WO2020026609A1

WO2020026609A1 - Breaker

Info

Publication number: WO2020026609A1
Application number: PCT/JP2019/023705
Authority: WO
Inventors: 貢森; 祐也三ケ田; 智也出口; 隆之介今枝; 雄大相良; 遼太森岡
Original assignee: 三菱電機株式会社
Priority date: 2018-07-31
Filing date: 2019-06-14
Publication date: 2020-02-06
Also published as: CN112514018B; CN112514018A; WO2020026357A1; JPWO2020026609A1; TWI709990B; TW202018748A; JP6987253B2

Abstract

This breaker is provided with a transmission mechanism which, with movement of an electromagnetic solenoid plunger, moves a movable piece and changes the breaker from the breaking state to the closing state, and a drive circuit (70) which drives the electromagnetic solenoid. The drive circuit (70) is provided with a series body (85) comprising a diode (86) and a current reducing unit (87) which reduces the current flowing through the diode (86), and the series body (85) is connected in parallel with a coil (22) of the electromagnetic solenoid.

Description

Breaker

The present invention relates to a circuit breaker using an electromagnetic solenoid for the closing operation.

Conventionally, circuit breakers that use an electromagnetic solenoid for closing operation are known. For example, Patent Literature 1 has a link mechanism as a transmission mechanism for interlocking a plunger of an electromagnet and a movable contact, and moves the plunger by energizing a coil of the electromagnet to make the movable contact a fixed contact. A circuit breaker adapted to be closed is disclosed.

JP 2010-44927 A

A circuit breaker is required to have a function that can be shut down immediately after the closing operation starts. Therefore, in a conventional breaker that performs closing by an electromagnet, the transmission mechanism has a complicated mechanism in order to prevent the return operation of the plunger immediately after the start of the closing operation due to the inertia and residual magnetism of the plunger of the electromagnet to be delayed. Therefore, the number of components constituting the transmission mechanism increases. Since many parts work in conjunction with each other, the behavior becomes complicated, and if used for a long period of time, the parts may be damaged or the mechanical characteristics may change over time, thereby reducing the reliability of the circuit breaker. Could be done.

The present invention has been made in view of the above, and an object of the present invention is to provide a circuit breaker capable of simplifying a transmission mechanism.

解決 In order to solve the above-described problems and achieve the object, a circuit breaker of the present invention includes a housing, a fixed terminal, a mover, an electromagnetic solenoid, a transmission mechanism, and a drive circuit. The fixed terminal has a fixed contact and is fixed to the housing. The mover has a movable contact facing the fixed contact. The electromagnetic solenoid has a plunger that moves linearly. The transmission mechanism moves the mover in accordance with the movement of the plunger, and changes from a cutoff state in which the movable contact is separated from the fixed contact to a closed state in which the movable contact comes into contact with the fixed contact and is energized. The drive circuit drives the electromagnetic solenoid by energizing the coil of the electromagnetic solenoid. The drive circuit includes a series body of a diode and a current reduction unit that reduces a current flowing through the diode, and the series body is connected in parallel to a coil of the electromagnetic solenoid.

According to the present invention, there is an effect that the transmission mechanism can be simplified.

Sectional drawing which shows the example of a structure of the circuit breaker concerning Embodiment 1 of this invention. Enlarged view of the tripping mechanism shown in FIG. FIG. 2 is a diagram illustrating a configuration example of an electric circuit of a circuit breaker including a drive circuit according to the first embodiment; FIG. 3 is a diagram illustrating an example of a specific configuration of a drive circuit according to the first embodiment; FIG. 2 is a configuration diagram showing a circuit breaker according to the first embodiment in a cutoff state; Enlarged view of the tripping mechanism shown in FIG. FIG. 2 is a configuration diagram showing a state at the moment when the contact of the circuit breaker according to the first embodiment is started. Enlarged view of the tripping mechanism shown in FIG. FIG. 2 is a configuration diagram illustrating a state where the circuit breaker according to the first embodiment has reached a maximum closing position. Enlarged view of the tripping mechanism shown in FIG. Enlarged view of the tripping mechanism after the trip lever rotates from the state shown in FIG. FIG. 2 is a configuration diagram showing a state where the circuit breaker according to the first embodiment has reached the closing completion position. Enlarged view of the tripping mechanism shown in FIG. FIG. 3 is a diagram illustrating a configuration example of a current reduction unit and a control switch according to the first embodiment; FIG. 3 is a diagram illustrating a configuration example of a current reduction unit and a control switch according to the first embodiment; FIG. 3 is a diagram illustrating a configuration example of a current reduction unit and a control switch according to the first embodiment; FIG. 4 is a diagram illustrating a relationship between a movement position of an iron core plunger and a load applied to an electromagnetic solenoid according to the first embodiment. Diagram showing a configuration example of the MCR mechanism Diagram showing a configuration example of the MCR mechanism FIG. 4 is a diagram illustrating a configuration example of an electric circuit of a circuit breaker including a drive circuit according to a second embodiment of the present invention. Timing chart for explaining the MCR function of the circuit breaker according to the second embodiment

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 by the embodiment.

Embodiment 1 FIG.
The circuit breaker according to the first embodiment is an aerial circuit breaker that opens and closes an electric circuit such as a low-voltage distribution line, and detects at least one of an overcurrent and a leak to cut off the electric circuit. In the following, 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, the X-axis negative direction is set to the left, and the Y-axis positive direction is set to the front, The Y-axis negative direction is the rear. In the following, clockwise and counterclockwise mean clockwise and counterclockwise in the drawings described later.

FIG. 1 is a diagram illustrating a configuration example of the circuit breaker according to the first embodiment of the present invention. As shown in FIG. 1, a circuit breaker 1 according to a first embodiment includes a housing 2 formed of an insulating member, and a power supply side attached to the housing 2 through a wall 2 a of the housing 2. A terminal 3 and a load-side terminal 4, and a flexible conductor 5 having one end 5 a connected to the load-side terminal 4 inside the housing 2. In the circuit breaker 1, a movable element 6 having one end 6 a connected to the other end 5 b of the flexible conductor 5 and one end 7 a is rotatably attached to the housing 2 inside the housing 2. The movable member holder 7 includes a contact pressure spring 8 having one end and the other end attached to the other end 7 b of the mover holder 7 and the other end 6 b of the mover 6.

(4) 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. A fixed contact 10 is electrically connected to the power supply side terminal 3 inside the housing 2, and a movable contact 11 is electrically connected to the other end 6 b of the mover 6. The power supply terminal 3 and the load terminal 4 are fixed apart from each other. In the example illustrated in FIG. 1, the power supply terminal 3 is disposed above the load terminal 4, but the load terminal 4 may be disposed above the power supply terminal 3.

The flexible conductor 5 is a conductor having flexibility, and one end 5 a is connected to the load terminal 4 and the other end 5 b is connected to the mover 6. The load side terminal 4 and the mover 6 are electrically connected by the flexible conductor 5. As described above, the movable contact 11 is electrically connected to the mover 6, and when the movable contact 11 contacts the fixed contact 10, the circuit breaker 1 electrically connects the power supply terminal 3 and the load terminal 4 to each other. Is connected to the power-on state. When the movable contact 11 is separated from the fixed contact 10, the circuit breaker 1 enters a cutoff state in which the power supply terminal 3 and the load terminal 4 are electrically cut off.

一端 One end 7a of the mover holder 7 is attached to the housing 2 by a holder shaft 12 so as to be rotatable about a holder axis 12a. The middle part 7c of the mover holder 7 is rotatably attached to one end 6a of the mover 6 by a connecting pin 13. The mover holder 7 is provided with a mover stopper 9.

The mover stopper 9 restricts the angle at which the mover 6 rotates about the connecting pin 13 with respect to the mover holder 7. One end 6a of the mover 6 is in contact with the mover stopper 9 in the state shown in FIG. For this reason, rotation of the other end 6 b of the mover 6 in a direction away from the other end 7 b of the mover holder 7 is restricted by the mover stopper 9, but the other end 6 b of the mover 6 is It is possible to rotate the holder 7 in a direction approaching the other end 7b.

The contact pressure spring 8 is a spring for pressing the movable contact 11 against the fixed contact 10. In the state shown in FIG. 1, the contact pressure spring 8 is in a state in which the contact pressure spring 8 is charged shorter than its natural length, and has a predetermined initial contact pressure in advance. Therefore, when the other end 6b of the mover 6 rotates in a direction approaching the other end 7b of the mover holder 7, the distance between the other end 6b of the mover 6 and the other end 7b of the mover holder 7 becomes smaller. As a result, the contact pressure spring 8 is further charged.

Further, the circuit breaker 1 transmits an electromagnetic solenoid 20 disposed inside the housing 2 as a closing actuator of the circuit breaker 1 and a driving force of the electromagnetic solenoid 20 to the mover 6, and the fixed contact of the movable contact 11. A transmission mechanism 30 that contacts and separates the transmission mechanism 10, an opening spring 40 having one end and the other end attached to the transmission mechanism 30 and the housing 2, and maintains the closed state and releases the closed state And a drive circuit 70 for driving the electromagnetic solenoid 20. Note that the arrangement of the driving circuit 70 is not limited to the arrangement shown in FIG.

The electromagnetic solenoid 20 includes a yoke 21 made of a magnetic material, a loading coil 22 wound around a bobbin (not shown) and fixed inside the yoke 21, and an iron core plunger 23 that can reciprocate linearly in a vertical direction. And a protrusion 24 formed on the upper part of the iron core plunger 23. At least one of the electromagnetic solenoid 20 and the housing 2 is provided with a guide (not shown) for guiding the moving direction of the iron core plunger 23 in the vertical direction, and the core plunger 23 is displaced only in the vertical direction by such a guide. It is possible. It is sufficient that the core plunger 23 and the protruding portion 24 are fixed, and the method of fixing the core plunger 23 and the protruding portion 24 does not matter.

(4) When the drive coil 70 energizes the input coil 22, an electromagnetic attraction force is generated in the electromagnetic solenoid 20. Due to the generation of the electromagnetic attraction, the iron core plunger 23 moves upward, and when the gap 25 between the iron core plunger 23 and the inside of the input coil 22 disappears, the movement of the iron core plunger 23 is restricted and the iron plunger 23 is moved. Stops physically. As described above, the position where the iron core plunger 23 stops is the position where the iron core plunger 23 is in the uppermost direction, and is hereinafter described as the maximum insertion position or the maximum movement position. The structure in which the iron core plunger 23 stops is not limited to the above-described example. For example, a configuration may be employed in which a projecting portion is provided below the iron core plunger 23 and the projecting portion is locked to the bobbin or yoke 21 of the input coil 22 so that the iron core plunger 23 physically stops.

後 After a certain period of time has elapsed since the position of the iron core plunger 23 has reached the maximum closing position, the electromagnetic solenoid 20 stops generating the electromagnetic attraction force by stopping the power supply to the closing coil 22. When the electromagnetic attraction force of the electromagnetic solenoid 20 disappears, the iron core plunger 23 exerts a downward force from the maximum closing position due to the own weight of the iron core plunger 23 and the opening force of the opening spring 40, for example.

The transmission mechanism 30 includes a connecting link 31 having one end 31 a rotatably connected to the protrusion 24 of the electromagnetic solenoid 20, a lever 32 rotatably connected to the other end 31 b of the connecting link 31, and a lever 32. An insulating bar 33 rotatably connected to the one end 32a.

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

The lever 32 is attached to the lever shaft 37 so as to be rotatable around a lever shaft center 36 whose absolute position is fixed to the housing 2. In the lever 32, a region closer to the release mechanism 50 than the lever shaft 37 is connected to the other end 31 b of the connection link 31 by a connection pin 35. Further, 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 32 b of the lever 32.

One end 33a of the insulating bar 33 is rotatably connected to one end 32a of the lever 32 by a connecting pin 38, and the other end 33b is rotatably mounted to the one end 6a of the mover 6 by the connecting pin 13. . The insulating bar 33 is made of a material having high electrical insulation such as a resin. Therefore, when the circuit breaker 1 is in the energized state, the current flowing between the power supply terminal 3 and the load terminal 4 does not leak through the lever 32. Note that the entirety of the insulating bar 33 does not need to be made of an insulating material, and a part of the insulating bar 33 may be formed of a conductor as long as the connecting pin 13 and the connecting pin 38 are in an insulating state.

The lever 32 and the insulating bar 33 constitute a toggle mechanism in a four-joint link with the lever axis 36 and the holder axis 12a as fixed rotation centers. Therefore, the transmission mechanism 30 can be driven with a smaller force as the lever shaft center 36, the connection pin 38, and the connection pin 13 approach the dead center where they are linearly arranged. The protrusion 24, the connection link 31, the lever 32, the insulating bar 33, the mover 6, and the mover holder 7 constitute a link structure.

One end and the other end of the opening spring 40 are attached to the lever 32 and the housing 2 as described above, and the transmission mechanism 30 is moved by the elastic restoring force of the opening spring 40 to a shut-off state position to be described later. It is urged in the direction of displacement.

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

As shown in FIG. 2, the tripping mechanism 50 includes a trip lever 52 that engages with an engagement pin 51 fixed to the other end 32 b of the lever 32, and one end portion of the trip lever 52 and the housing 2. A first reset spring 53 having an end attached thereto. The tripping mechanism 50 includes a trip bar 54 that is rotated by a driving force of an actuator (not shown), a second reset spring 55 having one end and the other end attached to the trip bar 54 and the housing 2. Is provided.

The engagement pin 51 projects rightward from the lever 32 in a direction perpendicular to the direction in which the lever 32 extends. The trip lever 52 has an arc portion 56 having an arc surface that comes into contact with the engagement pin 51 in the closing process at one end portion 52 a, and the other end portion 52 b is formed around a trip lever axis 60 fixed to the housing 2. It is rotatably mounted on. In the middle of the trip lever 52, a concave portion 52c that is recessed rearward is formed. An engagement surface 57 that engages with the engagement pin 51 in the closed state is formed in the concave portion 52c. Further, an engagement portion 59 that engages with the trip bar 54 is provided in a region on the front side of the other end portion 52 b of the trip lever 52.

One end 54 a of the trip bar 54 is attached to the housing 2 so as to be rotatable about a trip bar axis 61, and has a semicircular semicircular portion 58 centered on the trip bar axis 61. I have. The semicircular portion 58 is formed by an arc portion 58a having an arc surface and a flat portion 58b having a flat surface.

The driving force of the actuator (not shown) causes the semicircular portion 58 to rotate about the trip bar axis 61, and the arc portion 58 a of the semicircular portion 58 engages with the engaging portion 59 formed on the other end 52 b of the trip lever 52. By this, the rotation of the one end 52a of the trip lever 52 forward is restricted.

The second reset spring 55 urges the trip bar 54 in a direction to rotate the other end 54b of the trip bar 54 facing upward in the forward direction about the trip bar axis 61. That is, the second reset spring 55 urges the trip bar 54 clockwise.

FIG. 3 is a diagram illustrating a configuration example of an electric circuit of the circuit breaker including the drive circuit according to the first embodiment. As shown in FIG. 3, the circuit breaker 1 according to the first embodiment includes a drive circuit 70 that energizes the closing coil 22, an internal ON switch 71 provided in front of the circuit breaker 1, And an external ON switch 72 that enables the circuit breaker 1 to be turned on from a position away from the switch. When the control power supply 73 is connected to the terminal block provided on the circuit breaker 1, power is supplied to the drive circuit 70.

The circuit breaker 1 has an internal off switch 74 that is linked to an unshown off operation button provided on the front of the circuit breaker 1 and a pull that enables the circuit breaker 1 to be turned off from a position away from the circuit breaker 1. And a detachable attachment device 75. The trip attachment device 75 can perform control to automatically trip the circuit breaker 1 when the voltage of the drive circuit 70 falls below the reference value.

The circuit breaker 1 also includes a detection unit 76 that detects an overcurrent or a leakage in the electric circuit, a trip coil 77 that drives an actuator (not shown), and a drive circuit 78 that energizes the trip coil 77. The detection unit 76 includes a current transformer 97 whose primary side is provided in the electric circuit, and a trip relay 98 connected to the secondary side of the current transformer 97. The trip relay 98 detects an overcurrent or a leakage based on the secondary current of the current transformer 97 and outputs a high-level voltage as a trip command. Note that the detection unit 76 may be any configuration as long as it detects an overcurrent or a leakage and outputs a trip command, and is not limited to the example illustrated in FIG. 3.

The drive circuit 78 energizes the trip coil 77 when the detection command is output from the detection unit 76. When the trip coil 77 is energized, an actuator (not shown) is driven, and the actuator drives the trip bar 54 shown in FIG. 2 to rotate counterclockwise. Thus, the engagement of the tripping mechanism 50 with the transmission mechanism 30 is released. Therefore, the movable contact 11 is separated from the fixed contact 10, and the circuit breaker 1 is turned off.

When there is an ON operation using the internal ON switch 71 or when there is an ON operation using the external ON switch 72, the drive circuit 70 supplies a current to the closing coil 22 to energize the closing coil 22. . Thereby, the iron core plunger 23 moves, and the fixed contact 10 and the movable contact 11 come into contact with each other, so that the circuit breaker 1 is turned on.

In addition, the drive circuit 70 is used for turning on when there is an off operation using the internal off switch 74, when there is an off operation using the trip accessory 75, or when the voltage of the drive circuit 70 falls below the reference value. The energization of the coil 22 is stopped. The drive circuit 78 is used for tripping when there is an off operation using the internal off switch 74, when there is an off operation using the trip attachment 75, or when the voltage of the drive circuit 70 falls below the reference value. The coil 77 is energized.

FIG. 4 is a diagram illustrating an example of a specific configuration of the drive circuit according to the first embodiment. As shown in FIG. 4, the drive circuit 70 according to the first embodiment includes a rectifier circuit 80, a constant voltage circuit 81, a control circuit 83, a control switch 84, a series body 85, and resistors R1, R2, R3. And Note that the drive circuit 70 may have a configuration including the resistor R4.

(4) The rectifier circuit 80 rectifies the AC voltage output from the control power supply 73 and converts it into a DC voltage Va. The constant voltage circuit 81 reduces the DC voltage Va output from the rectifier circuit 80 and outputs a constant voltage Vb. The constant voltage Vb is, for example, 24V. The control circuit 83 performs control switches based on the state of each of the internal ON switch 71, the external ON switch 72, the internal OFF switch 74, and the tripping accessory 75, and the detection result of overcurrent or leakage by the detection unit 76. 84 is turned on or off.

The control switch 84 is connected between the other end of the input coil 22 to which the DC voltage Va is supplied at one end and the ground, and performs connection and disconnection between the other end of the input coil 22 and the ground. . When the control switch 84 is in the ON state, the other end of the closing coil 22 and the ground are in a short-circuit state, and the excitation current is supplied to the closing coil 22. When the control switch 84 is in the off state, the connection between the other end of the closing coil 22 and the ground is in a cutoff state, and the supply of the exciting current to the closing coil 22 is stopped.

The series body 85 is connected in parallel to the input coil 22 of the electromagnetic solenoid 20. The series body 85 is configured by connecting a diode 86 and a current reducing unit 87 in series. The diode 86 has an anode connected to the control switch 84 and a cathode connected to one end of the current reducing unit 87. The DC voltage Va is applied to the other end of the current reducing section 87.

The current reduction unit 87 reduces the return current flowing through the insertion coil 22 via the diode 86 when the control switch 84 is turned off from the on state and the energization of the insertion coil 22 is stopped. With the current reduction unit 87, the breaking can be performed immediately after the closing operation of the circuit breaker 1 is started, as described later, without the transmission mechanism 30 having a complicated configuration.

The control circuit 83 includes OR

circuits

91 and 95, a latch circuit 92, an AND circuit 93, a logical NOT circuit 94, and terminals T1, T2, T3, T4, T5, and T6. The terminal T1 is connected to the internal ON switch 71. The terminal T2 is connected to the external ON switch 72. Terminal T3 is connected to a switch block that includes an internal off switch 74 and a trip accessory 75. The terminal T4 is connected to an output terminal of the detection unit 76. The terminal T5 is connected to a micro switch 88 that operates in conjunction with the operation of the core plunger 23 being turned on.

In the OR circuit 91, one input terminal is connected to the terminal T1, and the other input terminal is connected to the terminal T2. The OR circuit 91 outputs a closing signal to the latch circuit 92 when the closing signal is output from the internal ON switch 71 or the external ON switch 72. In the example illustrated in FIG. 4, when the internal ON switch 71 or the external ON switch 72 is short-circuited, a high-level voltage is input to the OR circuit 91 as a closing signal, and the high-level voltage is input from the OR circuit 91 as a closing signal. Output to the latch circuit 92.

The latch circuit 92 outputs, for example, a high-level voltage to the AND circuit 93 as an ON signal when the control circuit 84 is not in the ON state and the ON signal is output from the OR circuit 91 for a certain period of time. Note that the latch circuit 92 has a built-in timer circuit, and outputs a low-level voltage to the AND circuit 93 as an off signal when a certain period of time has elapsed since the output of the on signal.

The AND circuit 93 has one input terminal connected to the terminal T3 to which the cutoff signal is input from the internal off switch 74 or the trip attachment device 75, and the other input terminal connected to the output terminal of the latch circuit 92. ing. When the ON signal is output from the latch circuit 92 in a state where the cutoff signal is not output from the internal OFF switch 74 or the trip attachment device 75, the AND circuit 93 outputs a high level voltage to the control switch 84. Output as In the example shown in FIG. 4, the cutoff signal is a low-level voltage.

The control switch 84 has an input terminal connected to the terminal T6, and is turned on when an on signal is output from the AND circuit 93 via the terminal T6. When the control switch 84 is turned on, the excitation current is supplied to the closing coil 22. Thereby, the closing operation by the iron core plunger 23 starts.

The AND circuit 93 turns off the low-level voltage to the control switch 84 when the off signal is output from the latch circuit 92 or when the cutoff signal is output from the internal off switch 74 or the trip attachment 75. Output as a signal. The control switch 84 switches from the on state to the off state when the signal output from the AND circuit 93 changes from the on signal to the off signal. When the control switch 84 is turned off, the supply of the exciting current to the closing coil 22 is stopped.

The OR circuit 95 is a three-input one-output OR circuit. The OR circuit 95 has a first input terminal connected to the terminal T4, a second input terminal connected to the output terminal of the logical NOT circuit 94, and a third input terminal connected to the terminal T5. The input terminal of the logical NOT circuit 94 is connected to the terminal T3.

The OR circuit 95 outputs a tripping command from the detection unit 76, outputs a cutoff signal from the internal off switch 74 or the tripping attachment device 75, or outputs a high-level voltage from the microswitch 88. In this case, a high-level voltage is output to the latch circuit 92 as a reset signal. When the reset signal is output from the OR circuit 95 while the ON signal is being output, the latch circuit 92 switches the output signal from the ON signal to the OFF signal. Note that the configuration of the control circuit 83 is not limited to the configuration illustrated in FIG. 4, and the control circuit 83 may be a circuit that can realize the above-described functions.

動作 The operation of the circuit breaker 1 configured as described above will be specifically described. FIG. 5 is a configuration diagram illustrating a cutoff state of the circuit breaker according to the first embodiment, and FIG. 6 is an enlarged view of the tripping mechanism illustrated in FIG. FIG. 7 is a configuration diagram illustrating a state at the moment when the contact of the circuit breaker according to the first embodiment starts, and FIG. 8 is an enlarged view of the tripping mechanism illustrated in FIG. 7. 9 is a configuration diagram illustrating a state where the circuit breaker according to the first embodiment has reached the maximum closing position, FIG. 10 is an enlarged view of the tripping mechanism illustrated in FIG. 9, and FIG. FIG. 6 is an enlarged view of the tripping mechanism after the trip lever has rotated from the state shown in FIG. FIG. 12 is a configuration diagram illustrating a state where the circuit breaker according to the first embodiment has reached the closing completion position, and FIG. 13 is an enlarged view of the tripping mechanism illustrated in FIG. 5 to 13, the housing 2 is indicated by a broken line.

As shown in FIG. 5, when the circuit breaker 1 is in the cutoff state, the iron core plunger 23 forming the electromagnetic solenoid 20 reaches the lowermost portion by the opening spring 40 and is in physical contact with the housing 2. You can no longer descend downwards. At this time, the size of the gap 25 is maximum.

When the iron core plunger 23 is at the lowermost position, the other end 32b of the lever 32 is located below the one end 32a, and is located at a position facing the one end 52a of the trip lever 52 in the left-right direction. One end 52a of the trip lever 52 is tensioned rearward by the elastic restoring force of the first reset spring 53. Therefore, the engagement pin 51 attached to the other end 32 b of the lever 32 is in contact with the arc portion 56 formed on the one end 52 a of the trip lever 52.

When the breaker 1 is in the cutoff state, the rotation of the mover 6 in the direction in which the other end 6b of the mover 6 is separated from the other end 7b of the mover holder 7 by the mover stopper 9 of the mover holder 7, that is, Clockwise rotation of the mover 6 is limited. Since the contact pressure spring 8 has a predetermined initial contact pressure as described above, as long as the reaction force from the fixed contact 10 to the movable contact 11 does not exceed the initial contact pressure, One end 6a of the mover 6 does not separate from the mover stopper 9.

As shown in FIG. 5, when the circuit breaker 1 is in the cut-off state, the separation distance, which is the physically shortest distance between the movable contact 11 and the fixed contact 10 of the mover 6, is maximum. In the state shown in FIG. 5, as shown in FIG. 6, the flat portion 58b of the semicircular portion 58 of the trip bar 54 is elastically restored by the second reset spring 55 which tries to rotate the trip bar 54 clockwise. As a result, it is in contact with the corner of the engaging portion 59 formed on the other end 52b of the trip lever 52. Therefore, the rotation of the trip lever 52 is restricted, and the state shown in FIG. 6 is maintained.

Further, the one end portion 52a of the trip lever 52 is formed into a circular arc portion by the elastic restoring force of the first reset spring 53 that attempts to rotate the trip lever 52 clockwise so that the one end portion 52a of the trip lever 52 moves backward. At 56, it is in contact with the engagement pin 51 of the lever 32. Thereby, the clockwise rotation of the trip lever 52 is restricted, and the state shown in FIG. 6 is maintained.

Next, the operation of the drive circuit 70 for energizing the closing coil 22 of the electromagnetic solenoid 20 when the circuit breaker 1 is in the cut-off state will be described with reference to FIG. In the following, it is assumed that the control power supply 73 supplies power to the drive circuit 70 and that the rectifier circuit 80 and the constant voltage circuit 81 operate normally.

(4) When the internal ON switch 71 or the external ON switch 72 is short-circuited by the ON operation while the circuit breaker 1 is in the interrupted state, a closing signal is output from the internal ON switch 71 or the external ON switch 72 to the control circuit 83. The control circuit 83 outputs an ON signal to the control switch 84 when the ON signal is output from the internal ON switch 71 or the external ON switch 72. Thus, power is supplied to the input coil 22.

When the drive coil 70 energizes the closing coil 22, the core plunger 23 moves upward as shown in FIG. The upward movement of the core plunger 23 causes the lever 32 to rotate about the lever axis 36, and the connection angle between the lever 32 and the insulating bar 33 decreases. The connection angle is an angle formed by the extension direction of the lever 32 and the extension direction of the insulating bar 33, and the connection angle becomes smaller as the circuit breaker 1 changes from the state shown in FIG. 5 to the state shown in FIG.

につれて As the connection angle decreases, the mover 6 moves forward, and the fixed contact 10 and the movable contact 11 come into contact with each other. The state at the moment when the movable contact 11 and the fixed contact 10 start contact is the contact contact start state. At this time, a current flows between the power supply terminal 3 and the load terminal 4 through the fixed contact 10, the movable contact 11, and the flexible conductor 5.

As shown in FIGS. 6 and 8, the engagement pin 51 attached to the tip of the lever 32 rotatable about the lever axis 36 is provided with a first reset spring 53 as the connection angle becomes smaller. While maintaining the state of contact with the trip lever 52 to which the elastic restoring force has been given by the elastic member, the circular arc portion 56 formed on the one end portion 52a of the trip lever 52 is slid.

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

When the circuit breaker 1 reaches the contact abutment start state, the mover 6 is restricted from rotating clockwise by the mover stopper 9 provided on the mover holder 7, but can be rotated counterclockwise. It is. When the iron core plunger 23 further advances from the contact abutment start state shown in FIG. 7, the contact reaction force from the fixed contact 10 to the movable contact 11 attached to the other end 6b of the mover 6 increases, and The other end 6 b of the armature 6 rotates counterclockwise around the connection pin 13 and approaches the other end 7 b of the mover holder 7. Therefore, the contact pressure spring 8 is further charged from the state shown in FIG.

As shown in FIG. 9, when the position of the iron core plunger 23 becomes the maximum closing position due to the upward movement of the iron core plunger 23, the movable contact 11 causes the movable element 6 to move with respect to the movable element holder 7 by the contact reaction force from the fixed contact 10. The angle of rotation is maximum, and the amount of stored energy of the contact pressure spring 8 is also maximum.

When the position of the iron core plunger 23 reaches the maximum closing position, as shown in FIG. 10, the engaging pin 51 sliding on the arc portion 56 of the trip lever 52 passes through the arc portion 56 of the trip lever 52. To reach the upper part of the engagement surface 57 of the trip lever 52. Therefore, the engagement pin 51 momentarily comes into non-contact with the trip lever 52.

(4) The clockwise rotation of the trip lever 52 whose rotation has been restricted by the engagement pin 51 is released when the relationship with the engagement pin 51 changes to a non-contact state. Therefore, as shown in FIG. 11, the concave portion 52 c of the trip lever 52 rotates clockwise by the elastic restoring force of the first reset spring 53 and comes into contact with the engaging pin 51. When the engagement pin 51 comes into contact with the concave portion 52c of the trip lever 52, clockwise rotation of the trip lever 52 is restricted.

When the engagement pin 51 reaches the upper part of the engagement surface 57 of the trip lever 52 and the trip lever 52 rotates, the trip bar 54, whose rotation in the clockwise direction is restricted by the trip lever 52, becomes a second reset spring 55. 10 and 11, the arc portion 58a of the semicircular portion 58 goes over the engaging portion 59 and stops. The circuit breaker 1 is provided with a stopper (not shown) for restricting the rotation of the trip bar 54, and restricts the rotation of the trip bar 54 in the state shown in FIGS.

ため Since the micro switch 88 shown in FIG. 4 is short-circuited in conjunction with the operation of turning on the core plunger 23, a high-level voltage is output from the micro switch 88 to the control circuit 83. When a high-level voltage is output from the micro switch 88, the control circuit 83 outputs an off signal to the control switch 84. As a result, when the iron core plunger 23 enters the closed state, the power supply to the closing coil 22 is stopped. When the core plunger 23 is in the closed state, the position of the core plunger 23 is the maximum inserted position.

This completes the energization of the electromagnetic solenoid 20 after the position of the iron core plunger 23 has reached the maximum insertion position. When the energization of the electromagnetic solenoid 20 is completed, the drive of the transmission mechanism 30 by the electromagnetic solenoid 20 is released.

Therefore, the reaction force of the stored contact pressure spring 8 acts between the fixed contact 10 and the movable contact 11, and moves the iron core plunger 23 of the electromagnetic solenoid 20 from the maximum closing position to the shut-off position through the transmission mechanism 30. A force is generated that pushes back in the direction to move to. Further, the force in the direction of moving the iron core plunger 23 from the maximum closing position to the shut-off state is also applied by the own weight of the iron core plunger 23 and the opening force of the opening spring 40. Thus, the core plunger 23 starts moving downward from the maximum insertion position shown in FIG.

When the iron core plunger 23 moves downward from the maximum closing position, the lever 32 rotates counterclockwise about the lever axis 36. When the lever 32 rotates counterclockwise, the engaging pin 51 rotates counterclockwise about the lever axis 36, and as shown in FIGS. As a result, the core plunger 23 reaches the closing completion position, and the closing operation of the circuit breaker 1 is completed.

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

Therefore, despite the fact that a force based on the reaction force of the contact pressure spring 8 for rotating the trip lever 52 counterclockwise with respect to the trip lever axis 60 is applied to the trip lever 52 through the engagement pin 51, the trip lever 52 is 13, does not rotate due to the rotation restriction by the arc portion 58a of the semicircular portion 58, as shown in FIG.

As described above, when the circuit breaker 1 is in the cut-off state, a constant initial contact pressure is applied to the contact pressure spring 8 in advance, and from the moment when the movable contact 11 starts to contact the fixed contact 10, the fixed contact 10 Is set such that the contact pressure of the movable contact 11 with respect to Therefore, when the circuit breaker 1 is in the energized state, the occurrence of separation between the contacts due to the electromagnetic repulsion generated between the movable contact 11 and the fixed contact 10 is prevented, and after the tripping command is issued. The separation speed between the movable contact 11 and the fixed contact 10, ie, the opening speed, can be increased.

Next, the tripping operation of the circuit breaker 1 will be described. The operation of the drive circuit 70 when the overcurrent or the leakage occurs in the electric circuit when the circuit breaker 1 is in the closed position shown in FIG. 12 will be described with reference to FIG.

The detecting unit 76 outputs a tripping command when detecting an overcurrent or a leakage in the electric circuit. The drive circuit 78 energizes the trip coil 77 when a detection command is output from the detection unit 76. When the trip coil 77 is energized, an actuator (not shown) is driven, and the actuator drives the trip bar 54 shown in FIGS. 12 and 13 to rotate counterclockwise.

Due to the counterclockwise rotation of the trip bar 54, the arc portion 58a of the semicircular portion 58 of the trip bar 54 separates 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. Is done. Therefore, the trip lever 52 rotates counterclockwise around the trip lever shaft center 60 by the force based on the reaction force of the contact pressure spring 8, and the iron core plunger 23 goes through the state shown in FIG. Return. Thereby, the tripping of the circuit breaker 1 is completed.

By the way, immediately after the start of the closing operation of the circuit breaker 1, the control circuit 83 outputs an ON signal, and the control switch 84 is in the ON state, so that the exciting current flows through the closing coil 22. When a trip command is output from the detection unit 76 in a state where the exciting current is flowing through the closing coil 22, the control circuit 83 outputs an off signal to the control switch 84. Thus, the supply of the exciting current to the closing coil 22 is stopped.

When the supply of the excitation current to the closing coil 22 is stopped by turning off the control switch 84, the back electromotive force of the closing coil 22 is generated. Such a back electromotive force is also called a surge voltage. The drive circuit 70 is provided with a diode 86 for preventing an overvoltage from being applied to the control switch 84 by a surge voltage. Such a diode 86 is also called a protection diode or a freewheeling diode.

還流 A return current flows through the closing coil 22 via the diode 86 due to the surge voltage. In order to reduce such a return current, the circuit breaker 1 is provided with the current reducing section 87 in series with the diode 86 as described above. When the supply of the exciting current to the making coil 22 is stopped, the current reduction unit 87 reduces the return current flowing through the making coil 22 via the diode 86. Therefore, the closed state can be prevented from being maintained by the return current, and the return operation of the plunger immediately after the start of the closing operation can be prevented from being delayed. Therefore, the transmission mechanism 30 can have a simple configuration.

FIGS. 14 to 16 are diagrams illustrating a configuration example of the current reduction unit and the control switch according to the first embodiment. In the example shown in FIGS. 14 and 16, the current reducing section 87 is configured by the resistor R10. In the example shown in FIG. 15, the current reducing section 87 has a configuration in which a resistor R10 and a capacitor C10 are connected in series.

The current reducing section 87 shown in FIG. 15 has a configuration in which the resistor R10 and the capacitor C10 are connected in series, but may have a configuration in which the resistor R10 and the capacitor C10 are connected in parallel. The configuration including the resistor R10 and the capacitor C10 is also called a snubber circuit.

14 and 15, the control switch 84 is configured using an N-channel MOSFET 79a, and in the example illustrated in FIG. 16, the control switch 84 is configured using a P-channel MOSFET 79b. In the case of the control switch 84 shown in FIG. 16, the control circuit 83 is configured such that a signal having a polarity opposite to that of the example shown in FIG. 4 is output from the terminal T6.

In FIG. 16, the current reducing section 87 may be formed by the snubber circuit described above. It is preferable to use a fast recovery diode as the diode 86 so that the inductance energy of the input coil 22 can be quickly consumed by the resistor R10.

When the supply of the exciting current to the closing coil 22 is stopped, if there is no current reduction unit 87, the return current flowing through the closing coil 22 via the diode 86 causes the electromagnetic solenoid 20 to maintain the closing operation. . Therefore, it may be difficult to cut off immediately after the start of the closing operation of the circuit breaker 1. However, since the circuit breaker 1 is provided with the current reducing section 87, the return current flowing through the closing coil 22 via the diode 86 is reduced. Can be reduced.

This makes it possible to quickly shut off the circuit breaker 1 immediately after the start of the closing operation without using a complicated transmission mechanism. The current reducing unit 87 sets the value of the resistor R10 and the value of the capacitor C10 so that the return current does not hinder the tripping by the tripping mechanism 50 after the supply of the exciting current to the closing coil 22 is stopped. You. For example, the value of the resistor R10 included in the current reduction unit 87 is set to a value that can reduce the return current until the throw input by the return current falls below the electromagnetic repulsion force and tripping force at the time of interruption.

In the above-described example, an example in which an overcurrent or a short circuit is detected immediately after the start of the closing operation has been described. However, the circuit breaker 1 is disconnected from the internal off switch 74 or the trip attachment 75 immediately after the start of the closing operation. Even when a signal is output, it is possible to shut off immediately after the start of the closing operation without using a complicated transmission mechanism.

Here, the relationship between the moving position of the iron core plunger 23 and the load applied to the electromagnetic solenoid 20 will be described. FIG. 17 is a diagram illustrating a relationship between the movement position of the iron core plunger according to the first embodiment and the load applied to the electromagnetic solenoid. The iron core plunger 23 moves in a range from the position shown in FIG. 5 to the maximum insertion position shown in FIG.

In the following, the upward movement of the core plunger 23 is referred to as forward, and the downward movement of the core plunger 23 is referred to as retreat. In addition, the moving position of the core plunger 23 when the core plunger 23 moves forward is described as a forward position, and the moving position of the core plunger 23 when the core plunger 23 retreats is described as a retreat position. Further, a load applied to the electromagnetic solenoid 20 when the iron core plunger 23 moves forward is referred to as a forward load, and a load applied to the electromagnetic solenoid 20 when the iron core plunger 23 moves backward is referred to as a reverse load.

As shown in FIG. 17, when the forward position of the core plunger 23 is the interrupted state position from the interrupted state position to the contact abutment start position, the transmission is performed in a state where the fixed contact 10 and the movable contact 11 are not in contact with each other. The mechanism 30 is driven. Therefore, when the forward position of the iron core plunger 23 is in the shut-off state position, the load applied to the electromagnetic solenoid 20 is relatively small. Then, when the forward position of the iron core plunger 23 becomes the contact contact start position, the contact of the movable contact 11 with the fixed contact 10 starts. Therefore, the lever 32 receives the reaction force from the contact pressure spring 8 via the connecting

pins

13 and 38 as a counterclockwise load torque around the lever axis 36, and the load applied to the electromagnetic solenoid 20 rapidly increases. growing.

However, when the iron core plunger 23 further advances, the component in the direction perpendicular to the straight line connecting the lever axis 36 and the connecting pin 38 in the reaction force from the contact pressure spring 8 acting on the connecting pin 38, which is the action point, suddenly decreases. Become. Therefore, the counterclockwise load torque around the lever axis 36 starts to decrease. As the load torque decreases, the load applied to the electromagnetic solenoid 20 required to rotate the lever 32 also starts to decrease.

In the mechanism state of the circuit breaker 1 in which the iron core plunger 23 is further advanced and the advanced position is the maximum closing position for the first time after the start of the closing operation, the lever 32 and the insulating bar 33 are brought closer to a straight line. Is the closest to the dead center. Therefore, the component of the reaction force from the contact pressure spring 8 acting on 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 electromagnetic solenoid 20 necessary for rotating the lever 32 is rotated. Also rapidly approach zero. That is, the load force action is the distance that the iron core plunger 23 of the electromagnetic solenoid 20 moves forward to apply a load torque to the lever 32 in accordance with the throwing power of the electromagnetic solenoid 20 that increases due to the displacement from the shut-off state position to the closed state position. The distance is reduced. Therefore, not only can the electromagnetic attraction force of the electromagnetic solenoid 20 be efficiently used for the closing operation of the circuit breaker 1, but also the electromagnetic solenoid 20 having a size corresponding to the change in the working distance of the load force required for the closing operation of the circuit breaker 1. Can be used, and the size and cost of the electromagnetic solenoid 20 can be reduced. In the circuit breaker 1 according to the first embodiment, the iron core plunger 23 is configured to stop moving forward before the above-described toggle mechanism crosses the dead center. , The configuration of the tripping mechanism 50 can be prevented from becoming complicated.

In the state after the contact of the circuit breaker 1 with the contact, the contact between the movable contact 11 and the fixed contact 10 generates a contact pressure receiving the reaction force from the contact pressure spring 8. Directional pressing force is generated. When a pressing force against the lever shaft 37 is generated, a friction torque is generated against the lever shaft 37, and a vertical sliding friction load of the electromagnetic solenoid 20 due to a front-rear component of the load transmitted to the electromagnetic solenoid 20 through the connection link 31. Are combined, and the input load of the electromagnetic solenoid 20 is increased as a friction force that cannot be ignored.

後 After the core plunger 23 reaches the maximum insertion position, when the moving direction of the core plunger 23 is changed to the backward direction, the direction of the frictional force applied to the entire transmission mechanism 30 is also changed. Therefore, the load on the tripping mechanism 50 in the closed state can be reduced by the effect of reducing the tripping load derived from the frictional force.

As described above, since the load on the tripping mechanism 50 in the closed state can be reduced, the configuration of the tripping mechanism 50 can be simplified. Therefore, the size of the tripping mechanism 50 can be reduced, the size of the circuit breaker 1 can be reduced, and the number of components of the tripping mechanism 50 can be reduced, so that the durability of the tripping mechanism 50 can be reduced. Sex can be raised.

Until the movable contact 11 comes into contact with the fixed contact 10, a frictional force is generated mainly by the rotation of the rotating portions of the connecting

pins

13, 38, the lever shaft 37, and the connecting

pins

34, 35. Therefore, until the movable contact 11 contacts the fixed contact 10, the friction torque on the lever shaft 37 and the vertical sliding friction load of the electromagnetic solenoid 20 are reduced by the contact pressure spring 8 after the contact between the movable contact 11 and the fixed contact 10. Smaller than the state after the contact pressure due to the reaction force from Therefore, as shown in FIG. 17, the difference between the applied load due to the frictional force before contacting the contact and the applied load due to the frictional force after the contacting is smaller than the difference between the applied load due to the frictional force after the contact.

について Regarding a series of closing operation and closing load of the circuit breaker 1, the load characteristics required for closing the electromagnetic solenoid 20 in the circuit breaker 1 can be formulated. For example, by formulating the load characteristics required for turning on the electromagnetic solenoid 20 in each of the states shown in FIGS. 5, 7, 9 and 12, the mechanical load at the time of the trip is greatly reduced by utilizing the mechanical friction. It is possible to design the circuit breaker 1 to reduce the input load characteristic of the electromagnetic solenoid 20 and reduce the hysteresis.

As described above, the circuit breaker 1 according to the first embodiment includes the housing 2, the power supply side terminal 3, the mover 6, the electromagnetic solenoid 20, the transmission mechanism 30, and the drive circuit 70. The power supply side terminal 3 is an example of a fixed terminal, and is fixed to the housing 2 with a fixed contact 10 attached thereto. The movable contact 6 has a movable contact 11 facing the fixed contact 10. The electromagnetic solenoid 20 has an iron core plunger 23 that moves linearly. The iron core plunger 23 is an example of a plunger. The transmission mechanism 30 moves the movable element 6 in accordance with the movement of the iron core plunger 23, and switches the movable contact 11 from the fixed contact 10 to the closed state where the movable contact 11 contacts the fixed contact 10 and energizes the movable contact 11. Change to The drive circuit 70 energizes the closing coil 22 of the electromagnetic solenoid 20 to drive the electromagnetic solenoid 20. The drive circuit 70 includes a series body 85 of a diode 86 and a current reducing unit 87 for reducing a current flowing through the diode 86, and the series body 85 is connected in parallel to the input coil 22 of the electromagnetic solenoid 20. Thus, the breaking can be performed immediately after the closing operation of the circuit breaker 1 is started without taking a complicated mechanism. Therefore, the transmission mechanism 30 can be simplified.

The current reducing section 87 includes the resistor R10 or the resistor R10 and the capacitor C10. Thereby, the current flowing through the diode 86 can be easily reduced.

The circuit breaker 1 further includes a detection unit 76 that detects an overcurrent or a leakage of an electric circuit that is brought into a conductive state by the contact between the fixed contact 10 and the movable contact 11 and outputs a trip command indicating the detection result as a detection result. Prepare. The drive circuit 70 stops energizing the closing coil 22 based on the trip command output from the detection unit 76. Thus, in the case where an overcurrent or a short circuit occurs in the electric circuit immediately after the start of the closing operation of the circuit breaker 1, the breaking can be performed immediately after the start of the closing operation of the circuit breaker 1 without taking a complicated mechanism. Therefore, the transmission mechanism 30 can be simplified. The trip command is an example of a detection signal.

遮断 The circuit breaker 1 according to the first embodiment includes the tripping mechanism 50. The tripping mechanism 50 engages with the transmission mechanism 30 to hold the closed state, and releases the engagement with the transmission mechanism 30 to release the held state. The transmission mechanism 30 includes a lever 32 and an insulating bar 33. The lever 32 rotates around a lever axis 36 fixed to the housing 2 as the iron core plunger 23 moves. The lever axis 36 is an example of a first axis. One end 33 a of the insulating bar 33 is rotatably connected to one end 32 a of the lever 32, and the other end 33 b is rotatably connected to the mover 6. The core plunger 23 of the electromagnetic solenoid 20 reaches the maximum movement position where the movement of the core plunger 23 is restricted before the toggle mechanism including the lever 32 and the insulating bar 33 becomes a dead center. Therefore, for example, by setting the maximum movement position of the iron core plunger 23 to a position immediately before the toggle mechanism becomes a dead center, the leverage of the toggle mechanism causes the electromagnetic solenoid 20 necessary for rotating the lever 32 to be turned on. The load can be rapidly reduced to zero. Therefore, the load applied to the tripping mechanism 50 in the closed state can be reduced. The position immediately before the above-mentioned dead center is a position where the dead center is not reached even when there is a manufacturing error. The maximum movement position is an example of a first position. In addition, the tripping mechanism 50 engages with the transmission mechanism 30 in a state where the iron core plunger 23 is retracted after reaching the maximum movement position and is in the loading completion position, and holds the loading state. The loading completion position is an example of a second position. Accordingly, when the moving direction of the iron core plunger 23 is changed to the backward direction, the direction of the frictional force applied to the entire transmission mechanism 30 is also changed. Thus, the load on the trip mechanism 50 in the closed state can be reduced. Therefore, it is possible to reduce the necessity of making the tripping mechanism of the circuit breaker a complicated mechanism, and it is possible to reduce the size of the tripping mechanism 50 and to improve the assemblability.

遮断 The circuit breaker 1 further includes an engagement pin 51 attached to the other end 32b of the lever 32. The engagement pin 51 is an example of an engagement portion. The tripping mechanism 50 includes a trip lever 52 and a trip bar 54. The trip lever 52 is rotatably attached to the housing 2 in a state where the trip lever 52 is urged in a direction toward the engagement pin 51, and is in contact with the engagement pin 51 during a closing process of shifting from a blocking state to a closing state. Is maintained, and the core plunger 23 is engaged with the engagement pin 51 in the state where it is in the closing completion position, thereby restricting the rotation of the lever 32 around the lever axis 36. The trip bar 54 regulates the rotation of the trip lever 52 and releases the regulation. As described above, since the tripping mechanism 50 can be constituted by at least two members including the trip lever 52 and the trip bar 54 except for the engagement pin 51, the tripping mechanism 50 can be downsized and the assemblability can be improved. Can be achieved. Further, since the engagement pin 51 is brought into contact with the trip lever 52 from the shut-off state to the closing state, the tripping operation can be easily performed only by changing the movable amount of the trip lever 52 in the direction away from the engagement pin 51. be able to.

The trip lever 52 has an arc shape centered on the lever axis 36, and engages with the arc portion 56 with which the engaging pin 51 is movably contacted during the closing process, and with the engaging pin 51 in the closed state. And a recess 51c. Thus, since the position of the trip lever 52 does not change during the closing process, it is possible to suppress the load applied to the electromagnetic solenoid 20 that drives the transmission mechanism 30 from being varied by the trip lever 52 during the closing process.

トリップ The trip lever 52 has a semicircular portion 58 formed with an arc portion 58 a and a flat portion 58 b and rotating around a trip bar axis 61 fixed to the housing 2. The trip bar axis 61 is an example of a second axis. The trip lever 52 contacts the flat portion 58b of the semicircular portion 58 in the shut-off state and is restricted from rotating. The trip lever 52 contacts the arc portion 58a of the semicircular portion 58 in the closed state and restricts the rotation. Accordingly, the amount of movement of the trip lever 52 in the direction away from the engagement pin 51 can be easily adjusted only by rotating the trip lever 52.

Embodiment 2 FIG.
The circuit breaker according to the second embodiment is different from the circuit breaker 1 according to the first embodiment in that the circuit breaker according to the second embodiment is provided in a drive circuit that realizes an MCR (Making Current Release) function. In the following, components having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The following description focuses on differences from circuit breaker 1 of the first embodiment.

First, the MCR mechanism that realizes the MCR function will be described. The MCR mechanism enables the instantaneous tripping characteristic during the closing operation of the circuit breaker, instantaneously trips for a short circuit accident during the closing operation, and invalidates the instantaneous tripping characteristic after the closing operation of the circuit breaker is completed. As a result, it is possible to expand a selection cooperative area with a load device having a large inrush current or a lower circuit breaker.

FIGS. 18 and 19 are diagrams showing a configuration example of the MCR mechanism. FIG. 18 shows a state at the time of the closing operation of the circuit breaker, and FIG. 19 shows a state after the closing operation of the circuit breaker is completed. In the following, clockwise and counterclockwise mean clockwise and counterclockwise in FIGS. 18 and 19, respectively. The MCR mechanism 100 shown in FIGS. 18 and 19 will be described as being included in the circuit breaker 1 described above.

The MCR mechanism 100 shown in FIG. 18 includes an MCR plate 101, an insulating plate 102, a micro switch 103, and an auxiliary plate 104. The insulating plate 102, the microswitch 103, and the auxiliary plate 104 are fixed to the MCR plate 101 at two points by screws 105. A normally closed terminal is used for the microswitch 103. The microswitch 103 is provided with an actuator 106, and the actuator 106 is fixed to a rotating shaft 109 rotatably supported by the MCR plate 101.

The MCR mechanism 100 includes a weight 107 attached to the other end of the actuator 106 and a spring 108 suspended between the MCR plate 101 and the weight 107. The spring 108 applies a force to the actuator 106 in a direction in which the spring 108 rotates counterclockwise about the rotation shaft 109. Therefore, when the closing operation of the circuit breaker 1 is not performed, as shown in FIG. 19, one end of the actuator 106 presses the micro switch button 103a. The micro switch 103 transmits an always-on signal to the trip relay 98 shown in FIGS. 3 and 4 while the micro switch button 103a is being pressed. As a result, in the trip relay 98, the instantaneous trip characteristic becomes invalid.

The receiving portion 106a of the actuator 106 has a shape for receiving the operation of the lever shaft 37 in the mechanism for opening and closing the main contact of the circuit breaker 1. In the actuator 106, the receiving portion 106a rotates clockwise around the rotation shaft 109 by rotation of the lever shaft 37 during the closing operation of the circuit breaker 1, and one end presses the micro switch button 103a for about several ms. As a result, the microswitch 103 trips the off signal of about several ms and transmits it to the relay 98. The instantaneous trip characteristic is effective while the off signal of about several ms is being input to the trip relay 98. As described above, the MCR mechanism 100 can invalidate the instantaneous tripping characteristic during the closing operation of the circuit breaker 1 while disabling the instantaneous tripping characteristic except during the closing operation of the circuit breaker 1.

Next, a drive circuit of the circuit breaker according to the second embodiment will be described. FIG. 20 is a diagram illustrating a configuration example of an electric circuit of the circuit breaker including the drive circuit according to the second embodiment of the present invention. As shown in FIG. 20, the drive circuit 70A of the circuit breaker 1A according to the second embodiment is different from the drive circuit 70 of the circuit breaker 1 in having an MCR circuit 79 that realizes an MCR function.

As shown in FIG. 20, the MCR circuit 79 is connected to the terminal T6 and receives a signal output from the AND circuit 93. The signal input from the AND circuit 93 to the MCR circuit 79 is the same signal as the signal input from the AND circuit 93 to the control switch 84. The MCR circuit 79 outputs an ON signal or an OFF signal to the trip relay 98 based on a signal input from the AND circuit 93. The MCR circuit 79 includes a photocoupler and the like in order to keep the control circuit 83 and the like and the trip relay 98 insulated.

When the ON signal is input from the AND circuit 93, the MCR circuit 79 outputs an ON signal that is a high-level voltage to the trip relay 98. The ON signal output to the trip relay 98 is a signal for validating the instantaneous trip characteristic, and may be hereinafter referred to as an MCR control signal. The trip relay 98 issues a trip command to the drive circuit 78 when an overcurrent or a leakage is detected based on the secondary current of the current transformer 97 while the MCR control signal is output from the MCR circuit 79. Output. As a result, the trip coil 77 is energized, and the circuit breaker 1A is turned off.

{Circle around (4)} When the OFF signal is output from the AND circuit 93, the MCR circuit 79 outputs a low-level voltage to the trip relay 98 to invalidate the instantaneous trip characteristic. The trip relay 98 issues a trip command to the drive circuit 78 even when an overcurrent or a leakage is detected based on the secondary current of the current transformer 97 in a state where a low level voltage is output from the MCR circuit 79. Is not output. As a result, the instantaneous trip characteristic can be invalidated after the closing operation of the circuit breaker 1A is completed.

FIG. 21 is a timing chart for explaining the MCR function of the circuit breaker according to the second embodiment. At time t1, when the internal ON switch 71 or the external ON switch 72 is turned on, a closing signal, which is a high level voltage, is output from the OR circuit 91 to the latch circuit 92 as shown in FIG. When the input signal is output from the OR circuit 91, the latch circuit 92 outputs a high-level voltage to the AND circuit 93. Therefore, the AND circuit 93 outputs a high-level voltage to the MCR circuit 79 and the control switch 84 as an ON signal. The MCR circuit 79 outputs a high-level voltage to the relay 98 as an MCR control signal while the ON signal is being output from the AND circuit 93. As a result, the instantaneous trip characteristic becomes effective during the closing operation of the circuit breaker 1A.

The control switch 84 is turned on when an on signal is output from the AND circuit 93 via the terminal T6. When the control switch 84 is turned on, the excitation current is supplied to the closing coil 22. Accordingly, the closing operation by the iron core plunger 23 starts, and at time t2, a high-level voltage is output to the control circuit 83 from the microswitch 88 that is linked to the operation of bringing the iron core plunger 23 into the closing state. When a high-level voltage is output from the microswitch 88, the latch circuit 92 is reset, and a low-level voltage is output from the control circuit 83 to the control switch 84 as an off signal.

As described above, since the AND circuit 93 outputs the high-level voltage as the ON signal during the period from time t1 to time t2, the MCR circuit 79 outputs the high-level voltage during the period from time t1 to time t2. The voltage is output as an MCR control signal to the relay 98. The period from time t1 to time t2 is, for example, about 200 ms, whereby a stable MCR control signal is output to the trip relay 98. Therefore, the instantaneous trip characteristic of the trip relay 98 can be stably activated during the period in which the MCR control signal is output.

(4) After time t2, a low-level voltage is output from the AND circuit 93 as an off signal. The MCR circuit 79 trips the low-level voltage and outputs it to the relay 98 while the off signal is being output from the AND circuit 93. As a result, the instantaneous trip characteristic is invalidated after the closing of the circuit breaker 1A is completed.

When the control switch 84 has the configuration shown in FIG. 16, the control circuit 83 outputs a low-level voltage as an ON signal. In this case, the control circuit 83 is provided with, for example, a logical NOT circuit between the logical product circuit 93 and the terminal T6. The MCR circuit 79 trips the high-level voltage as the MCR control signal and outputs it to the relay 98 while the control circuit 83 outputs the low-level ON signal. Note that the MCR control signal output from the MCR circuit 79 may be a low-level voltage. In this case, the tripping relay 98 has an instantaneous tripping characteristic at a low-level voltage.

As described above, the circuit breaker 1A according to the second embodiment is configured to output a trip command when an overcurrent or a short circuit occurs in a circuit that is brought into a conductive state by the contact between the fixed contact 10 and the movable contact 11. A relay 98 is provided. The drive circuit 70A includes a control circuit 83, which is an example of a first control circuit, and an MCR circuit 79, which is an example of a second control circuit. The control circuit 83 outputs an ON signal for driving the electromagnetic solenoid 20 when the internal ON switch 71 or the external ON switch 72 is turned ON, and interlocks with the operation in which the iron core plunger 23 of the electromagnetic solenoid 20 is turned on. The output of the ON signal is stopped based on the signal from the micro switch 88 to be turned on. The internal ON switch 71 or the external ON switch 72 is an example of an ON switch. The MCR circuit 79 outputs the MCR control signal to the trip relay 98 while the ON signal is being output from the control circuit 83, and enables the trip command to be output from the trip relay 98. Thereby, in the circuit breaker 1A, the MCR function can be realized without providing the MCR mechanism 100 as shown in FIG. 18 and FIG.

The configurations described in the above embodiments are merely examples of the contents of the present invention, and can be combined with other known technologies, and can be combined with other known technologies without departing from the gist of the present invention. Parts can be omitted or changed.

1 breaker, 2 housing, 2a wall, 3 power terminal, 4 load terminal, 5 flexible conductor, 5a, 6a, 7a, 31a, 32a, 33a, 52a, 54a, one end, 5b, 6b, 7b, 31b, 32b, 33b, 52b, 54b {other end, 6} mover, 7 # mover holder, 7c # midway, 8 # contact pressure spring, 9 # mover stopper, 10 # fixed contact, 11 # movable contact, 12 # holder shaft, 12a holder axis, 13, 34, 35, 38 connection pin, 20 electromagnetic solenoid, 21 yoke, 22 closing coil, 23 iron plunger, 24 projection, 25 gap, 30 transmission mechanism, 31 connection link, 32 lever, 33 Insulation bar, 36 ° lever axis, 37 ° lever axis, 40 ° opening spring, 50 ° release mechanism, 51 ° engaging pin, 52 ° Lever, 52c concave portion, 53 first reset spring, 54 trip bar, 55 second reset spring, 56 arc portion, 57 engagement surface, 58 semicircle portion, 58a arc portion, 58b flat portion, 59 engagement portion, 60 trip lever shaft center, 61 trip bar shaft center, 70, 78 drive circuit, 71 オン internal on switch, 72 external on switch, 73 control power supply, 74 internal off switch, 75 tripping attachment device, 76 detection unit, 77 trip Coil, 79 MCR circuit, 80 rectifier circuit, 81 constant voltage circuit, 83 control circuit, 84 control switch, 85 series, 86 diode, 87 current reducing section, 88 micro switch, 91, 95 OR circuit, 92 latch circuit, 93 logical AND circuit, 94 logical NOT circuit, 97 current transformer, 8 trip relay, 100 MCR mechanism, 101 MCR plate, 102 insulating plate, 103 micro switch, 103 a micro switch button, 104 auxiliary plate, 105 screw, 106 actuator, 106 a receiving part, 107 weight, 108 spring, 109 rotating shaft, C10 capacitor, R1, R2, R3, R4, R10 resistor, T1, T2, T3, T4, T5, T6 terminal.

Claims

A housing,
A fixed terminal to which a fixed contact is attached and fixed to the housing;
A mover having a movable contact facing the fixed contact,
An electromagnetic solenoid having a plunger that moves linearly;
A transmission mechanism for moving the mover with the movement of the plunger to change from a cut-off state in which the movable contact is separated from the fixed contact to a closed state in which the movable contact comes into contact with the fixed contact and is energized; ,
A drive circuit for energizing the coil of the electromagnetic solenoid to drive the electromagnetic solenoid,
The driving circuit includes:
A circuit breaker, comprising: a series body of a diode and a current reduction unit that reduces a current flowing through the diode, wherein the series body is connected in parallel to a coil of the electromagnetic solenoid.
The current reducing unit includes:
The circuit breaker according to claim 1, comprising a resistor or a resistor and a capacitor.
A detection unit that detects an overcurrent or a leakage of an electric circuit that is brought into a conductive state by contact between the fixed contact and the movable contact, and outputs a detection signal indicating a result of the detection,
The driving circuit includes:
The circuit breaker according to claim 1, wherein energization of the coil is stopped based on a detection signal output from the detection unit.
A trip mechanism that engages with the transmission mechanism to hold the closed state, and releases the engagement with the transmission mechanism to release the held state,
The transmission mechanism,
A lever that rotates about a first axis fixed to the housing with movement of the plunger;
An insulating bar having one end rotatably connected to one end of the lever and the other end rotatably connected to the mover, and an engaging portion attached to the other end of the lever. ,
The trip mechanism is
It is rotatably attached to the housing in a state where it is urged in the direction toward the engaging portion, and maintains a state of contact with the engaging portion in a closing process of shifting from the blocking state to the closing state. A trip lever that engages with the engagement portion in the closed state to restrict rotation of the lever around the first axis;
The circuit breaker according to any one of claims 1 to 3, further comprising: a trip bar configured to restrict rotation of the trip lever and release the restriction.
The trip lever is
An arc portion having an arc shape centered on the first axis, wherein the engagement portion is movably contacted in the inserting process;
The circuit breaker according to claim 4, further comprising: a concave portion that engages with the engaging portion in the closed state.
The trip bar is
An arc portion and a flat portion are formed, and a semi-circular portion that rotates around a second axis fixed to the housing is provided.
The trip lever is
The rotation is regulated by contacting the flat portion of the semicircular portion in the shut-off state, and the rotation is regulated by contacting the arc portion of the semicircular portion in the closed state. The circuit breaker according to the above.
A trip relay that outputs a trip command when an overcurrent or leakage occurs in an electric circuit that is brought into a conductive state by contact between the fixed contact and the movable contact,
The driving circuit includes:
An on signal for driving the electromagnetic solenoid is output when an on switch is turned on, and the output of the on signal is output based on a signal from a micro switch that is interlocked with an operation in which a plunger of the electromagnetic solenoid is turned on. A first control circuit to stop;
7. A second control circuit which enables the trip command to be output from the trip relay while the on signal is being output from the first control circuit. 8. The circuit breaker according to any one of the above.