contact 11 when the fixed contact 10 and the movable contact 11 are in contact. The electromagnetic solenoid 20 has a plunger 23 moving linearly. The plunger 23 is an example of a plunger. The transmission mechanism 30 moves the mover 6 in accordance with the movement of the core plunger 23, and changes from an open state in which the movable contact 11 is separated from the fixed contact 10 to a closed state in which the movable contact 11 is in contact with the fixed contact 10 and current is supplied. The trip mechanism 50 engages with the transmission mechanism 30 to maintain the closed state, and releases the engagement with the transmission mechanism 30 to release the maintenance of the closed state. The transmission mechanism 30 has a rod 32 and an insulating rod 33. The rod 32 rotates around a rod axis 36 fixed to the frame 2 in accordance with the movement of the core plunger 23. The rod shaft center 36 is an example of the 2 nd shaft center. One end 33a of the insulating rod 33 is rotatably coupled to one end 32a of the rod 32, and the other end 33b is rotatably coupled to the movable element 6. The plunger 23 of the solenoid 20 reaches a maximum moving position where the movement of the plunger 23 is restricted before a toggle mechanism constituted by a rod 32 and an insulating rod 33 comes to a dead center. Therefore, for example, by setting the maximum moving position of the plunger 23 to a position immediately before the toggle mechanism comes to a dead point, the closing load of the electromagnetic solenoid 20 required to rotate the rod 32 can be rapidly brought close to 0 by the lever effect achieved by the toggle mechanism. Therefore, the load applied to the trip mechanism 50 can be reduced in the closed state. The position immediately before the dead center is a position at which the position does not reach the dead center even if there is a manufacturing error. The maximum movement position is an example of the 1 st position. The trip mechanism 50 engages with the transmission mechanism 30 to maintain the closed state in a state where the core plunger 23 is retracted to be at the closed completion position after reaching the maximum movement position. The closing completion position is an example of the 2 nd position. Accordingly, when the moving direction of the core plunger 23 is changed to the backward direction, the direction of the frictional force received by the entire transmission mechanism 30 is also changed, and therefore, the load on the trip mechanism 50 in the closed state can be reduced by the effect of reducing the load by the frictional force, that is, the hysteresis of the closing load characteristic. Therefore, the necessity of making the trip mechanism of the circuit breaker a complicated mechanism can be reduced, and the miniaturization and the improvement of the assembling property of the trip mechanism 50 can be realized.

The circuit breaker 1 further includes an engagement pin 51 attached to the other end 32b of the lever 32. The engaging pin 51 is an example of an engaging portion. In addition, the trip mechanism 50 has a trip bar 52 and a trip bar 54. The trip lever 52 is rotatably attached to the housing 2 in a state biased in a direction toward the engagement pin 51, maintains a state of contact with the engagement pin 51 in a closing process of switching from the open state to the closed state, and engages with the engagement pin 51 in a state where the core plunger 23 is at the closing completion position to restrict rotation of the lever 32 about the lever axis 36. The trip bar 54 restricts and releases the rotation of the trip lever 52. As described above, since the trip mechanism 50 can be configured by at least 2 components including the trip bar 52 and the trip bar 54 in addition to the engaging pin 51, the size reduction and the improvement of the assembling property of the trip mechanism 50 can be achieved. Further, since the engaging pin 51 is brought into contact with the trip lever 52 from the open state to the closed state, the trip operation can be easily performed only by changing the movable amount of the trip lever 52 in the direction of separating from the engaging pin 51.

Further, the trip lever 52 has: an arc portion 56 having an arc shape centering on the lever axis 36 and movably contacting the engagement pin 51 during closing; and a concave portion 52c that engages with the engagement pin 51 in a closed state. Accordingly, since the position of the trip lever 52 does not change during closing, it is possible to suppress a variation in the closing load of the electromagnetic solenoid 20 that drives the transmission mechanism 30 due to the trip lever 52 during closing.

The trip lever 52 has a semicircular portion 58, and the semicircular portion 58 has a circular arc portion 58a and a flat portion 58b, and rotates around a trip rod axis 61 fixed to the housing 2. The trip bar hub 61 is an example of the 3 rd hub. The trip lever 52 is restricted from rotating by contacting the flat portion 58b of the semicircular portion 58 in the open state, and restricted from rotating by contacting the arc portion 58a of the semicircular portion 58 in the closed state. Thus, the amount of movement of the release lever 52 in the direction of separation from the engagement pin 51 can be easily adjusted simply by rotating the release lever 52.

Embodiment 2.

Embodiment 2 is different from embodiment 1 in that a trip latch and a 3 rd return spring are additionally provided between a trip lever and a trip bar in a trip mechanism. 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. 13 is a configuration diagram showing a breaking state of the circuit breaker according to embodiment 2, fig. 14 is an enlarged view of the trip mechanism shown in fig. 13, and fig. 15 is a configuration diagram showing a state of the trip mechanism in a state at a contact start instant of the circuit breaker according to embodiment 2. Fig. 16 and 17 are structural diagrams showing a state of the trip mechanism in a state where the circuit breaker according to embodiment 2 reaches the maximum closing position, and fig. 18 is a structural diagram showing a state of the trip mechanism in a state where the circuit breaker according to embodiment 2 reaches the closing completion position. In fig. 13 to 18, the housing 2 is indicated by a broken line.

As shown in fig. 13, a circuit breaker 1A according to embodiment 2 includes a housing 2, a power supply side terminal 3, a load side terminal 4, a flexible conductor 5, a mover 6, a mover holder 7, a pressure contact spring 8, an electromagnetic solenoid 20, a transmission mechanism 30, a trip spring 40, and a trip mechanism 70.

As shown in fig. 14, the trip mechanism 70 includes: a trip lever 71 that engages with an engagement pin 51 fixed to the other end 32b of the lever 32; and a 1 st return spring 72 having one end and the other end attached to the trip lever 71 and the frame 2. In addition, the trip mechanism 70 includes: a trip bar 73 rotated by a driving force of an actuator not shown; and a 2 nd return spring 74 having one end and the other end attached to the trip rod 73 and the housing 2. The trip mechanism 70 includes: a trip latch 75 provided between the trip bar 71 and the trip bar 73; and a 3 rd return spring 76 having one end and the other end attached to the trip latch 75 and the housing 2.

The trip lever 71 is rotatably attached to the housing 2 about a trip lever axis 80, and an arc portion 77 that comes into contact with the engagement pin 51 during closing is formed at one end portion 71a of the trip lever 71. The other end 71b of the trip lever 71 projects forward and faces the trip latch 75. A recess 71c recessed rearward is formed in the middle of the trip lever 71. An engagement surface 79 with which the engagement pin 51 engages is formed in the recess 71 c. The 1 st return spring 72 biases the trip lever 71 counterclockwise about the trip lever axial center 80.

The trip bar 73 is attached to the housing 2 such that one end 73a is rotatable about a trip bar axis 81, and the trip bar 73 has a semicircular portion 78 having a semicircular shape about the trip bar axis 81. The 2 nd return spring 74 biases the other end 73b of the trip bar 73 clockwise about the trip bar shaft center 81. The trip bar 73 is rotated about a trip bar shaft center 81 by a driving force of an actuator not shown.

The release latch 75 is formed in an L shape in side view, and a central portion 75c is rotatably attached to the housing 2 around a release latch axis 82. The 3 rd return spring 76 biases the trip latch 75 counterclockwise about the trip latch axis 82.

The state of the circuit breaker 1A shown in fig. 14 is a broken state. In the disconnection state shown in fig. 14, the trip lever 71 is biased counterclockwise by the elastic restoring force of the 1 st return spring 72. Therefore, the state in which the arc portion 77 formed in front of the one end portion 71a of the trip lever 71 is in contact with the engagement pin 51 is maintained.

The trip latch 75 is biased counterclockwise by the elastic restoring force of the 3 rd return spring 76, and one end portion 75a of the trip latch 75 contacts the other end portion 71b of the trip lever 71. The trip bar 73 is biased by the elastic restoring force of the 2 nd return spring 74, and the other end portion 75b of the trip latch 75 contacts the flat portion 78b of the semicircular portion 78 of the trip bar 73. Therefore, the trip lever 71 is biased counterclockwise by the 2 nd return spring 74 and the 3 rd return spring 76 in addition to the 1 st return spring 72.

Next, a state at the moment when contact of the breaker 1A starts will be described. The state of the circuit breaker 1A shown in fig. 15 is a state at the moment of contact start. In the state shown in fig. 15, the arc portion 77 formed in the trip lever 71 is shaped, and only the engagement pin 51 rotates about the lever axis 36 from the state shown in fig. 14, but the positional relationship among the trip lever 71, the trip bar 73, and the trip latch 75 constituting the trip mechanism 70 does not change. Here, as the shape characteristic of the arc portion 77, an arc centered on the shaft axis 36 and the shape of the arc portion 77 of the trip lever 71 are concentric, but may not be an arc.

Next, a state in which the breaker 1A reaches the maximum on position will be described. In the state shown in fig. 16, the engagement pin 51 is located above the arc portion 77 of the trip lever 71, and the contact state between the arc portion 77 of the trip lever 71 and the engagement pin 51 is completed, so that the trip lever 71 and the engagement pin 51 are instantaneously in a non-contact state. Since the trip lever 71 is biased counterclockwise, it instantaneously comes into a non-contact state with the engagement pin 51, and then rotates counterclockwise to come into contact with the engagement pin 51 again.

If the trip lever 71 is rotated counterclockwise from the state shown in fig. 16, the other end 71b of the trip lever 71 moves rearward. Therefore, the one end portion 75a of the trip latch 75 that is in contact with the other end portion 71b of the trip lever 71 moves rearward, and the trip latch 75 rotates counterclockwise about the trip latch shaft center 82. The trip latch 75 is biased counterclockwise by the elastic restoring force of the 3 rd return spring 76, and thus a state in which one end portion 75a of the trip latch 75 is in contact with the other end portion 71b of the trip lever 71 is maintained.

By the counterclockwise rotation of the trip latch 75, the other end portion 75b of the trip latch 75 moves in a direction separating from the semicircular portion 78 formed in the trip bar 73 as shown in fig. 17, and thus the contact state with the flat portion 78b of the semicircular portion 78 in the trip bar 73 is released. Therefore, as shown in fig. 17, the trip bar 73 is rotated clockwise by the elastic restoring force of the 2 nd return spring 74, and the arc portion 78a of the semicircular portion 78 formed in the trip bar 73 is positioned to face the other end portion 75b of the trip latch 75 and is engaged with the other end portion 75 b.

Next, a change from a state in which the breaker 1A reaches the maximum closing position to a state in which the breaker reaches the closing completion position will be described. When the energization of the electromagnetic solenoid 20 is terminated after the plunger 23 reaches the maximum closing position, the driving of the transmission mechanism 30 by the electromagnetic solenoid 20 is released and the pressing of the movable contact 11 against the fixed contact 10 is released. Therefore, similarly to the case of the circuit breaker 1, the reaction force of the pressure contact spring 8 acts between the fixed contact 10 and the movable contact 11, and the core plunger 23 starts to move downward from the maximum closing position shown in fig. 17.

When the core plunger 23 moves downward from the maximum switching position, the engagement pin 51 moves counterclockwise about the lever axis 36 in accordance with the counterclockwise rotation of the lever 32 about the lever axis 36. Therefore, as shown in fig. 18, the engagement pin 51 engages with the engagement surface 79 formed in the concave portion 71c of the trip lever 71, and reaches the closing completion position of the breaker 1A, and the closing operation of the breaker 1A is completed. In the above example, the engagement pin 51 has been described as an example of the engagement portion with the trip lever 52, but the engagement portion with the trip lever 52 is not limited to the engagement pin 51, and may be in any shape that can engage with the trip lever 52.

As described above, the arc portion 78a of the semicircular portion 78 of the trip bar 73 engages with the other end portion 75b of the trip latch 75 when the maximum closing position is reached, and restricts the clockwise rotation of the trip latch 75.

Therefore, although a force based on the reaction force of the pressure contact spring 8 that attempts to rotate counterclockwise with respect to the trip lever axial center 80 acts on the trip lever 71 via the engagement pin 51, the rotation of the trip lever 71 is restricted by the trip latch 75 whose counterclockwise rotation is restricted by the arc portion 78a of the semicircular portion 78, as shown in fig. 18.

Next, a trip operation of the circuit breaker 1A will be described. When the circuit breaker 1A is in the state of the closing completion position shown in fig. 18, if a trip command is given to the circuit breaker 1A from the outside, the trip bar 73 is driven to rotate counterclockwise by an actuator, not shown, provided to the circuit breaker 1A.

By the counterclockwise rotation of the trip bar 73, the contact position of the circular arc portion 78a of the semicircular portion 78 of the trip bar 73 to the trip latch 75 is changed from the circular arc portion 78a of the semicircular portion 78 to the flat portion 78b, and the trip latch 75 can be rotated clockwise. Therefore, the trip lever 71 is rotated clockwise about the trip lever axial center 80 by the force based on the reaction force of the pressure contact spring 8, and the operation is performed in reverse to the operation of the trip mechanism 70 from the trip state to the maximum closing state, and the trip state shown in fig. 13 and 14 is returned. Thereby, the trip of the circuit breaker 1A is completed.

As described above, the trip mechanism 70 of the circuit breaker 1A according to embodiment 2 includes the trip lever 71, the trip bar 73, and the trip latch 75. The trip lever 71 is rotatably attached to the housing 2 in a state biased in a direction toward the engagement pin 51, maintains a state of contact with the engagement pin 51 in a closing process of switching from the open state to the closed state, and engages with the engagement pin 51 in the closed state to restrict rotation of the lever 32 about the lever axis 36. The middle portion of the trip latch 75 is rotatably supported by the housing 2, and one end portion 75a contacts the trip lever 71. The trip bar 73 has a semicircular portion 78, and the semicircular portion 78 has a circular arc portion 78a and a flat portion 78b and rotates around a trip latch shaft center 82 fixed to the housing 2. The trip latch hub 82 is an example of a 3 rd hub. The other end 75b of the trip latch 75 is restricted from rotating by contacting the flat portion 78b of the semicircular portion 78 in the open state, and restricted from rotating by contacting the arc portion 78a of the semicircular portion 78 in the closed state. Thus, the trip mechanism 70 can easily adjust the amount of movement of the trip lever 71 in the direction of separating from the engagement pin 51 by simply rotating the trip bar 73.

In the circuit breakers 1 and 1A, the rotation direction of the lever 32 from the open-state position to the maximum closing position is not limited to the counterclockwise direction about the lever axis 36. The circuit breakers 1 and 1A may be configured to rotate clockwise by adding an appropriate link member between the coupling link 31 and the lever 32.

The circuit breakers 1 and 1A may not be configured such that the engagement pin 51 slides in the arc portions 56 and 77 of the trip levers 52 and 71 around the lever axis 36 of the lever 32. That is, in the circuit breakers 1 and 1A, the shapes of the sliding portions of the trip levers 52 and 71 and the engagement pin 51 may not be circular arc shapes.

Further, the circuit breakers 1 and 1A stop the rotation of the trip levers 52 and 71 by the contact of the trip levers 52 and 71 with the engagement pins 51, but may be configured to stop by providing a rotation stopper dedicated to the trip levers 52 and 71.

In addition, in embodiments 1 and 2 described above, the trip bars 54 and 73 are operated by an actuator not shown so as to rotate counterclockwise, but the trip bars 54 and 73 may be operated so as to rotate counterclockwise by a link not shown or manually.

In embodiments 1 and 2 described above, the load side terminals 4 and the movable contacts 11 are electrically connected by the flexible conductors 5, but the load side terminals 4 and the movable contacts 11 may not be connected by the flexible conductors 5. For example, the movable element 6, the coupling pin 13, and the movable element holder 7 may be conductors, and the load side terminal 4 and the holder shaft center 12a may be electrically connected by a slip ring or a conductive brush.

The opening spring 40 may be formed by 2 or more springs, and the pressure contact spring 8 may be formed by 2 or more springs with respect to the mover 6.

The circuit breakers 1 and 1A are configured such that the toggle mechanism including the rod 32 and the insulating rod 33 does not reach the dead point, but the configuration is not limited thereto. The circuit breakers 1 and 1A may be configured as a mechanism that can trip even when the toggle mechanism reaches or passes a dead point when the forward position of the core plunger 23 reaches the maximum closing position, and for example, by adding a structure in which the lever axis 36 and the holder axis 12a are movable rotation centers, the closing mechanism is configured without changing the basic performance of the circuit breakers 1 and 1A.

In the circuit breakers 1 and 1A, the core plunger 23 is displaceable only in the vertical direction, but the moving direction of the core plunger 23 is not limited to the vertical direction, and may be an oblique direction, and the moving direction may be changed in the middle.

The configuration described in the above embodiment is an example of the content of the present invention, and may be combined with other known techniques, and a part of the configuration may be omitted or modified without departing from the scope of the present invention.

Description of the reference symbols

1. 1A breaker, 2 frame, 2a wall, 3 power source side terminal, 4 load side terminal, 5 flexible conductor, 5a, 6a, 7a, 31A, 32a, 52a, 54a, 71A, 72a, 73a, 75a end, 5b, 6b, 7b, 31b, 32b, 52b, 54b, 71b, 72b, 73b, 75b other end, 6 movable piece, 7 movable piece holder, 7c, 72c middle part, 8 press spring, 9 movable piece stopper, 10 fixed contact, 11 movable contact, 12 holder shaft, 12a holder shaft center, 13, 34, 35, 38 connecting pin, 20 electromagnetic solenoid, 21 yoke, 22 closing coil, 23 core plunger, 24 protrusion, 25 gap, 30 transmission mechanism, 31 connecting link, 32 rod, 33 insulating rod, 36 rod shaft center, 37, 38b flat part, 40 opening spring, 50. the trip mechanism 70, the trip pin 51, the trip rod 52, 71, the concave part 52c, 71c, the 1 st return spring 53, 72, the trip rod 54, 73, the 2 nd return spring 55, 74, the arc part 56, 77, the trip surface 57, 79, the arc part 58, 78 semicircle part, the arc part 58a, 78a, the flat part 58b, 78b, the trip part 59, the axis of the trip rod 60, 80, the axis of the trip rod 61, 81, the trip latch 75, the center part 75c, the reset spring 76 3, the trip latch axis 82.

Claims (5)

1. A circuit breaker, characterized by having:

a frame body;

a fixed terminal to which a fixed contact is attached and which is fixed to the housing;

a movable element holder rotatably coupled to the housing around a 1 st axis fixed to the housing;

a movable element rotatably coupled to the movable element holder and having a movable contact mounted thereon;

a pressure contact spring that applies pressure to the fixed contact and the movable contact when the fixed contact and the movable contact are in contact;

an electromagnetic solenoid having a plunger that moves linearly;

a transmission mechanism that moves the movable element in accordance with movement of the plunger so as to change from an open state in which the movable contact is separated from the fixed contact to a closed state in which the movable contact is in contact with the fixed contact and current is applied to the movable contact; and

a trip mechanism which engages with the transmission mechanism to maintain the closed state and releases the engagement with the transmission mechanism to release the maintenance of the closed state,

the transmission mechanism includes:

a rod that rotates around a 2 nd axis fixed to the frame in accordance with the movement of the plunger;

An insulating rod having one end rotatably coupled to one end of the rod and the other end rotatably coupled to the movable element,

the plunger reaches a 1 st position where movement of the plunger is restricted before a toggle mechanism constituted by the rod and the insulating rod comes to a dead center,

the trip mechanism is engaged with the transmission mechanism to maintain the closed state in a state where the plunger retreats to a 2 nd position after reaching the 1 st position,

as the transmission mechanism, even when the plunger is at the same position, a load on the trip mechanism due to the frictional force is reduced by a change in the direction of the frictional force in the case of the backward movement as compared with the case of the forward movement.

2. The circuit breaker of claim 1,

has an engaging portion attached to the other end of the rod,

the trip mechanism has:

a trip lever rotatably attached to the housing in a state of being biased in a direction toward the engagement portion, maintaining a state of being in contact with the engagement portion in a closing process of switching from the open state to the closed state, and engaging with the engagement portion in a state where the plunger is at the 2 nd position to restrict rotation of the lever about the 2 nd axis; and

And a trip bar that restricts rotation of the trip lever and releases the restriction on the rotation of the trip lever.

3. The circuit breaker of claim 2,

the trip bar has:

an arc portion having an arc shape centered on the 2 nd axis and movably contacting the engaging portion in the closing process; and

and a recess portion that engages with the engagement portion in the closed state.

4. The circuit breaker of claim 3,

the trip bar has a semicircular part which is formed with an arc part and a flat part and rotates around a 3 rd axis fixed on the frame body,

the trip lever is restricted from rotating by contacting the flat portion of the semicircular portion in the open state, and restricted from rotating by contacting the arc portion of the semicircular portion in the closed state.

5. The circuit breaker of claim 3,

the trip mechanism has a trip latch which is rotatably supported at a middle portion thereof by the frame and has one end portion thereof in contact with the trip lever,

the trip bar has a semicircular part which is formed with an arc part and a flat part and rotates around a 3 rd axis fixed on the frame body,

The other end of the trip latch is in contact with the flat portion of the semicircular portion in the open state to be restricted from rotating, and in contact with the arc portion of the semicircular portion in the closed state to be restricted from rotating.

Images