JPH09161643A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the consumption of a fixed contact and the deterioration of an insulating material in the periphery of the fixed contact by quickly moving an arc generated between contacts to a grid aggregate. SOLUTION: A circuit breaker has a pair of arc extinguishing side plates 128 which interposes a grid aggregate 124 and extends toward a fixed contact 112a, a fixed contact side arc runner 132 which exists on the inside of the arc extinguishing side plate 128 and extends toward the grid aggregate 124 from the specified position, and a pair of arc suction plates 134 made of a ferromagnetic material which exists on the outside of the arc extinguishing side plate 128 and is arranged so as to have the specified distance to the fixed contact 112a. An arc is sucked to an arc suction plate 134, and quickly moves from the fixed contact 112a toward the grid aggregate 124. By arranging an arc drive plate 238 made of a ferromagnetic material so as to interpose the fixed contact 112a, an effect is further enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker used for a distribution board, for example, and more particularly to a circuit breaker capable of reducing wear of fixed contacts and insulation deterioration of insulating members around the fixed contacts. is there.

[0002]

2. Description of the Related Art FIG. 9 and FIG.
FIG. 9 shows a conventional arc extinguishing device for a circuit breaker disclosed in Japanese Patent No. 31627, FIG. 9 is a side sectional view of a main part, and FIG. 10 is a perspective view of the main part. In these figures, a fixed contact 12 is provided on the base 10, and a fixed contact 12 a is fixed to the fixed contact 12. The movable contactor 14 has a movable contact 14a provided at the end thereof, and the movable contact 14a is arranged to face the fixed contact 12a. The movable contactor 14 is operated by an operating mechanism (not shown) to come into contact with and separate from the fixed contact 12a in the direction of arrow A as shown by the solid line and the alternate long and short dash line in FIG.

The arc extinguishing device 20 has an arc extinguishing chamber 22, a fixed contact side arc runner 30, and a movable contact side arc runner 36. The arc extinguishing chamber 22 has a grid block 24 and an arc extinguishing side plate 28. The grid block 24 is configured by stacking grid plates 26 in the vertical direction at predetermined intervals. The grid plate 26 is provided with a notch groove 26a on the side facing the fixed contact 12a. The arc-extinguishing side plate 28 holds the stacked grid plates 26 by sandwiching them in a direction perpendicular to the plane of FIG. The grid block 24 is provided at a predetermined distance from the fixed contact 12a. The fixed contact side arc runner 30 includes a vertical portion 30.
It has an L-shape with a and a horizontal portion 30b.
The vertical portion 30a extends downward from the fixed contact 12 in FIG. 9, and the horizontal portion 30b extends horizontally from the vertical portion 30a to the lower portion of the grid block 24.

The U-shaped frame 32 made of ferrite is a vertical piece 32a.
And both side pieces 32b, which are integrally formed in a U-shape using soft ferrite having an excellent insulating property. The U-shaped frame 32 made of ferrite is arranged such that both side pieces 32b sandwich the fixed contact 12a and the vertical portion 30a of the fixed contactor-side arc runner 30 and are spaced from the fixed contact 12a. The iron U-shaped frame 34 has a vertical portion 34a.
And both side portions 34b, and these are integrally formed in a U-shape by a steel plate. The iron U-shaped frame 34 is provided outside the ferrite U-shaped frame 32 in close contact with the ferrite U-shaped frame 32. Movable contact side arc runner 36
Extends from the vicinity of the left side of the movable contact 14a to the open position to the upper portion of the grid block 24.

As described above, the U-shaped frame 32 made of soft ferrite having excellent insulating properties is used to reduce the space between the fixed contact 12a and the space, and at the same time, the back side is made of a steel plate having a high magnetic flux density. The magnetic efficiency is improved.

Next, the operation will be described. Due to the trip operation due to the abnormal current, the movable contact 14a is fixed to the fixed contact 12
When separated from a, an arc is generated between the fixed contact 12a and the movable contact 14a. The generated arc is driven toward the grid block 24 by the magnetic driving force of the magnetic field generated by the U-shaped frame made of ferrite 32 and the U-shaped frame made of iron 34 which are U-shaped. Further, the arc is sucked into the grid block 24, shredded by the grid plate 26, and expanded and cooled by the pyrolysis gas generated by acting on the arc extinguishing side plate 28 to be cut off. As described above, the grid block 24 is provided separately from the fixed contact 12a, and the arc is cut off at a position distant from the fixed contact, so that insulation deterioration between the power source side and the load side or thermal melt due to the arc occurs. This prevents malfunctions and the like due to adhesion to the operating mechanism.

[0007]

The conventional circuit breaker is constructed as described above, and can be miniaturized and excellent in breaking performance. However, since the U-shaped frame made of ferrite 32 and the U-shaped frame made of iron 34 are provided apart from the grid block 24, this electromagnetic force promptly drives the arc toward the grid block 24 and wears the fixed contact 12a. There is a limit to reducing the insulation deterioration around the fixed contacts such as the base 10, the cover (not shown) and the like. For this reason, there has been a demand to reduce wear of the fixed contact 12a and deterioration of an insulating member around the fixed contact such as the base 10 to further improve performance and durability.

The present invention has been made in order to satisfy the above-mentioned requirements, and the arc generated between the fixed contact and the movable contact can be promptly transferred to the grid assembly to reduce the wear of the fixed contact. It is also an object of the present invention to provide a circuit breaker that can reduce the deterioration of the insulating member around the fixed contacts. Another object is to obtain an inexpensive circuit breaker that is easy to process.

[0009]

A circuit breaker according to a first aspect of the present invention is a pair of circuit breakers sandwiching a grid assembly provided apart from fixed contacts and extending toward the fixed contacts. A facing arc extinguishing member, an arc runner made of a conductive material, which is inside the arc extinguishing member, extends from a predetermined position toward the grid assembly, and is electrically connected to the fixed contact, and the facing arc extinguishing member. A pair of arc attracting members made of a ferromagnetic material and provided outside the arc member at a predetermined distance from the fixed contact in the extending direction of the arc runner.

In the circuit breaker according to a second aspect of the present invention, the arc runner and the arc attracting member are integrally formed of a steel plate, and the arc runner and the arc attracting member extend in the extending direction of the arc runner. The cross section in the direction orthogonal to each other has a U-shape.

In the circuit breaker according to claim 3 of the present invention, the arc runner is formed by extending the fixed contacts toward the grid assembly, and the U-shaped suction is formed in a U-shape. The opposing portions of the members are arc suction members, and the arc runner is positioned inside the U-shaped portion of the U-shaped suction member.

A circuit breaker according to a fourth aspect of the present invention is provided with a pair of arc drive members made of a ferromagnetic material so as to sandwich the fixed contact in a direction orthogonal to the extending direction of the arc runner.

According to a fifth aspect of the present invention, in the circuit breaker, the arc runner, the arc suction member, and the arc driving member are integrally formed of a steel plate, and the arc runner and the arc suction member are combined to form the arc runner. The cross section in the direction orthogonal to the extending direction is formed into a U-shape,
The cross section in the direction orthogonal to the extending direction of the arc runner is formed in a U shape by the arc runner and the arc driving member.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment of the Invention 1 to 3 show an embodiment of the present invention. FIG. 1 is a side sectional view showing an internal structure of a circuit breaker, and FIG. 2 is a section of an arc extinguishing device on a cutting plane II-II in FIG. A sectional view and FIG. 3 are exploded perspective views of an arc extinguishing device portion. In these figures, a housing 110 is a base 110 which is an insulating member molded of synthetic resin.
a and a cover 110b, which will be described later.
12, the movable contact 114, the arc extinguishing device 120, etc. are accommodated. The fixed contact 112 has a fixed contact 112 at one end.
a is brazed, and the other end is connected to a power supply side terminal 144 described later. The movable contact 114 has a fixed contact 112.
A movable contact 114a is brazed so as to face a, and the movable contactor-side arc runner 136 is integrally extended to the right of FIG. 1 in the L shape to the vicinity of the upper portion of a grid assembly 124 (described later). There is.

The arc extinguishing device 120 has an arc extinguishing chamber 122 and an arc driving assembly 130. The arc extinguishing chamber 122 has a grid assembly 124 and an arc extinguishing side plate 128 which is an arc extinguishing member. The grid assembly 124 is configured by stacking grid plates 126, which are grid members punched from ferromagnetic steel plates, at predetermined intervals in the vertical direction in FIG. Also, grid plate 1
26, an elongated U-shaped notch 126a is provided in the central portion on the side facing the fixed contact 112a (FIG. 3).

The arc-extinguishing side plate 128 is manufactured by punching out fiber paper as an electrically insulating material, supports the stacked grid plates 126 by sandwiching them from the side, and extends to the fixed contact 112a. . Further, as shown in FIG. 3, the arc extinguishing side plate 128 is provided with a bending portion 128a for reinforcement at the upper portion by bending. The bent portion 128a is the arc extinguishing side plate 12.
This is for preventing the horizontal bending deformation of FIG. 8 of FIG.

The arc drive assembly 130 is composed of a fixed contact side arc runner 132 and an arc suction plate 134.
It is integrally formed by press working from a steel plate which is a magnetic material. The fixed contact side arc runner 132 has a bent portion 132a on the left side of FIG.
It is bent in two steps from b. Bending part 132
The end of the fixed contact 112 is inserted between the fixed contact 112a portion of the fixed contact 112 and the base 110a.
To be in electrical contact with.

The arc suction plate 134, which is a pair of arc suction members, is a bottom surface portion 13 of the fixed contact side arc runner 132.
It is erected from the fixed contactor side arc runner 132 to the left of 2b, and the fixed contactor side arc runner 132 has a U-shaped cross section in the direction perpendicular to the extending direction of the arc runner. The arc suction plate 134 is located outside the arc extinguishing side plate 128. Arc suction plate 134
As shown in FIG. 1, it is provided at a predetermined distance from the fixed contact 112a and partially overlaps with the grid assembly 124 of the arc extinguishing chamber 122.

The bottom surface portion 132b of the fixed contact side arc runner 132 extends to the lower portion of the arc extinguishing chamber 122. When the movable contact 114a is separated from the fixed contact 112a, the movable contact 114a passes between the arc suction plates 134 facing each other via the arc extinguishing side plate 128. The arc drive assembly 1 including the fixed contact side arc runner 132 and the arc suction plate 134
The reference numeral 30 is integrally formed by punching and pressing a steel plate which is a ferromagnetic material.

The arc extinguishing chamber 122 and the arc driving assembly 130 configured as described above are combined to form a box, and the movable contact side arc runner 136 and the arc extinguishing chamber 12 are combined.
2 and the arc driving assembly 130, the arc extinguishing device 120
Is composed. The operation mechanism 140 is connected to the operation handle 142, and the movable contact 114 connected to the operation mechanism 140 is opened and closed with the fixed contact 112. The power supply side terminal 144 is provided on a conductor integrally extended from the fixed contact 112 and is connected to a power supply side electric wire. The load-side terminal 146 is connected to the movable contact 114 via the overcurrent trip device 148.

In the circuit breaker configured as described above, when an excessive current such as a short circuit current flows, the overcurrent trip device 148 operates to open the movable contact 114, and the fixed contact 112a and the movable contact 114a. An arc is generated between and. The generated arc is the fixed contact side arc runner 13
After being guided to the second bent portion 132a, it is attracted toward the arc attraction plate 134 by the magnetic action of the arc attraction plate 134 made of a magnetic material. At this time, arc suction plate 1
34 is isolated from the arc by the arc extinguishing side plate 128 made of an insulating material, so that arcing does not occur between the arc suction plate 134 and the movable contact 114, and the fixed contact side arc runner 132 is exposed. The arc runs on the bottom surface portion 132b.

Therefore, the arc is placed on the arc runner 132 on the fixed contact side, which has the same potential as the fixed contact 112a, on the arc extinguishing chamber 1.
It quickly runs toward the 22 grid assemblies 124.
The arc that reaches the grid plate 126 is drawn into the grid assembly 124 by the magnetic attraction action of the ferromagnetic grid assembly 124 having the U-shaped cutout portion 126a, divided, cooled, and extinguished. As mentioned above,
Since the arc is strongly attracted by the arc suction plate 134 made of a ferromagnetic material to extinguish the arc quickly in the grid assembly 124, the breaking performance is improved. Further, the stagnation time of the arc at the fixed contact 112a becomes shorter, and the fixed contact 112a
Damage to the housing 110 around a and the fixed contact can be suppressed to a slight extent. Since the arc driven assembly 130 is integrally formed from a steel plate, it can be processed easily and the cost can be reduced.

Embodiment 2 of the Invention 4 and 5 show another embodiment of the present invention. FIG. 4 is a side sectional view showing the internal structure of a circuit breaker, and FIG. 5 is a perspective view showing an arc drive assembly. In these figures, as shown in FIG. 5, the arc drive assembly 230 includes a bent portion 132a of the fixed contact side arc runner 132 in FIG.
Further, an arc driving plate 238, which is a pair of arc driving members, is provided integrally with the bent portion 132a so that a cross section in a direction perpendicular to the extending direction of the arc runner has a U-shape. The arc drive plate 238 is formed so as to sandwich the fixed contact 112a with a gap provided in the direction perpendicular to the fixed contact 112a and the plane of FIG. Also, the arc drive plate 238
Are arranged in close contact with the arc extinguishing side plate 128 on the outside of the arc extinguishing side plate 128 facing each other, as shown in FIG.

This arc drive assembly 230 is similar to the arc drive assembly 130 of FIG. 3 in that it includes an arc drive plate 238, a fixed contact side arc runner 132, and an arc suction plate 1.
34 is integrally formed by punching and bending from a steel plate which is a magnetic material. For other configurations, see FIG.
Since it is similar to the embodiment of the invention shown in FIG. 3, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

According to the second embodiment of the present invention, the fixed contact 112a is provided by the arc drive plate 238 made of a ferromagnetic material.
The magnetic field around the contact point between the movable contact 114a and the movable contact 114a,
By strengthening the arc driving force at the initial stage of opening, the arc suction plate 134 and the grid assembly 124 can be more quickly.
Since the arc can be transferred, the fixed contact 11
The arc stagnation time in the portion 2a is shortened, and the breaking performance is improved. Further, damage to the fixed contact 112a and the casing 110 around the fixed contact can be suppressed to a slight extent. Of course, since the arc drive assembly 230 is integrally formed from a steel plate, the arc drive assembly 230 can be processed easily and the cost can be reduced.

Embodiment 3 of the Invention 6A and 6B show another embodiment of the present invention. FIG. 6A is a plan view of the arc extinguishing chamber, and FIG. 6B is a side view of the arc extinguishing chamber. The arc drive assembly 330 has a structure in which the bent portion 132a of the fixed contact side arc runner 132 shown in FIG.
A pair of arc drive plates 338 are integrally formed with the arc-extinguishing side plate 12a.
It is provided so as to be located inside 8, and these are integrally formed by press working from a steel plate which is a magnetic material. The arc drive plate 338 is bent in a U-shape from the bent portion 132a, and is arranged inside the arc-extinguishing side plate 128 so as to sandwich the fixed contact 112a with a gap in the direction perpendicular to the paper surface of FIG. By disposing the arc drive plate 338 inside the arc extinguishing side plate 128, the end of the arc extinguishing side plate 128 is prevented from being deformed inward.

Other structures are the same as those of the embodiment of the invention shown in FIGS. 1 to 3, and therefore, corresponding parts are designated by the same reference numerals and the description thereof will be omitted. As described above, since the arc drive plate 338 prevents the end of the arc extinguishing side plate 128 from being deformed inward, the deformation due to moisture absorption can be prevented even if an inexpensive insulating material such as a paper base material such as fiber paper is used. Therefore, an inexpensive material can be used as the arc extinguishing side plate 128.

The arc drive plate 338 and the fixed contact 11
The gap with 2a is determined in terms of the distance to the arc drive plate 338 when the movable contact 114a is opened, the required magnetic drive force, and the like. Therefore, in the embodiment of FIG. 6, the surface of the arc drive plate 338 is not covered with an insulating coating. However, for example, the arc drive plate 338 is subjected to an insulating coating process to drive the arc when the movable contact 114a is opened. The arc drive plate 338 may be provided close to the fixed contact 112a so as not to ignite with the plate 338.

Fourth Embodiment of the Invention 7 and 8 show another embodiment of the present invention. FIG. 7 is a side sectional view showing a main part of a circuit breaker, and FIG. 8A is a plan view of an arc extinguishing chamber. FIG. 8B is a side view of the arc extinguishing chamber. The arc drive assembly 430 is configured by fixing the U-shaped suction member 434 and the U-shaped drive member 438 to the arc extinguishing side plate 128 with an adhesive. The U-shaped suction member 434 is a plate-shaped arc suction portion 43 facing each other as an arc suction member.
4a and a connecting portion 43 for connecting the arc suction portion 434a
4b, and is formed by bending a steel plate, which is a magnetic material, into a U shape by pressing. The arc suction portion 434 a of the U-shaped suction member 434 is the arc extinguishing side plate 12.
8, the connecting portion 434b extends downward from the arc-extinguishing side plate 128 by the plate thickness thereof, as shown in FIG.

The U-shaped driving member 438 has an opposing plate-shaped arc driving portion 438a which is an arc driving member and a connecting portion 438b which connects the arc driving portion 438a.
Similarly, it is formed by bending a steel plate, which is a magnetic material, in a U-shape. The arc drive portion 438a of the U-shaped drive member 438 is provided outside the arc extinguishing side plate 128, and the connecting portion 438b is provided with the arc extinguishing side plate 1 as shown in FIG.
From 28, it extends to the left by that thickness.

In the fixed contactor side arc runner 432, the conductor forming the fixed contactor 112 is extended as it is to the lower portion of the grid assembly 124, and the U-shaped suction member 434 and the U-shaped driving member 438 are connected to each other. The U-shaped suction member 434 and the U-shaped driving member 438 are arranged inside the U-shaped portion and are in contact with and electrically connected to the connecting portions 434b and 438b, respectively. In addition, the arc suction unit 434a
By adhering the arc driving part 438a to the arc extinguishing side plate 128, it is possible to prevent the end part of the arc extinguishing side plate 128 from being deformed inward or outward.

Since other structures are the same as those of the embodiment of the invention shown in FIGS. 1 to 3, corresponding parts are designated by the same reference numerals and the description thereof will be omitted. As described above, the U-shaped suction member 434 and the U-shaped driving member 438 are individually formed by pressing from a steel plate,
The forming process becomes easy and the amount of steel sheet used can be reduced.

As shown in FIGS. 7 and 8, instead of adhering the U-shaped drive portion 438 to the arc extinguishing side plate 128 by positioning the arc drive portion 438a outside the arc extinguishing side plate 128, Alternatively, the U-shaped drive member 438 may be brazed to the fixed contact 112 such that the fixed contact 112a is sandwiched therebetween, and the arc extinguishing side plate 128 may be assembled later. In this case, the U-shaped driving member 438 may be brought into contact with the inner side of the arc-extinguishing side plate 128 to prevent the end portion of the arc-extinguishing side plate 128 from being deformed inward. In addition, the U-shaped suction member 434 and the U-shaped driving member 438 are not formed in the U shape, and the connecting portions 434b and 438b are omitted, so that the pair of plate-shaped arc suction portions 434a and the arc driving portion 438 are formed.
It is also possible to bond a to the arc extinguishing side plate 128 to form an arc suction plate and an arc drive plate, respectively.

Others. In the second to fourth embodiments of the invention described above, the arc-extinguishing side plate 128 is made of various insulating materials that generate gas for arc extinguishing when exposed to an arc. Therefore, it is often used. As the grid plate 126, a ceramic material such as cordierite is used in addition to a ferromagnetic steel plate.

[0035]

As described above, according to the circuit breaker of claim 1 of the present invention, the grid assembly provided apart from the fixed contact is sandwiched and extended toward the fixed contact. A pair of opposed arc extinguishing members, an arc runner made of a conductive material, which is inside the arc extinguishing side plate, extends from a predetermined position toward the grid assembly, and is electrically connected to the fixed contact. Since a pair of arc attracting members made of a ferromagnetic material is provided outside the opposing arc extinguishing member at a predetermined distance from the fixed contact in the extending direction of the arc runner, the arc is generated by the arc attracting member. Since the time of being sucked and quickly guided to the grid assembly and staying at the fixed contacts is shortened, it is possible to reduce wear of the fixed contacts and deterioration of the insulating member around the fixed contacts.

According to the circuit breaker of the second aspect of the present invention, the arc runner and the arc suction member are integrally formed of a steel plate, and the arc runner is extended by the arc runner and the arc suction member. Since the cross section in the direction orthogonal to the direction has a U-shape, the manufacturing is easy and the price is low.

According to the circuit breaker of the third aspect of the present invention, the arc runner is formed by extending the fixed contacts toward the grid assembly, and the arc runner is formed in a U shape. The opposing portion of the suction member is an arc suction member, and the arc runner is located inside the U-shaped portion of the U-shaped suction member. Easy to make.

According to the circuit breaker of the fourth aspect of the present invention, a pair of arc driving members made of a ferromagnetic material are provided so as to sandwich the fixed contact in a direction orthogonal to the extending direction of the arc runner. Therefore, the arc generated at the fixed contact is more strongly driven toward the grid assembly by the synergistic effect of the driving force by the arc driving member and the suction force by the arc suction member, and the time at which it stays at the fixed contact is further shortened. It is possible to more effectively reduce wear of the fixed contacts and deterioration of the insulating member around the fixed contacts.

According to the circuit breaker of the fifth aspect of the present invention, the arc runner, the arc suction member and the arc drive member are integrally formed of a steel plate, and the arc runner and the arc suction member are formed. The cross section of the arc runner in a direction orthogonal to the extending direction is formed into a U-shape, and the arc runner and the arc driving member form a U-shaped cross section in a direction orthogonal to the extending direction of the arc runner. Since the arc runner, the arc suction member, and the arc drive member are easily manufactured, the price is low.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an internal structure of a circuit breaker according to an embodiment of the present invention.

2 is a cross-sectional view of an arc extinguishing device portion taken along a cutting plane II-II in FIG.

FIG. 3 is an exploded perspective view of an arc extinguishing device portion in FIG.

FIG. 4 is a side sectional view showing an internal structure of a circuit breaker according to another embodiment of the present invention.

5 is a perspective view showing the arc drive assembly in FIG. 4. FIG.

6A and 6B show an arc extinguishing chamber according to another embodiment of the present invention, FIG. 6A being a plan view and FIG. 6B being a side view.

FIG. 7 is a side sectional view showing an essential part of a circuit breaker according to another embodiment of the present invention.

8 is a drawing showing the arc-extinguishing chamber in FIG. 7. FIG.
7A is a plan view, and FIG. 7B is a side view.

FIG. 9 is a side sectional view of a main part showing a main part of a conventional circuit breaker.

FIG. 10 is a perspective view of a main part of a conventional circuit breaker.

[Explanation of symbols]

110a ... Base, 112 ... Fixed contact, 112a ... Fixed contact, 114 ... Movable contact, 114a ... Movable contact, 1
24 ... Grid assembly, 126 ... Grid plate, 128 ...
Arc extinguishing side plate, 130, 230, 330, 430 ... Arc drive assembly, 132, 432 ... Fixed contact side arc runner, 134 ... Arc suction plate, 238, 338 ... Arc drive plate, 434 ... U-shaped suction member, 434a ... arc suction part, 438 ... U-shaped drive member, 438a ... arc drive part.

Claims (5)

[Claims] 1. A fixed contact having a fixed contact fixed to an insulating member, a movable contact having a movable contact contacting and separating from the fixed contact, and a plurality of grid members stacked at intervals to stack the fixed contact. A grid assembly provided apart from the contacts, a pair of opposing arc extinguishing members provided so as to sandwich the grid assembly and extend toward the fixed contact, and inside the opposing arc extinguishing members. And an arc runner made of a conductive material extending from a predetermined position toward the grid assembly and electrically connected to the fixed contact, and from the fixed contact outside the opposing arc extinguishing member. A circuit breaker comprising: a pair of arc attracting members made of a ferromagnetic material and provided at a predetermined distance in the extending direction of the arc runner. 2. The arc runner and the arc suction member are integrally formed of a steel plate, and the arc runner and the arc suction member have a U-shaped cross section in a direction orthogonal to the extending direction of the arc runner. The circuit breaker according to claim 1, wherein the circuit breaker is configured to be made. 3. The arc runner is formed by extending a fixed contact toward the grid assembly, and the opposing portions of the U-shaped suction member formed in a U shape are arc suction members. The circuit breaker according to claim 1, wherein the arc runner is located inside the U-shaped portion of the U-shaped suction member. 4. The circuit breaker according to claim 1, wherein a pair of arc driving members made of a ferromagnetic material are provided so as to sandwich the fixed contact in a direction orthogonal to the extending direction of the arc runner. . 5. An arc runner, an arc suction member, and an arc driving member are integrally formed of a steel plate,
The arc runner and the arc suction member form a U-shaped cross section in the direction orthogonal to the extending direction of the arc runner, and the arc runner and the arc driving member form a cross section in a direction orthogonal to the extending direction of the arc runner. The circuit breaker according to claim 4, wherein the circuit breaker has a V shape.