Switchgear

Abstract

To prevent a power-on defect due to wearing, etc., caused by an arc in a stationary-side electrode.SOLUTION: A switchgear (10) includes: a stationary-side electrode (11); a stationary-side conductive hold part (13) which electrically connects an external circuit and the stationary-side electrode while holding the stationary-side electrode; a movable-side electrode (12) which acts to be in contact with and separated from the stationary-side electrode; and an insulating support part (50) which is disposed in the stationary-side conductive hold part. The stationary-side electrode includes a contact piece (18) which electrifies the stationary-side conductive hold part and the movable-side electrode and a tension spring (51) which presses the contact piece to the movable-side electrode. In a close-circuit state where the movable-side electrode is stopped, the contact piece comes into contact with the stationary-side conductive hold part and the movable-side electrode. Further, the contact piece is separated from the movable-side electrode by the action when shifting the close--circuit state of the movable-side electrode to an open-circuit state, thereby being separated from the stationary-side conductive hold part by being displaced by an elastic force of the tension spring while being supported by the insulating support part. Thus, the contact piece can be brought into an electrically floating state in the open-circuit time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a switchgear, and more particularly to a switchgear used for power receiving and distribution equipment. [Background technology]

[0002] Patent Document 1 discloses a gas-insulated switchgear equipped with a conductive fixed contact and a cylindrical movable contact that moves coaxially with the fixed contact and can be brought into contact with or separated from the fixed contact. When the gas-insulated switchgear is in a closed state, the inside of the fixed contact and the outer periphery of the movable contact fit together to form an electrical connection. A coil spring is arranged around the outer periphery of the fixed contact, and the coil spring presses the fixed contact against the movable contact, ensuring an electrical connection between the fixed contact and the movable contact. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-77542 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, when the opening operation starts, the movable contact and the fixed contact are separated but a voltage is still applied, causing an arc discharge between them. Even if the fixed contact and the movable contact are separated, the arc discharge may be extended and maintained. In this case, current continues to flow between the movable contact and the fixed contact, causing wear and deterioration of the fixed contact and other parts, which can cause closing failures.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a switching device that can prevent closing failures due to wear and tear caused by arcing at the fixed electrode. [Means for solving the problem]

[0006] One aspect of the switching device of the present invention is a switching device comprising: a fixed-side electrode; a fixed-side conductive holding portion that holds the fixed-side electrode and electrically connects the fixed-side electrode to an external circuit; a movable-side electrode that operates to move toward and away from the fixed-side electrode; and an insulating support portion provided on the fixed-side conductive holding portion, wherein the fixed-side electrode comprises a contact piece that conducts electricity between the fixed-side conductive holding portion and the movable-side electrode, and an elastic member that presses the contact piece against the movable-side electrode, and the contact piece comes into contact with the fixed-side conductive holding portion and the movable-side electrode when the movable-side electrode is stopped in a closed-circuit state, and separates from the movable-side electrode when the movable-side electrode is changed from the closed-circuit state to an open-circuit state, thereby being supported by the insulating support portion and displaced by the elastic force of the elastic member to separate from the fixed-side conductive holding portion. [Effects of the Invention]

[0007] According to the present invention, when the circuit is opened, the contact of the fixed electrode is supported by the insulating support portion while being separated from both the movable electrode and the fixed conductive holder. In this state, the contact can be kept in an electrically floating state, which makes it possible to prevent the current of the arc generated when the circuit is opened from flowing through the contact. This makes it possible to suppress wear, deterioration, and welding of the contact due to the arc, and to prevent the occurrence of closing failures caused by these. [Brief explanation of the drawings]

[0008] [Figure 1] 3 is a schematic partial cross-sectional view of a switching device according to an embodiment in a closed state; FIG. [Figure 2] FIG. 2 is a partial cross-sectional view similar to FIG. 1, illustrating the open state of the switchgear. [Figure 3] 2 is a partial cross-sectional view similar to FIG. 1 showing a state in which the switching device is in the middle of changing from a closed state to an open state. [Figure 4] 2 is a partial cross-sectional view similar to FIG. 1 showing a state in which an arc is generated in the switchgear. DETAILED DESCRIPTION OF THE INVENTION

[0009] An opening / closing device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The present invention is not limited to the following embodiment, and can be implemented by appropriate modifications within the scope of the present invention. In the following figures, for the sake of convenience, some components may be omitted, such as omitting illustration of symmetrical structures across a central position in cross-sectional views. Here, in this specification and claims, "front" and "rear" are used based on the directions indicated by arrows in each figure.

[0010] Fig. 1 is a schematic partial cross-sectional view of a switchgear according to an embodiment in a closed state. Fig. 2 is a partial cross-sectional view similar to Fig. 1, showing the switchgear in an open state. Fig. 3 is a partial cross-sectional view similar to Fig. 1, showing the switchgear in an intermediate state from a closed state to an open state. Fig. 4 is a partial cross-sectional view similar to Fig. 1, showing a state in which an arc is generated in the switchgear. As shown in Figs. 1 to 4, a switchgear 10 includes a fixed electrode 11 and a movable electrode 12 arranged side by side in the front-to-rear direction.

[0011] In this embodiment, the fixed electrode 11 is disposed in the front and the movable electrode 12 is disposed in the rear on the same axis. The switchgear 10 includes a housing (not shown) that forms a sealed internal space, and the fixed electrode 11 and the movable electrode 12 are disposed in this internal space. When the switchgear 10 is a gas-insulated switchgear, the internal space is filled with an insulating gas such as sulfur hexafluoride (SF6) or dry air, but instead of an insulating gas, the internal space may be maintained in a vacuum.

[0012] The switchgear 10 further includes a fixed-side conductive holder 13 and a movable-side conductive holder 14 that are energized through conductors (not shown) that constitute an external circuit. The fixed-side conductive holder 13 and the movable-side conductive holder 14 are provided in a generally cylindrical shape with their axial directions facing the front-to-rear direction. The fixed-side conductive holder 13 holds the fixed-side electrode 11 and electrically connects the fixed-side electrode 11 to an external circuit (not shown). The movable-side conductive holder 14 holds the movable-side electrode 12 and electrically connects the circuit to the movable-side electrode 12. In this embodiment, the electrodes 11, 12 and the conductive holders 13, 14 form a disconnector that opens and closes the circuit.

[0013] The movable electrode 12 is formed in the shape of a round shaft with a central axis extending parallel to the front-rear direction. The movable electrode 12 is moved in the front-rear direction by an operating mechanism (not shown). The operating mechanism transmits driving force from a driving source such as an appropriate rotation mechanism or cylinder to the movable electrode 12 via a lever or link mechanism.

[0014] The movable electrode 12 is located at the rear and separated from the fixed electrode 11 in the open state shown in Fig. 2, and is located at the front and comes into contact with the fixed electrode 11 at its tip (front end) in the closed state shown in Fig. 1. Thus, the movable electrode 12 is capable of opening and closing, moving toward and away from the fixed electrode 11, and the direction of the opening and closing movement of the movable electrode 12 is parallel to the front-to-rear direction. The opening and closing movement (advancing and retreating movement) of the movable electrode 12 causes the movable electrode 12 to approach and separate from the fixed electrode 11.

[0015] The fixed side electrode 11 has a fixed side main contact 16 and a fixed side arc contact 17 that can be brought into contact with and separated from the movable side electrode 12, and the fixed side arc contact 17 is arranged to be displaceable in the forward and backward directions, which are the same as the opening and closing direction of the movable side electrode 12.

[0016] The fixed-side main contact 16 is configured by arranging a plurality of contact pieces 18 in the circumferential direction. Therefore, the fixed-side main contact 16 is provided in an annular shape around a central axis that is parallel to the same central axis of the movable-side electrode 12 in the front-rear direction, and has an opening in the center through which the movable-side electrode 12 is inserted and removed. The contact pieces 18 of the fixed-side main contact 16 and their surrounding structure will be described later.

[0017] The fixed side arc contact 17 includes a round shaft-shaped fixed side arc contact body 21 having an outer diameter smaller than the opening diameter of the fixed side main contact 16, and a disk-shaped base 22 connected to the rear end of the fixed side arc contact body 21 and having a larger diameter than the fixed side arc contact body 21. In the closed state shown in Fig. 1, the tip (rear end) of the fixed side arc contact body 21 of the fixed side arc contact 17 comes into contact with the tip of the movable side electrode 12, allowing current to flow.

[0018] The fixed-side arc contact 17 is disposed in a movable space 13b formed in a round hole shape at the axial center of the fixed-side conductive holding part 13 so as to be displaceable in the front-rear direction. An annular wall part 13c that protrudes inward is formed in the middle part of the movable space 13b in the front-rear direction. In the fixed-side arc contact 17, the fixed-side arc contact main body 21 is inserted into the annular wall part 13c, and the base part 22 abuts against the front surface of the annular wall part 13c, thereby restricting rearward displacement of the fixed-side arc contact 17.

[0019] Annular sliding portions 24, 25 are embedded in the inner periphery of the annular wall portion 13c and the outer periphery of the base portion 22. The sliding portions 24, 25 are formed of low-friction sliding members such as wear rings. The inner periphery of the sliding portion 24 provided on the annular wall portion 13c slides against the outer periphery of the fixed-side arc contact main body 21, which displaces in the front-rear direction. The inner periphery of the sliding portion 25 provided on the base portion 22 slides against the inner periphery of the fixed-side conductive holding portion 13 (the surface on which the movable space 13b is formed) when the sliding portion 25 displaces in the front-rear direction. The sliding of the sliding portions 24, 25 guides the displacement of the fixed-side arc contact 17 in the front-rear direction.

[0020] A contact band 27 is provided on the outer periphery of the base 22 of the fixed-side arc contact 17. Electricity is passed between the inner circumferential surface of the fixed-side conductive holding part 13 and the base 22 of the fixed-side arc contact 17 via the contact band 27, and this current flow is maintained regardless of the forward or backward displacement of the fixed-side arc contact 17.

[0021] A spring member 28 is housed in the movable space 13b of the fixed-side conductive holding part 13, in front of the fixed-side arc contact 17. In this embodiment, the spring member 28 is configured by a compression coil spring, and its front end is fixed by a pressing member 29 that closes the front part of the movable space 13b. The spring member 28 is disposed between the pressing member 29 and the base 22 of the fixed-side arc contact 17. In this state, the spring member 28 is compressed from its natural length and stored in energy, applying an elastic force in a direction that displaces the fixed-side arc contact 17 rearward.

[0022] 2, when the rear surface of the base 22 is pressed against the front surface of the annular wall portion 13c by the elastic force of the spring member 28, the rearward displacement of the fixed-side arc contact 17 is restricted and the fixed-side arc contact 17 is positioned in the front-rear direction. In this state, the rear end surface of the fixed-side arc contact 17 is located rearward of the rear surface of the fixed-side main contact 16.

[0023] The switchgear 10 further includes an electric field mitigation shield 30 attached to the rear end side of the fixed-side conductive holding portion 13 so as to cover the fixed-side electrode 11 from behind.

[0024] The electric field mitigation shield 30 is formed in a dome shape that bulges backward, and is provided at a position where it surrounds the rear ends of the fixed-side main contact 16 and the fixed-side arc contact 17, which are contact portions of the fixed-side electrode 11 with the movable-side electrode 12. The opening of the electric field mitigation shield 30 is formed so as to open in the front-rear direction at the rear of the electric field mitigation shield 30, and is formed with an opening diameter larger than the outer diameter of the movable-side electrode 12. Therefore, the tip (front end) side of the movable-side electrode 12 can be inserted into and removed from the opening of the electric field mitigation shield 30 in the front-rear direction.

[0025] The movable side electrode 12 is supported by the movable side conductive holder 14 via two sliding parts 34. The sliding parts 34 are configured similarly to the sliding parts 24 described above, and guide the displacement of the movable side electrode 12 in the front-rear direction.

[0026] The movable-side conductive holder 14 is provided with a contact 36 that makes contact with the movable-side electrode 12 when it is inserted therethrough. The contact 36 is composed of an annular conductor that slides while being inserted through the movable-side electrode 12, and is provided with multiple grooves formed at predetermined intervals in the circumferential direction or multiple strips arranged in the circumferential direction to provide flexibility or elasticity in the radial direction. Electricity can be passed between the movable-side conductive holder 14 and the movable-side electrode 12 via the contact 36.

[0027] An electric field mitigation shield 38 is attached to the front end side of the movable conductive holding part 14. The electric field mitigation shield 38 is provided so as to cover the contacts 36 from the front, and performs the same function as the electric field mitigation shield 30 described above.

[0028] Here, permanent magnets 41, 42 are provided on both the fixed electrode 11 and the movable electrode 12. The permanent magnet 41 provided on the fixed electrode 11 is embedded in the rear end (tip) side of the fixed arc contact 17 and is arranged so as not to be exposed when viewed from the movable electrode 12 side. The permanent magnet 42 provided on the movable electrode 12 is embedded in the front end (tip) side of the movable electrode 12 and is arranged so as not to be exposed when viewed from the fixed electrode 11 side.

[0029] 1, the permanent magnets 41, 42 are arranged close to each other in the front-to-rear direction. Here, the permanent magnets 41, 42 are arranged so that the same poles face each other, for example, so that the rear part of the permanent magnet 41 provided on the fixed electrode 11 and the front part of the permanent magnet 42 provided on the movable electrode 12 both have north poles.

[0030] Next, the contact piece 18 and its surrounding structure will be described. In the closed state shown in Fig. 1, the contact piece 18 conducts electricity between the fixed-side conductive holder 13 and the movable-side electrode 12, and in the open state shown in Fig. 2, the contact piece 18 is supported by an insulating support part 50. The fixed-side main contact 16 also includes a tension spring 51 and an auxiliary tension spring 52, which serve as elastic members. The insulating support part 50 is made of, for example, polytetrafluoroethylene (PTFE) or a synthetic resin containing glass fiber. The tension spring 51 and the auxiliary tension spring 52 are arranged in a ring shape so as to surround the outer periphery of the multiple contact pieces 18 arranged side by side in the circumferential direction.

[0031] The insulating support part 50 is provided on the rear end side (tip side) of the fixed-side conductive holding part 13. The insulating support part 50 includes an annular base part 54 that is connected to the tip side of the annular protrusion 13a and extends in the front-rear direction, and a rotation support part 55 that protrudes outward from a central part in the front-rear direction on the outer circumferential surface of the base part 54. The tip of the rotation support part 55 has a bulging curved surface, such as an arc-shaped cross section. The tip of this rotation support part 55 supports the contact piece 18 so that it can be rotated and displaced.

[0032] The contact piece 18 has a first contact-separation portion 18a that contacts and separates with the annular protrusion 13a of the fixed side conductive holding portion 13, a second contact-separation portion 18b that contacts and separates with the movable side electrode 12, and a connecting portion 18c that extends along the front-to-rear direction to connect the first contact-separation portion 18a and the second contact-separation portion 18b.

[0033] The first contact-separation portion 18a is provided to protrude inward (downward in FIG. 1) from the front end of the connecting portion 18c as its base end, and its tip contacts and separates with the annular protrusion 13a. The second contact-separation portion 18b is provided to protrude inward from the rear end of the connecting portion 18c as its base end, and its tip contacts and separates with the movable-side electrode 12. The tips of the second contact-separation portions 18b of the multiple contact pieces 18 form an opening in the fixed-side main contact 16. The protruding lengths of the first contact-separation portion 18a and the second contact-separation portion 18b differ depending on the diameters of the annular protrusion 13a and the movable-side electrode 12, and in this embodiment, the second contact-separation portion 18b is longer than the first contact-separation portion 18a.

[0034] In the open state shown in Fig. 2, connecting portion 18c is supported on its inner surface by rotation support portion 55. More specifically, connecting portion 18c has receiving portion 18d formed on its inner surface at a middle portion in the front-rear direction, and receiving portion 18d receives the tip side of rotation support portion 55. Receiving portion 18d is formed by recessing the inner surface of connecting portion 18c into a curved shape corresponding to the tip of rotation support portion 55. Contact piece 18 including connecting portion 18c is supported so as to be rotationally displaceable with the contact portion between the inner circumferential surface of receiving portion 18d and the tip of rotation support portion 55 as a rotation fulcrum.

[0035] The connecting portion 18c is pressed from the outer surface side by a tension spring 51 and an auxiliary tension spring 52. On the outer surface side of the connecting portion 18c, the tension spring 51 is arranged rearward of the rotation support portion 55, and the auxiliary tension spring 52 is arranged forward of the rotation support portion 55.

[0036] The elastic force of the tension spring 51 presses the connecting portion 18c to rotate clockwise in each figure. As a result, in the closed circuit state shown in Figure 1, the tip of the second contact / separation portion 18b of the contact piece 18 is pressed against the outer peripheral surface of the tip side of the movable electrode 12, which is in the advanced position. Therefore, the fixed main contact 16 including the multiple contact pieces 18 comes into contact with the movable electrode 12, allowing current to flow.

[0037] 2, when the movable electrode 12 moves back, the elastic force of the tension spring 51 presses the front surface of the second contact / separation portion 18b against the tip (rear end) of the base portion 54, restricting the rotation of the contact piece 18 and bringing it to a stopped state. In other words, the tip of the base portion 54 restricts the rotational displacement of the contact piece 18 due to the force of the tension spring 51, and the tip of the base portion 54 at the insulating support portion 50 forms a rotation restriction portion 57.

[0038] Furthermore, the connecting portion 18c is pressed so as to rotate counterclockwise in each figure by the elastic force of the auxiliary tension spring 52. When the force of the auxiliary tension spring 52 is applied, the connecting portion 18c rotates clockwise by the elastic force of the tension spring 51, but the force with which the tip of the second contact-separation portion 18b presses against the movable-side electrode 12 is weakened. As a result, the tip of the second contact-separation portion 18b is pressed against the outer peripheral surface of the tip side of the movable-side electrode 12 with an appropriate force, ensuring electrical continuity therebetween.

[0039] 1 , the movable electrode 12 moves forward and is inserted into the fixed main contact 16, where it stops. The front end of the movable electrode 12 comes into contact with the rear end of the fixed arc contact 17, pushing the fixed arc contact 17 forward, causing the fixed arc contact 17 to move to its advanced position and compressing the spring member 28. In the closed state, the elastic force of the spring member 28 presses the rear end of the fixed arc contact body 21 of the fixed arc contact 17 against the front end of the movable electrode 12, and the fixed main contact 16 comes into contact with the outer peripheral surface of the front end of the movable electrode 12 with an appropriate contact pressure.

[0040] To further explain the state of the contact piece 18 of the fixed-side main contact 16 in the closed state, the tip of the first contact-separation portion 18a of the contact piece 18 is in contact with the annular protrusion 13a of the fixed-side conductive holder 13, and the tip of the second contact-separation portion 18b is in contact with the movable-side electrode 12. This electrically connects the fixed-side conductive holder 13 and the movable-side electrode 12 via the contact piece 18. At this time, the connecting portion 18c of the contact piece 18 is pressed from the outer surface side by the tension spring 51 and the auxiliary tension spring 52. This ensures contact pressure between the first contact-separation portion 18a and the annular protrusion 13a, and also ensures contact pressure between the second contact-separation portion 18b and the movable-side electrode 12.

[0041] 1, in the closed state, the receiving portion 18d of the contact piece 18 and the tip of the rotation support portion 55 are separated and out of contact, and the contact piece 18 is out of contact with the insulating support portion 50. In other words, the protruding lengths of the contact / separation portions 18a, 18b and the rotation support portion 55 are set so that the contact piece 18 and the insulating support portion 50 are out of contact in this closed state.

[0042] In addition, in the closed state, a current path is formed in which current flows to the fixed side conductive holding part 13 via the movable side electrode 12 and the fixed side main contact 16, and a current path is formed in which current flows to the fixed side conductive holding part 13 via the movable side electrode 12, the fixed side arc contact 17, and the contact band 27.

[0043] To change from the closed state to the open state shown in Fig. 2, the movable electrode 12 is moved backward from the position shown in Fig. 1. In the initial stage of this movement, the fixed arc contact 17 is also displaced forward following the movement of the movable electrode 12 due to the elastic force of the spring member 28, and the electrical connection between the movable electrode 12 and the fixed arc contact 17 is maintained.

[0044] 3, when the movable electrode 12 moves backward to change from a closed state to an open state, the movable electrode 12 comes out of the fixed main contact 16, and the fixed main contact 16 is separated from the movable electrode 12. As a result, the current path through the fixed main contact 16 is cut off in the fixed electrode 11, and current flows through the current path through the fixed arc contact 17.

[0045] To further explain the operation of the contact piece 18 at this time, the rearward movement of the movable-side electrode 12 separates the movable-side electrode 12 from the tip of the second contact-separation portion 18b, causing the contact piece 18 to pivot from the state shown in Fig. 1 to the state shown in Fig. 3. In the initial stage of this pivotal displacement, the elastic force of the tension spring 51 causes the contact piece 18 to pivot clockwise in the figure around the contact position between the annular protrusion 13a and the tip of the first contact-separation portion 18a, and as shown in the enlarged view of Fig. 3, the receiving portion 18d of the contact piece 18 comes into contact with the tip of the pivot support portion 55. This contact causes the contact piece 18 to be supported by the pivot support portion 55.

[0046] Thereafter, the elastic force of the tension spring 51 causes the contact piece 18 to further rotate about the contact position between the receiving portion 18d of the contact piece 18 and the tip of the rotation support portion 55. As a result, the annular protrusion 13a of the fixed-side conductive holding portion 13 and the tip of the first contact-separation portion 18a are separated. Then, the front surface of the second contact-separation portion 18b of the contact piece 18 abuts against the rotation restriction portion 57 of the insulating support portion 50, restricting the rotation of the contact piece 18. In this state, the contact piece 18 is supported by the insulating support portion 50, but is not in contact with the movable-side electrode 12 or the fixed-side conductive holding portion 13, and is in an electrically floating state.

[0047] As shown in FIG. 4 , when the rear end of the fixed arc contact 17 (fixed arc contact body 21) is displaced rearward relative to the rear end of the fixed main contact 16, the base 22 of the fixed arc contact 17 abuts against the annular wall 13c, stopping the rearward displacement of the fixed arc contact 17. In this state, the movable electrode 12 continues to move rearward, and the movable electrode 12 moves away from the fixed arc contact 17 inside the electric field mitigation shield 30. When the movable electrode 12 moves away from the fixed arc contact 17, an arc AR is generated between them. Therefore, the position where the arc AR is generated on the fixed electrode 11 becomes the fixed arc contact 17. As described above, each contact piece 18 is electrically floating, preventing the generation of the arc AR at the fixed main contact 16. The arc AR extends in an irregular but generally longitudinal direction.

[0048] In this embodiment, when the movable electrode 12 and the fixed arc contact 17 separate to generate an arc AR, a magnetic field is generated between them by the permanent magnets 41 and 42. The magnetic field generated by the permanent magnets 41 and 42 extends in the front-rear direction from the N-pole formation surface, then immediately curves and generates a component perpendicular to the front-rear direction. This allows a Lorentz force to be exerted in a direction that drives the arc AR generated by the magnetic field of the permanent magnets 41 and 42, thereby effectively magnetically driving the arc AR in the circumferential direction. This therefore transports the heat of the arc AR to the surroundings, causing the arc AR to lose its conductivity, shortening the time it takes for the arc AR to disappear. As a result, the arc extinguishing performance is improved, and the arc AR is prevented from sticking, thereby reducing the wear of the movable electrode 12 and the fixed arc contact 17.

[0049] When switching from the open state shown in Fig. 2 to the closed state shown in Fig. 2, the movable electrode 12 moves forward from the position shown in Fig. 2 and is inserted into the opening of the fixed main contact 16. The state of the contact piece 18 at this time is described as follows: the second contact-separation portion 18b of the contact piece 18 of the fixed main contact 16 comes into contact with the operating movable electrode 12, causing the contact piece 18 to pivot from the state shown in Fig. 3 to the state shown in Fig. 1. In the initial stage of this pivotal displacement, the contact piece 18 pivots counterclockwise in the figure around the tip of the pivot support portion 55 against the elastic force of the tension spring 51. This causes the annular protrusion 13a of the fixed conductive holder 13 to come into contact with the tip of the first contact-separation portion 18a, electrically connecting the fixed conductive holder 13 and the movable electrode 12 via the contact piece 18.

[0050] After the annular protrusion 13a and the first contact-separation portion 18a come into contact with each other, the contact piece 18 continues to rotate about the contact position between the annular protrusion 13a and the tip of the first contact-separation portion 18a, resulting in the state shown in Figure 1 in which the receiving portion 18d of the contact piece 18 and the tip of the rotation support portion 55 are separated, and the movable electrode 12 enters a closed state in which current flows through the fixed main contact 16 and the fixed arc contact 17.

[0051] According to the above embodiment, during operation of the movable electrode 12 to open the circuit, the contact piece 18 of the fixed electrode 11 can be separated from both the movable electrode 12 and the fixed conductive holder 13, and can be supported only by the insulating support part 50. Therefore, the contact piece 18 is electrically disconnected from each component of the switching device 10 and has an independent potential, i.e., is electrically floating.

[0052] This prevents the arc AR, which occurs when the circuit is opened, from commutating from the fixed-side arcing contact 17 to the contact piece 18 (fixed-side main contact 16). In particular, when the arc AR is magnetically driven using permanent magnets 41, 42, the flow of conductive gas accompanying the magnetic drive tends to transport the arc AR to the vicinity of the contact piece 18, but commutation of the arc AR can be prevented by keeping the contact piece 18 in an electrically floating state. As a result, wear, deterioration, and welding of the contact piece 18 due to the arc AR can be suppressed, and malfunctions of the movable-side electrode 12 and closing failures at the movable-side electrode 12 caused by these factors can be avoided.

[0053] Furthermore, since the contact piece 18 is rotationally displaced via the rotation support portion 55 of the insulating support portion 50, it is easy to design the contact piece 18 to be displaced by the force of the tension spring 51 or the movement of the movable electrode 12.

[0054] Furthermore, since the insulating support part 50 has a rotation control part 57, the contact piece 18 can be stably maintained in a separated and electrically floating state with both the movable side electrode 12 and the fixed side conductive holding part 13 separated, and commutation of the arc AR can be better prevented.

[0055] Furthermore, since the contact piece 18 is not in contact with the insulating support part 50 in the closed state of FIG. 1, it is possible to prevent a high voltage from being applied to the insulating support part 50, and it is possible to protect the insulating support part 50.

[0056] Furthermore, since the contact piece 18 has a connecting portion 18c and two contact and separation portions 18a, 18b, the force of the tension spring 51 or the like acts on the connecting portion 18c, and the contact piece 18 can be rotated and displaced like a seesaw, thereby switching between contact and separation with the movable side electrode 12 and the fixed side conductive holding portion 13.

[0057] The present invention is not limited to the above-described embodiment, and various modifications can be made to the embodiment. In the above-described embodiment, the size, shape, orientation, etc. shown in the accompanying drawings are not limited to these, and can be modified as appropriate within the scope of the effects of the present invention. In addition, the present invention can be modified as appropriate without departing from the scope of the object of the present invention.

[0058] In the above embodiment, the contact piece 18 of the fixed electrode 11 is configured to be rotationally displaced, but the displacement direction of the contact piece 18 is not limited to the rotational direction and may be changed, for example, to a linear direction intersecting the front-to-rear direction.

[0059] Furthermore, the fixed electrode 11 may be configured without the fixed arc contact 17. However, a configuration including the fixed arc contact 17 is advantageous in that, when an arc AR occurs, the position of the arc can be maintained at the fixed arc contact 17.

[0060] In the above embodiment, the permanent magnets 41, 42 are provided on both the fixed-side arc contact 17 (fixed-side electrode 11) and the movable-side electrode 12, but one of the permanent magnets 41, 42 may be omitted as long as the direction of the magnetic field can be set as described above. In other words, the permanent magnets 41, 42 may be provided on at least one of the fixed-side arc contact 17 (fixed-side electrode 11) and the movable-side electrode 12. Furthermore, the permanent magnets 41, 42 may be omitted from both electrodes 11, 12.

[0061] Furthermore, the auxiliary tension spring 52 may be omitted as long as the contact pressure from the fixed main contact 16 to the movable electrode 12 by the tension spring 51 can be maintained at an appropriate level and the displacement of the contact piece 18 can be carried out as described above.

[0062] Furthermore, although the tension spring 51 is used as the elastic member, the present invention is not limited to this, and a configuration other than the tension spring 51 that applies force to the contact piece 18 by elastic deformation may also be used.

[0063] Furthermore, the above-mentioned configuration has been described as being applied to the disconnector of the switchgear 10, but it is not limited to being applied to a disconnector, and can also be applied to a circuit breaker, a grounding switch, a disconnector with a grounding switch, etc. that open and close the electric circuit of a power system. [Explanation of symbols]

[0064] 10: Switchgear 11: Fixed side electrode 12: Movable side electrode 13: Fixed side conductive holding part 16: Fixed side main contact 17: Fixed side arc contact 18: Contact piece 18a: First contact section 18b: 2nd contact / separation part 18c: Connection part 50: Insulation support part 51: Tension spring (elastic member) 55: Rotation support part 57: Rotation control part AR: Arc

Claims

1. A fixed electrode; a fixed-side conductive holding portion that holds the fixed-side electrode and electrically connects the fixed-side electrode to an external circuit; a movable electrode that moves toward and away from the fixed electrode; a switching device including an insulating support portion provided on the fixed-side conductive holding portion, The fixed electrode includes a contact piece that electrically connects the fixed conductive holder and the movable electrode; an elastic member that presses the contact piece against the movable electrode, a contact piece that comes into contact with the fixed-side conductive holding portion and the movable-side electrode when the movable-side electrode is stopped in a closed-circuit state, and that separates from the movable-side electrode when the movable-side electrode is changed from a closed-circuit state to an open-circuit state, and thereby displaces due to the elastic force of the elastic member while being supported by the insulating support portion and separates from the fixed-side conductive holding portion.

2. The fixed electrode has a fixed main contact that can be brought into contact with and separated from the movable electrode. a fixed arc contact that is provided so as to be displaceable in the movement direction of the movable electrode and that generates an arc when it moves away from the movable electrode, The switchgear according to claim 1 , wherein the fixed main contact is provided in an annular shape with a plurality of the contact pieces arranged in a circumferential direction.

3. 3. The switching device according to claim 1, wherein the insulating support portion includes a rotation support portion that supports the contact piece so that the contact piece can be rotated and displaced.

4. The contact piece has a first contact-separation portion that contacts and separates with the fixed-side conductive holding portion; a second contact / separation portion that contacts and separates from the movable electrode; a connecting portion connecting the first contact-separation portion and the second contact-separation portion, 4. The opening and closing device according to claim 3, wherein the connecting portion is supported on an inner surface side by the rotation support portion and is pressed from an outer surface side by the elastic member.

5. 3. The switching device according to claim 1, wherein the insulating support portion includes a rotation restricting portion that restricts rotational displacement of the contact piece due to the force of the elastic member.

6. 3. The switchgear according to claim 1, wherein the contact piece is out of contact with the insulating support portion in a closed state where the movable electrode is stopped.

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