JP7149754B2 - circuit breaker - Google Patents

Description

The present invention relates to a circuit breaker that interrupts current.

A circuit breaker that cuts off current generally has a fixed electrode and a movable electrode that moves forward and backward relative to the fixed electrode. An arc is generated when the movable contact of the movable electrode separates from the fixed contact of the fixed electrode. If the arc is still generated, the current cannot be interrupted and the contacts will be worn out, so measures are taken to extinguish the arc.

In the circuit breaker described in Patent Document 1, arc horns corresponding to the fixed electrode and the movable electrode are provided respectively, and the arc generated between the contacts is commutated to the arc horn. Archorns flare upwards. The commutated arc extends along the arc horn and the arc voltage increases. The arc eventually reaches a plurality of arc-extinguishing grids, is divided by the arc-extinguishing grids, and the arc voltage is further increased for current-limiting interruption.

In the circuit breaker, the commutation of the arc utilizes the Lorentz force generated by the current of the arc itself, and further utilizes the buoyancy due to the gas blowing from the bottom of the electrode. For example, when a short-circuit current of several kA flows at the time of interrupting a large current such as a short-circuit accident, the Lorentz force acting on the arc becomes considerably large and the arc is likely to commutate. On the other hand, when a small current of several hundred amperes is interrupted, the buoyancy due to gas blowing is effective because it is difficult to commutate the arc only by the Lorentz force acting on the arc.

JP 2017-4769 A

By the way, blowing gas against the arc may not always commutate sufficiently quickly. Further, the provision of a gas blowing mechanism complicates the apparatus and increases the cost. Furthermore, even if the arc generated between the contacts could be quickly commutated to the arcing horn, the contact would inevitably wear out due to the generation of the arc, and further commutation from the arcing horn to the arc extinguishing grid would be required. It will take some time.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a circuit breaker capable of suppressing wear of contacts and rapidly extinguishing an arc with a simple structure. aim.

In order to solve the above-described problems and achieve the object, the circuit breaker according to the present invention provides a pair of main electrodes capable of moving toward and away from each other and through which current flows through main contacts; a pair of arcing electrodes movable toward and away from each other and having current flow through arcing contacts, said arcing electrodes forming a parallel circuit to said main electrodes at least prior to opening of said main electrodes. and is opened after the pair of main electrodes are opened.

a plurality of arc-extinguishing grids provided between the pair of arcing electrodes; and insulating and flexible connecting members respectively connecting the pair of arcing electrodes and the plurality of arc-extinguishing grids. , the pair of arcing electrodes are closed by sandwiching the arcing contacts and the plurality of arc-extinguishing grids, and the arcing electrodes and the arc-extinguishing grids are closed when the pair of arcing electrodes are separated from each other and opened The grids may be spaced apart from each other by said connectors.

Both sides of the operating range of the plurality of arc-extinguishing grids may be sandwiched between insulating plates, and the insulating plates may be sandwiched between magnetic plates on both sides.

The arc-extinguishing grid may be U-shaped with two parallel extensions in a direction perpendicular to the direction of motion.

The arc-extinguishing grid may be a magnetic material.

Both sides of the arc-extinguishing grid in the direction of motion may be magnetic.

The arcing electrode may be rotatable about an axis, and may have a grid guide that guides movement of the arc-extinguishing grid in an arc shape about the axis.

At least one of the pair of main electrodes is configured to be rotatable and has a protruding extension arm, and when the pair of main electrodes are closed, the extension arm presses the arcing electrode, thereby A plurality of arc-extinguishing grids may be sandwiched through arcing contacts.

At least one of the pairs of the pair of main electrodes and the pair of arcing electrodes has an interlocking portion for mechanically interlocking the main electrodes and the arcing electrodes, and the pair of main electrodes are connected to each other. After being separated from each other and opened, the main electrode may operate the arcing electrode via the interlocking portion to open.

The pair of arcing electrodes are arranged in parallel in a direction orthogonal to the operating direction when closed, and after the pair of main electrodes are separated from each other and opened, the electromagnetic action of the current flowing through the arcing electrodes. The electrodes may be separated from each other by opening.

The pair of main electrodes may be opened and closed in conjunction with each other, and the pair of arcing electrodes may be opened and closed in association with the main electrodes.

The circuit breaker according to the present invention has a pair of main electrodes and a pair of arcing electrodes, and the pair of arcing electrodes is opened after the pair of main contacts are opened. There is no wear due to arcing. In addition, since the arc is generated between the pair of arcing electrodes from the beginning, there is no need to commutate the arc from the main electrode to the arcing electrode, and the arc can be quickly extinguished with a simple structure.

1 is a partially omitted side view of a closed circuit breaker according to a first embodiment; FIG. FIG. 2 is a partially omitted side view of the circuit breaker according to the first embodiment in a state where an opening operation is started. FIG. 3 is a partially omitted side view of the circuit breaker according to the first embodiment in a state in the middle of opening operation. FIG. 4 is a partially enlarged side view of the circuit breaker in the middle of opening operation. FIG. 5 is a partially omitted side view of the circuit breaker according to the first embodiment in the final stage state of the opening operation. FIG. 6 is a side view of the arc-extinguishing grid and its surroundings. FIG. 7 is a partially enlarged plan view of the circuit breaker. FIG. 8 is a partially enlarged plan view of a circuit breaker according to a modification. FIG. 9 is a partially omitted side view of a closed state of the circuit breaker according to the second embodiment. FIG. 10 is a partially omitted side view of the circuit breaker according to the second embodiment in the final stage state of the opening operation.

DETAILED DESCRIPTION OF THE INVENTION A first embodiment and a second embodiment of a circuit breaker according to the present invention will be described in detail below with reference to the drawings. In addition, this invention is not limited by this embodiment.

(First embodiment)
FIG. 1 is a partially omitted side view showing a circuit breaker 10a according to a first embodiment of the present invention. The circuit breaker 10a is a device for interrupting direct current, and generally has a lower main circuit section 12 and an upper arc extinguishing section 14. As shown in FIG. The main circuit section 12 and the upper arc-extinguishing section 14 need not be clearly separated.

The circuit breaker 10a basically has a symmetrical structure, one of which corresponds to the positive side and the other to the negative side. In the following description of the constituent elements of the main circuit section 12 and the arc-extinguishing section 14, it is assumed that they are provided as a left and right pair unless otherwise specified.

The main circuit section 12 has a conductor section 16 , a main electrode body 18 , a main current lead 20 and a sub-current lead 22 . The main electrode body 18 includes a base portion 24, a shaft 26 at the lower end of the base portion 24, a main electrode 28 provided on the upper half of the base portion 24, a main contact 30 provided on the main electrode 28, a base portion and an extension arm 32 projecting upwardly from 24 . The base portion 24 is rotatably supported by a shaft 26 . A pair of main contacts 30 are provided facing each other, and are opened and closed by the rotation of the main electrode assembly 18 . The material of the main contact 30 is, for example, copper, silver, tungsten, alloys thereof, or powder metallurgy, and it is desirable that the amount of consumption is small.

The base portion 24 can be rotated left and right around a shaft 26 by a rotation mechanism (not shown). This rotating mechanism operates to open the circuit breaker 10a, for example, when a short circuit is detected by the short circuit detection unit. The pair of main electrode bodies 18 are interlocked and rotate symmetrically, but it is sufficient if they can be relatively moved toward and away from each other. The pair of main electrodes 28 and main contacts 30 are opened and closed as the main electrode body 18 is operated. A main current lead 20 electrically connects the conductor portion 16 and the main electrode 28 .

The arc-extinguishing portion 14 has an arcing electrode body 34 , a large number of arc-extinguishing grids 36 , and a string member (interlocking portion) 38 . The arcing electrode body 34 has a base portion 40, a shaft 42 at the lower end of the base portion 40, an elongated arcing electrode 44 projecting upward from the base portion 40, and an arcing contact 46 provided on the arcing electrode 44. . The base portion 40 is rotatably supported by a shaft 42 . The shaft 42 is arranged above the shaft 26 . A pair of arcing contacts 46 are provided facing each other.

Each arc-extinguishing grid 36 is provided between a pair of arcing electrode bodies 34. Between the arcing electrode body 34 and each arc-extinguishing grid 36, insulating and flexible connecting members 47a and 47b (see FIG. 4) are connected. The connecting member 47a is provided farther from the shaft 42 and is slightly longer, and the connecting member 47b is provided closer to the shaft 42 than it and is slightly shorter. The arcing electrode 44 is provided at a height approximately equal to the intermediate position of the arc extinguishing grid 36 .

Each arc-extinguishing grid 36 operates in an arc and is formed in a U-shape having somewhat long extensions 36a and 36b (see FIG. 6) parallel to each other in a direction perpendicular to the direction of operation and an upper opening 36c. ing. 1 to 5, 9, and 10, however, the arc-extinguishing grid 36 is simply shown as a bar. Each arc-extinguishing grid 36 is a magnetic material. The U-shape is defined in a broad sense, and refers to a shape in which one end of the two extensions 36a and 36b is connected and the other end is open.

When the pair of main electrodes 28 are closed, the extension arm 32 presses the arcing electrode 44 from the outside in the closing direction, thereby sandwiching a plurality of arc extinguishing grids 36 via the arcing contact 46 . As a result, adjacent arc-extinguishing grids 36 abut each other. Therefore, the pair of arcing contacts 46 are connected through the arc extinguishing grid 36 and are closed. The sub-current lead 22 electrically connects the conductor portion 16 and the lower end portion of the arcing electrode 44 . As a result, the sub-current leads 22, 22, the arc electrodes 44, 44, the arc contacts 46, 46 and the plurality of arc extinguishing grids 36 of the arc extinguishing section 14 become conductive, and the main contacts 30, 30 of the main circuit section 12 are connected. will be connected in parallel.

When the main electrode 28 is closed, the arcing electrode 44 is also normally closed via the arc-extinguishing grid 36. It is sufficient if a parallel circuit is formed.

The string member 38 is a flexible member, such as a wire, that connects the middle of the arcing electrode 44 and the distal end of the extension arm 32 . When the main electrode 28 is closed, the string material 38 is slightly loose or has a slight margin of elastic deformation. The pair of main electrode bodies 18 are operated so as to open each other during the opening operation, and the arcing electrode body 34 is pulled through the string member 38 to be operated so as to be opened. In other words, the string member 38 is a mechanical interlocking portion that interlocks the main electrode body 18 and the arcing electrode body 34 during the opening operation. In addition, since the string member 38 has slackness or elastic deformation margin, the arcing electrode body 34 starts operating slightly later than the main electrode body 18 during the opening operation. In order to reliably delay the operation start timing of the arcing electrode body 34 from that of the main electrode body 18, the arcing electrode body 34 may be biased with a weak elastic force in the closing direction by an elastic body.

Such an interlocking portion may be provided in at least one of the positive electrode side group and the negative electrode side group formed by the pair of main electrode bodies 18 and the pair of arcing electrode bodies 34 (see FIG. 9). . Such an interlocking portion is not limited to the string material 38, and may be, for example, a link having a play allowance, an elongated hole engaging mechanism, or a gear mechanism.

The arc-extinguishing part 14 further covers the operating range of the arcing electrode body 34 and the operating range of the main electrode 28 from both sides in the direction perpendicular to the paper surface of FIG. and a pair of magnetic plates 52 . In FIG. 1, the insulating plate 50 and the magnetic plate 52 on the front side of the paper are omitted so that other components can be seen.

The insulating plate 50 is provided close to the arcing electrode body 34 and the arc-extinguishing grid 36 in the direction perpendicular to the paper surface (see FIG. 7), and has a shape that is narrow at the bottom and wide at the top. The insulating plate 50 is formed with two pairs of grid guides 50 a and 50 b having circular arc shapes about the pair of shafts 42 and guiding the movement of the arc-extinguishing grid 36 . The grid guides 50a, 50b are groove-shaped. The arc-extinguishing grid 36 is moved in an arc by the grid guides 50a and 50b. The grid guide 50 a is provided along the vicinity of the tip of the arcing electrode 44 at a position far from the shaft 42 . The grid guide 50b is provided along approximately the middle position of the arcing electrode 44. As shown in FIG. The grid guides 50a and 50b are provided, for example, at positions close to the connecting members 47a and 47b, respectively.

Each arc-extinguishing grid 36 is provided with small projections 54a, 54b, 54c, 54d (see FIG. 6) extending in the direction perpendicular to the paper surface. The small protrusions 54a and 54c are provided on the extension portion 36a, and the small protrusions 54b and 54d are provided on the extension portion 36b. Each of the small projections 54a to 54d protrudes on both sides in the direction perpendicular to the paper surface, so there are eight in total. The small projections 54a and 54b fit into the grid guide 50a, and the small projections 54c and 54d fit into the grid guide 50b. With such grid guides 50a, 50b and small projections 54a-54d, each arc-extinguishing grid 36 spreads stably in an arc shape when the arcing electrode body 34 operates in the opening direction.

Next, the operation of the circuit breaker 10a configured in this manner will be described.

As shown in FIG. 1, when the main electrode 28 is closed, the current I flows from either the left or right conductor portion 16, flows to the main current lead 20, the main electrode 28, the main contact 30, and the other. flows out from the main contact 30 to the conductor portion 16 . However, since a parallel circuit to the main contact 30 is also formed in the arc-extinguishing portion 14 as described above, the current also flows through that portion in a bypass manner.

As shown in FIG. 2, when the circuit breaker 10a performs the opening operation, first, the pair of main electrode bodies 18 interlock and begin to rotate about the shaft 26 in the directions away from each other. However, even if the extension arm 32 of the main electrode body 18 begins to operate, the arcing electrode body 34 connected to the string material 38 does not immediately start operating because the string material 38 has slack or elastic margin. Therefore, the pair of main electrodes 28 are separated from each other by the operation of the main electrode body 18 and opened, but the current I flows from either the left or right conductor portion 16 as indicated by the broken line, and the sub-current lead 22 and the arcing electrode 44 , arcing contact 46 , arc-extinguishing grid 36 , and bypass from the other arcing contact 46 to conductor portion 16 . As a result, no arc A is generated between the pair of main contacts 30 . On the other hand, the current I flowing through the pair of arcing electrodes 44 increases.

As shown in FIG. 3, as the opening operation of the main electrode 28 progresses, the pair of main electrode bodies 18 are interlocked and further separated from each other while centering on the axis 26 . In conjunction with this, the pair of arcing electrode bodies 34 begin to rotate about the shaft 42 in a direction away from each other. This rotational movement of the arcing electrode body 34 is due to two effects.

First, the first action is a mechanical action. Rotation of the pair of main electrode bodies 18 eliminates slack or elastic margin in the string 38, pulling the arcing electrode 34 connected to the string 38. It works. The second action is an electromagnetic action, in which the opening between the pair of main contacts 30 increases the current I flowing through the pair of arcing electrodes 44, and the current I flows in the opposite directions to each other to separate them from each other due to the self-magnetic field. works. In particular, the pair of arcing electrodes 44 are arranged in parallel in a direction orthogonal to the direction of operation at the start of the opening operation (see FIG. 2), are appropriately long, and have no inclusions between them in substantially lower halves. A self-magnetic field is likely to act, and it is easy to separate.

By these two actions, the arcing electrode bodies 34 are separated from each other, and the plurality of arc-extinguishing grids 36 are pulled by the connecting members 47a and 47b and begin to separate from both sides in order and move along the grid guides 50a and 50b. The rotation of the arcing electrode body 34 is mainly based on the first mechanical action when interrupting a small current, and is mainly based on the second electromagnetic action when interrupting a large current. When a large current is interrupted and the electromagnetic force as the second action is strong, the separation speed of the arcing electrode body 34 increases, and the arcing electrode 44 abuts and presses the extension arm 32 , so that the main electrode body 18 assists the rotation of Thus, the extension arm 32 has an assisted action of being pressed by the arcing electrode 44 when a large current is interrupted, and an action of pressing the pair of arcing electrodes 44 when closing the pole as described above.

As shown in FIG. 4, when the arcing electrode body 34 operates, the arcing electrode 44 is separated from the arc-extinguishing grid 36, and an arc A is generated at this portion. An arc A is also generated at a portion spaced apart between the arc-extinguishing grids 36, and the arc voltage increases. As is clear from FIG. 4, the arc A is not commutated from the main electrode 28, but is generated at the location where the arc-extinguishing grid 36 exists. commutate towards That is, the arcing electrode 44 can be said to be a member similar in position and shape to a conventional arcing horn, but differs in that the arc A does not commutate from the main electrode 28 .

As shown in FIG. 5, when the opening operation of the main electrodes 28 further progresses and the pair of main electrode bodies 18 and the pair of arcing electrode bodies 34 reach the maximum opening, all the arc-extinguishing grids 36 are connected to each other. They are pulled apart by 47a and 47b and move along grid guides 50a and 50b, respectively. The opening of the pair of arcing electrodes 44 moves, for example, to about 100°, and the arcing electrodes 44 and the arc-extinguishing grid 36 spread radially at substantially equal angular intervals. Arc A is generated between a pair of arcing contacts 46 through all arc extinguishing grids 36, and current I flows along this path. The arc A moves above the arc-extinguishing part 14 by its own Lorentz force while receiving arc-extinguishing action by many arc-extinguishing grids 36, and the arc-extinguishing force is further strengthened by widening the distance between the arc-extinguishing grids 36. extinguish the arc.

Adjacent arc-extinguishing grids 36 have a function of separating them from each other, which will be described below.

As shown in FIG. 6, when passing through one arc-extinguishing grid 36, the current I flows downward from one extension 36a, passes through the bottom of the U-shape, and rises through the other extension 36b, Further, it becomes an arc A and flows out to the adjacent arc extinguishing grid 36 . In other words, the current I flows in the opposite directions in the extending portion 36a and the extending portion 36b.

As shown in FIG. 7, one of two adjacent arc-extinguishing grids 36 is distinguished as an arc-extinguishing grid 36α and the other as an arc-extinguishing grid 36β. The current flowing through the extending portion 36a of the arc-extinguishing grid 36α and the current flowing through the extending portion 36b of the arc-extinguishing grid 36β are opposite in direction. Here, focusing on the magnetic flux Φ generated by the current flowing in the former, the magnetic path of this magnetic flux Φ is secured by the arc extinguishing grid 36α and the magnetic plates 52 on both sides, and leakage to the outside is prevented. less. Thus, the magnetic flux Φ acts moderately strongly on the extension 36b of the adjacent arc-extinguishing grid 36β.

The direction of current flow is opposite between the extending portion 36a and the extending portion 36b, and the magnetic flux Φ is substantially orthogonal to the current flowing through the extending portion 36b. , receives the Lorentz force in the direction away from the arc-extinguishing grid 36α. Since such action works between adjacent arc-extinguishing grids 36, they are separated from each other quickly. As the arc extinguishing grids 36 are rapidly separated from each other, the arc A is extended, the arc voltage is further increased, and the arc is extinguished quickly.

In addition, depending on conditions such as arc-extinguishing performance, arc-resistant performance, and welding resistance, the arc-extinguishing grid 36 itself is not made of a magnetic material, but is made of a non-magnetic material as shown in FIG. Both side surfaces may be composed of the magnetic material 36d. Permalloy processing, for example, can be used for the magnetic material 36d. According to such a magnetic body 36d, it is expected that the operating speed will be improved due to the improvement of the magnetic collecting performance.

According to the circuit breaker 10a configured in this manner, the arcing electrode 44 for generating the arc A during the opening operation is provided separately from the main electrode 28 for energization during closing. No arc A occurs at the main contact 30, and there is almost no consumption. Therefore, it is not necessary to consider the arc resistance performance of the main contact 30, and instead, the material can be selected with emphasis on the performance of reducing the contact resistance and contact heat generation, and the current carrying performance can be improved. .

On the other hand, regarding the arcing contact 46 of the arcing electrode 44, there is no need to particularly consider the energization performance when the energization is closed, and instead the material can be selected with emphasis on the arc resistance performance. For example, measures such as increasing the content of tungsten can be taken. Thereby, the consumption amount of the arcing contact 46 can be suppressed.

In the circuit breaker 10a, the arc A is generated between the pair of arcing electrodes 44 during the closing operation, and many arc-extinguishing grids 36 are provided in this portion. Therefore, unlike the conventional circuit breaker, the arc A generated between the main electrodes does not need to be commutated to the arc horn and then to the arc extinguishing grid, and the arc A can be quickly extinguished by the arc extinguishing grid 36. Arc can be extinguished. In particular, when the circuit breaker according to the prior art interrupts a small current, the electromagnetic force is small. Since the arc A is generated at the arcing contact 46 through the arc extinguishing grid 36 regardless of the magnitude of the current in the device 10a, the current limiting breaking performance is high. Also, the arc voltage of the arc A generated between the arcing electrode 44 and the arc extinguishing grid 36 can be improved (high current limiting performance).

Furthermore, since the arc-extinguishing grid 36 has a folded U-shape, the arc-extinguishing grid 36 itself spreads apart from each other due to the electromagnetic repulsive force during the opening operation, and the arc-extinguishing of the arc A can be accelerated. .

Furthermore, since the pair of main electrodes 28 and the pair of main contacts 30 are not fixed and are opened and closed in conjunction with each other, the operating range of the pair of arcing electrodes 44 and the pair of arcing contacts 46 that are associated with them is widened. , the arc A becomes easier to extinguish.

The circuit breaker 10a can extinguish the arc A during power saving interruption without a gas blowing mechanism like the circuit breaker according to the prior art, and is simple in structure and inexpensive. may use a gas blowing mechanism or other mechanisms in combination.

(Second embodiment)
FIG. 9 is a partially omitted side view showing a circuit breaker 10b according to a second embodiment of the present invention. Components in the circuit breaker 10b that are the same as those in the circuit breaker 10a are denoted by the same reference numerals, and detailed description thereof will be omitted. Schematically, the circuit breaker 10b has a configuration in which either the left or right half of the circuit breaker 10a described above is housed sideways in a housing 60. As shown in FIG. The housing 60 is provided with a vent 60a.

As shown in FIG. 9, the lower circuit of the circuit breaker 10b is composed of the conductor portion 16 and the horizontally elongated metal plate 62. As shown in FIG. The metal plate 62 serves both as the main electrode 28 and the arcing electrode 44 . In the upper circuit of the circuit breaker 10b, the main electrode 28 also serves as the base portion 24, and the cord member 38 also serves as the sub-current lead 22. As shown in FIG. The extension arm 32 in this case is a conductor. It should be noted that the term "upper side" or "lower side" as used herein is for convenience of explanation, and the direction in which the circuit breaker 10b is installed is not limited to the examples in FIGS.

The pair of conductor portions 16 extends inward from the left and right sides of the housing, one of which is connected to the upper main electrode 28 via the main current lead 20 and the other of which is connected to the metal plate 62 . The metal plate 62 and one of the conductor portions 16 (on the left side in FIG. 9) are vertically arranged in parallel with an insulating material interposed therebetween. The other conductor portion 16 (right side in FIG. 9) is also covered with an insulating material.

Although the metal plate 62 is not provided with the main contact 30 , the portion indicated by the phantom line in contact with the upper main contact 30 is regarded as the main contact 30 . Similarly, the metal plate 62 is not provided with the arcing contact 46 , but the point indicated by the phantom line where the upper arcing contact 46 contacts with the arc extinguishing grid 36 is regarded as the arcing contact 46 .

As shown in FIG. 10, when the main electrode assembly 18 rotates, the arcing electrode assembly 34 is also pulled by the string member 38 and rotated. The main electrode 28 opens and commutates current to the arcing electrode 44 . An arc A is generated between the arcing electrode 44 and each arc-extinguishing grid 36, but the action of the arc-extinguishing grid 36 extends the arc length, increases the arc voltage, and extinguishes the arc.

Such a circuit breaker 10b can obtain the same effects as the circuit breaker 10a, has a compact and inexpensive structure, and can be used as a breaker, for example.

It goes without saying that the present invention is not limited to the above-described embodiments, and can be freely modified without departing from the gist of the present invention.

10a, 10b Circuit breaker 12 Main circuit part 14 Arc extinguishing part 16 Conductor part 18 Main electrode body 20 Main current lead 22 Sub current lead 26, 42 Shaft 28 Main electrode 30 Main contact 32 Extension arm 34 Arc electrode body 36, 36α, 36β arc-extinguishing grids 36a, 36b extension portion 36d magnetic body 38 string member (interlocking portion)
44 arcing electrode 46 arcing contacts 47a, 47b connecting members 50a, 50b grid guide 50 insulating plate 52 magnetic plate

Claims (9)

a pair of main electrodes capable of moving toward and away from each other and through which current flows through main contacts;
a pair of arcing electrodes capable of moving toward and away from each other and having current flow through the arcing contacts;
a plurality of arc-extinguishing grids provided between the pair of arcing electrodes;
an insulating and flexible connecting member that connects between the plurality of arc-extinguishing grids and between the arc-extinguishing grids at both ends and the arcing electrodes adjacent thereto;
has
the arcing electrode forms a parallel circuit with the main electrode at least before the opening operation of the main electrode, and is opened after the pair of main electrodes are opened ;
The pair of arcing electrodes are closed by sandwiching the arcing contact and the plurality of arc-extinguishing grids,
When the pair of arcing electrodes are separated from each other and opened, the arc-extinguishing grids adjacent to each other and the arc-extinguishing grids at both ends and the arcing electrodes adjacent thereto are separated from each other by the connecting members . A circuit breaker characterized by: The circuit breaker of claim 1 , wherein
A circuit breaker, wherein both sides of an operating range of said arc-extinguishing grids are sandwiched between insulating plates, and said insulating plates are sandwiched between magnetic plates on both sides thereof. The circuit breaker according to claim 1 or 2 ,
A circuit breaker, wherein the arc-extinguishing grid has a U-shape having two extending portions arranged in parallel in a direction perpendicular to the operating direction. In the circuit breaker according to any one of claims 1 to 3 ,
A circuit breaker, wherein the arc-extinguishing grid is a magnetic material. In the circuit breaker according to any one of claims 1 to 3 ,
A circuit breaker, wherein the arc-extinguishing grid is made of magnetic material on both sides along the operating direction. In the circuit breaker according to any one of claims 1 to 5 ,
the arcing electrode is rotatable about an axis;
A circuit breaker comprising a grid guide that guides movement of the arc-extinguishing grid in an arc shape centered on the axis. In the circuit breaker according to any one of claims 1 to 6 ,
at least one of the pair of main electrodes is configured to be rotatable and has a protruding extension arm;
A circuit breaker characterized in that when the pair of main electrodes are closed, the extension arm presses the arcing electrodes, thereby sandwiching the plurality of arc-extinguishing grids through the arcing contacts. vessel. In the circuit breaker according to any one of claims 1 to 7 ,
an interlocking portion for mechanically interlocking the main electrodes and the arcing electrodes in at least one of the sets formed by the pair of main electrodes and the pair of arcing electrodes,
After the pair of main electrodes are separated from each other and opened, the main electrodes cause the pair of arcing electrodes to separate from each other based on the mechanical action via the interlocking portion. vessel. In the circuit breaker according to any one of claims 1 to 8 ,
The pair of arcing electrodes are arranged in parallel in a direction orthogonal to the operating direction when closed, and after the pair of main electrodes are separated from each other and opened , in addition to the mechanical action, the arcing electrodes A circuit breaker, characterized in that it separates from each other based on the electromagnetic action of the current flowing through it.

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