TW202018748A - Circuit breaker - Google Patents

Abstract

A circuit breaker includes a transmission mechanism that moves a mover in accordance with the movement of a plunger of an electromagnetic solenoid to change it from a cut-off state to a closing state, and a drive circuit (70) that drives the electromagnetic solenoid. The drive circuit (70) includes a serial body (85) of a diode (86) and a current reduction unit (87) that reduces the current flowing through the diode (86), and the serial body (85) is connected to a coil (22) of the electromagnetic solenoid in parallel.

Description

breaker

The present invention relates to a circuit breaker using an electromagnetic solenoid to be put into operation.

Conventionally, there has been known a circuit breaker that uses an electromagnetic solenoid to be put into operation. For example, Patent Document 1 discloses a circuit breaker that has a link mechanism as a transmission mechanism that links a plunger of an electromagnet with a movable contactor, and moves the mandrel by energizing the coil of the electromagnet to move the movable contactor Put into a fixed contact. [Prior Technical Literature] [Patent Literature]

Patent Literature 1: Japanese Patent Publication No. 2010-44927

[Problems to be solved by the invention]

There is a demand for a circuit breaker that can be opened immediately after the start of the operation. Therefore, in the conventional circuit breaker using the electromagnet to input, in order to prevent the return action of the heart rod just after the start of the input operation from being delayed due to the inertia and residual magnetism of the core rod of the electromagnet, the transmission mechanism has a complicated mechanism that constitutes the transmission mechanism Have many components. Since many components operate in association with each other and become complicated operations, the components may be damaged when used for a long period of time, and the mechanism characteristics may change with time, and the reliability of the circuit breaker may be reduced.

The present invention has been completed in view of the above-mentioned problems, and an object thereof is to provide a circuit breaker that can simplify the transmission mechanism. [Means to solve the problem]

In order to solve the above-mentioned problems and achieve the object of the invention, the circuit breaker of the present invention includes a case, a fixed terminal, a mover, an electromagnetic solenoid, a transmission mechanism, and a drive circuit. The fixed terminal is installed with fixed contacts and fixed to the housing. The movable element is installed with a movable contact facing the fixed contact. The electromagnetic solenoid has a heart rod that moves linearly. The transmission mechanism makes the mover move with the movement of the mandrel, and changes from the disconnected state where the movable contact is separated from the fixed contact to the input state where the movable contact is in contact with the fixed contact and is energized. The drive circuit energizes the coil of the electromagnetic solenoid to drive the electromagnetic solenoid. The drive circuit is provided with a series body of a diode and a current reducing part that reduces the current flowing to the diode, and the series system is connected in parallel with the coil of the electromagnetic solenoid. [Effect of invention]

According to the present invention, the effect that the transmission mechanism can be simplified can be achieved.

Hereinafter, a circuit breaker according to an embodiment of the present invention will be described in detail based on the drawings. However, the present invention is not limited by this embodiment.

Embodiment 1. The circuit breaker according to the first embodiment is an air circuit breaker that switches a circuit such as a low-voltage distribution line and opens the circuit when at least one of overcurrent and leakage is detected. Hereinafter, for convenience of explanation, the positive direction of the Z axis is referred to as upward, the negative direction of the Z axis is referred to as downward, the positive direction of the X axis is referred to as right, the negative direction of the X axis is referred to as left, and the positive direction of the Y axis is referred to as For the front, the negative direction of the Y axis is called the rear. In the following description, the so-called clockwise and counterclockwise directions refer to clockwise and counterclockwise directions in the drawings described later.

FIG. 1 is a diagram showing a configuration example of a circuit breaker according to Embodiment 1 of the present invention. As shown in FIG. 1, the circuit breaker 1 of the first embodiment includes a case 2 formed of an insulating material, and a power-side terminal 3 and a load-side terminal that are respectively installed in the case 2 through the wall 2 a of the case 2. 4. And the flexible conductor 5 whose one end 5a is connected to the load-side terminal 4 inside the housing 2. The circuit breaker 1 further includes a movable member 6 having one end 6a connected to the other end 5b of the flexible conductor 5, and one end 7a of the inside of the housing 2 is rotatably attached to the movable holder of the housing 2 7. A contact pressure spring 8 with one end and the other end respectively mounted on the other end 7b of the movable bracket 7 and the other end 6b of the movable 6.

The power-side terminal 3 is connected to a power-side conductor (not shown) outside the housing 2, and the load-side terminal 4 is connected to a load-side conductor (not shown) outside the housing 2. The power supply terminal 3 is electrically connected to the fixed contact 10 inside the housing 2, and the movable end 11 is electrically connected to the other end 6 b of the movable element 6. The power terminal 3 and the load terminal 4 are separated and fixed. In the example shown in FIG. 1, the power-side terminal 3 is arranged above the load-side terminal 4, but the load-side terminal 4 may be arranged above the power-side terminal 3.

The flexible conductor 5 is a flexible conductor, one end 5 a of which is connected to the load-side terminal 4, and the other end 5 b of which is connected to the mover 6. By this, the flexible conductor 5 electrically connects the load-side terminal 4 and the mover 6. As described above, the movable contact 11 is electrically connected to the movable element 6, and when the movable contact 11 contacts the fixed contact 10, the circuit breaker 1 becomes the power-on state in which the power-side terminal 3 and the load-side terminal 4 are electrically connected and energized . By moving the movable contact 11 away from the fixed contact 10, the circuit breaker 1 becomes a disconnected state in which the power-side terminal 3 and the load-side terminal 4 are electrically separated.

One end portion 7a of the movable bracket 7 is rotatably attached to the housing 2 around the bracket axis 12a via the bracket shaft 12. In addition, the intermediate portion 7c of the movable member holder 7 is rotatably attached to the one end portion 6a of the movable member 6 by the connecting pin 13. The movable bracket 7 is provided with a movable block 9.

The movable blocker 9 restricts the rotation angle of the movable element 6 with respect to the movable element holder 7 with the connection pin 13 as the center. In the state shown in FIG. 1, the one end 6 a of the movable element 6 is in contact with the movable element blocking portion 9. Therefore, the rotation of the other end portion 6b of the movable member 6 in the direction away from the other end portion 7b of the movable member holder 7 is restricted by the movable member blocking portion 9, but the other end portion 6b of the movable member 6 can be moved closer to the movable member holder The direction of the other end 7b of 7 is rotated.

The contact pressure spring 8 is a spring for pressing the movable contact 11 to the fixed contact 10. In the state shown in FIG. 1, the contact pressure spring 8 is in a compressed state shorter than the natural length, and has a predetermined initial contact pressure. Therefore, when the other end portion 6b of the movable member 6 rotates toward the other end portion 7b of the movable member holder 7, the distance between the other end portion 6b of the movable member 6 and the other end portion 7b of the movable member holder 7 becomes smaller and more Compression contact pressure spring 8.

The circuit breaker 1 further includes an electromagnetic solenoid 20 disposed inside the case 2 as an input actuator of the circuit breaker 1, and transmits a driving force of the electromagnetic solenoid 20 to the movable element 6 to make a movable contact 11 The transmission mechanism 30 that contacts and separates from the fixed contact 10, one end and the other end are respectively installed in the transmission mechanism 30 and the open pole spring 40 of the housing 2, a trip mechanism 50 that can maintain the input state and release the input state And a driving circuit 70 for driving the electromagnetic solenoid 20. The configuration of the drive circuit 70 is not limited to the configuration shown in FIG. 1.

The electromagnetic solenoid 20 includes a yoke 21 formed of a magnetic body, an input coil 22 wound around a bobbin (not shown) and fixed inside the yoke 21, and a core rod 23 capable of linearly reciprocating up and down And the protrusion 24 formed on the upper part of the core rod 23. At least one of the electromagnetic solenoid 20 and the housing 2 is provided with a guide member (not shown) for guiding the moving direction of the core rod 23 in the up and down direction, by which the core rod 23 can only be moved up and down Displacement. In addition, the core rod 23 and the protrusion 24 may be fixed, and the method of fixing the core rod 23 and the protrusion 24 is not limited.

When the drive circuit 70 is energized to the input coil 22, the electromagnetic solenoid 20 generates electromagnetic attraction. Due to the generation of this electromagnetic attraction force, the core rod 23 moves upward, and the movement of the core rod 23 stops when the gap 25 between the core rod 23 and the inside of the putting coil 22 disappears due to physical restrictions. In this way, the position where the iron core bar 23 stops is the position where the iron core bar 23 becomes the uppermost position, and is hereinafter referred to as the maximum input position or the maximum movement position. In addition, the structure in which the core rod 23 stops moving is not limited to the above example. For example, a configuration may be provided in which the protruding portion is provided at the lower portion of the core rod 23, and the protruding portion is caught in the bobbin or yoke 21 of the input coil 22 to physically stop the core rod 23.

After a certain time has elapsed since the position of the core rod 23 reached the maximum input position, the electromagnetic solenoid 20 is no longer generating electromagnetic suction force due to the energization of the input coil 22 being stopped. Since the electromagnetic attraction force of the electromagnetic solenoid 20 disappears, the iron core bar 23 is subjected to a force moving downward from the maximum input position due to, for example, the weight of the iron core bar 23 itself and the opening force of the opening spring 40.

The transmission mechanism 30 includes: a connecting link 31 that is rotatably connected to the protruding portion 24 of the electromagnetic solenoid 20 at one end 31 a, a lever 32 that is rotatably connected to the other end 31 b of the connecting link 31, and a turnable The insulating rod 33 is ground-connected to one end 32a of the lever 32.

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

The lever 32 is attached to a lever shaft 37 that can rotate around a lever axis 36 whose absolute position is fixed relative to the housing 2. The lever 32 is connected to the other end portion 31b of the connecting link 31 by a connecting pin 35 in a region closer to the trip mechanism 50 side than the lever shaft 37. In addition, the transmission mechanism 30 of the circuit breaker 1 includes an engagement pin 51 that is fixed to the other end 32 b of the lever 32.

The insulating rod 33 has one end 33a rotatably connected to the one end 32a of the lever 32 by a connecting pin 38, and the other end 33b is rotatably attached to one end 6a of the mover 6 by a connecting pin 13. The insulating rod 33 is made of a material with high electrical insulation such as resin. Therefore, when the circuit breaker 1 is in the energized state, the current flowing between the power supply side terminal 3 and the load side terminal 4 does not leak through the lever 32. It is not necessary that the entire insulating rod 33 is made of an insulating material as a whole, and if the connecting pin 13 and the connecting pin 38 are in an insulated state, a part may be made of a conductor.

The lever 32 and the insulating rod 33 are configured as a four-bar toggle mechanism with the lever axis 36 and the bracket axis 12a as fixed rotation centers. Therefore, as the lever axis 36, the connecting pin 38, and the connecting pin 13 are closer to the dead point where they are linearly arranged, the transmission mechanism 30 can be driven with a smaller force. The protruding portion 24, the connecting link 31, the lever 32, the insulating rod 33, the movable element 6 and the movable element bracket 7 constitute a link structure.

The open pole spring 40 is as described above, and one end portion and the other end portion thereof are respectively mounted on the lever 32 and the housing 2, and the elastic restoring force of the open pole spring 40 displaces the transmission mechanism 30 to the off-state position described later Directional bounce (that is, to impart potential energy).

The trip mechanism 50 is as described above, and has a function capable of maintaining the input state and releasing the input state. Figure 2 is an enlarged view of the trip mechanism shown in Figure 1. In the second figure, the case 2 of the circuit breaker 1 is shown in broken lines.

As shown in FIG. 2, the trip 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 and the other end are respectively mounted on the trip lever 52 and the first return spring 53 of the housing 2. The trip mechanism 50 further includes a trip bar 54 rotated by a driving force of an actuator (not shown), and a second return spring 55 to which the one end and the other end are respectively attached to the trip bar 54 and the housing 2 .

The engagement pin 51 protrudes from the lever 32 to the right orthogonal to the extending direction of the lever 32. The trip lever 52 is formed at one end 52a with a circular arc portion 56 having a circular arc surface, which is in contact with the engaging pin 51 during the loading process, and the other end 52b is capable of a fixed trip lever shaft The core 60 is rotatably attached to the housing 2 as a center. In addition, the intermediate portion of the trip lever 52 is formed with a recessed recess 52c on the rear side. An engagement surface 57 that engages with the engagement pin 51 in the throw-in state is formed in this recess 52c. In addition, in the other end portion 52b of the trip lever 52, an engagement portion 59 that engages with the trip bar 54 is provided in a region on the front side.

One end portion 54a of the trip bar 54 is rotatably attached to the housing 2 about the trip bar axis 61, and has a semi-circular semi-circular portion 58 centered around the trip bar axis 61. The semicircular portion 58 is formed by an arc portion 58a having an arc surface and a flat portion 58b having a flat surface.

With the driving force of an actuator not shown, the semicircular portion 58 rotates around the tripping rod axis 61 as a center until the arc portion 58a of the semicircular portion 58 engages with the other end portion 52b formed on the tripping lever 52 The portion 59 is engaged to restrict the rotation of the one end 52a of the trip lever 52 to the front side.

The second return spring 55 causes the other end portion 54b of the trip bar 54 facing upward to rotate in the direction toward the front with the trip bar axis 61 as a center, and urges the trip bar 54. That is, the second return spring 55 urges the trip bar 54 clockwise.

Fig. 3 is a diagram showing a configuration example of a circuit including a circuit breaker of a driving circuit according to the first embodiment. As shown in FIG. 3, the circuit breaker 1 of the first embodiment includes: a drive circuit 70 for energizing the input coil 22; an internal ON switch 71 provided on the front of the circuit breaker 1; The external ON switch 72 for the ON operation of the circuit breaker 1. By connecting the control power supply 73 to the terminal block provided on the upper part of the circuit breaker 1, electric power is supplied to the drive circuit 70.

The circuit breaker 1 further includes: an internal OFF switch 74 linked to an OFF operation button (not shown) provided on the front of the circuit breaker 1 and a trip attachment device that can perform the OFF operation of the circuit breaker 1 from a position away from the circuit breaker 1 75. The trip attachment device 75 can perform control to automatically trip the circuit breaker 1 when the voltage of the drive circuit 70 drops below the reference value.

In addition, the circuit breaker 1 further includes a detection unit 76 that detects overcurrent or leakage of the 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 converter 97 having a primary side provided in the circuit, and a trip relay 98 connected to the secondary side of the converter 97. The trip relay 98 detects an overcurrent or leakage based on the secondary side current of the converter 97, and outputs a high-level voltage as a trip command. The detection unit 76 may be configured as long as it can detect overcurrent or leakage and output a trip command, and is not limited to the example shown in FIG. 3.

The drive circuit 78 performs energization to the trip coil 77 when a trip command is output from the detection unit 76. When the trip coil 77 is energized, an actuator (not shown) is driven, and the trip bar 54 shown in FIG. 2 is driven to rotate counterclockwise by the actuator. Thereby, the engagement between the trip mechanism 50 and the transmission mechanism 30 is released. Therefore, the movable contact 11 is separated from the fixed contact 10, so that the circuit breaker 1 is turned off.

The drive circuit 70 flows current to the input coil 22 to energize the input coil 22 when the internal ON switch 71 performs the ON operation or when the external ON switch 72 performs the ON operation. Thereby, the iron core bar 23 moves, the fixed contact 10 and the movable contact 11 are brought into contact, and the circuit breaker 1 is brought into an energized state.

The drive circuit 70 stops the energization of the input coil 22 when the internal OFF switch 74 is used for the OFF operation, when the trip attachment device 75 is used for the OFF operation, or when the voltage of the drive circuit 70 drops below the reference value . In addition, the drive circuit 78 performs the trip coil when the OFF operation is performed by the internal OFF switch 74, the OFF operation is performed by the trip attachment device 75, or the voltage of the drive circuit 70 falls below the reference value. Power on 77.

FIG. 4 is a diagram showing an example of a specific configuration of the drive circuit in the first embodiment. As shown in FIG. 4, the drive circuit 70 in 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, and R3. The driving circuit 70 may be configured to include the resistor R4.

The rectifier circuit 80 rectifies and converts the AC voltage output from the control power supply 73 into a DC voltage Va. The constant voltage circuit 81 reduces the DC voltage Va output from the rectifier circuit 80 to output a constant voltage Vb. The constant voltage Vb is 24 V, for example. The control circuit 83 controls the switch 84 based on the state of each of the internal ON switch 71, the external ON switch 72, the internal OFF switch 74, and the trip attachment device 75, and the detection result of the overcurrent or leakage by the detection unit 76. It becomes ON state or OFF state.

The control switch 84 is connected between the other end of the input coil 22 that receives the supply of the DC voltage Va at one end and the ground, and connects and disconnects 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 input coil 22 is short-circuited to the ground, and the exciting current to the input coil 22 is supplied. When the control switch 84 is in the OFF state, the other end of the input coil 22 is disconnected from the ground, and the supply of the exciting current to the input coil 22 is stopped.

The series body 85 is connected in parallel with the input coil 22 of the electromagnetic solenoid 20. The series body 85 is composed of a diode 86 and a current reduction unit 87 connected in series. The anode of the diode 86 is connected to the control switch 84, and the cathode is connected to one end of the current reduction section 87. The other end of the current reduction unit 87 receives the application of the DC voltage Va.

The current reduction unit 87 reduces the return current flowing to the input coil 22 via the diode 86 when the control switch 84 is changed from the ON state to the OFF state to stop the energization of the input coil 22. With this current reduction section 87, the transmission mechanism 30 does not adopt a complicated structure, and as will be described later, it can be opened immediately after the switching operation of the circuit breaker 1 starts.

The control circuit 83 includes logical OR circuits 91 and 95, a latch circuit 92, a logical 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. The terminal T3 is connected to a switch box including an internal OFF switch 74 and a trip attachment 75. The terminal T4 is connected to the output terminal of the detection unit 76. The terminal T5 is connected to the micro switch 88, and the micro switch 88 is interlocked with the operation in which the core rod 23 is put in the put state.

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

The latch circuit 92 outputs a high-level voltage as the ON signal to the logic AND circuit 93 for a certain period of time, for example, when the control switch 84 is not in the ON state and outputs the input signal from the logic OR circuit 91. In addition, the latch circuit 92 has a built-in timer circuit, and when a certain time elapses from the time when the ON signal is output, it outputs a low-level voltage as the OFF signal to the logic AND circuit 93.

The logic AND circuit 93 has one input terminal connected to the terminal T3 inputting a disconnect signal from the internal OFF switch 74 or the trip accessory device 75, and the other input terminal connected to the output terminal of the latch circuit 92. The logic AND circuit 93 outputs the high level voltage of the ON signal to the control when the ON signal is output from the latch circuit 92 when the OFF signal is not output from the internal OFF switch 74 or the trip accessory device 75 Switch 84. In the example shown in Figure 4, the disconnect signal is a low-level voltage.

The control switch 84 is an input terminal connected to the terminal T6, and becomes an ON state when an ON signal is output from the logical AND circuit 93 via the terminal T6. When the control switch 84 is turned ON, the excitation current to the input coil 22 is supplied. With this, the throwing operation by the iron core bar 23 is started.

In addition, the logic AND circuit 93 outputs a low-level voltage as the OFF signal to the control switch when the OFF signal is output from the latch circuit 92, or when the OFF signal is output from the internal OFF switch 74 or the trip accessory device 75. 84. The control switch 84 is switched from the ON state to the OFF state when the signal output from the logical 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 input coil 22 is stopped.

The logical OR circuit 95 is a three-input one-output logical OR circuit. The logical OR circuit 95 is 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. In addition, the input terminal of the logical negation circuit 94 is connected to the terminal T3.

The logical OR circuit 95 is used as a reset when the trip command output is output from the detection unit 76, when the internal OFF switch 74 or the trip accessory device 75 outputs a disconnection signal, or when the micro switch 88 outputs a high-level voltage. The high level voltage of the signal is output to the latch circuit 92. The latch circuit 92 continuously outputs the ON signal, and if the reset signal is output from the logical OR circuit 95, the output signal is switched from the ON signal to the OFF signal. In addition, the configuration of the control circuit 83 is not limited to the configuration shown in FIG. 4, and the control circuit 83 may be a circuit that can realize the above-mentioned functions.

Hereinafter, the operation of the circuit breaker 1 configured as described above will be specifically described. Fig. 5 is a configuration diagram showing the opened state of the circuit breaker of the first embodiment, and Fig. 6 is an enlarged view of the trip mechanism shown in Fig. 5. FIG. 7 is a configuration diagram showing the state at the moment when the contacts of the circuit breaker of the first embodiment start to contact, and FIG. 8 is an enlarged view of the trip mechanism shown in FIG. 7. Fig. 9 is a structural diagram showing a state where the circuit breaker of Embodiment 1 reaches the maximum input position, Fig. 10 is an enlarged view of the trip mechanism shown in Fig. 9, and Fig. 11 is the trip lever from Fig. 9 An enlarged view of the trip mechanism after turning in the state shown. Fig. 12 is a configuration diagram showing a state where the circuit breaker of the first embodiment reaches the input completion position, and Fig. 13 is an enlarged view of the trip mechanism shown in Fig. 12. In FIGS. 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 off state, the iron core rod 23 constituting the electromagnetic solenoid 20 reaches the lowermost part due to the action of the open pole spring 40 and physically contacts the case 2 and cannot be lowered further . At this time, the size of the gap 25 becomes the largest.

In addition, when the iron core bar 23 is located at the lowermost portion, the other end 32b of the lever 32 is located below the one end 32a, and is located at a position facing the left and right direction of the one end 52a of the trip lever 52. In addition, the one end portion 52a of the trip lever 52 imparts tension to the rear by the elastic restoring force of the first return spring 53. Therefore, the engagement pin 51 attached to the other end 32b of the lever 32 comes into contact with the arc portion 56 formed at the one end 52a of the trip lever 52.

When the circuit breaker 1 is in an open state, the movable block 6 of the movable bracket 7 restricts the rotation of the movable end 6 of the movable end 6 toward the direction away from the other end 7b of the movable holder 7 , That is, the clockwise rotation of the movable element 6 is restricted. In addition, as described above, the contact pressure spring 8 has a certain initial contact pressure in advance, so as long as the reaction force against the movable contact 11 pushing against the fixed contact 10 does not exceed the initial contact pressure, one end of the mover 6 The portion 6a will not leave the movable blocker 9.

As shown in FIG. 5, when the circuit breaker 1 is in the off state, the separation distance between the movable contact 11 of the mover 6 and the fixed contact 10 becomes the maximum. In the state shown in FIG. 5, as shown in FIG. 6, the flat portion 58b of the semi-circular portion 58 of the trip bar 54 is the elastic restoring force of the second return spring 55 that rotates the trip bar 54 clockwise, The corner portion of the engaging portion 59 formed at the other end 52b of the trip lever 52 contacts. Therefore, the rotation of the trip lever 52 is restricted and the state shown in FIG. 6 is maintained.

In addition, the one end 52a of the trip lever 52 is an elastic restoring force of the first return spring 53 which rotates the trip lever 52 clockwise by turning the one end 52a of the trip lever 52 toward the rear. The engagement pin 51 of the lever 32 contacts, thereby restricting the clockwise rotation of the trip lever 52 to maintain the state shown in FIG. 6.

Next, the operation of the drive circuit 70 that energizes the input coil 22 of the electromagnetic solenoid 20 when the circuit breaker 1 is in the open state will be described with reference to FIG. 4. In the following description, it is assumed that the control power supply 73 supplies power to the drive circuit 70, and the rectifier circuit 80 and the constant voltage circuit 81 operate normally.

When the circuit breaker 1 is in the off state and short-circuited by the ON operation of the internal ON switch 71 or the external ON switch 72, the input signal is output to the control circuit 83 from the internal ON switch 71 or the external ON switch 72. The control circuit 83 outputs an ON signal to the control switch 84 when receiving the input signal from the internal ON switch 71 or the external ON switch 72. With this, the energization of the input coil 22 is performed.

When the drive circuit 70 energizes the input coil 22, as shown in FIG. 7, the core rod 23 moves upward. As the core rod 23 moves upward, the lever 32 rotates about the lever axis 36 as a center, and the connection angle of the lever 32 and the insulating rod 33 becomes smaller. The connection angle is the angle between the extending direction of the lever 32 and the extending direction of the insulating rod 33. As the circuit breaker 1 changes from the state shown in FIG. 5 to the state shown in FIG. 7, the connection angle becomes smaller.

As the connection angle becomes smaller, the movable element 6 moves forward, so that the movable contact 11 contacts the fixed contact 10. The state at the moment when the movable contact 11 and the fixed contact 10 start contacting is the contact contact starting state. At this time, between the power-side terminal 3 and the load-side terminal 4, the fixed contact 10, the movable contact 11, and the flexible conductor 5 are brought into an energized state.

Also, as shown in FIGS. 6 and 8, the engagement pin 51 mounted on the front end of the lever 32 that can rotate about the lever axis 36 as the center, as the connection angle becomes smaller, to maintain and receive the first return The state in which the trip lever 52 is in contact with the elastic restoring force of the spring 53 slides along the arc portion 56 formed at one end 52 a of the trip lever 52.

The arc portion 56 of the trip lever 52 is formed in an arc shape centered on the lever axis 36 of the lever 32. Therefore, from the state shown in FIG. 6 to the state shown in FIG. 8, there is no change even if the position where the engagement pin 51 moves the trip lever 52.

When the circuit breaker 1 reaches the contact abutment starting state, the movable element 6 restricts the clockwise rotation due to the movable element blocking portion 9 provided in the movable element holder 7, but it can rotate counterclockwise. When the core rod 23 continues to advance from the contact abutment state shown in FIG. 7, the contact reaction force from the fixed contact 10 to the movable contact 11 attached to the other end portion 6b of the mover 6 increases, Therefore, the other end portion 6b of the movable member 6 rotates counterclockwise about the connecting pin 13 and approaches the other end portion 7b of the movable member holder 7. Therefore, the contact pressure spring 8 is further compressed from the state shown in FIG. 7.

As shown in FIG. 9, when the core rod 23 moves upward so that the position of the core rod 23 reaches the maximum input position, the movable contact 11 receives the contact reaction force from the fixed contact 10 and moves relative to the movable holder 6 of the movable member 6 The rotation angle of 7 becomes the maximum, and the compression amount of the contact pressure spring 8 also becomes the maximum.

In addition, when the position of the core rod 23 reaches the maximum input position, as shown in FIG. 10, the engagement pin 51 sliding on the arc portion 56 of the trip lever 52 is reached through the arc portion 56 of the trip lever 52 The upper part of the engaging surface 57 of the trip lever 52 is tripped. Therefore, the engagement pin 51 is in a state where the trip lever 52 is not contacted for an instant.

The trip lever 52, which was originally restricted by the engagement pin 51 and cannot rotate clockwise, is released when the relationship with the engagement pin 51 becomes non-contact. Therefore, as shown in FIG. 11, the concave portion 52 c of the trip lever 52 is rotated clockwise by the elastic restoring force of the first return spring 53 and comes into contact with the engagement pin 51. Since the engagement pin 51 comes into contact with the recess 52c of the trip lever 52, the clockwise rotation of the trip lever 52 is restricted.

In addition, 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 which was originally restricted by the trip lever 52 and cannot rotate clockwise is returned by the second The elastic restoring force of the spring 55 rotates clockwise, and as shown in FIGS. 10 and 11, the arc portion 58 a of the semi-circular portion 58 rotates above the engaging portion 59 and stops. In addition, the circuit breaker 1 is provided with a stopper (not shown) that restricts the rotation of the trip bar 54 and restricts the rotation of the trip bar 54 in the state shown in FIGS. 10 and 11.

The micro switch 88 shown in FIG. 4 is in a short-circuit state in conjunction with the operation in which the core rod 23 is put into the input state, so the high level voltage is output from the micro switch 88 to the control circuit 83. The control circuit 83 outputs an OFF signal to the control switch 84 when it receives the high-level voltage from the micro switch 88. As a result, when the iron core bar 23 is in the put state, the energization to the put coil 22 is stopped. In addition, when the core rod 23 is in the put-in state, the position of the core rod 23 is at the maximum put-in position.

With this, after the position of the core rod 23 becomes the maximum input position, the energization of the electromagnetic solenoid 20 is ended. When the energization of the electromagnetic solenoid 20 is completed, the driving of the transmission mechanism 30 by the electromagnetic solenoid 20 is released.

Therefore, the elastic restoring force of the compressed contact pressure spring 8 acts between the fixed contact 10 and the movable contact 11, and the iron rod 23 of the electromagnetic solenoid 20 is cut off from the maximum input position via the transmission mechanism 30. The restoring force is pushed by the moving direction of the open position. In addition, the force of the core rod 23 itself and the opening force of the opening spring 40 that causes the core rod 23 to move from the maximum insertion position to the off-state position also act simultaneously. As a result, the core rod 23 starts to move downward from the maximum insertion position shown in FIG. 9.

When the core rod 23 moves downward from the maximum input position, the lever 32 rotates counterclockwise with the lever axis 36 as the center. When the lever 32 rotates counterclockwise, the engagement pin 51 rotates counterclockwise with the lever axis 36 as the center. As shown in FIGS. 12 and 13, it contacts the engagement surface 57 of the trip lever 52 and becomes a core rod 23 When the input completion position is reached, the input operation of the circuit breaker 1 is completed.

The trip lever 52 is such that when the core rod 23 reaches the throw-in completion position, the arc portion 58a of the semi-circular portion 58 engages with the flat portion of the engaging portion 59 formed at the other end 52b of the trip lever 52 to restrict the trip lever One end portion 52a of 52 rotates forward.

Therefore, even if a force due to the elastic restoring force of the contact pressure spring 8 acts on the trip lever 52 via the engaging pin 51 to rotate counterclockwise relative to the trip lever axis 60, the trip lever 52 is as shown in FIG. 13 As shown, it cannot be rotated because it is restricted by the arc portion 58a of the semicircular portion 58.

As described above, when the circuit breaker 1 is in an open state, the contact pressure spring 8 is preliminarily applied with a certain initial contact pressure, and is set to be fixed with respect to the fixed contact from the moment when the movable contact 11 begins to contact the fixed contact 10 The contact pressure of the movable contact 11 at the point 10 increases. Therefore, when the circuit breaker 1 is in the energized state, not only can the occurrence of separation between the contacts due to the electromagnetic repulsion force between the movable contact 11 and the fixed contact 10 be prevented, but also the movement after the trip command is issued can be accelerated The separation speed of the contact 11 and the fixed contact 10, that is, the opening speed.

Next, the tripping operation of the circuit breaker 1 will be described. The operation of the drive circuit 70 when an overcurrent or leakage occurs in the circuit in the state where the circuit breaker 1 is in the input completion position shown in FIG. 12 will be described with reference to FIG. 4.

The detection unit 76 outputs a trip command when it detects overcurrent or leakage in the circuit. The drive circuit 78 performs energization to the trip coil 77 when receiving the trip command output by the detection unit 76. When the energization of the trip coil 77 starts, an actuator (not shown) is driven, and the trip bar 54 shown in FIGS. 12 and 13 is driven to rotate counterclockwise by the actuator.

When the trip bar 54 rotates counterclockwise, 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 of the arc portion 58a and the engagement portion 59 is released. Therefore, the trip lever 52 is rotated counterclockwise about the trip lever axis 60 by the force of the elastic restoring force of the contact pressure spring 8, and the iron core rod 23 passes through the state shown in FIG. 7 and returns to the 5 Figure off position. With this, the tripping of the circuit breaker 1 is completed.

In addition, immediately after the start operation of the circuit breaker 1 is started, the control circuit 83 outputs an ON signal to control the switch 84 to be in an ON state, so that an excitation current flows through the input coil 22. When the excitation current flows in the input coil 22, if a trip command is output from the detection unit 76, the control circuit 83 outputs an OFF signal to the control switch 84. With this, the supply of the exciting current to the input coil 22 is stopped.

When the control switch 84 is turned off and the supply of the exciting current to the input coil 22 is stopped, the input coil 22 generates a counter electromotive force. This back electromotive force is also called a surge voltage. In the drive circuit 70, a diode 86 is provided to prevent the surge voltage from damaging the control switch 84 from overvoltage. This diode 86 is also called a protective diode or a reflux diode.

Due to the surge voltage, a return current flows through the diode 86 to the input coil 22. In order to reduce the return current, as described above, the circuit breaker 1 is provided with a current reduction section 87 connected in series with the diode 86. When the supply of the exciting current to the input coil 22 is stopped, the current reduction unit 87 reduces the return current flowing through the diode 86 to the input coil 22. Therefore, it is possible to prevent the state of being maintained in the thrown-in state due to the return current, and prevent the return operation of the mandrel immediately after the throwing-in operation from being delayed. Therefore, the transmission mechanism 30 can have a simple structure.

14 to 16 are diagrams showing configuration examples of the current reduction unit and the control switch in the first embodiment. In the examples shown in FIGS. 14 and 16, the current reduction section 87 is composed of the resistor R10. In the example shown in FIG. 15, the current reduction unit 87 is formed by connecting the resistor R10 and the capacitor C10 in series.

The current reduction section 87 shown in FIG. 15 is configured by connecting the resistor R10 and the capacitor C10 in series, but it may also be configured by connecting the resistor R10 and the capacitor C10 in parallel. The configuration including the resistor R10 and the capacitor C10 is also called a snubber circuit.

In addition, the example shown in FIGS. 14 and 15 uses the N-channel MOSFET 79a to configure the control switch 84, and the example shown in FIG. 16 uses the P-channel MOSFET 79b to configure the control switch 84. In the case of controlling the switch 84 shown in FIG. 16, the control circuit 83 is configured to output a signal having a polarity opposite to the example shown in FIG. 4 from the terminal T6.

In addition, in FIG. 16, the current reduction section 87 may be configured using the above-mentioned snubber circuit. In addition, in order to be able to quickly consume the inductance energy of the input coil 22 with the resistor R10, it is preferable to use a fast recovery diode for the diode 86.

When the supply of the exciting current to the input coil 22 is stopped, if there is no current reduction section 87, the return current flowing through the diode 86 to the input coil 22 will be dedicated to maintaining the electromagnetic solenoid 20 in the input operation . Therefore, it may be difficult to open the circuit breaker 1 immediately after the switching operation of the circuit breaker 1 is started. However, since the circuit breaker 1 of the present embodiment is provided with a current reducing part 87, the flow to the input coil via the diode 86 can be reduced 22 return current.

Thereby, without using a complicated transmission mechanism, the opening operation of the circuit breaker 1 can be quickly opened immediately after the start of the switching operation. In addition, the value of the resistance R10 of the current reduction unit 87 and the value of the capacitor C10 are set so that after the supply of the excitation current to the input coil 22 is stopped, the return current is reduced so as not to hinder the jump by the trip mechanism 50 Off. For example, the value of the resistor R10 constituting the current reduction section 87 is set to a value that can reduce the return current so that the input force generated by the return current is lower than the electromagnetic repulsive force and the trip force at the time of disconnection.

In addition, the above example has explained an example in which an overcurrent or leakage is detected immediately after the start of the start operation, but the output of the circuit breaker 1 from the internal OFF switch 74 or the trip attachment device 75 is broken immediately after the start of the start operation When the signal is turned on, it can also be disconnected immediately after the input operation without using a complicated transmission mechanism.

Here, the relationship between the moving position of the core rod 23 and the load acting on the electromagnetic solenoid 20 will be described. Fig. 17 is a diagram showing the relationship between the moving position of the core rod and the load acting on the electromagnetic solenoid in the first embodiment. The core rod 23 is moved from the position shown in FIG. 5 to the maximum input position shown in FIG. 9.

Hereinafter, the movement of the iron core rod 23 upward is referred to as forward, the movement of the iron core rod 23 downward is referred to as backward, the movement position when the iron core rod 23 is advanced is referred to as the forward position, and the movement position when the iron core rod 23 is retracted is referred to as For the backward position, the load acting on the electromagnetic solenoid 20 when the iron core bar 23 moves forward is referred to as the forward load, and the load acting on the electromagnetic solenoid 20 when the iron core bar 23 moves backward is referred to as the reverse time load.

As shown in FIG. 17, when the advance position of the iron core bar 23 is in the off-state position from the off-state position to the contact abutment start position, it is in a state where the fixed contact 10 and the movable contact 11 are not in contact Bottom drive transmission mechanism 30. Therefore, when the advance position of the core rod 23 is in the off state position, the load acting on the electromagnetic solenoid 20 is relatively small. Then, when the advancing position of the core rod 23 becomes the contact abutment start position, the contact between the movable contact 11 and the fixed contact 10 starts. Therefore, the lever 32 receives the elastic restoring force from the contact pressure spring 8 via the connecting pins 13 and 38 as the load torque that rotates counterclockwise about the lever axis 36, and the input load acting on the electromagnetic solenoid 20 changes rapidly Big.

However, when the iron core bar 23 is further advanced, the component of the elastic restoring force from the contact pressure spring 8 acting on the connecting pin 38 that becomes the point of action is a component perpendicular to the direction of the straight line connecting the lever axis 36 and the connecting pin 38. Become smaller. Therefore, the counterclockwise load torque centering on the lever axis 36 starts to decrease. As the load torque decreases, the input load of the electromagnetic solenoid 20 required to rotate the lever 32 also decreases.

The iron core rod 23 further advances, and the advanced position finally reaches the maximum input position after the start of the input operation. At this time, the mechanical state of the circuit breaker 1 is that the lever 32 and the insulating rod 33 are in a nearly linear state, and the lever 32 and the insulating rod 33 The toggle mechanism formed is closest to the dead center. Therefore, the component of the elastic restoring force from the contact pressure spring 8 acting on the connecting pin 38 that is perpendicular to the straight line connecting the lever axis 36 and the connecting pin 38 is close to 0, and the electromagnetic spiral required to rotate the lever 32 The input load of the tube 20 is also sharply close to zero. That is, the iron rod 23 of the electromagnetic solenoid 20 is reduced in order to apply the load torque to the lever 32 in accordance with the input force of the electromagnetic solenoid 20 that increases with the displacement from the off-state position to the put-in state position. The composition of the distance of the load force acting distance. Therefore, not only can the electromagnetic suction force of the electromagnetic solenoid 20 be efficiently used for the switching operation of the circuit breaker 1, but also an electromagnetic solenoid of a magnitude corresponding to a change in the load force acting distance required for the switching operation of the circuit breaker 1 can be used For the tube 20, the electromagnetic solenoid 20 can be reduced in size and cost. In addition, the circuit breaker 1 of the first embodiment is configured such that the core rod 23 stops advancing before the toggle mechanism passes the dead point, and since the dead state is not passed when the input state is changed to the off state, the trip mechanism 50 can be avoided The composition becomes complicated.

When the contact of the circuit breaker 1 is in contact, when the movable contact 11 comes into contact with the fixed contact 10 and the contact pressure generated by the elastic restoring force from the contact pressure spring 8 occurs, the insulation rod 33 and the lever are generated. 32 and the pushing force acting on the lever shaft 37 in the front and back directions. When the pushing force on the lever shaft 37 is generated, friction torque on the lever shaft 37 is generated, and the electromagnetic spiral caused by the component in the front-rear direction of the load transmitted to the electromagnetic solenoid 20 via the connecting link 31 is added The sliding friction load in the vertical direction of the tube 20 increases the input load of the electromagnetic solenoid 20 and becomes a friction force that cannot be ignored.

After the core rod 23 reaches the maximum input position, the direction of the frictional force acting on the entire transmission mechanism 30 also changes as the movement direction of the core rod 23 changes to retreat. Therefore, the load applied to the trip mechanism 50 in the input state can be reduced by reducing the effect of the trip load due to friction.

As described above, since the load applied to the trip mechanism 50 in the throw-in state can be reduced, the configuration of the trip mechanism 50 can be simplified. Therefore, the trip mechanism 50 can be miniaturized, the circuit breaker 1 can be miniaturized, and the reliability of the trip mechanism 50 can be improved by reducing the number of components of the trip mechanism 50.

Until the movable contact 11 comes into contact with the fixed contact 10, frictional forces are mainly generated as the rotating parts of the connecting pins 13, 38, the lever shaft 37, and the connecting pins 34, 35 rotate. Therefore, compared with the state after the contact pressure caused by the elastic restoring force from the contact pressure spring 8 after the movable contact 11 comes into contact with the fixed contact 10, until the movable contact 11 comes into contact with the fixed contact 10, The friction torque of the lever shaft 37 and the sliding friction load of the electromagnetic solenoid 20 in the vertical direction are small. Therefore, as shown in FIG. 17, the difference between the input load caused by the friction force before the contact abuts and the input load caused by the friction force after the contact abutment is smaller than the difference.

Regarding the series of input operations and input loads of the circuit breaker 1, the load characteristics necessary for the input of the electromagnetic solenoid 20 in the circuit breaker 1 can be formulated. For example, the load characteristics necessary for the input of the electromagnetic solenoid 20 in each state of FIG. 5, FIG. 7, FIG. 9, and FIG. 12 can be formulated to design a mechanism to greatly reduce the friction of the mechanism. The circuit breaker 1 has a mechanical load at the time of tripping, and the input load characteristic of the electromagnetic solenoid 20 has hysteresis.

As described above, the circuit breaker 1 of the first embodiment includes the case 2, the power-side terminal 3, the mover 6, the electromagnetic solenoid 20, the transmission mechanism 30, and the drive circuit 70. The power-side terminal 3 is an example of a fixed terminal, a fixed contact 10 is attached, and is fixed to the case 2. The movable element 6 is equipped with a movable contact 11 facing the fixed contact 10. The electromagnetic solenoid 20 has a core rod 23 that moves linearly. The core rod 23 is an example of a core rod. The transmission mechanism 30 causes the movable element 6 to move with the movement of the iron core rod 23, from the disconnected state where the movable contact 11 is separated from the fixed contact 10 to the powered-on state where the movable contact 11 contacts the fixed contact 10 and is energized . The drive circuit 70 energizes the input coil 22 of the electromagnetic solenoid 20 to drive the electromagnetic solenoid 20. The drive circuit 70 is provided with a series body 85 of both a diode 86 and a current reducing part 87 that reduces the current flowing to the diode 86, and the series body 85 is connected in parallel with the input coil 22 of the electromagnetic solenoid 20. Thereby, the disconnection immediately after the start of the throwing operation can be performed without using a complicated mechanism. Therefore, the transmission mechanism 30 can be simplified.

In addition, the current reduction unit 87 includes the resistor R10, or includes the resistor R10 and the capacitor C10. By this, the current flowing to the diode 86 can be easily reduced.

In addition, the circuit breaker 1 is provided with: detecting the overcurrent or leakage of the circuit in the conductive state by the contact of the fixed contact 10 and the movable contact 11, and outputting the trip command indicating the detection result as the detection result Detection section 76. The drive circuit 70 stops the energization of the input coil 22 based on the trip command output by the detection unit 76. Thereby, when an overcurrent or a leakage of the circuit occurs immediately after the start operation of the circuit breaker 1, the disconnection immediately after the start operation of the circuit breaker 1 can be performed without using a complicated mechanism. Therefore, the transmission mechanism 30 can be simplified. Among them, the trip command is an example of the detection signal.

In addition, the circuit breaker 1 of the first embodiment includes a trip mechanism 50. The trip mechanism 50 can be engaged with the transmission mechanism 30 to maintain the input state, and can be released from the engagement with the transmission mechanism 30 to release the maintenance of the input state. The transmission mechanism 30 includes a lever 32 and an insulating rod 33. The lever 32 rotates about the lever axis 36 fixed to the housing 2 as the iron core rod 23 moves. The lever axis 36 is an example of a first axis. The insulating rod 33 has one end 33a rotatably connected to the one end 32a of the lever 32 and the other end 33b rotatably connected to the mover 6. The core rod 23 of the electromagnetic solenoid 20 reaches the maximum movement position that restricts the movement of the core rod 23 before the toggle mechanism composed of the lever 32 and the insulating rod 33 reaches the dead point. Therefore, for example, by setting the maximum moving position of the core rod 23 to a position immediately before the toggle mechanism reaches the dead point, the lever effect of the toggle mechanism can be used to make the electromagnetic solenoid 20 required to rotate the lever 32 The input load suddenly dropped to zero. Therefore, the load on the trip mechanism 50 in the put state can be reduced. The above-mentioned position immediately before the dead point refers to a position that will not reach the dead point even if there is a manufacturing error. The maximum moving position is an example of the first position. In addition, the trip mechanism 50 moves backward after the core rod 23 reaches the maximum movement position, and engages with the transmission mechanism 30 at the state of the input completion position to maintain the input state. The input completion position is an example of the second position. With this, the direction of the frictional force acting on the entire transmission mechanism 30 also changes when the moving direction of the iron core bar 23 is shifted back, so that the load reduction effect due to the frictional force, that is, the input load The hysteresis of the characteristic reduces the load of the trip mechanism 50 in the input state. Therefore, the necessity of making the trip mechanism of the circuit breaker into a complicated mechanism can be reduced, and the trip mechanism 50 can be reduced in size and improved in assemblability.

In addition, the circuit breaker 1 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 part. In addition, the trip 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 of being urged toward the engagement pin 51, and maintains a state of contact with the engagement pin 51 during the input process from the disconnected state to the input state In a state where the iron core bar 23 is at the input completion position, it engages with the engagement pin 51 to restrict the lever 32 from rotating around the lever axis 36. The trip bar 54 is used to restrict and release the rotation of the trip lever 52. In this way, the trip mechanism 50 can be composed of at least two members including the trip lever 52 and the trip bar 54 in addition to the engagement pin 51, so the trip mechanism 50 can be miniaturized and the assembly can be improved . In addition, the trip lever 52 is brought into contact with the engagement pin 51 from the disconnected state to the throw-in state, so the trip can be easily performed only by changing the movable amount of the trip lever 52 in the direction away from the engagement pin 51. Take off.

In addition, the trip lever 52 is provided with an engaging pin 51 which is movably contacted during the input process, and has an arc-shaped arc portion 56 centered on the lever axis 36 as the center, and an engaging pin in the input state 51 engages the concave portion 51c. Thereby, the position of the trip lever 52 does not change during the throw-in process, so that the throw-in load of the electromagnetic solenoid 20 that drives the transmission mechanism 30 can be suppressed from changing due to the trip lever 52 during the throw-in process.

In addition, the trip lever 52 includes a semicircular portion 58 formed with an arc portion 58a and a flat portion 58b and rotating around the trip bar axis 61 fixed to the housing 2 as a center. The tripping rod 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 off state to restrict rotation, and contacts the arc portion 58a of the semicircular portion 58 in the throwing state to restrict rotation. Thereby, by merely rotating the trip lever 52, the amount of movement of the trip lever 52 in the direction away from the engagement pin 51 can be easily adjusted.

Embodiment 2. The circuit breaker of the second embodiment differs from the circuit breaker 1 of the first embodiment in that it is provided with a drive circuit that realizes the function of judging whether to make an instantaneous trip (MCR) based on the current at the time of input. Hereinafter, the constituent elements having the same functions as those of the first embodiment are denoted by the same symbols, and descriptions thereof will be omitted, and the differences from the circuit breaker 1 of the first embodiment will be mainly described.

First, the MCR mechanism that realizes the MCR function will be described. The MCR mechanism makes the instantaneous tripping characteristic effective when the circuit breaker is put into operation to instantaneously trip the short-circuit accident when the circuit breaker is put into operation, and makes the instantaneous tripping characteristic invalid after the circuit breaker is put into operation. With this, the selection and coordination field of load devices with large inrush current or lower circuit breakers can be expanded.

Figures 18 and 19 are diagrams showing examples of the configuration of the MCR mechanism. Figure 18 shows the state when the circuit breaker is put into operation, and Figure 19 shows the state after the circuit breaker is put into operation. Hereinafter, the so-called clockwise and counterclockwise means the clockwise and counterclockwise directions in FIGS. 18 and 19. Furthermore, 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 board 101, an insulating board 102, a micro switch 103, and an auxiliary board 104. The insulating plate 102, the micro switch 103, and the auxiliary plate 104 are fixed to the MCR board 101 by locking two points with screws 105. The micro switch 103 adopts normally closed terminals. The micro switch 103 is provided with an actuating lever 106 which is fixed to a rotating shaft 109 rotatably supported on the MCR board 101.

The MCR mechanism 100 includes a weight 107 attached to the other end of the actuation lever 106 and a spring 108 hooked between the MCR plate 101 and the weight 107. The spring 108 urges the actuating lever 106 in a counterclockwise direction with the rotation shaft 109 as the center. Therefore, in a state where the opening operation of the circuit breaker 1 is not performed, as shown in FIG. 19, one end of the actuation lever 106 presses the micro switch button 103a. The micro switch 103 constantly transmits an ON signal to the trip relay 98 shown in FIGS. 3 and 4 while the micro switch button 103a is pressed. Therefore, in the trip relay 98, the instantaneous trip characteristic becomes invalid.

The driven portion 106a of the actuation lever 106 is shaped to receive the operation of the lever shaft 37 in the mechanism portion that opens and closes the main contact of the circuit breaker 1. The actuation lever 106 is rotated by the lever shaft 37 when the circuit breaker 1 is put into operation, the driven part 106a rotates clockwise around the rotation shaft 109, and one end thereof presses the micro switch button 103a for about several microseconds. Accordingly, the micro switch 103 sends an OFF signal of about several microseconds to the trip relay 98. In the trip relay 98, the instantaneous trip characteristic becomes effective during the OFF signal input of about several microseconds. As described above, the MCR mechanism 100 can invalidate the instantaneous tripping characteristics other than when the circuit breaker 1 is put in operation, and can make the instantaneous tripping characteristics effective when the circuit breaker 1 is put in operation.

Next, the drive circuit of the circuit breaker according to the second embodiment will be described. Fig. 20 is a diagram showing a configuration example of a circuit including a circuit breaker of a driving circuit according to Embodiment 2 of the present invention. As shown in FIG. 20, the drive circuit 70A of the circuit breaker 1A of the second embodiment is different from the drive circuit 70 of the circuit breaker 1 in that it has an MCR circuit 79 that realizes the MCR function.

As shown in FIG. 20, the MCR circuit 79 is connected to the terminal T6 and receives input of a signal output from the logical AND circuit 93. The signal input from the logical AND circuit 93 to the MCR circuit 79 and the signal input from the logical AND circuit 93 to the control switch 84 are the same signal. The MCR circuit 79 outputs an ON signal or an OFF signal to the trip relay 98 according to the signal input from the logical AND circuit 93. The MCR circuit 79 includes a photocoupler and the like in order to maintain the insulation of the control circuit 83 and the trip relay 98.

The MCR circuit 79 outputs the ON signal of the high-level voltage to the trip relay 98 when the ON signal is input from the logical AND circuit 93. The ON signal output to the trip relay 98 is used to make the instantaneous trip feature effective, and is also sometimes referred to as an MCR control signal below. The trip relay 98 outputs a trip command to the drive circuit 78 when overcurrent or leakage is detected based on the secondary side current of the converter 97 in the state where the MCR control signal is output from the MCR circuit 79. As a result, the tripping coil 77 is energized, and the circuit breaker 1A is turned off.

In addition, when the OFF signal is input from the logical AND circuit 93, the MCR circuit 79 outputs a low-level voltage for invalidating the instantaneous tripping characteristic to the tripping relay 98. The trip relay 98 is in a state where a low-level voltage is output from the MCR circuit 79, and even if overcurrent or leakage is detected based on the secondary side current of the converter 97, a trip command is not output to the drive circuit 78 . This makes it possible to invalidate the instantaneous tripping characteristic after the switching operation of the circuit breaker 1A is completed.

Fig. 21 is a timing chart for explaining the MCR function of the circuit breaker in the second embodiment. At time t1, when the internal ON switch 71 or the external ON switch 72 is turned ON, as shown in FIG. 21, the slave OR circuit 91 outputs the voltage as the high level of the input signal to the latch circuit 92. The latch circuit 92 outputs a high-level voltage to the logical AND circuit 93 when the input signal is output from the logical OR circuit 91. Therefore, the logical AND circuit 93 outputs the high-level voltage as the ON signal to the MCR circuit 79 and the control switch 84. The MCR circuit 79 outputs the high level voltage as the MCR control signal to the trip relay 98 while the logic AND circuit 93 outputs an ON signal. This makes the instantaneous tripping characteristic effective when the circuit breaker 1A is put into operation.

The control switch 84 is turned ON when the ON signal is output from the logical AND circuit 93 via the terminal T6. Since the control switch 84 is turned ON, the exciting current to the input coil 22 is supplied. As a result, the throw-in operation by the iron core bar 23 is started, and at time t2, a high-level voltage is output to the control circuit 83 from the micro switch 88 linked to the operation of the iron core bar 23 in the throw-in state. When the micro switch 88 outputs a high level voltage, the latch circuit 92 is reset, and a low level voltage as an OFF signal is output from the control circuit 83 to the control switch 84.

In this way, the logic AND circuit 93 outputs the voltage as the high level of the ON signal during the period from time t1 to time t2, so the MCR circuit 79 outputs the high level as the MCR control signal during the period from time t1 to time t2 Position voltage to trip relay 98. The period from time t1 to time t2 is, for example, about 200 microseconds, whereby a stable MCR control signal is output to the trip relay 98. Therefore, while the MCR control signal is output, the instantaneous tripping characteristics of the tripping relay 98 can be effectively stabilized.

In addition, after time t2, the logic AND circuit 93 outputs a low-level voltage as an OFF signal. The MCR circuit 79 outputs a low level voltage to the trip relay 98 while the logic AND circuit 93 outputs an OFF signal. As a result, the instantaneous tripping characteristic is invalidated after the circuit breaker 1A is completed.

In addition, 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. At this time, in the control circuit 83, for example, a logical NOT circuit is provided between the logical AND circuit 93 and the terminal T6. The MCR circuit 79 outputs the low level voltage as the MCR control signal to the trip relay 98 while the low level voltage is output from the control circuit 83 as the ON signal. In addition, the MCR control signal output from the MCR circuit 79 may also be a low-level voltage. At this time, the trip relay 98 is effective at the instantaneous trip characteristic with a low level voltage.

As described above, the circuit breaker 1A of the second embodiment includes: a trip relay 98 that outputs a trip command when an overcurrent or leakage occurs in a circuit that is in a conductive state by contact between the fixed contact 10 and the movable contact 11 . The drive circuit 70A includes a control circuit 83 as an example of a first control circuit, and an MCR circuit 79 as 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 is interlocked according to the action that the iron rod 23 of the electromagnetic solenoid 20 becomes in the on state The signal output by the micro switch 88 stops the output of the ON signal. 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 output from the control circuit 83 so that the trip command from the trip relay 98 can be output. With this, the circuit breaker 1A can realize the MCR function without providing the MCR mechanism 100 shown in FIGS. 18 and 19.

The configuration disclosed in the above embodiments is only an example for explaining the content of the present invention, and it may be combined with other known technologies, or a part of the configuration may be omitted or changed without departing from the scope of the present invention.

1: circuit breaker 2: shell 2a: Wall 3: Power side terminal 4: Load side terminal 5: Flexible conductor 5a, 6a, 7a, 31a, 32a, 33a, 52a, 54a: one end 5b, 6b, 7b, 31b, 32b, 33b, 52b, 54b: the other end 6: mover 7: movable bracket 7c: middle part 8: contact pressure spring 9: movable block 10: fixed contact 11: movable contact 12: bracket shaft 12a: Support axis 13, 34, 35, 38: connecting pin 20: electromagnetic solenoid 21: Yoke 22: Input coil 23: Iron Rod 24: protrusion 25: gap 30: Transmission mechanism 31: connecting rod 32: Leverage 33: Insulated rod 36: lever axis 37: lever shaft 40: open pole spring 50: Tripping mechanism 51: Card lock 52: tripping the lever 52c: recess 53: The first return spring 54: Tripping stick 55: Second return spring 56: arc part 57: snap-in surface 58: Semicircle 58a: arc part 58b: flat part 59: Engagement Department 60: Trip lever axis 61: tripping off the shaft 70, 78: drive circuit 71: Internal ON switch 72: External ON switch 73: Control power 74: Internal OFF switch 75: Tripping attachment 76: Inspection Department 77: Trip coil 79: MCR circuit 80: rectifier circuit 81: Constant voltage circuit 83: control circuit 84: control switch 85: Tandem 86: Diode 87: Current reduction section 88: Micro switch 91, 95: logical OR circuit 92: Latch circuit 93: logic and circuit 94: logical NOT circuit 97: converter 98: Trip relay 100: MCR agency 101: MCR board 102: Insulation board 103: Micro switch 103a: Micro switch button 104: auxiliary board 105: screw 106: actuating lever 106a: driven part 107: Heavy hammer 108: spring 109: axis of rotation C10: Capacitor R1, R2, R3, R4, R10: resistance T1, T2, T3, T4, T5, T6: terminals

FIG. 1 is a cross-sectional view showing a configuration example of a circuit breaker according to Embodiment 1 of the present invention. Figure 2 is an enlarged view of the trip mechanism shown in Figure 1. Fig. 3 is a diagram showing a configuration example of a circuit including a circuit breaker of a driving circuit according to the first embodiment. FIG. 4 is a diagram showing an example of a specific configuration of the drive circuit of the first embodiment. Fig. 5 is a configuration diagram showing the opened state of the circuit breaker in the first embodiment. Figure 6 is an enlarged view of the trip mechanism shown in Figure 5. FIG. 7 is a configuration diagram showing the state at the moment when the contacts of the circuit breaker of the first embodiment start to contact. Figure 8 is an enlarged view of the trip mechanism shown in Figure 7. Fig. 9 is a configuration diagram showing a state where the circuit breaker of the first embodiment reaches the maximum input position. Figure 10 is an enlarged view of the trip mechanism shown in Figure 9. Fig. 11 is an enlarged view of the trip mechanism after the trip lever is rotated from the state shown in Fig. 9. Fig. 12 is a configuration diagram showing a state where the circuit breaker of the first embodiment reaches the input completion position. Figure 13 is an enlarged view of the trip mechanism shown in Figure 12. Fig. 14 is a diagram showing a configuration example of a current reduction unit and a control switch in the first embodiment. Fig. 15 is a diagram showing a configuration example of a current reduction unit and a control switch in the first embodiment. Fig. 16 is a diagram showing a configuration example of the current reduction unit and the control switch in the first embodiment. Fig. 17 is a diagram showing the relationship between the moving position of the iron core rod and the load acting on the electromagnetic solenoid in the first embodiment. Figure 18 is a diagram showing an example of the structure of an MCR mechanism. Figure 19 is a diagram showing an example of the structure of an MCR mechanism. FIG. 20 is a diagram showing an example of the circuit configuration of a circuit breaker including a drive circuit according to Embodiment 2 of the present invention. Fig. 21 is a timing chart for explaining the MCR function of the circuit breaker in the second embodiment.

10: fixed contact

11: movable contact

22: Input coil

70, 78: drive circuit

71: Internal ON switch

72: External ON switch

73: Control power

74: Internal OFF switch

75: Tripping attachment

76: Inspection Department

77: Trip coil

80: rectifier circuit

81: Constant voltage circuit

83: control circuit

84: control switch

85: Tandem

86: Diode

87: Current reduction section

88: Micro switch

91, 95: logical OR circuit

92: Latch circuit

93: logic and circuit

94: logical NOT circuit

97: converter

98: Trip relay

R1, R2, R3, R4: resistance

T1, T2, T3, T4, T5, T6: terminals

Claims (7)

A circuit breaker with: case; The fixed terminal is installed with fixed contacts and fixed to the aforementioned housing; The movable element is installed with a movable contact opposite to the fixed contact; An electromagnetic solenoid with a heart rod that moves linearly; The transmission mechanism causes the movable element to move along with the movement of the mandrel, and changes from the disconnected state where the movable contact and the fixed contact are separated to the powered-on state where the movable contact and the fixed contact come into contact with electricity; as well as A drive circuit that energizes the coil of the electromagnetic solenoid to drive the electromagnetic solenoid; The driving circuit includes a series body of a diode and a current reducing part that reduces the current flowing to the diode, and the series system is connected in parallel with the coil of the electromagnetic solenoid. The circuit breaker as described in item 1 of the patent application scope, in which The aforementioned current reduction unit includes a resistor, or includes a resistor and a capacitor. The circuit breaker as described in item 1 or 2 of the scope of patent application shall have: The detection part detects the overcurrent or leakage of the circuit that is turned on by the contact between the fixed contact and the movable contact, and outputs a detection signal indicating the detection result; The drive circuit stops the energization of the coil based on the detection signal output by the detection unit. The circuit breaker as described in item 1 or 2 of the scope of patent application includes: The tripping mechanism can be engaged with the transmission mechanism to maintain the input state, and can release the engagement with the transmission mechanism to release the retention of the input state; The aforementioned transmission mechanism is equipped with: The lever rotates around the first axis fixed to the housing as the core rod moves; An insulating rod, one end of which is rotatably connected to one end of the lever, and the other end is rotatably connected to the mover; and The engaging portion is installed at the other end of the aforementioned lever; The aforementioned tripping mechanism is equipped with: The trip lever is rotatably attached to the housing in a state of being urged toward the engaging portion, and maintains contact with the engaging portion during the input process from the disconnected state to the input state State, and is engaged with the engaging portion in the input state to restrict the rotation of the lever about the first axis; and The trip bar performs the restriction of the rotation of the trip lever and the release of the restriction. The circuit breaker as described in item 4 of the patent application scope, in which The aforementioned trip lever is equipped with: The arc portion has an arc shape centered on the first axis, and the engaging portion is movably contacted during the insertion process; and The concave portion is engaged with the engaging portion in the input state. The circuit breaker as described in item 5 of the patent application scope, in which The tripping bar includes: a semicircular portion formed with an arc portion and a flat portion, and rotating around the second axis fixed to the casing; The trip lever is in contact with the flat portion of the semicircular portion in the off state to restrict rotation, and is in contact with the arc portion of the semicircular portion in the throwing state to restrict rotation. The circuit breaker as described in item 1 or 2 of the scope of patent application shall have: The trip relay is to output a trip command when an overcurrent or leakage occurs in the circuit that is in the conductive state by the contact between the fixed contact and the movable contact; The aforementioned drive circuit is provided with: The first control circuit outputs an ON signal for driving the electromagnetic solenoid when the ON switch is turned on, and according to the signal output by the micro switch that is linked to the action of the electromagnetic solenoid's heart rod being in the on state The output of the aforementioned ON signal stops; and The second control circuit enables the trip command from the trip relay to be output while the ON signal is output from the first control circuit.

Images