Circuit breaker

Abstract

To provide a circuit breaker that makes it possible to confirm operation of the second engaging part of a slider constituting an electromagnetic tripping device before assembly, and to improve productivity.SOLUTION: An electromagnetic tripping device 8 which, when an overcurrent flows in a main circuit, rotationally moves a trip crossbar 13 to separate a movable contact 11 via a make-and-break mechanism 4, comprises a control board 15, a device case 14 in which the control board is mounted, a trip coil 16 accommodated in the device case, and a slider 17 connected to a movable iron core 16a of the trip coil. The slider includes a first engaging part 22 that moves forward by drive of the trip coil so as to rotationally move the trip crossbar, and a second engaging part 23 capable of contacting a handle lever 5a that moves in linkage with an operation handle 5. A guide part 24 is formed in only the device case, which guides the second engaging part as it moves in the backward direction when the handle lever is brought into contact with the second engaging part and the slider retreats by reset motion of the operation handle.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a circuit breaker equipped with an electromagnetic tripping device. [Background technology]

[0002] 2. Description of the Related Art There is known a circuit breaker having an electromagnetic tripping device that rotates a trip crossbar to open a movable contact via an opening and closing mechanism when an overcurrent flows in a main circuit (for example, see Patent Document 1).

[0003] The electromagnetic trip device includes a control board on which a current detection circuit is mounted, a device case on which the control board is mounted, a trip coil housed in the device case, and a slider connected to the movable core of the trip coil and arranged to face the operation piece of the trip crossbar. When the trip coil is driven by a trip signal from the current detection circuit to move the movable core and the slider forward, the slider comes into contact with the operation piece of the trip crossbar to rotate the trip crossbar, and the movable contactor is opened via the opening / closing mechanism.

[0004] Meanwhile, a slider is known that is different from the slider of Patent Document 1 and has a first engagement portion that can come into contact with an operating piece of a trip crossbar and a second engagement portion that can come into contact with a handle lever that rotatably supports an operating handle of an opening / closing mechanism. When this slider is used, when performing a reset operation of the operating handle, the handle lever that rotates together with the operating handle abuts against the second engagement portion and applies a pushing force, causing the entire slider to retract, and the slider and trip coil are returned to the set position. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 3-233824 Summary of the Invention [Problem to be solved by the invention]

[0006] Here, when the slide is moved backward by the pushing force of the handle lever, external forces other than the backward direction also act on the second engagement part, which may cause deformation or damage to the second engagement part. Therefore, a guide part is provided to suppress the action of external forces other than the backward direction on the second engagement part and to guide the movement of the second engagement part in the backward direction.

[0007] Incidentally, the guide portion is composed of a guide wall provided on the device case of the electromagnetic tripping device and a guide wall provided inside the housing case of the circuit breaker, and currently, the operation of the second engagement portion is checked after the assembly of the circuit breaker is completed. Therefore, if there is a problem with the guiding of the guide portion relative to the second engagement portion, the circuit breaker must be disassembled to adjust the guide portion, which may reduce the productivity of the circuit breaker.

[0008] Therefore, an object of the present invention is to provide a circuit breaker that enables the operation of the second engagement portion of the slider to be checked before assembly, thereby improving productivity. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, a circuit breaker according to one embodiment of the present invention is a circuit breaker having an electromagnetic trip device that rotates a trip crossbar to open a movable contact via an opening and closing mechanism when an overcurrent flows in the main circuit, the electromagnetic trip device comprising a control board having a current detection circuit implemented therein, a device case in which the control board is mounted, a trip coil housed in the device case, and a slider connected to the movable iron core of the trip coil, the slider comprising a first engagement portion that moves forward when driven by the trip coil to rotate the trip crossbar, and a second engagement portion that can come into contact with a handle lever that is linked to an operating handle, and a guide portion that guides the second engagement portion to move in the backward direction when the handle lever abuts against the second engagement portion due to a reset operation of the operating handle and the slider moves backward is formed only on the device case. Effect of the Invention

[0010] According to the circuit breaker of the present invention, the operation of the second engagement portion of the slider can be checked before assembly, thereby improving productivity. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing a configuration of an electronic circuit breaker according to the present invention. [Diagram 2] FIG. 2 is a perspective view showing the electronic circuit breaker with a portion of the main body case removed. [Diagram 3] 11 is a diagram showing a set state of a trip coil and a slider housed in a device case. FIG. [Figure 4] FIG. 4 is a view taken along line AA in FIG. [Diagram 5] FIG. 4 is a perspective view of a main portion showing a guide portion provided on the device case. [Figure 6] 11A and 11B are diagrams showing the trip coil and slider housed in the device case in a tripped state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are given the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., differ from the actual ones. Therefore, the specific thickness and dimensions should be determined with reference to the following description. In addition, it goes without saying that the drawings include parts with different dimensional relationships and ratios.

[0013] In addition, the embodiments shown below are merely examples of devices and methods for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not specify the materials, shapes, structures, arrangements, etc. of the components to those described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0014] In the drawings shown below, for convenience, three directions perpendicular to each other are referred to as a first direction, a second direction, and a third direction.

[0015] FIG. 1 is a cross-sectional view showing a first embodiment of an electronic molded circuit breaker 1 for three-phase (R, S, T phase) AC connected between the power supply side and the load side of a circuit, and shows the circuit structure of one of the phases assembled in parallel in a main body case 2.

[0016] The electronic molded-case circuit breaker 1 has, inside a main body case 2, a switching mechanism 4 that opens and closes the switching contacts 3, an operating handle 5 that operates the switching mechanism 4, a current detection device 6 that detects the current in the main circuit, an arc extinguishing device 7, and an electromagnetic tripping device 8 that causes the switching mechanism 4 to perform a tripping operation when the current detection device 6 detects that an overcurrent flows in the main circuit.

[0017] The main body case 2 is constructed by assembling a power supply side intermediate case 2b and a load side intermediate case 2c on top of a lower case 2a, and assembling a top cover 2d on top of the power supply side intermediate case 2b and the load side intermediate case 2c. A power supply side main circuit terminal 10b and a load side main circuit terminal 11b are fixed to the lower case 2a. The switching contacts 3 are constructed of a fixed contactor 10 having a fixed contact 10a and a movable contactor 11 having a movable contact 11a, and the movable contactor 11 is rotatably supported by a holder unit 12. The fixed contactor 10 is connected to the power supply side main circuit terminal 10b, and the movable contactor 11 is connected to the load side main circuit terminal 11b via the holder unit 12 and the current detector 6.

[0018] The opening / closing mechanism 4 is composed of a toggle link mechanism (not shown) that links the movable contact 11 and the operating handle 5, a latch mechanism that combines a latch (not shown) and a trip crossbar 13. When the trip crossbar 13 rotates counterclockwise in Fig. 1, the movable contact 11 is opened by the rotation of the latch mechanism.

[0019] FIG. 2 is a diagram showing the internal structure of the electronic molded case circuit breaker 1 with the top cover 2d of the main case 2, the power supply side intermediate case 2b, and the load side intermediate case 2c removed.

[0020] The electromagnetic tripping device 8 comprises a device case 14 in the shape of a rectangular parallelepiped box with a bottom, and a control board 15 integrated into the upper opening of the device case 14. Circuit components of an overcurrent detection circuit that detects the occurrence of an overcurrent from the output level of a current detection device 41 are mounted on the control board 15. Also, Fig. 3 shows the inside of the device case 14 with the control board 15 removed, in which a trip coil 16 is disposed within the device case 14, and a slider 17 connected to the trip coil 16 is disposed in a recess 14b provided in a case side wall 14a of the device case 14 and protrudes to the outside.

[0021] As shown in Fig. 3, the trip coil 16 arranged in the device case 14 is a plunger-type electromagnet that includes an excitation coil 16b that arranges the movable core 16a so that it can move in the first direction, a permanent magnet 16c that attracts and holds the movable core 16a at a set position, and a magnetic yoke 16d arranged around the excitation coil 16b, and cancels the magnetic force of the permanent magnet 16c by reverse excitation. A slider 17 is connected to the tip of the movable core 16a of the trip coil 16. A drive spring 16e is arranged between the frame 16b1 of the excitation coil 16b and the slider 17. The drive spring 16e is a compression coil spring, and is set to be smaller than the magnetic attraction force of the movable core 16a by the permanent magnet 16c.

[0022] As shown in Fig. 3, the slider 17 is an L-shaped member when viewed from the third direction, and includes a crossbar engagement portion 22 connected to the tip of the movable iron core 16a and extending in the second direction, and a lever engagement portion 23 extending perpendicularly from one end of the crossbar engagement portion 22 in the second direction to one side in the first direction. The crossbar engagement portion 22 is slidably disposed in the first direction in a recess 14b provided in a case side wall 14a of the device case 14, and the lever engagement portion 23 protrudes to the outside from the case side wall 14a. An operation piece 13a of the trip crossbar 13 is disposed opposite to the crossbar engagement portion 22 on one side in the first direction.

[0023] It should be noted that a first engagement portion according to the present invention corresponds to the crossbar engagement portion 22, and a second engagement portion according to the present invention corresponds to the lever engagement portion .

[0024] The lever engagement portion 23 has a tip portion 23a formed in a wedge shape with thicknesses in the second and third directions gradually increasing from the tip toward the crossbar engagement portion 22, and a base portion 23b continuing from the tip portion 23a to the crossbar engagement portion 22. As shown in Fig. 4, the base portion 23b has a thick portion 23b1 having a larger dimension in the second direction on one side in the third direction, and a thin portion 23b2 having a smaller dimension in the second direction than the thick portion 23b1 on the other side in the third direction, and the base portion 23b is a portion that has an L-shaped cross section as viewed from the first direction and extends in the first direction with the same dimension (height) in the third direction.

[0025] As shown in FIG. 5, a guide portion 24 that guides the lever engagement portion 23 of the slider 17 in the first direction is formed on the case side wall 14a of the device case 14.

[0026] The guide portion 24 includes a first guide wall 25 having a first guide surface 25a that is flush with one of the recess side walls 14b1 in the second direction that forms the recess 14b and that protrudes in a flat shape in a direction away from the case side wall 14a (one side of the first direction), a second guide wall 26 that extends in a flat shape from one end of the first guide wall 25 in the third direction perpendicular to the other side of the second direction and has a second guide surface 26a that faces the other side of the third direction, a third guide wall 27 that has a third guide surface 27a that is flush with the recess bottom wall 14b2 that forms the recess 14b and that protrudes in a flat shape in a direction away from the case side wall 14a (one side of the first direction), and a fourth guide wall 28 that extends in a flat shape from the other side of the second direction of the third guide wall 27 to one side of the third direction and has a fourth guide surface 28a that faces one side of the second direction. The first guide surface 25a of the first guide wall 25 and the fourth guide surface 28a of the fourth guide wall 28 face each other in parallel, and the extended surfaces of the second guide surface 26a of the second guide wall 26 and the third guide surface 27a of the third guide wall 27 face each other in parallel.

[0027] When the slider 17 moves in one direction in the first direction and the other direction in the first direction, as shown in Fig. 4, the upper surface of the base end 23b of the lever engagement portion 23 facing one side in the third direction slides on the second guide surface 26a of the second guide wall 26, and the lower surface facing the other side in the third direction slides on the third guide surface 27a of the third guide wall 27. At the same time, the side surface of the base end 23b facing one side in the second direction slides on the first guide surface 25a of the first guide wall 25, and the side surface of the thin-walled portion 23b2 of the base end 23b facing the other side in the second direction slides on the fourth guide surface 28a of the fourth guide wall 28. As a result, when the slider 17 moves in the first direction, the lever engagement portion 23 guided by the guide portion 24 provided in the device case 14 is suppressed from being displaced in the second direction and the third direction.

[0028] The forward movement according to the present invention corresponds to one of the first directions, and the backward movement and the backward direction according to the present invention correspond to the other of the first directions. Also, the multiple guide surfaces according to the present invention correspond to the first guide surfaces 25a to 28a.

[0029] Next, the operation of the electromagnetic tripping device 8 and the opening and closing mechanism 4 when an overcurrent flows in the main circuit will be described.

[0030] When an overcurrent flows in the main circuit (between the power supply side main circuit terminal 10b and the load side main circuit terminal 11b), the current detector 6 detects the overcurrent and outputs a signal value of the overcurrent to the overcurrent detection circuit of the control board 15. After a delay time corresponding to the magnitude of the overcurrent has elapsed, the overcurrent detection circuit outputs a trip signal to the trip coil 16. When the trip coil 16 receives the trip signal, the excitation coil 16b is reverse excited, and the movable iron core 16a, whose magnetic attraction with the permanent magnet 16c is weakened, receives the spring force of the drive spring 16e and moves from the set position to one side in the first direction. At the same time as the movement of the movable iron core 16a, the slider 17 also moves to one side in the first direction, and as shown in FIG. 6, the crossbar engagement portion 22 moves the operation piece 13a of the trip crossbar 13 to one side in the first direction. As a result, as shown in Figure 1, the trip crossbar 13 rotates counterclockwise, and the rotation of the trip crossbar 13 engages the latch mechanism, causing the movable contact 11 to rapidly open, interrupting the electrical path of the main circuit, and completing the trip operation of the switching mechanism 4.

[0031] Next, the reset operation of the opening / closing mechanism 4 and the electromagnetic tripping device 8 after the tripping operation will be described.

[0032] During the reset operation, as shown in Fig. 2, the operating handle 5 is rotated to the other side in the first direction. The handle lever 5a also rotates in the other side in the first direction together with the operating handle 5. When the handle lever 5a rotates in the other side in the first direction, the tip portion 23a of the lever engagement portion 23 of the slider 17 comes into contact with the handle lever 5a, and the entire slider 17 is pushed in the other side in the first direction. The crossbar engagement portion 22 of the slider 17 pushed in the other side in the first direction pushes the movable iron core 16a in the other side in the first direction, and the movable iron core 16a approaches the permanent magnet 16c and is attracted by the magnetic attraction force of the permanent magnet 16c to move to the set position.

[0033] Here, when the slider 17 moves in the other direction in the first direction by the pushing force of the handle lever 5a, external forces in the second and third directions as well as the other direction in the first direction act on the lever engaging portion 23. However, the lever engaging portion 23 guided by the guide portion 24 provided in the device case 14 is restricted from being displaced in the second and third directions.

[0034] Therefore, in the electromagnetic tripping device 8 of the electronic wiring circuit breaker 1 of this embodiment, the lever engagement portion 23 is guided by the guide portion 24 to suppress displacement in the second and third directions, so that even if the operating handle 5 is rotated to the other side in the first direction during a reset operation and the handle lever 5a hits it, deformation and damage to the lever engagement portion 23 can be reliably prevented.

[0035] Furthermore, since the guide portion 24 is formed integrally with the device case 14, it is possible to easily check whether the guide portion 24 is properly guiding the lever engagement portion 23 before assembling the electromagnetic tripping device 8 to the lower case 2a, thereby improving the productivity of the electronic molded case circuit breaker 1.

[0036] Although the electronic molded case circuit breaker 1 has been described in the above embodiment, the same effects can be achieved with an electronic earth leakage circuit breaker including the electromagnetic tripping device 8 having the above configuration. [Explanation of symbols]

[0037] 1. Electronic circuit breaker 2 Main unit case 2a Lower Case 2b Power supply intermediate case 2c Load side intermediate case 2d Top cover 3 Switching Contacts 4 Opening and closing mechanism 5 Operating handle 5a Handle lever 6 Current detection device 7 Arc extinguishing device 8. Electromagnetic tripping device 10b Power supply side main circuit terminal 11b Load side main circuit terminal 10 Fixed contact 10a fixed contact 11 Movable contact 11a Movable contact 12 Holder unit 13 Trip Crossbar 13a Operation piece 14 Equipment case 14a Case side wall 14b Recess 14b1 Recess side wall 14b2 Bottom wall of recess 15 Control Board 16 Trip Coil 17 Slider 16a Movable core 16b Excitation coil 16b1 frame 16c permanent magnet 16d Magnetic Yoke 16e Drive spring 22 Crossbar engagement part 23 Lever engagement part 23a Tip of lever engagement part 23b Base end of lever engagement portion 23b1 Thick wall part 23b2 Thin wall part 24 Guide section 25 First Guide Wall 25a First guide surface 26 2nd Guide Wall 26a Second guide surface 27 3rd Guide Wall 27a 3rd guide surface 28 4th Guide Wall 28a 4th guide surface

Claims

1. A circuit breaker having an electromagnetic tripping device that rotates a trip crossbar and opens a movable contact via a switching mechanism when an overcurrent flows in a main circuit, The electromagnetic tripping device includes a control board on which a current detection circuit is mounted, a device case in which the control board is mounted, a trip coil housed in the device case, and a slider connected to a movable core of the trip coil, The slider includes a first engagement portion that moves forward by being driven by the trip coil to rotate the trip crossbar, and a second engagement portion that can come into contact with a handle lever that is linked to an operating handle, a guide portion formed only on the device case for guiding the movement of the second engagement portion in the backward direction when the handle lever abuts against the second engagement portion by a reset operation of the operating handle and the slider moves backward.

2. the slider is an L-shaped member in which the second engagement portion extends perpendicularly from one end of the first engagement portion in a longitudinal direction thereof, 2. The circuit breaker according to claim 1, wherein the first engagement portion is slidably disposed in a recess formed in a side wall of the device case.

3. The circuit breaker according to claim 2, characterized in that the guide portion is formed protruding from the periphery of the recess to the outside of the side wall, and has a plurality of guide surfaces that slidably support the second engagement portion while restricting displacement of the second engagement portion in a direction perpendicular to the direction in which the second engagement portion advances and retreats.

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