JP2011175926A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker with a thermal tripping device wherein the distance between a trip bar and a regulator can be adjusted in a short time. <P>SOLUTION: The thermal tripping device 42 includes a bimetal 43 having a guide groove 43a formed in one end side in contact with the trip bar 33 and an engagement hole 43b formed at a predetermined distance in the longitudinal direction from the guide groove 43a, and the regulator 44 that can pivot in a reverse direction against the deformation of the bimetal 43 with one end side engaged with the engagement hole 43b and the other end side sliding inside the guide groove 43a around the engagement hole 43b and that is fixed to the bimetal 43 while abutting against the trip bar 33 and then being pushed back by deformation. The regulator 44 has a bottom part 44c that slides on the bottom of the guide groove 43a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermal tripping device in a circuit breaker.

In a conventional thermal tripping device in a circuit breaker, the operating point of the tripping mechanism, that is, the position where the bimetal presses the trip bar is the processing of each component that constitutes the tripping mechanism, assembly error, variation in material characteristics, etc. Variations in the circuit breaker breaking time occur due to variations in manufacturing variations. Therefore, in order to absorb such manufacturing variations, a movable adjuster is attached to the tip of the bimetal, and a current is passed through the circuit breaker for a certain period of time. The adjuster is fixed to the bimetal by laser welding in a state of being moved back by being brought into contact with the trip bar (for example, Patent Document 1).
In addition, there was a problem that the adjuster fell off before it was fixed by laser welding in the process of manufacturing and adjusting the circuit breaker. Therefore, a shaft was provided on the bimetal, and the hook-shaped portion of the adjuster was elastically deformed. A method of attaching the adjuster to the bimetal shaft and a method of preventing the adjuster from falling off by plastically deforming the hook after engaging the hook of the adjuster with the bimetal shaft. (For example, Patent Document 2).

JP 2001-15006 (paragraph 0021 to paragraph 0023, FIG. 4) JP 2009-123416 A (paragraph 0022, paragraph 0023, paragraph 0036 to paragraph 0039, FIG. 1, FIG. 2)

  However, since the regulator of the thermal tripping device in the conventional circuit breaker was manufactured by press molding from a plate having a thickness of about 0.8 mm, the thin shape such as the arcuate portion of the regulator is press molded. Therefore, there has been a problem that a material with poor laser weldability such as a soft copper alloy has to be used.

  In addition, when the adjuster is inserted into the bimetal guide groove and the adjuster is laser welded to the bimetal, it is necessary to laser weld two locations at the boundary between the both ends of the adjuster and the guide groove, and time is required for welding. There was a problem that it took.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a circuit breaker including a thermal tripping device with a short adjustment time and high reliability.

  The circuit breaker of the present invention comprises an open / close contact for opening and closing an electric circuit, an open / close mechanism portion for opening the open / close contact, and a thermal trip device for driving the open / close mechanism portion. A bimetal having a guide groove formed at one end on the side in contact with the trip bar and an engagement hole formed at a predetermined interval in the longitudinal direction with the guide groove, and one end engaged with the engagement hole The other end can slide in the guide groove with the engagement hole as the center so that it can be rotated in the opposite direction to the deformation of the bimetal, and is fixed to the bimetal in a state of being brought into contact with the trip bar and pushed back by the deformation. The adjuster has a bottom surface portion that slides on the bottom surface of the guide groove.

  According to the present invention, since the adjuster has a bottom surface portion that slides in the guide groove of the bimetal, the thermal tripping device having a short time for adjusting the distance between the trip bar and the adjuster and having high adhesion reliability is provided. A circuit breaker can be obtained.

It is side surface sectional drawing which shows the circuit breaker in Embodiment 1 of this invention. It is a perspective view which shows the tripping device in the circuit breaker of Embodiment 1 of this invention. It is a side view which shows the tripping device in the circuit breaker of Embodiment 1 of this invention. It is a perspective view which shows the state before mounting | wearing a regulator with the tripping device in the circuit breaker of Embodiment 1 of this invention. It is a side view which shows the regulator of the tripping device in the circuit breaker of Embodiment 1 of this invention. It is a perspective view which shows the regulator of the tripping device in the circuit breaker of Embodiment 1 of this invention. It is a side view which shows the tripping device in the circuit breaker of Embodiment 2 of this invention. It is a side view which shows the regulator of the tripping device in the circuit breaker of Embodiment 2 of this invention. It is a perspective view which shows the regulator of the tripping device in the circuit breaker of Embodiment 2 of this invention. It is a top view of the trip device for demonstrating the effect of the circuit breaker of Embodiment 2 of this invention. It is a top view of the trip device for demonstrating the subject of the circuit breaker of Embodiment 1 of this invention. It is a side view which shows the regulator of the tripping device in the circuit breaker of Embodiment 3 of this invention. It is a perspective view which shows the regulator of the tripping device in the circuit breaker of Embodiment 3 of this invention.

Embodiment 1.
1 is a side sectional view showing a circuit breaker according to Embodiment 1 of the present invention, FIG. 2 is a perspective view showing a tripping device, FIG. 3 is a side view showing the tripping device, and FIG. 4 is adjusted to the tripping device. FIG. 5 is a perspective view showing a state before the child is mounted, FIG. 5 is a side view showing the adjuster of the tripping device, and FIG. 6 is a perspective view showing the adjuster of the tripping device.

  In FIG. 1, a circuit breaker 100 is configured by using a housing 10 including a base 11 and a cover 12 made of an insulating material. On the base 11, circuit breaker units of each phase (for example, three in the case of three phases) are arranged in parallel with each other for the number of poles, and an open / close having a well-known toggle link mechanism is provided above the central circuit breaker unit. The mechanism unit 30 is arranged. The cover 12 covers the circuit breaker unit of each phase on the base 11 and the opening / closing mechanism 30, and the operation handle 31 of the opening / closing mechanism 30 projects from the cover 12. The cover 12 is provided with an upper cover 12 a that can be opened and closed so that an internal accessory device can be disposed inside the circuit breaker 100.

  The circuit breaker units for each phase are configured in the same manner, and the crossbar 32 is arranged on the base 11 so as to be orthogonal to the circuit breaker units for each phase in common with the circuit breaker units for each phase.

  The circuit breaker unit for each phase includes a power supply side terminal 24 provided on the base 11, a fixed contact 21 extending from the power supply side terminal 24, a movable contact 22 contacting and separating from the fixed contact 21, and the movable contact 22 is provided at one end, and a movable contact 23 which is rotatably held by a cross bar 32, a tripping device 40 connected to the movable contact 23 via a mover holder 26, and a tripping device 40. And a load side terminal 25 provided on the base 11. The fixed contact 21 and the movable contact 22 constitute an open / close contact that opens and closes the electric circuit. When the movable contact 22 comes into contact with the fixed contact 21, the electrical circuit between the terminals 24 and 25 is turned on. When the movable contact 22 is separated from the fixed contact 21, the electrical circuit between the terminals 24 and 25 is turned off. It becomes.

  The cross bar 32 is disposed at the bottom of the base 11 and extends so as to be orthogonal to the paper surface of FIG. The cross bar 32 is rotated about its axis by the opening / closing mechanism 30 and each movable contact 23 in the circuit breaker unit of each phase is attached thereto. When the crossbar 32 rotates about its axis, the movable contacts 23 of the circuit breaker units of the respective phases are simultaneously rotated, and the movable contact 22 is fixed by the rotation of the movable contact 23. 21 The opening / closing mechanism 30 includes a known trip bar 33 that is driven by the tripping device 40.

  As shown in FIGS. 2 and 3, the tripping device 40 includes an electromagnetic tripping device 41 and a thermal tripping device 42. The electromagnetic trip device 41 includes a fixed iron core 41a, a movable iron core 41b that is attracted to the fixed iron core 41a when instantaneously interrupted to drive the trip bar 33, a return spring 41c that urges the movable iron core 41b, and a movable iron core 41b. And a supporting shaft 41d.

  The thermal tripping device 42 includes a heater 42a having a terminal 25 at one end, and a bimetal 43 fixed to a fixed iron core 41a by a rivet 41e (shown in FIG. 3) with the heater 42a interposed therebetween. .

  As shown in FIG. 4, the bimetal 43 is formed with a guide groove 43 a formed at one end on the side in contact with the trip bar 33, and an engagement formed with the guide groove 43 a at a predetermined interval in the longitudinal direction. The bimetal 43 has one end engaged with the engagement hole 43b, and the other end slides in the guide groove 43a around the engagement hole 43b. An adjuster 44 is provided that can be rotated in the opposite direction and is fixed to the bimetal 43 in a state of being brought into contact with the trip bar 33 and pushed back by this deformation.

  The bimetal 43 is formed in a strip shape by punching a plate-like member obtained by bonding two metal plates having different thermal expansion coefficients. The bimetal 43 has a guide groove 43a formed at one end, and an engagement hole 43b formed at a predetermined interval from the guide groove 43a in the longitudinal direction of the bimetal 43. The width of the guide groove 43a is slightly wider than the width of the bottom surface of the adjuster 44 described later so that the adjuster 44 can slide with a force smaller than the trip load at which the trip bar 33 trips.

  As shown in FIGS. 5 and 6, the adjuster 44 has a hook-shaped portion 44 a that engages with the engagement hole 43 b of the bimetal 43 at one end, and slides in the guide groove 43 a of the bimetal 43 at the other end. An arcuate portion 44b is formed. The arcuate portion 44b is formed, for example, by press-molding a thin stainless plate, and its cut surface is formed in an L shape, slides on the bottom surface of the guide groove 43a, and is equal to or greater than the plate thickness of the bimetal 43, preferably a plate of the bimetal 43. A bottom surface portion 44c having a width wider than the thickness and a side surface portion 44d substantially perpendicular to the bottom surface portion 44c. The bottom surface portion 44c of the adjuster 44 is a curved surface having a curvature that is substantially centered on the flange-shaped portion 44a. A locking portion 44e that engages with the guide groove 43a is provided at the tip of the arcuate portion 44b. Further, a contact portion 44f that contacts the trip bar 33 is provided between the other end of the arcuate portion 44b and the flange portion 44a. The contact portion 44f is mounted on the bimetal 43 after the adjuster 44 is mounted. Also, the adjuster 44 also serves as a weight portion that places the center of gravity on the trip bar 33 side. The weight portion does not necessarily serve as the contact portion 44f, and may be provided separately if it is between the contact portion 44f and the hook-shaped portion 44a.

  When the adjuster 44 is attached to the bimetal 43, the adjuster 44 is once elastically deformed, the locking portion 44e gets over the guide groove 43a, and the adjuster 44 is attached to the bimetal 43. When the adjuster 44 is attached to the bimetal 43, the locking portion 44e is engaged with the bottom surface of the guide groove 43a, so that the adjuster 44 can be prevented from falling off the bimetal 43. In the present embodiment, the bottom surface portion 44c is not provided in the locking portion 44e.

Next, a method for adjusting the thermal tripping device 42 will be described.
In the thermal tripping device 42, when the bimetal 43 becomes hot due to an energization current or the like, the bimetal 43 is warped due to a difference in linear expansion coefficient. The contact with the trip bar 33 is caused by the displacement due to the warpage, and the trip bar 33 is driven to drive the opening / closing mechanism 30 when the contact is made. The adjuster 44 is a distance between the trip bar 33 and the adjuster 44 in order to adjust the energizing current that causes the trip bar 33 to perform a trip operation when the thermal tripping device 42 contacts the trip bar 33 to a predetermined value. Is adjusted.

  In order to adjust the distance between the trip bar 33 and the adjuster 44, first, the thermal trip device 42 and the trip bar 33 are assembled to the base 11 of the circuit breaker 100, and the adjuster 44 is moved to the center of gravity on the trip bar 33 side. In this manner, the locking portion 44e of the adjuster 44 is locked in the guide groove 43a so that sliding is restricted and the posture is maintained. In this state, the thermal tripping device 42 is energized with a predetermined value of current for driving the trip bar 33 and operating the opening / closing mechanism 40. Next, since the heater 42a generates heat by a predetermined current, the temperature of the bimetal 43 rises, the bimetal 43 is deformed and deformed to the trip bar 33 side, and the contact portion 44f of the adjuster 44 is moved to the trip bar 33. However, since the bimetal 43 continues to be further deformed with the energization, the bottom surface portion 44c of the adjuster 44 slides in the guide groove 43a and moves in the direction opposite to the movement of the bimetal 43. Next, when energized for a certain period of time in this state, the bottom surface portion 44c of the adjuster 44 and the guide groove 43a of the bimetal 43 are fixed by at least one laser welding so that the adjuster 44 and the bimetal 43 are fixedly integrated. . This fixing may be fixing by an adhesive in addition to laser welding. Further, the side surface portion of the guide groove 43a of the bimetal 43 and the side surface portion 44d of the adjuster 44 may be fixed and reinforced by laser welding.

Next, the trip operation of the circuit breaker 100 will be described.
A current of a predetermined current or more flows through the heater 42a and the heater 42a generates heat, and the bimetal 43 is heated by this heat generation and deforms. When the bimetal 43 is deformed, the adjuster 44 is fixed to the bimetal 43. Therefore, the contact portion 44f of the adjuster 44 pushes the trip bar 33, and the opening / closing mechanism portion 30 is driven to rotate the mover 23. The movable contact 22 is separated from the fixed contact 21 by the rotation of the movable element 23, and the trip operation for interrupting the current is completed.

  When an excessive current such as a short circuit current flows, the movable iron core 41b is attracted to the fixed iron core 41a by the magnetic force generated in the fixed iron core 41a of the electromagnetic trip device 41, and the movable iron core 41b rotates around the shaft 41d. It rotates against the urging force of the return spring 41c as a moving shaft. By this rotation, the movable iron core 41b pushes the trip bar 33, and the opening / closing mechanism 30 is driven to rotate the mover 23. The movable contact 22 is separated from the fixed contact 21 by the rotation of the movable element 23, the excessive current is cut off, and the trip operation is completed.

  At this time, as described in the adjustment method of the thermal tripping device 42, the adjuster 44 is fixed with the bimetal 43 at a predetermined temperature with the tripping device 40 attached to the base 11. Even if there are manufacturing errors and mounting errors of the tripping device 40, the adjuster 44 can adjust with high accuracy.

  According to the present embodiment, the adjuster 44 has the bottom surface portion 44c, and at the time of adjusting the distance between the trip bar 33 and the adjuster 44, the bottom surface portion 44c of the adjuster 44 and the guide groove 43a of the bimetal 43 are at least provided. Since it can be fixed by one laser welding, the time for adjusting the distance between the trip bar 33 and the adjuster 44 can be shortened.

  Further, since the adjuster 44 can be formed from a thin plate such as stainless steel having relatively good laser weldability, the reliability of fixing by welding the bimetal 43 and the adjuster 44 can be improved.

  Further, since the bottom surface portion 44c of the adjuster 44 has a width equal to or greater than the plate thickness of the bimetal 43, when adjusting the distance between the trip bar 33 and the adjuster 44, the adjuster 44 is adjusted when sliding along the guide groove 43a. It is possible to suppress tilting of the circuit breaker units having a plurality of poles 44 in the arrangement direction.

  Further, since the bottom surface portion 44c of the adjuster 44 has a width equal to or greater than the plate thickness of the bimetal 43, the groove width of the guide groove 43a of the bimetal 43 may be slightly larger than the width of the bottom surface portion 44c. Therefore, the press working for forming the guide groove 43a can be facilitated.

  The adjuster 44 slides on the side surface of the guide groove 43, has a side surface portion 44d substantially perpendicular to the bottom surface portion 44c, and can stably form the curvature of the arcuate portion 44b. Since the adjustment member 44 can be smoothly slid in the distance adjustment with respect to the distance 44, the accuracy of the distance adjustment can be improved and the accuracy of the thermal tripping can be improved.

  Further, the adjuster 44 slides in the guide groove 43a of the bimetal 43 on the other end side and engages with the engagement hole 43b of the bimetal 43 on one end side, and centers on the hook-shaped portion 44a. Since the movable arcuate portion 44b is provided, the adjuster 44 slides smoothly in adjusting the distance between the trip bar 33 and the adjuster 44, the distance adjustment accuracy is improved, and the thermal tripping accuracy is improved. be able to.

  Further, since the adjuster 44 has a locking portion 44e that engages with the guide groove 43a at the tip of the arcuate portion 44b, the adjuster 44 can be removed when the adjuster 44 is assembled to the bimetal 43. This improves the yield of assembly and adjustment of circuit interruption.

  Further, since the bottom surface portion 44c is not provided in the locking portion 44e, the adjuster 44 can be easily formed.

  The adjuster 44 has a weight portion that also serves as a contact portion 44f between the hook-shaped portion 44a and the arcuate portion 44b. After the adjuster 44 is attached to the bimetal 43, the adjuster 44 is moved to the trip bar 33 side. Since the center of gravity can be applied, the distance between the trip bar 33 and the adjuster 44 can be easily adjusted, and the distance adjustment time can be shortened.

  In this embodiment, as the thermal tripping device, an example of the indirectly heated type in which the bimetal is heated by the heater is shown. It is applicable and has the same effect.

  Moreover, although the cross section which has one side part 44d substantially perpendicular | vertical to the bottom face part 44c showed the L-shaped regulator, the cross section which has the side part 44d at the both ends of the bottom face part 44c is respectively substantially U. A character-shaped adjuster may be used.

Embodiment 2. FIG.
7 is a side view showing a tripping device in a circuit breaker according to Embodiment 2 of the present invention, FIG. 8 is a side view showing a regulator of the tripping device, and FIG. 9 is a perspective view showing a regulator of the tripping device. 10 is a top view of the tripping device for explaining the effect of the circuit breaker in the second embodiment, and FIG. 11 is a top view of the tripping device for explaining the problem of the circuit breaker in the first embodiment. It is.

  In the first embodiment, since the bottom surface portion 44c of the adjuster 44 is not provided in the locking portion 44e, there is an advantage that it is easy to perform processing for forming the locking portion 44e. On the other hand, to adjust the distance between the thermal tripping device 42 and the trip bar 33, the center of gravity of the adjuster 44 is applied to the trip bar 33 side, and the locking portion 44e is locked to the guide groove 43a of the bimetal 43. Therefore, when the sliding is restricted, the bottom surface portion 44c is not extended to the locking portion 44e, so that the adjuster 44 is easily inclined.

  As shown in FIG. 11, when the adjuster 44 is attached to the bimetal 43 in an inclined state, the tip 44c1 of the bottom surface portion 44c may abut against the side surface of the guide groove 43a. When the distance from the adjuster 44 is adjusted, the adjuster 44 may not slide smoothly in the guide groove 43a when the adjuster 44 contacts the trip bar 33.

In the present embodiment, as shown in FIGS. 7 to 9, the bottom surface portion 44c is provided to extend to the tip of the locking portion 44e, and the bottom surface portion 44c is formed before the locking portion 44e is formed. The locking portion 44e having the bottom surface portion 44c is formed by forming on the entire arcuate portion and then processing by squeezing. Since other configurations are the same as those in the first embodiment, description thereof is omitted.

As shown in FIG. 10, since the bottom surface portion 44c is provided so as to extend to the tip of the locking portion 44e, the bottom surface portion 44c contacts the side surface of the guide groove 43a of the bimetal 43 and The inclination of the direction (arrangement direction of the multi-pole circuit breaker units) is suppressed, and when adjusting the distance between the trip bar 33 and the adjuster 44, the adjuster 44 slides more smoothly.

  According to the present embodiment, since the bottom surface portion 44c is provided so as to extend to the tip of the locking portion 44e, the bottom surface portion 44c contacts the side surface of the guide groove 43a of the bimetal 43 and the paper surface of the adjuster 44 The inclination in the vertical direction (arrangement direction of the multi-pole circuit breaker units) is suppressed, and the adjuster 44 slides more smoothly when adjusting the distance between the trip bar 33 and the adjuster 44, and the distance adjustment accuracy is improved. This improves the accuracy of thermal tripping.

  The adjuster 44 has a bottom surface portion 44c. When adjusting the distance between the trip bar 33 and the adjuster 44, the bottom surface portion 44c of the adjuster 44 and the guide groove 43a of the bimetal 43 are fixed by one laser welding. Therefore, the time for adjusting the distance between the trip bar 33 and the adjuster 44 can be shortened.

  Further, since the adjuster 44 can be formed from a thin plate such as stainless steel having relatively good laser weldability, the reliability of fixing by welding the bimetal 43 and the adjuster 44 can be improved.

  Further, since the bottom surface portion 44c of the adjuster 44 has a width equal to or greater than the plate thickness of the bimetal 43, when adjusting the distance between the trip bar 33 and the adjuster 44, the adjuster 44 is adjusted when sliding along the guide groove 43a. It is possible to suppress tilting of the circuit breaker units having a plurality of poles 44 in the arrangement direction.

  Further, since the bottom surface portion 44c of the adjuster 44 has a width equal to or greater than the plate thickness of the bimetal 43, the groove width of the guide groove 43a of the bimetal 43 may be slightly larger than the width of the bottom surface portion 44c. Therefore, the press working for forming the guide groove 43a can be facilitated.

  Further, the adjuster 44 slides on the side surface of the guide groove 43a and has the side surface portion 44d substantially perpendicular to the bottom surface portion 44c. Therefore, the curvature of the arcuate portion 44b can be stably formed, and the trip bar 33 and the adjuster can be formed. The adjustment member 44 can be smoothly slid in adjusting the distance to the shaft 44.

  Further, the adjuster 44 slides in the guide groove 43a of the bimetal 43 on the other end side and engages with the engagement hole 43b of the bimetal 43 on one end side, and centers on the hook-shaped portion 44a. Since the movable arcuate portion 44b is provided, the adjuster 44 slides smoothly in adjusting the distance between the trip bar 33 and the adjuster 44, the distance adjustment accuracy is improved, and the thermal tripping accuracy is improved. be able to.

  Further, since the adjuster 44 has a locking portion 44e that engages with the guide groove 43a at the tip of the arcuate portion 44b, the adjuster 44 can be removed when the adjuster 44 is assembled to the bimetal 43. This improves the yield of assembly and adjustment of circuit interruption.

Embodiment 3 FIG.
12 is a side view showing a regulator of the tripping device in the circuit breaker according to Embodiment 3 of the present invention, and FIG. 13 is a perspective view showing the regulator of the tripping device.

  In the first embodiment and the second embodiment, the abutment portion also serves as the weight portion in the adjuster 44. However, in this embodiment, as shown in FIGS. The contact portion 44f is provided in the vicinity of the shape portion 44a. Since other configurations are the same as those in the second embodiment, the description thereof is omitted.

  According to the present embodiment, since the weight portion 44g of the adjuster 44 is provided in the vicinity of the hook-shaped portion 44a separately from the contact portion 44f, the center of gravity of the adjuster 44 is closer to the hook-shaped portion 44a side. Therefore, when adjusting the distance between the trip bar 33 and the adjuster 44, the inclination of the adjuster 44 is suppressed, and the adjuster 44 can slide more smoothly in the guide groove 43a, and the accuracy of the distance adjustment is improved. The accuracy of thermal tripping can be improved.

21 fixed contact, 22 movable contact, 30 opening / closing mechanism, 33 trip bar,
42 thermal trip device, 43 bimetal, 43a guide groove, 43b engagement hole,
44 adjuster, 44a hook-shaped portion, 44b arcuate portion, 44c bottom surface portion.

Claims (7)

An open / close contact that opens and closes the electrical circuit, and an open / close mechanism that opens the open / close contact;
A thermal trip device for driving the opening and closing mechanism,
The thermal tripping device is
A guide groove formed at one end on the side in contact with the trip bar, a bimetal having an engagement hole formed at a predetermined interval in the longitudinal direction with respect to the guide groove, and one end side of the engagement hole The other end is slidable in the guide groove with the engagement hole as the center, and can be rotated in the direction opposite to the deformation of the bimetal, and is brought into contact with the trip bar and pushed back by the deformation. And a regulator fixed to the bimetal in a state where
The circuit breaker, wherein the adjuster includes a bottom surface portion that slides on a bottom surface of the guide groove. 2. The circuit breaker according to claim 1, wherein the bottom surface of the adjuster has a width equal to or greater than a thickness of the bimetal. The circuit breaker according to claim 2, wherein the adjuster has a side surface portion that slides on a side surface of the guide groove and is substantially perpendicular to the bottom surface portion. The adjuster has a hook-shaped portion engageable with the engagement hole of the bimetal on one end side, and an arcuate shape that slides in the guide groove of the bimetal on the other end side and is movable around the hook-shaped portion. The circuit breaker according to claim 3, further comprising a portion. The circuit breaker according to claim 4, wherein the adjuster has a locking portion that engages with the guide groove at a tip of the arcuate portion. The circuit breaker according to claim 5, wherein the adjuster is provided with a bottom surface portion in the engaging portion that engages with the guide groove at a tip of the arcuate portion. The circuit breaker according to any one of claims 4 to 6, wherein the adjuster has a weight part between the hook-shaped part and the arcuate part.

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