JP2020013757A - Circuit breaker - Google Patents

Abstract

To provide a circuit breaker that suppresses wearing of a contact using a simple structure and extinguishes an arc swiftly.SOLUTION: A circuit breaker 10a includes: a pair of main electrodes 28 that are capable of performing an approach and separation operation and through which a current is caused to flow via a main contact 30; a pair of arcing electrodes 44 that are capable of performing an approach and separation operation and through which a current is caused to flow via an arching contact 46; a plurality of arc-extinguishing grids 36 provided between the arcing electrodes 44; and a connection material 47a that is insulative and flexible and establishes each connection between the pair of arcing electrodes 44 and the plurality of arc-extinguishing grids 36. The arcing electrodes 44 form a parallel circuit with respect to the main electrodes 28 before an opening operation of the main electrodes 28, and are opened after the main electrodes 28 are opened. The arcing electrodes 44 are closed via the arcing contact 46 and the plurality of arc-extinguishing grids 36, and when the arcing electrodes 44 are opened, the arcing electrodes 44 and the arc-extinguishing grids 36 are separated from each other by the connection material.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a circuit breaker for interrupting a current.

  Generally, a circuit breaker that interrupts a current has a fixed electrode and a movable electrode that moves forward and backward with respect 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 cut off, and the contacts are consumed, so that a means for extinguishing the arc is used.

  In the circuit breaker described in Patent Literature 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. The arc horn is spreading upward. 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 to cut off the current.

  In the circuit breaker, the commutation of the arc utilizes Lorentz force generated by the current of the arc itself, and further uses buoyancy generated by blowing gas from below the electrode. For example, when a short-circuit current of several kA flows when a large current is interrupted due to, for example, a short-circuit accident, the Lorentz force acting on the arc becomes considerably large and the arc is easily commutated. On the other hand, when a small current of several hundred A is interrupted, it is difficult to commutate the arc only by the Lorentz force acting on the arc, so that buoyancy by gas blowing is effective.

JP 2017-4768 A

  By the way, commutation cannot always be performed sufficiently quickly even if gas is blown to the arc. Further, providing the gas blowing mechanism complicates the apparatus and increases the cost. Furthermore, even if the arc generated between the contacts can be quickly commutated to the arc horn, the occurrence of the arc inevitably causes some wear of the contacts, and furthermore, the arc horn is further commutated to the arc-extinguishing grid. It will take some time.

  The present invention has been made in view of the above problems, and provides a circuit breaker that can suppress the consumption of contacts with a simple configuration and can extinguish an arc quickly. Aim.

  In order to solve the above-described problems and achieve the object, a circuit breaker according to the present invention includes a pair of main electrodes that can perform relatively approaching and separating operations and that allow current to flow through a main contact. A pair of arcing electrodes capable of approaching and moving away from each other and through which an electric current flows through an arcing contact, wherein the arcing electrodes form a parallel circuit to the main electrode at least before the opening operation of the main electrode. Then, the pair of main electrodes are opened after being opened.

  A plurality of arc-extinguishing grids provided between the pair of arcing electrodes, and an insulating and flexible connecting member that connects the pair of arcing electrodes and the arc-extinguishing grids respectively. The pair of arcing electrodes are closed by sandwiching the arcing contact and the plurality of arc-extinguishing grids, and when the pair of arcing electrodes are separated from each other and open, the arcing electrode and the arc-extinguishing The grids may be separated from each other by the link.

  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 having two extending portions arranged in parallel in a direction orthogonal to the operation direction.

  The arc-extinguishing grid may be a magnetic material.

  The arc-extinguishing grid may be a magnetic body on both sides along the operation direction.

  The arcing electrode may be rotatable around an axis, and may have a grid guide that guides the 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, has a protruding extension arm, and when the pair of main electrodes is closed, the extension arm presses the arcing electrode, A plurality of the arc extinguishing grids may be sandwiched via arcing contacts.

  In at least one of the sets formed by the pair of main electrodes and the pair of arcing electrodes, the main electrode and the arcing electrode include an interlocking unit that mechanically interlocks the main electrode and the arcing electrode. The main electrode may be opened by operating the arcing electrode via the interlocking part after the electrode is separated and opened.

  The pair of arcing electrodes are arranged in parallel in a direction orthogonal to the operation direction at the time of closing, and the electromagnetic action of the current flowing through the arcing electrodes after the pair of main electrodes are separated from each other and opened. May be separated from each other to open the electrodes.

  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 conjunction 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 is opened. No arcing and no wear due to arcing. In addition, since the arc is initially generated between the pair of arcing electrodes, 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 configuration.

FIG. 1 is a partially omitted side view showing a state where a circuit breaker according to the first embodiment is closed. FIG. 2 is a partially omitted side view of the circuit breaker according to the first embodiment in a state where the opening operation is started. FIG. 3 is a partially omitted side view showing a state where the circuit breaker according to the first embodiment is in the middle of an opening operation. FIG. 4 is a partially enlarged side view showing a state where the circuit breaker is in the middle of the opening operation. FIG. 5 is a partially omitted side view of the circuit breaker according to the first embodiment in a final stage 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 state where the circuit breaker according to the second embodiment is closed. FIG. 10 is a partially omitted side view of the circuit breaker according to the second embodiment in a final stage of the opening operation.

  Hereinafter, a first embodiment and a second embodiment of a circuit breaker according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by the embodiment.

(1st 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 that cuts off direct current, and has a lower main circuit portion 12 and an upper arc extinguishing portion 14 schematically. The main circuit section 12 and the upper arc extinguishing section 14 need not be clearly separated.

  The circuit breaker 10a basically has a left-right symmetric structure, and one of them corresponds to the positive electrode side and the other corresponds to the negative electrode side. Hereinafter, in the description of the components of the main circuit section 12 and the arc extinguishing section 14, it is assumed that a pair of left and right is provided 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 24, a shaft 26 at a lower end of the base 24, a main electrode 28 provided on an upper half of the base 24, a main contact 30 provided on the main electrode 28, And an extension arm 32 protruding upward from 24. The base 24 is rotatably supported by a shaft 26. The pair of main contacts 30 are provided in opposite directions, and open and close by the rotation of the main electrode body 18. The material of the main contact 30 is, for example, copper, silver, tungsten or an alloy or powder metallurgy thereof, and it is desirable that the amount of consumption is small.

  The base 24 is rotatable left and right about a shaft 26 by a rotating mechanism (not shown). This turning mechanism operates when, for example, a short circuit is detected by the short circuit detection unit to open the circuit breaker 10a. The pair of main electrode bodies 18 are linked and rotate symmetrically, but it is sufficient that the pair of main electrode bodies 18 can relatively approach and separate. The pair of main electrodes 28 and the main contacts 30 open and close with the operation of the main electrode body 18. The main current lead 20 conducts the conductor 16 and the main electrode 28.

  The arc-extinguishing unit 14 has an arcing electrode body 34, a large number of arc-extinguishing grids 36, and a cord (an interlocking unit) 38. The arcing electrode body 34 has a base portion 40, a shaft 42 at a lower end of the base portion 40, a long arcing electrode 44 protruding upward from the base portion 40, and an arcing contact 46 provided on the arcing electrode 44. . The base 40 is rotatably supported by a shaft 42. The shaft 42 is disposed above the shaft 26. The pair of arcing contacts 46 are provided in opposite directions.

  Each arc extinguishing grid 36 is provided between a pair of arcing electrode bodies 34, and an insulating and flexible connecting member 47a, 47b is provided between the arcing electrode body 34 and each arc extinguishing grid 36 (FIG. 4). The connecting member 47a is provided at a position far from the shaft 42 and is slightly longer, and the connecting member 47b is provided at a position closer to the shaft 42 and slightly shorter. The arcing electrode 44 is provided at a height substantially equal to the middle position of the arc-extinguishing grid 36.

  Each arc-extinguishing grid 36 operates in an arc shape, and is formed in a U-shape having slightly longer extending portions 36a and 36b (see FIG. 6) arranged in parallel in a direction perpendicular to the operating direction and an upper opening 36c. ing. However, in FIGS. 1 to 5, 9 and 10, the arc-extinguishing grid 36 is schematically shown as a bar. Each arc extinguishing grid 36 is a magnetic material. The U-shape is in a broad sense and refers to a shape in which one ends of two extending portions 36a and 36b are connected and the other ends are open.

  When the pair of main electrodes 28 are closed, the extension arm 32 presses the arc-extinguishing grids 36 via the arcing contacts 46 by pressing in the closing direction from outside the arcing electrodes 44. As a result, adjacent arc extinguishing grids 36 abut each other. Therefore, the pair of arcing contacts 46 are connected via the arc-extinguishing grid 36 and are closed. The sub-current lead 22 electrically connects the conductor 16 to the lower end of the arcing electrode 44. As a result, the sub-current leads 22, 22, the arcing electrodes 44, 44, the arcing contacts 46, 46 and the plurality of arc-extinguishing grids 36 of the arc extinguishing section 14 conduct, and the main contacts 30, 30 of the main circuit section 12 are electrically connected. They 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, but the arcing electrode 44 is at least connected to the main electrode 28 before the main electrode 28 is opened. It is sufficient that a parallel circuit is formed.

  The string material 38 is a flexible member that connects the middle of the arcing electrode 44 and the tip of the extension arm 32, and is, for example, a wire. When the main electrode 28 is closed, the cord 38 has a slight slack or a margin of elastic deformation. The pair of main electrode bodies 18 operate to open each other during the opening operation, and further operate to pull and open the arcing electrode body 34 via the cord material 38. That is, the string member 38 is a mechanical interlocking unit 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 a slack or elastic deformation allowance, the arcing electrode body 34 starts the operation 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 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 pair on the positive electrode side and the pair on the negative electrode side formed by the pair of main electrode bodies 18 and the pair of arcing electrode bodies 34 (see FIG. 9). . Such an interlocking section is not limited to the string member 38, and may be, for example, a link having a play allowance, a long hole engagement mechanism, or a gear mechanism.

  The arc extinguishing unit 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. 1, and further covers the operating range of the plurality of arc extinguishing grids 36 from both sides. It has a pair of magnetic plates 52. In FIG. 1, the insulating plate 50 and the magnetic plate 52 on the near side of the drawing are omitted so that other components can be visually recognized.

  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 in which the lower part is narrow and the upper part is wide. The insulating plate 50 is formed with two pairs of grid guides 50a and 50b that guide the movement of the arc-extinguishing grid 36 in an arc shape centered on the pair of shafts 42. The grid guides 50a and 50b have a groove shape. The arc-extinguishing grid 36 operates in an arc shape by the grid guides 50a and 50b, and the operation direction is a direction in which the arc A is temporarily generated by the current I. The grid guide 50 a is provided at a position far from the axis 42 and along the vicinity of the tip of the arcing electrode 44. The grid guide 50b is provided along a substantially middle position of the arcing electrode 44. The grid guides 50a and 50b are provided, for example, at positions near 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 extending portion 36a, and the small protrusions 54b and 54d are provided on the extending portion 36b. Since each of the small projections 54a to 54d protrudes on both sides in the direction perpendicular to the paper surface, the total number is eight. The small protrusions 54a and 54b fit into the grid guide 50a, and the small protrusions 54c and 54d fit into the grid guide 50b. Due to such grid guides 50a, 50b and small protrusions 54a to 54d, each arc extinguishing grid 36 is stably spread in an arc shape when the arcing electrode body 34 operates in the opening direction.

  Next, the operation of the circuit breaker 10a thus configured will be described.

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

  As shown in FIG. 2, when the circuit breaker 10 a performs the opening operation, first, the pair of main electrode bodies 18 starts rotating in a direction away from each other with the shaft 26 as a center. However, even when the extension arm 32 of the main electrode body 18 starts operating, the arcing electrode body 34 connected to the stringing material 38 does not immediately start operating because the stringing material 38 has slack or elasticity margin. Accordingly, the pair of main electrodes 28 are separated from each other and opened by the operation of the main electrode body 18, but the current I flows from one of the right and left conductors 16 as shown by the broken line, and the sub-current lead 22 and the arcing electrode 44. , Arcing contacts 46, to the arc-extinguishing grid 36, and further out of the other arcing contacts 46 to the conductor 16. Thus, no arc A occurs 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, when the opening operation of the main electrode 28 progresses, the pair of main electrode bodies 18 cooperate with each other and further separate while being centered on the shaft 26. In conjunction with this, the pair of arcing electrode bodies 34 starts to rotate about the shaft 42 in a direction away from each other. The rotating operation of the arcing electrode body 34 is based on two functions.

  First, the first action is a mechanical action, and the string member 38 has no slack or elasticity due to the rotation of the pair of main electrode members 18 and pulls the arcing electrode member 34 connected to the string member 38. Works. The second operation is an electromagnetic operation, 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 flows in opposite directions to separate from each other by the self magnetic field. Works. In particular, at the start of the opening operation (see FIG. 2), the pair of arcing electrodes 44 are arranged in parallel in a direction orthogonal to the operation direction, are appropriately long, and have no intervening material in the substantially lower half. The self-magnetic field is easy to act on and is easily separated.

  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 start to separate sequentially from both sides, and move along the grid guides 50a and 50b. The rotation of the arcing electrode body 34 is mainly based on the mechanical first action when the small current is interrupted, and is mainly based on the electromagnetic second action when the large current is interrupted. When the electromagnetic force as the second action is strong at the time of interruption of the large current, the separation speed of the arcing electrode body 34 increases, and the arcing electrode 44 comes into contact with and presses the extension arm 32, so that the main electrode body 18 is pressed. Assists the rotation of As described above, the extension arm 32 has an assisted action pressed by the arcing electrode 44 when a large current is interrupted, and an action of pressing the pair of arcing electrodes 44 when the pole is closed 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, so that an arc A is generated in this portion. An arc A is generated at a place where the arc-extinguishing grids 36 are separated from each other, 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 a place where the arc extinguishing grid 36 is present. Commutation toward. That is, the arcing electrode 44 can be said to be a member similar in position and shape to a conventional arc horn, but is different in that the arc A is not commutated from the main electrode 28.

  As shown in FIG. 5, when the opening operation of the main electrode 28 further proceeds and the pair of main electrode members 18 and the pair of arcing electrode members 34 reach the maximum opening degree, all the arc-extinguishing grids 36 are also connected to each other. They are pulled and separated by 47a and 47b, and move along the grid guides 50a and 50b, respectively. The opening degree of the pair of arcing electrodes 44 moves until, for example, about 100 °, and the arcing electrodes 44 and the arc-extinguishing grid 36 spread radially at substantially equal angular intervals. Arc A occurs between all arcing contacts 46 and through all arc-extinguishing grids 36, and current I flows in this path. The arc A moves above the arc-extinguishing portion 14 by its own Lorentz force while being subjected to the arc-extinguishing action by the many arc-extinguishing grids 36, and the arc-extinguishing force is further strengthened by increasing the interval between the arc-extinguishing grids 36, Turn off the arc.

  Incidentally, the adjacent arc-extinguishing grids 36 have an action of being separated from each other, and 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 on the other extension 36b, Further, the arc A flows out to the adjacent arc extinguishing grid 36. That is, 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 identified as an arc-extinguishing grid 36α, and the other is identified as an arc-extinguishing grid 36β. The current flowing through the extending portion 36a of the arc-extinguishing grid 36α is opposite to the current flowing through the extending portion 36b of the arc-extinguishing grid 36β. Here, focusing on the magnetic flux Φ generated by the current flowing in the former, the magnetic flux is secured by the arc-extinguishing grid 36α, which is a magnetic material, 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 extending portion 36b of the adjacent arc-extinguishing grid 36β.

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

  Further, depending on conditions such as arc extinguishing performance, arc resistance, and welding resistance, the arc extinguishing grid 36 itself is not made of a magnetic material, but is made of a nonmagnetic material as shown in FIG. Both side surfaces may be made of the magnetic material 36d. For example, permalloy processing can be used for the magnetic body 36d. According to such a magnetic body 36d, an improvement in operating speed due to an improvement in magnetic flux collection performance is expected.

  According to the circuit breaker 10a configured as described above, the arcing electrode 44 for generating the arc A during the opening operation is provided separately from the main electrode 28 for energizing at the time of closing the electrode. The arc A is not generated in the main contact 30 and is hardly consumed. Therefore, it is not necessary to consider the arc resistance performance of the main contact 30. Instead, the material selection can be made with an emphasis on the performance of reducing the contact resistance and the contact heat generation, and the conduction performance can be improved. .

  On the other hand, with respect to the arcing contact 46 of the arcing electrode 44, it is not necessary to particularly consider the energizing performance during energizing when the electrode is closed. Instead, the material can be selected with an emphasis on arc resistance. For example, it is possible to take measures such as increasing the content of tungsten. Thereby, the consumption of the arcing contact 46 can be suppressed.

  In the circuit breaker 10a, the arc A during the closing operation is generated between the pair of arcing electrodes 44, and a large number of arc extinguishing grids 36 are provided in this portion. Therefore, there is no need to commutate the arc A generated between the main electrodes to the arc horn and further to the arc-extinguishing grid as in the circuit breaker according to the prior art. Can extinguish the arc. In particular, when a small current is interrupted in the circuit breaker according to the prior art, the electromagnetic force is small, so that it is difficult to commutate the arc A from the main electrode to the arc horn and the arc-extinguishing grid, or it takes time. In the case 10a, the arc A is generated at the arcing contact 46 via the arc-extinguishing grid 36 regardless of the magnitude of the current, so that the current limiting interruption performance is high. Further, the arc voltage of the arc A generated between the arcing electrode 44 and the arc-extinguishing grid 36 is improved (high current limiting performance).

  Furthermore, since the arc-extinguishing grid 36 has a folded U-shape, the arc-extinguishing grids 36 are separated from each other and spread by electromagnetic repulsion at the time of the opening operation, so that the arc A can be extinguished more quickly. .

  Further, since the pair of main electrodes 28 and the pair of main contacts 30 are not fixed and open and close in an interlocking manner, the operating range of the pair of arcing electrodes 44 and the pair of the arcing contacts 46 in conjunction therewith is widened. , Arc A can be easily extinguished.

  The circuit breaker 10a can extinguish the arc A at the time of power saving interruption without a gas blowing mechanism unlike the circuit breaker according to the related art, and has a simple and inexpensive structure. May be used in combination with a gas blowing mechanism or another mechanism.

(2nd Embodiment)
FIG. 9 is a partially omitted side view showing a circuit breaker 10b according to a second embodiment of the present invention. In the circuit breaker 10b, the same components 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 one of the left and right halves of the circuit breaker 10a is housed horizontally in the housing 60. The housing 60 is provided with a vent 60a.

  As shown in FIG. 9, the lower circuit in the circuit breaker 10b is composed of the conductor 16 and a horizontally long metal plate 62. The metal plate 62 also serves 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 24, and the cord 38 also serves as the sub-current lead 22. In this case, the extension arm 32 is a conductor. Note that the upper side or the lower side here is for convenience of explanation, and the direction in which the circuit breaker 10b is installed is not limited to the examples of FIGS.

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

  Although the main contact 30 is not provided on the metal plate 62, a portion indicated by an imaginary 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 a portion indicated by an imaginary line that contacts the upper arcing contact 46 via the arc-extinguishing grid 36 is regarded as the arcing contact 46.

  As shown in FIG. 10, when the main electrode body 18 rotates, the arcing electrode body 34 is also pulled by the string material 38 and rotates. The main electrode 28 opens and commutates the current to the arcing electrode 44. An arc A is generated between the arcing electrode 44 and each arc extinguishing grid 36, but the arc length is extended by the operation of the arc extinguishing grid 36, and the arc voltage is increased to extinguish the arc.

  Such a circuit breaker 10b has the same effect as the above-described circuit breaker 10a, and has a compact and inexpensive structure, and can be used, for example, as a breaker.

  The present invention is not limited to the above-described embodiment, and can be freely modified without departing from the gist of the present invention.

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

Claims (11)

A pair of main electrodes, which are relatively close to and separated from each other and through which current flows through the main contact;
A pair of arcing electrodes capable of relatively approaching and moving apart and having current flowing through the arcing contacts;
Has,
The circuit breaker, wherein the arcing electrode forms a parallel circuit with the main electrode at least before the main electrode is opened, and is opened after a pair of the main electrodes is opened. The circuit breaker according to claim 1,
A plurality of arc-extinguishing grids provided between the pair of arcing electrodes,
An insulating and flexible connecting member that connects between the pair of arcing electrodes and the plurality of arc-extinguishing grids,
Has,
The pair of arcing electrodes are closed by sandwiching the arcing contact and the plurality of arc-extinguishing grids,
A circuit breaker, wherein the arcing electrode and the arc-extinguishing grid are separated from each other by the connecting member when the pair of arcing electrodes are separated from each other and opened. The circuit breaker according to claim 2,
A circuit breaker, wherein both sides of an operation range of the plurality of arc extinguishing grids are sandwiched between insulating plates, and the insulating plates are sandwiched between magnetic plates on both sides. The circuit breaker according to claim 2 or 3,
The circuit breaker is characterized in that the arc-extinguishing grid has a U-shape having two extending portions arranged in parallel in a direction orthogonal to an operation direction. The circuit breaker according to any one of claims 2 to 4,
The circuit breaker, wherein the arc-extinguishing grid is made of a magnetic material. The circuit breaker according to any one of claims 2 to 4,
The circuit breaker according to claim 1, wherein the arc-extinguishing grid is made of a magnetic material on both sides along an operation direction. The circuit breaker according to any one of claims 2 to 6,
The arcing electrode is rotatable about an axis;
A circuit breaker having a grid guide that guides the movement of the arc-extinguishing grid in an arc shape around the axis. The circuit breaker according to any one of claims 2 to 7,
At least one of the pair of main electrodes is configured to be rotatable and has a protruding extension arm,
When the pair of main electrodes are closed, the extension arm presses the arcing electrode, thereby clamping the plurality of arc-extinguishing grids via the arcing contact. vessel. The circuit breaker according to any one of claims 1 to 8,
In at least one set of a set formed by the pair of main electrodes and the pair of arcing electrodes, the main electrode and the arcing electrode have an interlocking unit that mechanically interlocks the arcing electrode,
A circuit breaker, wherein after the pair of main electrodes are separated from each other and opened, the main electrodes are opened by operating the arcing electrode via the interlocking portion. The circuit breaker according to any one of claims 1 to 9,
The pair of arcing electrodes are arranged in parallel in a direction orthogonal to the operation direction at the time of closing, and the electromagnetic action of the current flowing through the arcing electrodes after the pair of main electrodes are separated from each other and opened. A circuit breaker, characterized in that the circuit breakers are separated from each other and opened. The circuit breaker according to any one of claims 1 to 10,
A circuit breaker, wherein the pair of main electrodes open and close in conjunction with each other, and the pair of arcing electrodes open and close in conjunction with the main electrodes.

Images