JPH10255639A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the assembling work by tripping a circuit breaker when the detected voltage becomes the reference voltage or below, releasing the engagement with a crossbar, and moving an actuator to the reset position with a reset lever via the energizing force of a lever spring. SOLUTION: When the detected voltage is lowered to the reference voltage or below, the electromagnetic force of an electromagnet 21 is decreased, and the attracting force attracting a plunger 22 to an anvil 21b is weakened. The attracting force becomes smaller than the energizing force of a plunger spring 23, and the plunger 22 is dissociated from the anvil 21b. An actuator 25 is interlocking moved in the direction of an arrow K by the energizing force of the plunger spring 23, a trip bar 40 is rotated CCW to the position shown by a solid line from the position shown by a chain line, and the opening/closing mechanism section of a circuit breaker is operated to trip the circuit breaker.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker with an undervoltage trip device that cuts off an electric circuit when a detection voltage falls below a reference voltage, for example.

[0002]

2. Description of the Related Art FIG.
It is a partial side sectional view showing the conventional circuit breaker with the undervoltage trip device shown in Japanese Patent Publication No. 54-54. In the figure, 1
Denotes an electromagnet, which includes a yoke 1a, an anvil 1b, and a coil 1.
c, a plunger guide 1d, and a bobbin 1e. Reference numeral 2 denotes a mounting base for fixing the undervoltage trip device to a groove (not shown) of the circuit breaker main body housing. A fixing screw 3 fixes the electromagnet 1 to the mounting base 2.

A plunger 4 is movably inserted into the center of the electromagnet 1 so as to face the anvil 1b. Reference numeral 5 denotes a latch, on one end of which is formed an iron piece 5a which engages with the plunger 4, and on the other end, a roller 7 rotatably supported by a roller pin 6 is provided.
The shaft is pivotally supported by the plunger guide 1d. Reference numeral 9 denotes a latch spring, which biases the latch 5 in the direction of arrow A in which the plunger 4 is attracted to the anvil 1b via the iron piece 5a.

[0004] Reference numeral 10 denotes a lever, which is interlocked with an engaging arm 11 having an engaging surface 11a and a locking end surface 11b which are in releasable contact with the roller 7, and an overcurrent trip device (not shown) of the circuit breaker. It is formed by an actuator 13 which can be engaged with a trip bar 12 which is movable. Reference numeral 14 denotes a lever pin for pivotally supporting the lever 10, and reference numeral 15 denotes a lever spring. The urging force is stronger than the latch spring 9, and urges the actuator 13 in the direction in which the trip bar 12 trips. A reset lever 16 is supported by a reset lever pin 17 and has a leg 16a that can be engaged with the trip bar 12. Reference numeral 18 denotes a U pin that connects the lever 10 and the reset lever 16.

A conventional circuit breaker with an undervoltage trip device is configured as described above. When a detection voltage is applied to the coil 1c of the electromagnet 1, the plunger 4 moves in the direction of arrow A as shown in FIG. The iron piece 5a of the latch 5 engaged with the plunger 4 rotates counterclockwise, and the roller 7 supported on one end of the latch 5 by the roller pin 6 engages the engaging surface of the lever 10. 11a, the actuator 13 of the lever 10 is connected to the lever spring 1
5 is held against the urging force. That is, the actuator 13 is held at the reset position where it does not engage with the trip bar 12 of the circuit breaker body.

FIG. 16 is a partial side sectional view showing a state in which a conventional undervoltage trip device is incorporated in a circuit breaker, and shows a state in which a detection voltage applied to a coil of an electromagnet is lower than a reference voltage. . In this state, when the detection voltage applied to the coil 1c falls below the reference voltage and the attraction force of the plunger 4 decreases, the lever 10 rotates the iron piece 5a clockwise by the urging force of the lever spring 15, The plunger 4 is separated from the anvil 1b and moves in the direction of arrow B. At this time, the roller 7 supported on one end of the latch 5 by the roller pin 6 moves from the engagement surface 11a of the lever 10 to the locking end surface 11b in the direction of arrow C and engages.
The actuator 13 rotates counterclockwise about the lever pin 14 to move the trip bar 12 in the direction of arrow D, and trips the circuit breaker.

FIG. 17 is a side sectional view showing a state in which the conventional undervoltage trip device is incorporated in a circuit breaker, and shows a state in which the circuit breaker has tripped. When the breaker trips, the trip bar 12 moves in the direction of arrow E from the position of the dashed line to abut the leg 16a of the reset lever 16 and pushes the reset lever 16, so that the reset lever 16 moves the reset lever pin 17 Since the lever 10 is turned in the direction of arrow F as a fulcrum and the lever 10 is turned clockwise through the U pin 18, the actuator 13
Is disengaged. At the same time, since the lever 10 also rotates in the direction of arrow G, the roller 7
Move in the direction of the engagement surface 11a from the
Pushes the plunger 4 in the direction of arrow H by the urging force of the latch spring 9, and the plunger 4 automatically returns to a position where it can be sucked (that is, a reset position).

[0008]

In the conventional undervoltage trip device as described above, as shown in FIG. 18, when the undervoltage trip device is incorporated in the breaker body in the direction of the arrow,
Since the detection voltage is not applied to the undervoltage trip device, the plunger 4 is not attracted to the anvil 1b, and thus the leg 16a of the reset lever 16 projects.

When the main body of the circuit breaker is in the trip state, the trip bar 12 is at the trip position shown by the solid line.
The leg 16a hits the trip bar 12 and cannot be assembled. When the breaker body is off, the trip bar 1
2 is located at the position shown by the one-dot chain line.
The actuator 13 and the reset lever 16 need to be manually held and assembled to a reset position where the actuator 13 and the reset lever 16 do not hit the trip bar 12, and there has been a problem that the assembling workability is poor.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and there is no need to assemble the undervoltage release device while holding the actuator and the reset lever by hand so that the reset position is at the reset position. ,
An object of the present invention is to provide a circuit breaker with an undervoltage trip device that can easily perform an assembling operation.

[0011]

A circuit breaker according to the present invention is a circuit breaker provided with an undervoltage trip device for cutting off a circuit when a detection voltage falls below a reference voltage.
When a detection voltage exceeding the reference voltage is applied to the electromagnet at the reset position and the electromagnet to which the detection voltage is applied, the electromagnet is attracted. When the detection voltage falls below the reference voltage, it is released and can be moved by the plunger spring. A plunger, an actuator interlocked with the plunger, a trip bar that moves and engages the actuator by the biasing force of the plunger spring to trip the circuit breaker, and biases the plunger in a resetting direction. A reset spring for moving the plunger to a reset position by a biasing force of the lever spring.
A crossbar that engages with the reset lever and is linked to the movable contact of the circuit breaker. When the circuit breaker is on and the detection voltage exceeds the reference voltage, the reset lever engages with the crossbar. And is held in the operable position,
When the detected voltage falls below the reference voltage, the circuit breaker is tripped, the engagement with the crossbar is released, and the reset lever moves the actuator to the reset position by the biasing force of the lever spring.

Further, the circuit breaker according to the present invention has a cam interlocked with the opening / closing mechanism, and one end is connected to the cam when the detected voltage is lower than the reference voltage and the circuit breaker is reset from the trip state to the off state. And the other end is engaged with the reset lever, and the reset operation of the cam rotates to move the reset lever, and the movement of the reset lever causes the actuator linked to the plunger to move the trip bar to the trip position. With a lever.

Further, in the circuit breaker according to the present invention, the intermediate lever of the undervoltage trip device is configured to be detachable.

Still further, the circuit breaker of the present invention includes a cam which is interlocked with the opening / closing mechanism, and a switch which is engaged with the cam and outputs an electric signal when the circuit breaker trips. .

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a partial sectional side view showing an undervoltage trip device according to Embodiment 1 of the present invention, and shows a state where a detection voltage is not applied to a coil of an electromagnet. FIG.
FIG. 3 is a partial side sectional view showing a state in which the undervoltage trip device is incorporated in the circuit breaker main body, and shows a state in which a voltage exceeding a reference voltage is applied to the coil of the electromagnet with the circuit breaker turned on. FIG. 3 is a partial side sectional view showing a state in which the undervoltage trip device is incorporated in the circuit breaker main body, and a state in which the detection voltage applied to the coil of the electromagnet is lower than the reference voltage when the circuit breaker is on. Is shown. FIG. 4 is a partial side sectional view showing a state where the undervoltage trip device is incorporated in the breaker body, and shows a state where the breaker has tripped or is in an off state.
FIG. 5 is a diagram showing a process of incorporating the undervoltage trip device into the circuit breaker.

In FIG. 1, reference numeral 20 denotes an undervoltage trip device. Reference numeral 21 denotes an electromagnet, which includes a coil 21a, an anvil 21b, a yoke 21c, a plunger guide 21d,
It is constituted by a bobbin 21e. 22 is an electromagnet 21
A plunger 23 is movably inserted into the center of the plunger 21b so as to oppose the anvil 21b. A plunger spring 23 urges the plunger 22 in a direction to release the electromagnet 21 from being attracted. A spring presser 25 of the plunger spring 23 is an actuator coupled to the plunger 22, and the tip of the actuator presses a trip bar 40 (shown in FIG. 2) of the breaker body.

Reference numeral 26 denotes a frame integrally formed with the yoke 21c. Reference numeral 27 denotes a reset lever formed of a synthetic resin material. The reset lever 27 engages with the spring retainer 24 to move the plunger 22 to the reset position, and the movable contact 41 of the circuit breaker main body (shown in FIG. 2). It has a leg portion 27b that engages with a step portion 42a of an interlocking cross bar 42 (shown in FIG. 2), and is supported on the frame 26 by a lever pin 28.

Reference numeral 29 denotes a lever spring, which has a larger urging force than the plunger spring 23, and urges the reset lever 27 in a direction for resetting the plunger 22 (a direction for attracting the anvil 21b). Reference numeral 30 denotes a mounting base, and an undervoltage trip device 20 is mounted by opening an upper cover 43b in an accessory storage space 43a (shown in FIG. 5) formed in a cover 43 (shown in FIG. 5) of the breaker body. Is what you do. Reference numeral 31 denotes a cover of the undervoltage trip device 20. 44 is a fixed contact of the circuit breaker main body,
The movable contact 41 is installed so as to be able to contact and separate from the movable contact 41 (shown in FIG. 2).

Next, the operation will be described. When the circuit breaker in FIG. 2 is in the ON state, the movable contact 41 of the circuit breaker main body is in contact with the fixed contact 44, and the circuit is closed. A detection voltage is applied to the coil 21a of the electromagnet 21, and the plunger 22 is attracted by the action of the electromagnetic force in the direction of the arrow J by the magnetic path formed by the yoke 21c and the plunger guide 21d. When the detected voltage exceeds the reference voltage, the attraction force of the plunger 22 to the anvil 21b is larger than the urging force of the plunger spring 23, and the plunger 22 is attracted to the anvil 21b. Plunger 22
Is not in contact with the trip bar 40, and the circuit breaker does not trip and remains on.

When the circuit breaker is on, the step 42a of the crossbar 42 is connected to the leg 2 of the reset lever 27.
7b, the reset lever 27 is held at the position shown in FIG. 2 against the clockwise rotational force generated by the urging force of the lever spring 29. The arm 27a of the reset lever 27 is The spacing, ie, the plunger 22 is released from the anvil 21b and the actuator 25 is
When the trip bar 40 is moved to the left, the trip bar 40 is rotated, whereby the opening / closing mechanism (not shown) of the circuit breaker operates to allow the circuit breaker to trip (in this embodiment, , This position is referred to as an “operable position”).

Referring to FIG. 3, a description will be given of a process leading to a trip operation when the detected voltage applied to the coil of the electromagnet of the undervoltage trip device 20 is lower than the reference voltage while the circuit breaker is on. When the detection voltage drops below the reference voltage, the electromagnetic force of the electromagnet 21 decreases, and the attraction force of the plunger 22 attracted to the anvil 21b weakens, and this attraction force becomes smaller than the urging force of the plunger spring 23. The plunger 22 is separated from the anvil 21b, and in conjunction with this, the actuator 25 moves in the direction of arrow K by the urging force of the plunger spring 23, and moves the trip bar 40 counterclockwise from the position shown by the dashed line in FIG. The circuit breaker is turned to the position shown by the solid line, and the opening / closing mechanism (not shown) of the circuit breaker operates to trip the circuit breaker to the position shown in FIG.

When the circuit breaker shown in FIG. 4 is in the trip state or the off state, the crossbar 42 rotates in the direction of arrow L from the on position (the position shown by the dashed line), and the movable contact 41 moves in conjunction with this. The circuit is cut off by separating from the fixed contact 44. When the crossbar 42 rotates in the direction of arrow L,
The engagement between the leg 27b of the reset lever 27 and the step 42a of the crossbar 42 is released, the reset lever 27 rotates clockwise around the lever pin 28, and the engagement arm 27a presses the spring retainer 24. While plunger 2
2 is a position where it comes into contact with the anvil 21b and can be sucked (in this embodiment, this position is referred to as a “reset position”).
Until the plunger 22 and the actuator 25 are moved in the direction of the arrow M.

In this state, the coil 21 of the electromagnet 21
If the detected voltage applied to the a exceeds the reference voltage, the plunger 22 maintains the state of being adsorbed by the anvil 21b. Once the circuit breaker is reset by moving the circuit breaker to the off state, the circuit breaker can be operated to the on state shown in FIG.

In the process of incorporating the undervoltage trip device 20 into the circuit breaker shown in FIG. 5, the circuit breaker is in a trip state or an off state. In addition, the undervoltage trip device 20
Is no voltage, and as described with reference to FIG. 1, the reset lever 27 and the actuator 25
Automatically returns to the “reset position” by the urging force of the lever spring 29 and holds that state.

The circuit breaker body is in a trip state or an off state, and the step 42a of the crossbar 42 has moved to a position where it does not engage with the leg 27b of the reset lever 27. Therefore, when the undervoltage trip device 20 is incorporated in the circuit breaker, the actuator 25 and the reset lever 2
7 can be easily assembled without hitting the trip bar 40 and the crossbar 42 without holding it by hand.

As described above, in the circuit breaker with the undervoltage trip device constructed as in the first embodiment, the reset lever 27 is actuated by the biasing force of the lever spring 29.
Is configured to automatically return and hold the actuator 25 to the reset position. Therefore, when the undervoltage trip device 20 is incorporated in the breaker body when the breaker is in the trip state or the off state, the reset lever 27 is used. Further, it is not necessary to hold the actuator 25 at the reset position by hand, and the assembling work is facilitated.

Embodiment 2 FIG. FIG. 6 is a partial sectional side view showing a state in which the undervoltage trip device according to Embodiment 2 of the present invention is incorporated in a circuit breaker main body, and shows a state in which a detection voltage is not applied to a coil of an electromagnet. FIG. 7 is a partial cross-sectional side view showing a state in which the undervoltage trip device according to Embodiment 2 of the present invention is incorporated in a circuit breaker main body, and a coil of an electromagnet of the undervoltage trip device with the circuit breaker turned on. Shows a state where a voltage exceeding the reference voltage is applied. FIG. 8 is a partial cross-sectional view showing a state in which the undervoltage trip device is incorporated in the breaker main body, in a state where the detection voltage applied to the coil of the electromagnet is lower than the reference voltage when the breaker is on. Is shown.

FIG. 9 is a partial sectional side view showing a state in which the undervoltage trip device is incorporated in the circuit breaker main body, and shows a state in which the circuit breaker has tripped. FIG. 10 is a partial cross-sectional view showing a state in which the undervoltage trip device is incorporated in the breaker body, and shows an operation when the breaker is reset from a trip state to an off state. FIG. 11 is a diagram showing a process of incorporating the undervoltage trip device according to the second embodiment of the present invention into a circuit breaker.

Generally, there are two types of undervoltage trip devices depending on the purpose of use. As described in the first embodiment, even when the detected voltage is lower than the reference voltage, the circuit breaker body can be reset from the trip state to the off state. And a type in which the reset operation is prohibited unless the detected voltage returns to the reference voltage.

In the former, for example, even if the detection voltage of the undervoltage trip device drops below the reference voltage and the circuit breaker trips, it can be turned on immediately after the detection voltage recovers to the reference voltage. It is used, for example, when configuring a circuit that causes the circuit breaker to stand by in the off state even when the detection voltage is zero. In the latter case, if the detection voltage is zero, the circuit breaker will trip if it is turned on from the off state.Therefore, if the detection voltage is zero, the circuit breaker will not be turned on. It is used when constructing a circuit that cannot perform such operations.

FIGS. 6 and 7 show an undervoltage trip device of the latter type. In FIG. 6, reference numerals 21 to 30 denote the same components as those of the undervoltage trip device according to the first embodiment, and a description thereof will be omitted. 50 is an undervoltage trip device. An intermediate lever 32 is detachably and rotatably supported on a rotating shaft 33 provided on the mounting base 30, and includes an engaging arm 32a which engages with a cam 45 (shown in FIG. 7) of the circuit breaker. An engagement projection 32b that engages with the reset lever 27 is provided. The cam 45 rotates in conjunction with the axis of a cradle (not shown) constituting an opening / closing mechanism (not shown). When the circuit breaker is in an ON state and an OFF state, as shown in FIG. It moves to the position shown by the solid line in the trip state.

Next, the operation will be described. When the voltage exceeding the reference voltage is applied to the coil 21a of the electromagnet 21 of the undervoltage trip device 20 with the circuit breaker shown in FIG. 7 turned on, the plunger 22 is driven by the anvil 21b by the action of the electromagnetic force of the electromagnet 21. And the leg 27b of the reset lever 27 is engaged with the step 42a of the cross bar 42, so that the reset lever 27 is in a position where the circuit breaker can be tripped, that is, an "operable position". Will be retained.

On the other hand, the intermediate lever 32 rotates counterclockwise around the rotation shaft 33 as a fulcrum due to the engagement between the engagement arm 32a and the cam 45. When the circuit breaker is on, the reset lever 27 and the intermediate lever 32 are rotated. There is a gap between the engaging lever 32 and the engaging projection 32b, and the engaging lever 32b does not engage. Therefore, the reset lever 27 maintains the “operable position”.

In a state in which the detection voltage applied to the coil of the electromagnet is lower than the reference voltage while the circuit breaker shown in FIG. 8 is on, if the detection voltage drops below the reference voltage, the electromagnetic force of the electromagnet 21 decreases. The plunger 22 is separated from the anvil 21b, and the actuator 25 moves in the direction of the arrow K by the urging force of the plunger spring 23,
The trip bar 40 is rotated from the position shown by the dashed line to the position shown by the solid line, and the circuit breaker is tripped.

As shown in FIG. 9, when the circuit breaker trips, similar to the operation of the device shown in FIG.
When the crossbar 42 rotates in the direction of arrow L from the ON position (the position indicated by the dashed line), the leg 2 of the reset lever 27
7b and the step 42a of the cross bar 42 are released, and the reset lever 27 rotates clockwise about the lever pin 28 as a fulcrum by the urging force of the lever spring 29,
It operates to automatically return to the “reset position”.

On the other hand, the cam 45 of the circuit breaker rotates in an arrow M direction from an ON position (a position shown by a dashed line) to a trip position (a position shown by a solid line) in conjunction with an opening / closing mechanism (not shown). Accordingly, the intermediate lever 32 also rotates clockwise about the rotation shaft 33 as a fulcrum. In this state, the intermediate lever 32
Since the engaging projection 32b of the second member escapes without pressing the reset lever 27, it does not hinder the reset lever 27 from returning to the reset position.

As shown in FIG. 10, when the circuit breaker is reset from the trip state to the off state by moving the handle (not shown), the cam 45 of the circuit breaker moves from the position indicated by the dashed line to the position indicated by the solid line. With the rotation in the N direction, the engagement arm 32a of the intermediate lever 32 engages with the cam 45 and rotates counterclockwise about the rotation shaft 33 as a fulcrum. The part 32b rotates the reset lever 27 counterclockwise about the lever pin 28 to move it to the "operable position".

In this state, if the detected voltage of the undervoltage trip device 50 is lower than the reference voltage, the plunger 22
Is not adsorbed to the anvil 21b, the spring holder 24 moves in the direction of arrow K while contacting the arm 27a by the urging force of the plunger spring 23 with the movement of the reset lever 27. Is moved from the position of the dashed line to the position of the solid line in the K direction (in the second embodiment, this position is moved to the “trip position” to operate the trip bar 40, so that the circuit breaker is reset from the trip state to the off state. Can not.

When the detected voltage exceeds the reference voltage, the plunger 22 is maintained in a state of being attracted to the anvil 21b, so that the reset operation causes the reset lever 27 to become "operable" via the cam 45 and the intermediate lever 32. Even if it moves to the "position," the actuator 25 does not move and does not perform a trip operation, so that the circuit breaker can be reset to the off state and can be operated to the on state shown in FIG.

In the process of incorporating the undervoltage trip device 50 shown in FIG. 11 into the circuit breaker, as described in FIG. 6, even if the detection voltage of the undervoltage trip device 50 is zero, the reset lever 27 and actuator 2
5 automatically returns to the reset position by the urging force of the lever spring 29 and holds that state.

On the other hand, when the main body of the circuit breaker is in the trip state, as described with reference to FIG.
Moves to a position where it does not engage with the leg 27b of the reset lever 27, and the cam 45 of the circuit breaker main body also moves to the intermediate lever 32.
Has been moved to a position where it does not operate. Therefore,
When the undervoltage trip device is incorporated in the circuit breaker, the undervoltage trip device can be easily assembled without hitting the trip bar 40 and the crossbar 42 without manually holding the actuator 25 and the reset lever 27 of the undervoltage trip device. .

According to the second embodiment, the lever spring 2
Since the reset lever 27 is configured to automatically return and hold the actuator 25 to the reset position by the urging force of No. 9, the undervoltage trip device 50 is incorporated into the main body of the breaker when the breaker is tripped. In this case, there is no need to manually hold the actuator 25 and the reset lever 27 at the reset position, and the assembling work is facilitated. When the breaker is reset from the trip state to the off state when the detection voltage is equal to or lower than the reference voltage, the intermediate lever 32 engages with the cam 45 of the breaker to move the reset lever 27, and the actuator 25 is moved to the trip position. , The circuit breaker cannot be reset from the trip state to the off state.

Embodiment 3 FIG. 12 is a partial sectional side view showing a state in which the undervoltage trip device according to Embodiment 3 of the present invention is incorporated in a circuit breaker main body, and shows a state in which a detection voltage is not applied to a coil of an electromagnet. In the figure, 6
Reference numeral 0 denotes an undervoltage trip device. In Embodiment 2, an intermediate lever 32 detachably attached to the rotation shaft 33.
To a rotating shaft 33 provided on the mounting base 30.
It is the same as that removed from.

In this state, the rotating shaft 33 is disposed at a position where the operation of the reset lever 27 is not hindered. The operation of the undervoltage trip device 60 is the same as that of the first embodiment, and the description thereof is omitted. I do. That is, even if the circuit breaker is in the trip state or the off state and the detection voltage is lower than the reference voltage, the reset lever 2 of the undervoltage trip device 60
7 and the actuator 25 are held at the “reset position”.

According to the third embodiment, the rotating shaft 33 is provided on the mounting base 30 of the circuit breaker, and the intermediate lever 32 is detachably attached to the rotating shaft 33. Therefore, the third embodiment will be described in the second embodiment. The above two types of undervoltage trip devices can be changed as necessary, and the remodeling operation can be easily performed only by attaching and detaching the intermediate lever 32.
Further, since all the components of the undervoltage trip device 60 can be shared except for the intermediate lever 32, the device can be manufactured at low cost.

Embodiment 4 13 and 14 are partial sectional side views showing a state in which an alarm switch according to Embodiment 4 of the present invention is incorporated in a circuit breaker main body. FIG. 13 is a circuit breaker ON state, and FIG. 14 is a circuit breaker. Indicates a trip state. In the figure, reference numeral 45 denotes an opening / closing mechanism of the circuit breaker main body (not shown).
This is the same as the cam that operates the undervoltage trip device described in the second embodiment shown in FIG.

Reference numeral 70 denotes an alarm switch for outputting an electric signal when the circuit breaker trips. The alarm switch 70 has substantially the same structure as a known alarm switch.
And a lever 72 for operating the microswitch 71
And a spring 73 for urging the lever 72.
It is attached to an accessory storage section 43a (shown in FIG. 11) formed on a cover 43 (shown in FIG. 11) of the circuit breaker in the same manner as the undervoltage trip device.

Next, the operation will be described. FIG. 13 shows a state in which the circuit breaker is on, and the lever 72 is engaged with the cam 45 and is separated from the microswitch 71. Further, the position of the cam 45 is the same as that of the ON state even when the circuit breaker is OFF. FIG. 14 shows a state in which the circuit breaker has tripped. When the micro switch 71 is opened, the micro switch 71 is operated by the urging force of the spring 72, and the micro switch 46a outputs an electric signal indicating that the circuit breaker has tripped.

As described above, according to the fourth embodiment, the cam 45 interlocking with the switching mechanism of the circuit breaker is shared by the cam for operating the undervoltage trip device and the cam for operating the alarm switch. Since it is configured so that it is not necessary to manufacture a dedicated breaker body for each type of internal accessory, and if you want to change the internal accessory attached to the circuit breaker to another type of accessory However, it can be easily modified simply by replacing the internal accessories.

[0049]

Since the present invention is configured as described above, it has the following effects.

According to the circuit breaker of the present invention, when the detection voltage applied to the undervoltage trip device becomes equal to or lower than the reference voltage, the reset lever automatically returns the actuator to the reset position by the urging force of the lever spring. Therefore, when the undervoltage trip device is assembled when the circuit breaker body is tripped, the reset lever and the actuator do not have to be manually held at the reset position, and the assembling work is facilitated.

According to the circuit breaker of the present invention, the reset lever automatically returns the actuator to the reset position by the urging force of the lever spring. Therefore, when the undervoltage release device is incorporated in the breaker body. In addition, it is not necessary to hold the actuator and reset lever in the reset position by hand, which facilitates the assembly work.When the detection voltage is lower than the reference voltage and the breaker is reset from the trip state to the off state, the intermediate lever is reset. Engages with the cam of the circuit breaker to move the reset lever to move the actuator to the trip position, so that the circuit breaker cannot be reset from the trip state to the off state.

According to the circuit breaker of the present invention, since the intermediate lever is made detachable, two different types of undervoltage trip devices, that is, the main body of the circuit breaker is brought out of the trip state when the detection voltage is lower than the reference voltage. The undervoltage trip device of the type that can be reset in the off state and the type that does not allow the reset operation can be easily changed or modified simply by attaching and detaching the intermediate lever. Further, since all parts except the intermediate lever can be used in common, the device can be manufactured at low cost.

Further, according to the circuit breaker of the present invention, the cam linked to the opening / closing mechanism of the circuit breaker can be shared by the cam for operating the undervoltage trip device and the cam for operating the alarm switch. Because there is no need to manufacture a dedicated breaker body for each different type of internal accessory, and even if you want to change the internal accessory attached to the circuit breaker to another type of internal accessory It can be easily remodeled simply by replacing the internal accessories.

[Brief description of the drawings]

FIG. 1 is a partial side sectional view showing an undervoltage trip device according to a first embodiment of the present invention.

FIG. 2 is a partial side sectional view showing a state in which the undervoltage trip device according to Embodiment 1 of the present invention is incorporated in a circuit breaker main body.

FIG. 3 is a partial side sectional view showing a state in which the undervoltage trip device according to Embodiment 1 of the present invention is incorporated in a circuit breaker main body.

FIG. 4 is a partial cross-sectional view showing a state in which the undervoltage trip device according to Embodiment 1 of the present invention is incorporated in a circuit breaker main body.

FIG. 5 is a diagram showing a process of assembling the undervoltage trip device according to Embodiment 1 of the present invention into the circuit breaker main body.

FIG. 6 is a partial side sectional view showing a state in which the undervoltage trip device according to Embodiment 2 of the present invention is incorporated in a circuit breaker main body.

FIG. 7 is a partial cross-sectional side view showing a state where the undervoltage trip device according to Embodiment 2 of the present invention is incorporated in a circuit breaker main body.

FIG. 8 is a partial side sectional view showing a state in which the undervoltage trip device according to Embodiment 2 of the present invention is incorporated in a circuit breaker main body.

FIG. 9 is a partial side sectional view showing a state in which the undervoltage trip device according to Embodiment 2 of the present invention is incorporated in a circuit breaker main body.

FIG. 10 is a partial side sectional view showing a state in which the undervoltage trip device according to Embodiment 2 of the present invention is incorporated in a circuit breaker main body.

FIG. 11 is a partial side sectional view showing a process of incorporating the undervoltage trip device according to Embodiment 2 of the present invention into a circuit breaker main body.

FIG. 12 is a partial side sectional view showing a state in which the undervoltage trip device according to Embodiment 3 of the present invention is incorporated in a circuit breaker main body.

FIG. 13 is a partial side sectional view showing a state where an alarm switch according to Embodiment 4 of the present invention is incorporated in a circuit breaker main body.

FIG. 14 is a partial side sectional view showing a state where an alarm switch according to Embodiment 4 of the present invention is incorporated in a circuit breaker main body.

FIG. 15 is a partial side sectional view showing a conventional circuit breaker with an undervoltage trip device.

FIG. 16 is a partial side sectional view showing a state where a conventional undervoltage trip device is incorporated in a circuit breaker.

FIG. 17 is a partial side sectional view showing a state where a conventional undervoltage trip device is incorporated in a circuit breaker.

FIG. 18 is a partial side sectional view showing a state in which a conventional undervoltage trip device is incorporated in a circuit breaker.

[Explanation of symbols]

Reference Signs List 20 undervoltage trip device, 21 electromagnet, 22 plunger, 23 plunger spring, 25 actuator, 27 reset lever, 29 lever spring, 3
2 Intermediate lever, 40 trip bar, 41 movable contact, 42 crossbar, 45 cam, 50, 60 undervoltage trip device, 70 alarm switch

Claims (4)

[Claims] 1. A circuit breaker provided with an undervoltage trip device for shutting off a circuit when a detection voltage becomes equal to or lower than a reference voltage, comprising: an electromagnet to which the detection voltage is applied; and an electromagnet when the circuit breaker is in a reset position. When a detection voltage exceeding the reference voltage is applied to the electromagnet, the plunger is attracted to the electromagnet, and is released when the detection voltage becomes equal to or lower than the reference voltage and is movable by a plunger spring. A trip bar that moves and engages the actuator by the biasing force of the plunger spring to trip the circuit breaker; a lever spring that biases the plunger in a resetting direction; and a biasing force of the lever spring. A reset lever for moving the plunger to the reset position; A crossbar that is engaged with the movable contact of the circuit breaker, and when the circuit breaker is on and the detection voltage exceeds a reference voltage, the reset lever moves the crossbar. When the detection voltage falls below the reference voltage, the circuit breaker is tripped, the engagement with the crossbar is released, and the reset lever is actuated by the biasing force of the lever spring. A circuit breaker, wherein the actuator is moved to a reset position. 2. A cam interlocked with an opening / closing mechanism of the circuit breaker, wherein one end of the cam is engaged with the cam when the detected voltage is equal to or lower than a reference voltage and the circuit breaker is reset from a trip state to an off state. The end is engaged with the reset lever, the reset lever of the cam rotates to move the reset lever, and the movement of the reset lever causes the actuator linked to the plunger to move the trip bar to the trip position. The circuit breaker according to claim 1, further comprising: 3. The circuit breaker according to claim 2, wherein the intermediate lever is detachable. 4. A circuit breaker comprising: a cam interlocked with an opening / closing mechanism of a circuit breaker; and a switch engaged with the cam and outputting an electric signal when the circuit breaker trips. vessel.