JP2017022002A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker capable of preventing a high pressure difference from acting on bellows within a pressure container while making a dimension in an axial direction compact.SOLUTION: A circuit breaker 1 according to an embodiment comprises bellows 12 which surround a radially outer side of an operation rod 52 within a vacuum container 11 and is elongated/contracted in an axial direction in response to a movement of the operation rod 52. A central low-pressure chamber 44 is formed radially inside of an inter-electrode insulator 44 extending in the axial direction between an opening-side end plate 62 and a closing-side end plate 22. The bellows 12 separate the vacuum chamber 15 and the central low-pressure chamber 44. In the operation rod 52, an insulation part 55 consisting of an electric insulator opposes a high-pressure chamber 5 closer to an opening side in the axial direction than the opening-side end plate 62. In addition, an insulation cylinder 30 is coupled to an end portion 3e at a closing side in the axial direction in the pressure container 3, and a closing-side low-pressure chamber 33 extends to the end portion 3e.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to a circuit breaker capable of interrupting a current flowing in an electric circuit of a power system, and more particularly to a circuit breaker in which an electric circuit is opened and closed in vacuum.

  A circuit breaker capable of interrupting the current flowing through the electric circuit of the electric power system generally constitutes the electric circuit of the electric power system, and as a conductor (hereinafter referred to as a conductive part) through which the electric current flows, A movable contact that is movable in a predetermined direction (hereinafter referred to as an axial direction) so as to be separated from the fixed contact, and is coupled to the movable contact and extends in the axial direction and is driven by an operation mechanism to be movable. And an operating rod that moves together with the contact.

  The operation rod usually has a portion (hereinafter referred to as an insulating portion) made of an electrical insulator in order to prevent a current from flowing between the movable contact and the operation mechanism. In the following description, the direction in which the movable contact moves away from the fixed contact in the axial direction is referred to as “open side”, and the direction in which the movable contact approaches the fixed contact in the axial direction is referred to as “closed side”. .

  Such a circuit breaker includes a so-called vacuum circuit breaker that cuts off the current in vacuum. Such a circuit breaker has a vacuum chamber, which is a vacuum space, and has a container (hereinafter referred to as a vacuum container) that accommodates a stationary contact and a movable contact in the vacuum chamber. Yes. The operation rod described above extends through the vacuum vessel. In order to ensure the airtightness of the vacuum chamber, the vacuum vessel accommodates a substantially cylindrical and bellows-shaped member, a so-called bellows, together with a stationary contact and a movable contact. The bellows constitutes a so-called vacuum interrupter (also referred to as a vacuum valve) together with a vacuum vessel, a stationary contact and a movable contact.

  The bellows surrounds the radially outer side of the operating rod in the vacuum vessel, and usually the end on the axially open side is coupled to the vacuum vessel, and the end on the axially closed side is the operating rod. Are combined. The bellows is configured to expand and contract in the axial direction in accordance with the movement of the movable contact and the operation rod. The bellows defines a vacuum chamber together with the vacuum container, the inner peripheral surface on the radially inner side faces the operating rod, and the outer peripheral surface on the radially outer side faces the vacuum chamber. For this reason, the force resulting from the pressure difference between the inside and the outside acts on the bellows.

  When a large force acts on such a bellows, the bellows may be damaged due to buckling or the like. In order to prevent damage to the bellows, a structure for reducing the pressure difference between the inside and the outside of the bellows has been proposed (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 60-141038

  In such a circuit breaker, the bellows is made of a relatively thin stainless steel plate or the like so that it can easily expand and contract in the axial direction. Further, the bellows is generally manufactured on the assumption that the inside is used in an environment where the atmospheric pressure is about atmospheric pressure. For this reason, the bellows has a relatively low strength among the components constituting the circuit breaker, and it is difficult to significantly improve the strength due to its structure. In order to prevent damage to the bellows, the pressure acting on the inside of the bellows is preferably about atmospheric pressure, and it is desired to be 0.2 MPa or less.

  Further, in the above-described circuit breaker, in order to ensure the insulation performance of the electrical insulator, the electrical insulation such as the insulation portion of the operating rod is filled in a space filled with a relatively high electrical insulation gas such as an inert gas. The body is required to be placed. Such an electrical insulator is housed in a container (hereinafter, referred to as a pressure container) filled with an insulating gas together with the above-described vacuum container. A gas chamber, which is a space filled with an insulating gas at a predetermined pressure, is formed inside the pressure vessel, and an insulating portion of the operating rod is disposed in the gas chamber. As the pressure of the insulating gas is increased, the electrical insulation performance in the insulating portion can be improved.

  However, in the gas circuit breaker, when the vacuum vessel and the bellows are arranged in the gas chamber described above, the pressure of the relatively high-pressure insulating gas acts on the inside of the bellows, and the vacuum on the outside There arises a problem that the pressure difference with the chamber becomes large. Note that if the pressure of the insulating gas is made relatively low in order to reduce the pressure difference, the axial length of the insulating portion of the operating rod is made relatively long in order to ensure electrical insulation performance. Need arises. If the length of the operating rod in the axial direction is increased, the mass increases and the operating force required to drive the operating rod increases, so the problem is that the operating mechanism must be enlarged, and the axial direction of the pressure vessel As a result, there arises a problem that the axial dimension of the circuit breaker increases.

  The embodiment of the present invention has been made in view of the above circumstances, and is capable of suppressing the action of a high pressure difference on the bellows in the pressure vessel while making the axial dimension compact. The purpose is to provide a vessel.

  In order to achieve the above-described object, an embodiment of the present invention comprises a fixed contact that constitutes a conductive part of an electric circuit of a power system, and the conductive part that constitutes the conductive part and is axially separated from the fixed contact. A movable contact that can be moved to the open side, a vacuum chamber inside, a vacuum container that houses the fixed contact and the movable contact in the vacuum chamber, and the conductive portion, and the vacuum Arranged on the axially closed side from the container, constituting a closed side conductor coupled to the stationary contact, and the conductive part, arranged on the axially open side from the vacuum container, An open-side conductor that is electrically connected to the movable contact, and is coupled to the movable contact, and extends from the movable contact through the vacuum vessel and the open-side conductor to the axially open side. And movable by being driven by an operation mechanism An operation rod that moves in the axial direction integrally with the touch element, and an electric insulator, has a substantially cylindrical shape surrounding the radially outer side of the vacuum vessel, and the closed-side conductor and the open-side conductor, An interelectrode insulator that defines a central low-pressure chamber that extends in the axial direction and is filled with an insulating gas or air radially inward, and surrounds the radially outer side of the operating rod in the vacuum vessel. The end on the axially open side is coupled to the vacuum vessel, the end on the axially closed side is coupled to the operating rod, and the vacuum chamber and the central low-pressure chamber are partitioned and the operation is performed. It consists of a bellows that expands and contracts in the axial direction according to the movement of the rod, and an electrical insulator, has a substantially cylindrical shape with an axial center extending in the axial direction, and extends from the closed side conductor to the axially closed side. Insulating gas or air inside in the radial direction An insulating cylinder defining a closed low pressure chamber to be filled, and a high pressure chamber filled with an insulating gas at a higher pressure than the central low pressure chamber and the closed low pressure chamber, the high pressure chamber includes An opening-side conductor, the inter-electrode insulator, the closed-side conductor, and a pressure vessel that accommodates the insulating cylinder, and an insulating portion made of an electrical insulator in the operation rod is more than the opening-side conductor. Facing the high-pressure chamber on the axially open side, the insulating cylinder is coupled to an end portion on the axially close side of the pressure vessel, and the closed-side low pressure chamber extends to the end portion. The closed-side conductor is formed with an internal communication hole for communicating the central low-pressure chamber and the closed-side low-pressure chamber.

It is a section elevation showing the composition of the circuit breaker of a 1st embodiment. It is an expanded sectional view showing peripheral composition of a vacuum vessel and a bellows among circuit breakers of a 1st embodiment. It is an expanded sectional view showing peripheral composition of an operation rod and an opening side end board among circuit breakers of a 1st embodiment. It is an expanded sectional view which shows the periphery structure of an insulation cylinder among the circuit breakers of 2nd Embodiment. It is a section elevation showing the composition of the circuit breaker of a 3rd embodiment.

    Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to the embodiments described below, and various modifications can be made without departing from the scope of the invention.

[First Embodiment]
The structure of the circuit breaker of 1st Embodiment is demonstrated using FIGS. 1-3. FIG. 1 is a sectional elevation view showing the overall configuration of the circuit breaker of the present embodiment. FIG. 1 shows a state where the movable contact and the operation rod are located at a closed position. Further, in FIG. 1, hatching is omitted for the pressure vessel, the operation mechanism, and the like for easy understanding. FIG. 2 is an enlarged cross-sectional view showing the peripheral configuration of the vacuum vessel and the bellows in the circuit breaker of the present embodiment. FIG. 3 is an enlarged cross-sectional view showing the peripheral configuration of the operating rod and the open side end plate in the circuit breaker of the present embodiment.

  In FIG. 1, the vertical upper side is indicated by an arrow U, and the vertical lower side is indicated by an arrow D. FIG. 3 shows a state in which the movable contact and the operating rod are in the open position. Moreover, in FIG.1 and FIG.2, the axial center of a movable contactor and an operating rod is shown with the dashed-dotted line A. FIG. In addition, the direction along the axis, that is, the direction in which the movable contact moves away from the fixed contact in the axial direction is indicated as “Axial opening side” and is indicated by an arrow A1 in each figure, and the movable contact is fixed contact. The direction approaching the child is indicated as “Axial closing side” and indicated by an arrow A2.

  As shown in FIG. 1, the circuit breaker 1 is a switching device that opens and closes an electric circuit of a power system. In the present embodiment, the circuit breaker is a circuit breaker that opens and closes an electric circuit (cuts off an electric current) in a vacuum. It is configured as a vacuum circuit-breaker. In addition, the circuit breaker 1 is also configured as a gas-insulated switchgear. Specifically, the circuit breaker 1 has a pressure vessel 3 that houses a conductor that constitutes an electric circuit of a power system, that is, a so-called conductive part. The electric power system current flowing through the conductive portion is hereinafter referred to as “main circuit current”.

  The pressure vessel 3 has a space (hereinafter referred to as a high pressure chamber) 5 filled with an insulating gas. The pressure vessel 3 is configured as a so-called enclosure that encloses a conductive portion. The pressure vessel 3 is made of a metal such as an aluminum alloy and is electrically grounded (grounded).

  The pressure vessel 3 has a central part 3a surrounding the conductive part, an end part 3c on the axially opening side, and an end part 3e on the axially closing side. The circuit breaker 1 has a leg portion 2 that supports the pressure vessel 3 with respect to a horizontal installation surface (not shown) on the vertical lower side of the central portion 3 a of the pressure vessel 3. The circuit breaker 1 is installed so that the axial direction is horizontal.

The high-pressure chamber 5 is filled with an inert gas having a relatively high electrical insulation, so-called insulating gas. In the present embodiment, the high pressure chamber 5 is filled with sulfur hexafluoride (SF ₆ ) as an insulating gas. Note that nitrogen (N ₂ ), carbon dioxide (CO ₂ ), or dry air (dry air) can be used as the insulating gas filled in the high-pressure chamber 5. That is, the high pressure chamber 5 may be filled with sulfur hexafluoride, nitrogen, carbon dioxide, or dry air as an insulating gas. In the high pressure chamber 5, two or more kinds of mixed gases of sulfur hexafluoride, nitrogen, carbon dioxide, and dry air can be used as the insulating gas.

  The high pressure chamber 5 is filled with an insulating gas at a pressure in the range of 0.4 MPa to 0.8 MPa. In this embodiment, the insulating gas is filled at a pressure of about 0.6 MPa. The pressure vessel 3 is sealed in a state where the high-pressure chamber 5 is filled with an insulating gas at a predetermined pressure within the above-described range. The high-pressure chamber 5 is filled with an insulating gas at a higher pressure than the central low-pressure chamber 44 and the closed-side low-pressure chamber 33 described later. In the present specification, the pressures of the insulating gas and air are all indicated by gauge pressure (differential pressure with respect to outside air).

  The pressure vessel 3 accommodates a vacuum interrupter (also referred to as a vacuum valve) 10 in the center thereof. The vacuum interrupter 10 includes a fixed contact 20 and a movable contact 50 that constitute a conductive part of an electric circuit of a power system, and a vacuum vessel 11 that houses the fixed contact 20 and the movable contact 50. The vacuum container 11 has a vacuum space (hereinafter referred to as a vacuum chamber) 15 in which the fixed contact 20 and the movable contact 50 are disposed. The vacuum vessel 11 is supported with respect to the pressure vessel 3 via an electrical insulator.

  The movable contact 50 contacts the fixed contact 20 at the closed position shown in FIG. The movable contact 50 is configured to be movable with respect to the stationary contact 20 in the axial direction opening side indicated by an arrow A1 in the drawing. An operation rod 52 is coupled to the movable contact 50. The fixed contact 20 and the movable contact 50 are made of copper or an alloy containing copper. The direction opposite to the axially open side, that is, the direction in which the movable contact 50 is close to the fixed contact 20 is hereinafter referred to as “axially closed side” and is indicated by an arrow A2 in the figure.

  The operation rod 52 extends substantially linearly from the movable contact 50 through the above-described vacuum vessel 11 on the axially open side. The operating rod 52 is driven in the axial direction by an operating mechanism 57 that operates to move the movable contact 50.

  The operating rod 52 has an insulating portion 55 that is a portion made of an electrical insulator on the axially open side. The insulating portion 55 has a substantially rod shape and is also referred to as an “insulating rod”. As a material constituting the insulating portion 55, a fiber reinforced plastic having electrical insulation is used. In this embodiment, a composite material using an aramid fiber as a reinforcing material and an epoxy resin as a base material is used. ing. In addition, as long as it has electrical insulation, the reinforcement material which comprises the insulation part 55 can be used, for example, a glass fiber and a polyester fiber can be used as a reinforcement material.

  The operation mechanism 57 is disposed outside the pressure vessel 3. The operation mechanism 57 is disposed outside the end portion 3 c on the axially opening side of the pressure vessel 3, and is specifically disposed in the operation box 7 that houses the operation mechanism 57.

  The operating rod 52 is driven by the operating mechanism 57 and moves in the axial direction integrally with the movable contact 50. In the pressure vessel 3, the operation rod 52 extends through an opening side end plate 62 (described later) and the opening side in the axial direction of the vacuum vessel 11.

  As shown in FIG. 2, the vacuum vessel 11 is made of an electrical insulator, and has a substantially cylindrical portion (hereinafter referred to as an insulating cylindrical portion) 11 a that is coaxial with the operating rod 52, and an insulating cylinder. It has ends (so-called end plates) 11c and 11e that are respectively coupled to both ends of the axial portion 11a in the axial direction and are substantially disk-shaped coaxially with the operation rod 52. Specifically, the vacuum vessel 11 has an open end 11c coupled to the axially open side of the insulating cylindrical portion 11a, and a closed end 11e coupled to the axially closed side.

  In the present embodiment, the insulating cylindrical portion 11a is generally made of ceramics. On the other hand, the opening side end portion 11c and the closing side end portion 11e are generally made of a metal material, and in the present embodiment, are made of stainless steel.

  A through hole 13 through which the operation rod 52 passes is formed in the open side end portion 11c of the vacuum vessel 11. An end 12c on the axially open side of the bellows 12 is coupled to the vicinity of the through hole 13 in the open end 11c. An end 12 e on the axially closing side of the bellows 12 is coupled to the operation rod 52.

  The bellows 12 has a substantially cylindrical and bellows shape whose axial center extends in the axial direction, and is accommodated in a vacuum chamber 15 in the vacuum vessel 11. The bellows 12 surrounds the radially outer side of the operation rod 52 in the vacuum vessel 11. The bellows 12 defines a vacuum chamber 15 together with a vacuum vessel 11 including an insulating cylindrical portion 11a, an opening side end portion 11c, and a closing side end portion 11e.

  The bellows 12 expands and contracts in the axial direction in accordance with the movement of the movable contact 50 and the operation rod 52 in the axial direction. In this embodiment, the bellows 12 is made of stainless steel having a thickness of about 0.3 mm. The side of the bellows 12 facing the vacuum chamber 15 is hereinafter referred to as “outside” and the opposite side is referred to as “inside”.

  The bellows 12 has a radially inner surface (hereinafter simply referred to as an “inner surface”) 12 a facing the operating rod 52, and a radially outer surface (hereinafter simply referred to as an “outer surface”) 12 b. It faces the insulating cylindrical portion 11a of the vacuum vessel 11. The outer surface 12b faces the vacuum chamber 15, and the inner surface 12a faces a low-pressure chamber described later. A force resulting from a pressure difference between the pressure acting on the outer surface 12 b and the pressure acting on the inner surface 12 a acts on the bellows 12.

  Further, as shown in FIG. 2, the stationary contact 20 is accommodated on the axially closed side of the vacuum chamber 15 of the vacuum vessel 11 so as to face the movable contact 50. The fixed contact 20 has a substantially cylindrical shape coaxially with the operation rod 52, and a conductor (hereinafter referred to as a cylindrical conductor) 21 constituting the above-described conductive portion is coupled thereto. The columnar conductor 21 extends through the closed end 11e of the vacuum vessel 11 toward the axially closed side.

  As shown in FIG. 2, the columnar conductor 21 is a conductor having a substantially disk shape that expands in the radial direction on the axially closed side from the stationary contact 20 and the vacuum vessel 11 (hereinafter referred to as a closed side end plate). 22. The closed side end plate 22 is a conductor constituting a conductive portion, and is coupled to the end on the axially closed side of the interelectrode insulator 40 as shown in FIG.

  In addition, the conductor which comprises the electroconductive part of the electric circuit of an electric power system, Comprising: It couple | bonds with the stationary contact 20 and it is an axial close side from the stationary contact 20, The following is "closed side conductor." . On the other hand, a conductor that constitutes the conductive portion and is coupled to the movable contact 50 and is located on the axially open side with respect to the movable contact 50 is hereinafter referred to as an “open side conductor”. The closed-side conductor and the open-side conductor are made of a metal material having relatively high conductivity, for example, an aluminum alloy.

  A portion of the operation rod 52 that is closer to the axially closing side than the insulating portion 55 forms an open-side conductor. The open-side conductor includes a movable contact 50 and a conductor 62 (hereinafter referred to as an open-side end plate) 62 that has a substantially disk shape that extends in the radial direction on the axially open side from the vacuum vessel 11. The open side end plate 62 is a conductor constituting the conductive portion, that is, an open side conductor, and is coupled to the end of the interelectrode insulator 40 on the open side in the axial direction.

  The inter-electrode insulator 40 is made of an electrical insulator, and in this embodiment, is made of an epoxy resin. The interelectrode insulator 40 has a substantially cylindrical shape surrounding the radially outer side of the vacuum vessel 11, and extends in the axial direction between the open side end plate 62 and the close side end plate 22. In the present embodiment, the vacuum vessel 11, the operation rod 52, and the columnar conductor 21 have a substantially cylindrical shape that is coaxial.

  A space (hereinafter referred to as a central low pressure chamber) 44 filled with an insulating gas at a lower pressure than the high pressure chamber 5 described above is formed on the inner side in the radial direction of the interelectrode insulator 40. The inter-electrode insulator 40 defines a central low-pressure chamber 44 together with the open side end plate (open side conductor) 62, the closed side end plate (closed side conductor) 22, the vacuum vessel 11 and the bellows 12.

  The circuit breaker of this embodiment has an electrical resistance on the radially outer side of the interelectrode insulator 40, and includes an open side end plate (open side conductor) 62 and a closed side end plate (closed side conductor) 22. An inter-electrode resistor 46 extending in the axial direction along the inter-electrode insulator 40 is provided. The interelectrode resistor 46 has a substantially cylindrical shape surrounding the outside of the vacuum vessel 11, similarly to the interelectrode insulator 40.

  As the interelectrode resistor 46, for example, a wire made of an alloy containing chromium as a nickel main component, that is, a so-called nichrome wire is wound and impregnated with a synthetic resin such as an epoxy resin and molded. The interelectrode resistor 46 has a higher electrical resistance than a so-called conductor or semiconductor. Unlike the inter-electrode insulator 40, the inter-electrode resistor 46 is configured so that a slight current flows when a high voltage is applied between the closed-side end plate 22 and the open-side end plate 62. Yes.

  Further, the axially closed side of the closed side end plate 22 is made of an electrical insulator, has a substantially cylindrical shape, and a member that supports the closed side end plate 22 with respect to the pressure vessel 3 (hereinafter, referred to as “a member”). 30) (referred to as an insulating cylinder). The insulating cylinder 30 is provided coaxially with the operation rod 52, the columnar conductor 21, and the interelectrode insulator 40. The insulating cylinder 30 extends from the closed end plate 22 to the axially closed side, and is coupled to the axially closed end 3 e of the pressure vessel 3. The insulating cylinder 30 insulates the closed side end plate 22 from the pressure vessel 3 and supports the closed side end plate 22 with respect to the pressure vessel 3.

  A space 33 (hereinafter referred to as a closed-side low-pressure chamber) 33 that is filled with an insulating gas at a pressure lower than that of the above-described high-pressure chamber 5 is formed inside the insulating cylinder 30 in the radial direction. The insulating cylinder 30 and the closed side low-pressure chamber 33 extend in the axial direction between the axially closed end portion 3 e of the pressure vessel 3 and the closed side end plate 22. The insulating cylinder 30, together with the axially closing end 3 e of the pressure vessel 3 and the closing end plate (closing conductor) 22, defines a closing low pressure chamber 33.

  In the present embodiment, the closed side end plate 22 between the closed side low pressure chamber 33 and the central low pressure chamber 44 has a communication hole (hereinafter referred to as an internal communication hole) that allows the closed side low pressure chamber 33 and the central low pressure chamber 44 to communicate with each other. And a plurality of these are formed. As a result, the closed-side low pressure chamber 33 and the central low pressure chamber 44 have the same pressure when filled with the insulating gas.

In the present embodiment, the central low pressure chamber 44 and the closed side low pressure chamber 33 are filled with sulfur hexafluoride (SF ₆ ) as an insulating gas. Note that nitrogen (N ₂ ), carbon dioxide (CO ₂ ), or dry air (dry air) can also be used as the insulating gas filled in the central low-pressure chamber 44 and the closed-side low-pressure chamber 33. That is, the central low-pressure chamber 44 and the closed-side low-pressure chamber 33 may be filled with sulfur hexafluoride, nitrogen, carbon dioxide, or dry air as an insulating gas. The central low pressure chamber 44 and the closed side low pressure chamber 33 may be filled with two or more kinds of mixed gases of sulfur hexafluoride, nitrogen, carbon dioxide, and dry air as insulating gases.

  Further, the closed-side low pressure chamber 33 and the central low pressure chamber 44 are filled with an insulating gas at a pressure within the range of atmospheric pressure (ie, 0.0 MPa) to 0.2 MPa. Thereby, the pressure difference between the vacuum chamber 15 and the central low pressure chamber 44 is about 0.1 MPa to 0.3 MPa. A force resulting from the pressure difference acts on the vacuum vessel 11 and the bellows 12 that partition the vacuum chamber 15 and the central low-pressure chamber 44.

  In addition, the circuit breaker 1 is provided with a pressure measuring device that measures the pressure of the insulating gas in the closed low pressure chamber 33 and the central low pressure chamber 44. In the present embodiment, a pressure gauge 8 that measures the pressure in the low-pressure chambers 33 and 44 and displays the measured pressure is provided outside the pressure vessel 3. The pressure gauge 8 is disposed outside the end portion 3e on the axially closing side of the pressure vessel 3, specifically, at a position facing the closing side low-pressure chamber 33 with the end portion 3e interposed therebetween.

  In the present embodiment, the central low-pressure chamber 44 communicates with the closed-side low-pressure chamber 33 through the internal communication hole 32, and therefore has substantially the same pressure as the closed-side low-pressure chamber 33. Therefore, the pressure gauge 8 also measures the pressure in the central low pressure chamber 44. Since the pressure gauge 8 is disposed outside the pressure vessel 3, the pressure of the insulating gas filled in the low pressure chambers 33 and 44 can be easily known from the outside of the circuit breaker 1.

  As shown in FIG. 1, a conductor (hereinafter referred to as a closed-side extended conductor) 24 extends from the closed-side end plate 22 to the axially closed side on the vertical upper side of the closed-side end plate 22. In addition, a conductor (hereinafter referred to as a closed-side center conductor) 26 that extends substantially linearly inside the bushing 71 is coupled to the closed-side extended conductor 24 via an insulating spacer 28. The insulating spacer 28 insulates the closed side center conductor 26 from the pressure vessel 3 and hermetically separates the pressure vessel 3 from the bushing 71. The closing side extension conductor 24 and the closing side center conductor 26 together with the closing side end plate 22 constitute a closing side conductor.

  On the other hand, on the vertical upper side of the open-side end plate 62, as shown in FIG. 1, a conductor (hereinafter referred to as an open-side extended conductor) 64 extends from the open-side end plate 62 to the open side in the axial direction. In addition, a conductor (hereinafter referred to as an open-side center conductor) 66 that extends substantially linearly inside the bushing 72 is coupled to the open-side extended conductor 64 via an insulating spacer 68. The insulating spacer 68 insulates the opening-side center conductor 66 from the pressure vessel 3 and hermetically separates the pressure vessel 3 and the bushing 72 from each other. The open-side extending conductor 64 and the open-side center conductor 66 together with the open-side end plate 62 constitute an open-side conductor.

  The insulating spacer 28 and the insulating spacer 68 may be omitted if it is not necessary to separate the pressure vessel 3 from the bushing 71 or the bushing 72 in an airtight manner.

  As described above, the closing side central conductor 26 is coupled to the closing side end plate 22 and the stationary contact 20 via the closing side extending conductor 24. On the other hand, the open-side center conductor 66 is coupled to the open-side end plate 62 via the open-side extended conductor 64, and is electrically connected to the movable contact 50 via the operation rod 52.

  As shown in FIGS. 1 and 3, the open side conductor of the open side conductor from the open side end plate 62 is in sliding contact with the portion 53 of the operating rod 52 on the close side in the axial direction from the insulating portion 55. A portion (hereinafter referred to as a current-carrying contact portion) 63 through which a current (main circuit current) flows between the portion 53 is provided. The energizing contact portion 63 protrudes from the opening end plate 62 toward the opening side in the axial direction, and has a substantially cylindrical shape. The energizing contact portion 63 constitutes an open-side conductor and faces the high-pressure chamber 5.

  On the other hand, as shown in FIG. 3, the operation rod 52 of the present embodiment is provided with a portion (hereinafter referred to as a radial protrusion) 53 that protrudes radially outward from the insulating portion 55 on the axially closed side. ing. The radial protrusion 53 includes a member (hereinafter referred to as an energizing member) 54 that is in sliding contact with the above-described energizing contact portion 63 and allows current to flow between the open-side conductor and the movable contact 50.

  The radial protrusion 53 is a conductor portion of the operation rod 52 that is electrically connected to the movable contact 50. The radial protrusion 53 protrudes over the entire circumference of the operation rod 52. A current-carrying member 54 is held on the outer peripheral side of the radial protrusion 53.

  The energization member 54 has a substantially annular shape, is held by the radial protrusion 53, is in sliding contact with the inner wall of the energization contact portion 63, and allows a main circuit current to flow. The energizing member 54 is made of a material having relatively high conductivity. As the material constituting the energization member 54, for example, a metal material containing copper as a main component is used.

  On the other hand, the energizing contact portion 63 has a substantially cylindrical shape coaxially with the operation rod 52 and the radial protrusion 53. The energizing contact portion 63 is configured to surround the radially protruding portion 53 of the operating rod 52 and the radially outer side of the energizing member 54 at both the closed position (see FIG. 1) and the open position (see FIG. 3). .

  As shown in FIG. 3, in the present embodiment, the radial protrusion 53 of the operation rod 52 is formed with a groove that accommodates at least a part of the energization member 54. The energization member 54 is in sliding contact with the energization contact portion 63 of the open side end plate (open side conductor) 62 while being accommodated in the groove and held by the radial protrusion 53.

  As a result, the movable contact 50 and the operating rod 52 are electrically connected to the open-side conductor, that is, the open-side end plate 62, the open-side extended conductor 64, and the open-side central conductor 66 regardless of the open position and the closed position. . When the movable contact 50 and the operation rod 52 are in the closed position, the main circuit current flows through the radial protrusion 53, the energization member 54, and the energization contact 63.

  Note that a member (hereinafter referred to as a seal member) 61 for ensuring the airtightness of the above-described central low-pressure chamber 44 is provided on the radially inner side of the open-side end plate 62. The seal member 61 has a substantially annular shape, and is in sliding contact with the portion 51 on the axially closing side of the operating rod 52 from the radial protrusion 53. The seal member 61 is made of a material having relatively high lubricity such as PTFE.

  As described above, the circuit breaker 1 of the present embodiment surrounds the outer side in the radial direction of the operation rod 52 in the vacuum vessel 11 as shown in FIG. 1, and in the axial direction according to the movement of the operation rod 52. It has a bellows 12 that expands and contracts. An inter-electrode insulator 44 extends in the axial direction between the open side end plate 62 on the axially open side of the vacuum vessel 11 and the closed side end plate 22 on the axially closed side. A central low pressure chamber 44 is formed on the inner side in the radial direction of the interelectrode insulator 40, and the vacuum vessel 11 and the bellows 12 are disposed in the central low pressure chamber 44. The bellows 12 partitions the vacuum chamber 15 and the central low pressure chamber 44.

  An insulating portion 55 made of an electrical insulator in the operation rod 52 faces the high pressure chamber 5 on the axially open side from the open side end plate 62. In addition, the insulating cylinder 30 is coupled to the axially closed end 3e of the pressure vessel 3, and the closed low pressure chamber 33 extends to the end 3e. That is, the closed side low pressure chamber 33 is defined by the insulating cylinder 30, the closed side end plate 22, and the end 3 e of the pressure vessel 3.

  According to the present embodiment, the vacuum vessel 11 and the bellows 12 are located inside the interpolar insulator 40 between the closed side end plate 22 and the open side end plate 62 in the pressure vessel 3. Since it is accommodated in the chamber 44, the pressure difference between the inner surface 12 a and the outer surface 12 b of the bellows 12 can be reduced as compared with the case where it is accommodated in the high-pressure chamber 5.

  Further, in the pressure vessel 3, the insulating portion 55 of the operating rod 52 is accommodated in the high-pressure chamber 5 on the opening side in the axial direction from the opening-side end plate 62. In addition, the axial dimension of the insulating portion 55 and the axial distance between the opening-side end plate 62 and the end portion 3c of the pressure vessel 3 can be made relatively small. Thereby, the weight reduction of the insulation part 55 can be achieved and the high-speed operation | movement of the operating rod 52 is realizable.

  Further, in the pressure vessel 3, the insulating cylinder 30 is accommodated in the high-pressure chamber 5 on the axially closed side from the closing side end plate 22, and the above-described central portion is disposed on the radially inner side of the insulating cylinder 30. A closed-side low-pressure chamber 33 communicating with the low-pressure chamber 44 is formed, and the closed-side low-pressure chamber 33 extends to the end 3 e on the axially closing side of the pressure vessel 3.

  Since the outer side in the radial direction of the insulating cylinder 30 faces the high-pressure chamber 5, the dimensions of the insulating cylinder 30 in the axial direction, that is, the closed side end plate 22 and the insulating cylinder 30 can be improved while improving the electrical insulation performance of the insulating cylinder 30 The axial distance from the end 3e of the pressure vessel 3 can be made relatively small.

  On the other hand, on the radially inner side of the insulating cylinder 30, the closed-side low-pressure chamber 33 communicating with the central low-pressure chamber 44 extends to the end 3e of the pressure vessel 3, so that a pressure measuring device ( For example, it is easy to monitor the pressure in the low pressure chambers 33 and 44 by providing a pressure gauge 8) or the like.

  Thus, according to the circuit breaker 1 of the present embodiment, the axial dimension of the pressure vessel 3 is made compact while suppressing a high pressure difference from occurring in the bellows 12 facing the vacuum chamber 15. be able to.

  In the circuit breaker 1 of the present embodiment, the open-side conductor is in sliding contact with the current-carrying member 54 of the radially projecting portion 53 that is the portion closer to the axially closing side than the insulating portion 55 of the operation rod 52 and the current-carrying member 54 and an energizing contact portion 63 for flowing a main circuit current.

  In the present embodiment, the pressure measuring device that measures the pressure in the central low pressure chamber 44 and the closed side low pressure chamber 33 is a pressure gauge 8 that displays the measured pressure in the vicinity of the end 3e of the pressure vessel 3. However, the pressure measuring device according to the present invention is not limited to this mode. The pressure measuring device only needs to be able to measure at least the pressure in the closed-side low-pressure chamber 33, and various types of devices can be used regardless of the presence or absence of the pressure display function and the installation position.

  The central low-pressure chamber 44 and the closed-side low-pressure chamber 33 can be communicated with the outside of the pressure vessel 3 and filled by introducing outside air. One example will be described below.

[Second Embodiment]
The structure of the circuit breaker of 2nd Embodiment is demonstrated using FIG. FIG. 4 is an enlarged cross-sectional view showing the peripheral configuration of the insulating cylinder in the circuit breaker of the present embodiment. In addition, about the structure substantially common to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 4, the circuit breaker of the present embodiment has a communication hole (hereinafter referred to as an external communication) for introducing outside air into the closed-side low-pressure chamber 33 in the end 3 e on the axially closed side of the pressure vessel 3. 35) (denoted as holes). The external communication hole 35 allows the closed side low pressure chamber 33 to communicate with the outside of the pressure vessel 3. The external communication hole 35 extends in the axial direction (indicated by a dashed line A in the drawing). In the present embodiment, the closed-side low-pressure chamber 33 communicates with the central low-pressure chamber 44 through the internal communication hole 32.

  In the present embodiment, the external communication hole 35 is provided with a filter 37 that can separate at least one of dust and moisture from outside air. In the present embodiment, the filter 37 separates dust (foreign matter) and moisture (rain water) contained in the air flowing through the external communication hole 35.

  In the circuit breaker configured as described above, the central low-pressure chamber 44 and the closed-side low-pressure chamber 33 are passed through the external communication hole 35 and the filter 37 provided in the axially closed end 3e of the pressure vessel 3 through the pressure vessel. 3 Outside air (air) outside is introduced. The pressures of the air introduced into the central low pressure chamber 44 and the closed side low pressure chamber 33 are both atmospheric pressure.

  According to this embodiment, it is not necessary to monitor the pressure in the central low pressure chamber 44 and the closed low pressure chamber 33 with a pressure measuring device such as the pressure gauge 8 (see FIG. 1) described above. Even if the insulating gas filled in the high-pressure chamber 5 flows into the central low-pressure chamber 44 or the closed-side low-pressure chamber 33, the flowing insulating gas flows from the external communication hole 35 to the outside of the pressure vessel 3. Therefore, the pressure in the low pressure chambers 33 and 44 does not increase as in the high pressure chamber 5, and the bellows 12 that partitions the central low pressure chamber 44 and the vacuum chamber 15 does not break. .

[Third Embodiment]
The structure of the circuit breaker of 3rd Embodiment is demonstrated using FIG. FIG. 5 is a sectional elevation view showing the configuration of the circuit breaker of the present embodiment. FIG. 5 shows a state where the movable contact and the operation rod are located at a closed position. In FIG. 5, hatching is omitted for the pressure vessel, the operation mechanism, and the like for easy understanding. In addition, about the structure substantially common to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 5, in the circuit breaker 1 </ b> C of the present embodiment, outside air is closed to the closed side central conductor (closed side conductor) 27 extending substantially linearly inside the bushing 71 via the insulating spacer 28. A passage 29 (hereinafter simply referred to as “in-conductor passage”) 29 for introduction into the side low-pressure chamber 33 is formed inside. The in-conductor passage 29 extends in the longitudinal direction in the closed side central conductor 27.

  In addition, a passage 29 c for introducing outside air into the closed-side low-pressure chamber 33 is formed in the closed-side extended conductor (closed-side conductor) 24 and the insulating cylinder 30. The passage 29 c extends in the radial direction of the insulating cylinder 30. The passage 29c has a radially outer side connected to the in-conductor passage 29 and a radially inner side connected to the closed-side low pressure chamber 33. The outside of the pressure vessel 3 and the closed-side low-pressure chamber 33 communicate with each other via an in-conductor passage 29 and a passage 29c. Also in this embodiment, the closed-side low-pressure chamber 33 communicates with the central low-pressure chamber 44 through the internal communication hole 32.

  In the present embodiment, a filter 70 capable of removing at least one of dust and moisture is provided at the outer end of the pressure vessel 3 in the conductor passage 29. The filter 70 separates dust (foreign matter) and moisture (rainwater) contained in the air flowing through the in-conductor passage 29.

  In the circuit breaker 1 </ b> C configured as described above, the outside air (air) outside the pressure vessel 3 is passed through the central low pressure chamber 44 and the closed low pressure chamber 33 through the conductor inner passage 29 and the filter 70 in the closed central conductor 27. ) Is introduced. The pressures in the central low pressure chamber 44 and the closed side low pressure chamber 33 are both atmospheric pressure. Also in this embodiment, it is not necessary to monitor the pressure in the central low-pressure chamber 44 and the closed-side low-pressure chamber 33 by the pressure measuring device.

  In the present embodiment, the in-conductor passage 29 for introducing the outside air outside the pressure vessel 3 into the closed-side low pressure chamber 33 is formed in the closed-side central conductor 27. Such an in-conductor passage is not limited to this mode. For example, an in-conductor passage may be formed in the open-side center conductor 66, and outside air outside the pressure vessel 3 may be introduced into the central low-pressure chamber 44 through the in-conductor passage. Also according to this aspect, outside air (air) can be introduced into the central low-pressure chamber 44 and the closed-side low-pressure chamber 33.

[Other Embodiments]
In addition to the embodiment described above, various modifications can be made to the configuration of the circuit breaker. For example, in each of the above-described embodiments, the central low-pressure chamber 44 in which the vacuum vessel 11 and the bellows 12 are disposed, and the closed-side low-pressure chamber 33 on the axially closing side are closed end plates (closed conductors) 22. However, the mode of the central low pressure chamber and the closed side low pressure chamber according to the present invention is not limited to this mode. The central low-pressure chamber and the closed-side low-pressure chamber need only be introduced with an insulating gas or air having a lower pressure than that of the high-pressure chamber. For example, the central low pressure chamber and the closed side low pressure chamber may be filled with different types of insulating gases at different pressures.

  Although several embodiments of the present invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1, 1C Circuit breaker 2 Leg 3 Pressure vessel 3a Center 3c End (end of the pressure vessel in the axial direction)
3e end (end on the axially closing side of the pressure vessel)
5 High pressure chamber 7 Operation box 8 Pressure gauge (pressure measuring device)
10 Vacuum valve 11 Vacuum vessel 11a Insulating cylindrical part (electrical insulator)
11c Open side end 11e Closed side end 12 Bellows 12a Inner surface (bellows)
12b External surface (bellows)
13 Through-hole 15 Vacuum chamber 20 Fixed contact 21 Cylindrical conductor 22 Closed side end plate (Closed side conductor)
24 Closed-side stretched conductor (closed-side conductor)
26 Closed center conductor (closed conductor)
27 Closed center conductor (closed conductor)
28 Insulating spacer 29 Conductor inner passage 29c Passage 30 Insulating cylinder (electrical insulator)
32 Internal communication hole 33 Closed side low pressure chamber (low pressure chamber)
35 External communication hole 37 Filter 40 Inter-electrode insulator (electrical insulator)
44 Central low pressure chamber (low pressure chamber)
46 Interelectrode resistor 50 Movable contact 52 Operation rod 53 Radial protrusion 54 Current-carrying member 55 Insulation part (electrical insulator)
57 Operating mechanism 61 Seal member 62 Open side end plate (open side conductor)
63 Current-carrying contact (open side conductor)
64 Open side extended conductor (Open side conductor)
66 Open side center conductor (Open side conductor)
68 Insulating spacer 70 Filter 71 Bushing 72 Bushing

Claims (15)

A stationary contact constituting a conductive part of an electric circuit of the power system;
A movable contact that constitutes the conductive portion and is movable to the axially open side so as to be separated from the fixed contact;
A vacuum chamber having a vacuum chamber therein, and housing the fixed contact and the movable contact in the vacuum chamber;
Constituting the conductive part, disposed on the axially closed side from the vacuum vessel, and a closed conductor coupled to the fixed contact;
Constituting the conductive part, arranged on the axially open side from the vacuum vessel, and an open side conductor electrically connected to the movable contact;
It is coupled to the movable contact, extends from the movable contact through the vacuum vessel and the open-side conductor to the open side in the axial direction, and is driven by an operation mechanism so as to be integrated with the movable contact. An operating rod that moves in the axial direction;
It is made of an electrical insulator, has a substantially cylindrical shape surrounding the radially outer side of the vacuum vessel, extends in the axial direction between the closed-side conductor and the open-side conductor, and is radially inward. An interelectrode insulator defining a central low pressure chamber filled with insulating gas or air;
The vacuum vessel surrounds the outside of the operation rod in the radial direction, the end on the axial opening side is coupled to the vacuum vessel, and the end on the axial close side is coupled to the operation rod And a bellows that partitions the vacuum chamber and the central low-pressure chamber and expands and contracts in the axial direction according to the movement of the operation rod;
It is made of an electrical insulator, has a substantially cylindrical shape whose axial center extends in the axial direction, extends from the closed conductor to the axially closed side, and is filled with insulating gas or air radially inward. An insulating cylinder defining a closed side low pressure chamber;
The high-pressure chamber is filled with an insulating gas at a higher pressure than the central low-pressure chamber and the closed-side low-pressure chamber, and the open-side conductor, the interelectrode insulator, and the closed-side conductor are provided in the high-pressure chamber. And a pressure vessel that houses the insulating cylinder;
With
The insulating portion made of an electrical insulator among the operation rods faces the high-pressure chamber on the axially open side from the open-side conductor,
The insulating cylinder is coupled to an end portion on the axially closed side of the pressure vessel, and the closed-side low pressure chamber extends to the end portion,
The circuit breaker characterized in that an internal communication hole for communicating the central low-pressure chamber and the closed-side low pressure chamber is formed in the closing side conductor. 2. The open-side conductor has an energizing contact portion that is in sliding contact with a portion of the operating rod that is closer to the axially closing side than the insulating portion and that allows current to flow between the portion. Circuit breaker as described in. An interpolar resistor having an electrical resistance, having a substantially cylindrical shape surrounding the radially outer side of the vacuum vessel, and extending along the interpolar insulator between the closed side conductor and the open side conductor Body
The circuit breaker according to claim 1 or 2, further comprising: The circuit breaker according to any one of claims 1 to 3, wherein the high-pressure chamber is filled with an insulating gas at a pressure in a range of 0.4 MPa to 0.8 MPa. 2. The high-pressure chamber is filled with any one of sulfur hexafluoride, nitrogen, carbon dioxide, and dry air, or a mixed gas of two or more of them as an insulating gas. The circuit breaker according to any one of claims 4 to 4. 6. The insulating gas is filled in the central low pressure chamber and the closed-side low pressure chamber at a pressure within a range from atmospheric pressure to 0.2 MPa. 6. Circuit breaker as described in. The central low-pressure chamber and the closed-side low-pressure chamber are filled with one of sulfur hexafluoride, nitrogen, carbon dioxide, dry air, or a mixed gas of two or more of them as an insulating gas. The circuit breaker according to any one of claims 1 to 6. A pressure measuring device that is disposed outside the axially closed end of the pressure vessel and is capable of measuring at least the pressure of the closed low pressure chamber among the central low pressure chamber and the closed low pressure chamber;
The circuit breaker according to any one of claims 1 to 7, further comprising: An external communication hole for communicating the closed-side low pressure chamber and the outside of the pressure vessel is formed at an end portion on the axially close side of the pressure vessel,
9. The air at atmospheric pressure is introduced into at least the closed-side low-pressure chamber of the central low-pressure chamber and the closed-side low-pressure chamber through the external communication hole. Circuit breaker as described in any one. The circuit breaker according to claim 9, wherein the external communication hole is provided with a filter that separates at least one of dust and moisture from air. The open-side conductor is
An open-side end plate that is coupled to an end on the axially open side of the inter-electrode insulator and has a substantially disc shape extending radially on the axially open side from the movable contact;
An open-side center conductor that is coupled to the open-side end plate, has a substantially rod shape radially outward from the insulating portion, and extends inside the bushing;
The circuit breaker according to any one of claims 1 to 10, characterized by comprising: The closed conductor is:
A closed side end plate that is coupled to the end on the axially closed side of the interelectrode insulator, and has a substantially disc shape extending radially in the axially closed side from the fixed contact;
A closed side center conductor coupled to the closed side end plate, having a substantially rod shape radially outward from the insulating cylinder, and extending inside the bushing;
12. The circuit breaker according to claim 1, comprising: The closed-side central conductor is formed with an internal conductor passage through which the closed-side low-pressure chamber communicates with the outside of the pressure vessel, and air is introduced into the closed-side low-pressure chamber.
13. The circuit breaker according to claim 12, wherein air at atmospheric pressure is introduced into at least the closed-side low-pressure chamber of the central low-pressure chamber and the closed-side low-pressure chamber through the passage in the conductor. . The open-side center conductor is formed with an internal conductor passage for communicating the central low-pressure chamber and the outside of the pressure vessel to introduce air into the central low-pressure chamber,
The circuit breaker according to claim 12, wherein air at atmospheric pressure is introduced into at least the central low-pressure chamber of the central low-pressure chamber and the closed-side low-pressure chamber via the passage in the conductor. The block according to claim 13 or 14, wherein a filter that separates at least one of dust and moisture from air is provided at an end portion outside the pressure vessel of the passage in the conductor. vessel.

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