JP4744613B2 - Switchgear - Google Patents

Description

  The present invention provides a movable electrode of a main circuit switch that contacts and separates a bus-side conductor and a load-side conductor, and a transmission member that transmits an operating force to the movable electrode inside the vacuum vessel that houses the main circuit switch. The present invention relates to a connected switchgear.

  Switch gears (closed switchboards) used to distribute power received from the busbars to various load devices and other electrical rooms are for connecting the busbar side conductors for connection to the busbars and the power transmission cable to the load Internal devices such as main circuit switches that connect and disconnect the bus-side conductors and load-side conductors together with connecting conductors such as load-side conductors, ground switches for grounding the load-side conductors, and control devices required for monitoring and control Are appropriately arranged in an outer box made of ground metal.

As a kind of such switchgear, a main circuit switch that opens and closes a large current is housed in a vacuum vessel maintained at a high vacuum of about 10 ⁻⁷ Torr, and has a high dielectric strength in a high vacuum. There is a switchgear that uses the good arc extinguishing action to stably perform the opening and closing.

  FIG. 9 is a side sectional view showing a configuration of a main part of a conventional switch gear disclosed in Patent Document 1. As shown in FIG. This switchgear includes a bus-side conductor 18 supported by one lid plate 16 and a load side supported by the other lid plate 17 in a vacuum vessel 15 whose both sides are closed by lid plates 16 and 17. The conductor 19 is coaxially opposed to each other, and fixed contacts 22 and 23 are respectively fixed to the opposing end portions to constitute a fixed electrode, and the peripheral wall of the vacuum vessel 15 is axially extended via a bellows 25 The operation rod 24 is supported so as to be movable to the movable rod 27, and the movable contacts 27 and 28 are respectively fixed on both sides of the bridging conductor 26 fixed to the tip of the operation rod 24 so as to face the fixed contacts 22 and 23, respectively. Thus, the movable electrode is configured, the extension end of the bus-side conductor 18 to the outside of the lid plate 16 is connected to a bus bar (not shown) via the connection conductor 20, and the load-side conductor 19 to the outside of the lid plate 17 is connected. The extension end is connected to a power transmission cable to a load (not shown) via a connection conductor 21 to constitute a main circuit switch.

  In the main circuit switch thus configured, the operating rod 24 is operated outside the vacuum vessel 15 to move the bridging conductor 26, and the movable contacts 27, 28 on both sides thereof are fixed contacts 22, 23. As a result, the switching operation can be performed between the bus-side conductor 18 and the load-side conductor 19.

  That is, as shown by the solid line in the figure, in a closed state where the movable contacts 27 and 28 on both sides of the bridge conductor 26 are in contact with the fixed contacts 22 and 23, the current from the bus is connected to the connecting conductor 20 and the bus-side conductor. 18, flows to the bridging conductor 26 via the fixed contact 22 and the movable contact 27, and is further transmitted to the load side via the movable contact 28, the fixed contact 23, the load side conductor 19 and the connection conductor 21. As indicated by the chain line, in the open circuit state in which the movable contacts 27, 28 on both sides of the bridge conductor 26 are separated from the fixed contacts 22, 23, the current flows between the movable contacts 27, 28 and the fixed contacts 22, 23. Is cut off.

  The inner surface of the vacuum vessel 15 is covered by an arc shield 29 attached to the peripheral wall of the vacuum vessel 15 and shield cylinders 30 and 31 erected on the lid plates 16 and 17 on both sides, respectively, and the blocking operation is thereby performed. In some cases, metal vapor generated by the main circuit arc is sometimes captured to prevent adhesion to the insulator exposed inside the vacuum vessel 15.

Japanese Utility Model Publication No. 54-183669

  In the switch gear configured as described above, the operating rod 24 is automatically or manually operated outside the vacuum vessel 15, and this operating force is applied to the movable electrode composed of the bridging conductor 26 and the movable contacts 27 and 28. Acts as an operating member to convey. Therefore, in the configuration in which the operation rod 24 is automatically operated, in order to prevent the occurrence of an accident due to the inflow of abnormal current to the operation mechanism, and in the configuration in which the operation rod 24 is manually operated, the operation for performing this operation is performed. In order to ensure the safety of the operator, it is necessary to prevent the main circuit current that is opened and closed as described above from flowing into the operation rod 24 as the operation member. A connecting member made of an insulator is interposed at an appropriate position between the attachment end of the bridging conductor 26 on the side and the operation end on the other side to cut off the flow of the main circuit current.

  Such a connecting member can be provided inside and outside the vacuum vessel 15, but when provided inside, a short connecting member can be used utilizing the dielectric strength in high vacuum. On the other hand, when provided outside, an additional configuration such as providing an insulating chamber filled with an insulating gas such as sulfur hexafluoride around the insulating member so as to obtain predetermined insulating characteristics is required. In order to obtain a reduced switchgear, it is advantageous to provide the connecting member inside the vacuum vessel.

  However, when a connecting member is provided inside the vacuum vessel 15, metal vapor generated by the main circuit arc during the shut-off operation of the main circuit switch disposed in the common vacuum vessel 15 adheres to the surface of the connecting member. There is a problem of doing. Since this metal vapor has conductivity, the surface resistance and creepage breakdown voltage of the connecting member are reduced, it becomes impossible to prevent the main circuit current from flowing from the movable electrode to the operation member, and the adhesion increases with time. There is a problem that the insulation cannot be maintained by the metal, and there is a possibility of causing a ground fault, and the reliability of the product cannot be maintained.

  The present invention has been made in view of such circumstances, and in a configuration in which a connecting member made of an insulator for connecting a movable electrode and an operating member is arranged inside a vacuum vessel common to a main circuit switch, An object of the present invention is to provide a switchgear that can prevent deterioration of insulating properties due to the adhesion of vapor and can maintain good insulating properties over a long period.

The switchgear according to the present invention includes a main circuit switch that opens and closes a bus-side conductor and a load-side conductor by contact and separation of a movable contact provided at one end of the movable electrode with respect to the fixed electrode; An operating member for transmitting the operating force and an connecting member made of an insulator for connecting the operating member and the movable electrode inside a common vacuum vessel, and the movable electrode is connected to the axis of the movable electrode. In the crossing direction, an overhang is provided over the entire circumference of the connecting member , and the overhang extends in the axial direction of the operating member so that the outer periphery covers the connecting member. and wherein the tare Rukoto.

In the present invention, the movable electrode is provided with a projecting portion, and the outer peripheral portion of the projecting portion covers the outside of the connecting member. The overhang provided in this way acts to prevent metal vapor from the main circuit arc from adhering to the connecting member made of an insulator, and keeps the surface of the connecting member clean and maintains good insulating properties. To do.

  The switchgear of the present invention is characterized in that the connecting member includes an overhanging portion that extends over the entire circumference in a direction crossing the shaft of the connecting member.

  In the present invention, the connecting member is also provided with an overhanging portion, and metal vapor caused by the main circuit arc is prevented from adhering to the surface of the overhanging portion on the side of the operation member, thereby maintaining good insulation characteristics. .

Switchgear of the present invention is also the movable electrode with the connecting member is joined, overhang of the movable electrode, the bonding surface of the movable electrode in a direction crossing the axis of the movable electrode, the entire periphery It extends over the outer periphery of the connecting member over the entire area.

  In the present invention, the projecting portion of the movable electrode is formed by projecting the joint surface with the connecting member, and the metal vapor caused by the main circuit arc is effectively prevented from adhering to the connecting member.

  The switchgear of the present invention is characterized in that the projecting portion of the movable electrode is formed integrally with the movable electrode.

  In the present invention, the projecting portion of the movable electrode is formed integrally with the movable electrode to reduce the number of parts.

  In the switchgear of the present invention, the projecting portion provided on the movable electrode covers the connecting member made of an insulator and prevents the metal vapor due to the main circuit arc from adhering to the connecting member. It is possible to maintain the insulation characteristics, and reliably prevent the main circuit current from flowing into the operation member, thereby obtaining high reliability.

It is a sectional side view which shows the structure of the principal part of Embodiment 1 of the switchgear which concerns on this invention. It is a sectional side view of the connection part of a movable electrode and an operating rod. It is a sectional side view which shows the structure of the principal part of Embodiment 2 of the switchgear which concerns on this invention. It is a sectional side view which shows the structure of the principal part of Embodiment 3 of the switchgear which concerns on this invention. It is a sectional side view which shows the structure of the principal part of Embodiment 4 of the switchgear which concerns on this invention. It is a sectional side view which shows the structure of the principal part of the switchgear of the reference form 1. It is a sectional side view which shows the structure of the principal part of the switchgear of the reference form 2. It is a sectional side view which shows the structure of the principal part of the switchgear of the reference form 3. It is a sectional side view which shows the structure of the principal part of the conventional switchgear.

Embodiment 1
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. 1 is a side sectional view showing a configuration of a main part of a switchgear according to Embodiment 1 of the present invention. This switchgear constitutes a main circuit switch that opens and closes between the bus-side conductor 3 and the load-side conductor 4 inside the vacuum vessel 11 kept at high vacuum. The bus-side conductor 3 is supported through a support member 10a made of an insulator in such a manner that it passes through a substantially central portion of one end wall of the vacuum vessel 11, and the load-side conductor 4 is provided on the peripheral wall of the vacuum vessel 11. It is supported through a support member 10b made of an insulator so as to penetrate a part.

  An operation rod 6b is supported on the other end wall of the vacuum vessel 11 through the bellows 7 so as to be movable in the axial direction, and at the end of the operation rod 6b extending inside the vacuum vessel 11, The movable electrode 6a is connected as will be described later via an insulating connecting member 5 which is a characteristic part of the present invention. The tip of the movable electrode 6a is abutted substantially coaxially with the bus-side conductor 3, and the fixed contact 1 and the movable contact are connected to the tip of the movable electrode 6a and the tip of the bus-side conductor 3 as a fixed electrode. 2 are fixed to each other.

  An inner end portion of the load-side conductor 4 supported by the peripheral wall of the vacuum vessel 11 is connected to a fixing member 9 via a connecting conductor 8 having flexibility. The fixed member 9 is joined to an electrode member 6c provided integrally with an end portion of the movable electrode 6a on the connection side with the connection member 5. The outer end of the load-side conductor 4 is connected to a power transmission cable to a load (not shown), and the outer end of the bus-side conductor 3 supported by the end wall of the vacuum vessel 11 is connected to a bus (not shown). ing.

  The outer end of the operating rod 6b supported on the other end wall of the vacuum vessel 11 is connected to an operating mechanism (not shown), and the operating rod 6b is moved in the axial length direction according to the operation of the operating mechanism. This movement is transmitted to the movable electrode 6a via the connecting member 5, and the movable contact 2 at the tip of the movable electrode 6a contacts and separates from the fixed contact 1, and the bus side conductor 3 and the load side conductor 4 , That is, between the bus and the power transmission cable to the load.

  FIG. 1 shows an open circuit state. When the operating rod 6b is moved in the left direction of the figure from this state, the movable contact 2 is pressed via the connectionless member 5 and the movable electrode 6b to be a fixed contact. 1 is contacted to obtain a closed state. At this time, the main circuit current from the bus (not shown) flows to the movable electrode 6a through the bus-side conductor 3, the fixed contact 1 and the movable contact 2, and is further illustrated through the fixed member 9, the connection conductor 8 and the load-side conductor 4. Not transmitted to the transmission cable.

  On the other hand, in this closed state, when the operating rod 6b is moved in the right direction in the figure, the movable contact 2 is pulled away from the fixed contact 1 by the tensile force acting via the connecting member 5 and the movable electrode 6b. The open circuit state shown is obtained, and the flow of the main circuit current from the bus-side conductor 3 to the load-side conductor 4 is interrupted. Note that the fixed contact 1 and the movable contact 2 are disposed inside the vacuum vessel 11, and as shown in the figure, the main circuit current is cut off without being largely separated between the two contacts 1 and 2.

  FIG. 2 is a side cross-sectional view of a connecting portion between the movable electrode 6a and the operating rod 6b. This figure shows the configuration of the A portion surrounded by a broken line in FIG. The connecting member 5 that connects the movable electrode 6a and the operating rod 6b insulates the movable electrode 6a and the operating rod 6b during the closing, and the main circuit current flowing through the movable electrode 6a in the closed state is applied to the operating rod 6b. It prevents the inflow. As shown in the figure, the connecting member 5 is a disk-like member having a diameter larger than that of the movable electrode 6a and the operating rod 6b. In the direction crossing the axis of the operating rod 6b, the connecting member 5 is connected to the operating rod 6b. The projecting portion that projects over a predetermined length has a shape that is provided around the entire circumference. The overhang length of the overhang portion is set to a length exceeding the insulation creepage length required in a vacuum. The electrode member 6c (corresponding to the overhanging portion) provided integrally with the end portion of the movable electrode 6a on the connection side with the connection member 5 is larger than the connection member 5 and is on the side facing the connection member 5. Is provided with a recess 6d. The movable electrode 6a and the connecting member 5 are joined to each other so as to include the connecting member 5 in the recess 6d.

  In the switchgear configured as described above, when the movable contact 2 is pulled away from the fixed contact 1 in order to cut off the main circuit current, an arc discharge is generated between the contacts 1 and 2, and the high temperature in the arc is generated. By exposure, the surfaces of the contacts 1 and 2 are melted, and a part thereof becomes a metal vapor, and the liquid metal particles formed by gathering the metal vapor and the metal vapor gather between the contacts 1 and 2 and the peripheral member. Due to the pressure difference between them and the expansion force of the arc, it is scattered around and adheres to each member inside the vacuum vessel 11.

  Such adhesion of metal vapor also occurs on the surface of the connecting member 5 that connects the movable electrode 6a and the operating rod 6b, but this connecting member 5 has a protruding portion on the connecting side with the operating rod 6b as described above. And is included in a recess 6d provided in the electrode member 6c at the end of the movable electrode 6a. The side of the connecting member 5 facing the main circuit switch is covered with the electrode member 6c, and the outer periphery of the connecting member 5 is provided. The periphery of the recess 6d facing the surface with a space acts as a ridge. Therefore, the outer peripheral surface of the connecting member 5 and the surface of the connecting member 5 that is connected to the operation rod 6b, that is, the surface that does not face the fixed contact 1 and the movable contact 2 are clean with little adhesion of the metal vapor. Kept in a state.

  The size of the connecting member 5 is set so that the overhang length of the overhang portion including the width of the outer peripheral surface exceeds the insulating creepage length required in a vacuum. As a result, a desired insulation creepage length between the movable electrode 6a and the operating rod 6b is secured with a good cleanliness with little adhesion of metal vapor, and good creepage insulation characteristics can be maintained for a long time. Can be maintained throughout. Therefore, the connecting member 5 can reliably achieve the effect of preventing the main circuit current from flowing into the operating rod 6b, and can prevent the occurrence of an accident associated with the inflow, thereby providing a highly reliable switch gear. It becomes possible.

  Next, a method for manufacturing the switch gear as described above will be described. Since each member constituting the switchgear is used in a high vacuum inside the vacuum vessel 11, degreasing cleaning using an organic solvent is performed after processing into each shape to maintain the cleanliness of the surface. Assemble in the state. The fixed contact 1 and the movable contact 2 are formed by processing an alloy containing copper as a main component into a desired shape, and joining them to the bus-side conductor 3 made of oxygen-free copper and the movable electrode 6a. The fixing member 9 is joined to the part. Since these joints are required to be able to conduct the main circuit current without loss and to have a strength that can withstand opening and closing operations, joining means such as brazing, welding, and screwing are employed. .

  Further, an operating rod 6b is joined to the other end of the movable electrode 6a via a connecting member 5 included in a recess 6d of the electrode member 6c. Further, a bellows 7 is provided in the middle of the operating rod 6b. Join the edges. The joint between the connecting member 5 and the movable electrode 6a and the operating rod 6b needs to be strong enough to withstand the opening / closing operation force. The joint surface of the connecting member 5 made of an insulator is metalized with an alloy containing molybdenum. High strength bonding is performed by brazing the processing portion, the movable electrode 6a, and the operation rod 6b. The joining of the movable electrode 6a and the electrode member 6c can be realized by brazing, welding, or screwing. The movable electrode 6a and the electrode member 6c can be configured as an integrally processed product.

  On the other hand, the vacuum vessel 11 is constituted by a container member that can be divided into a plurality of parts, and the bus-side conductor 3 and the load-side conductor 4 are attached to the support members 10a and 10b joined to predetermined positions of these members, and the operation rod 6b The other edge of the bellows 7 is joined to the attachment part, and further, both ends of the connection conductor 8 are joined to the fixed member 9 and the load side conductor 4 of the movable electrode 6b, and finally the heating furnace maintained at high vacuum. The container members are joined to each other. As a material of the vacuum vessel 11, a metal for a vacuum member such as stainless steel is used.

  The joining of the supporting members 10a and 10b to the container member constituting the vacuum vessel 11 and the joining of the bellows 7 are performed by metallizing the joining surfaces of the supporting members 10a and 10b and the bellows 7 as in the connecting member 5. This is realized by brazing the portion and the container member. In this joining, since it is required that a sealing degree higher than the joining strength is obtained, the brazing material is applied thickly and brazing is performed. In addition, the joints at both ends of the connection conductor 8 conduct the main circuit current without loss and reduce the stress generated in the load side conductor 4 due to the deformation of the connection conductor 8 following the displacement of the movable electrode 6b. It is desirable to join by screwing.

  Hereinafter, other embodiments of the present invention will be described with reference to the respective drawings. 3 to 5 show the configuration of the portion A shown in the vicinity of the connecting member 5 that is a characteristic part of the present invention, that is, surrounded by a broken line in FIG. The configuration and operation of this part are the same as those in FIG.

Embodiment 2
FIG. 3 is a side sectional view showing a configuration of a main part of the switchgear according to the second embodiment of the present invention. In this switchgear, as in the first embodiment, an electrode member 6c that is larger than the connecting member 5 at the end of the movable electrode 6a on the connecting side with the connecting member 5 and has a recess 6d on the tip side is provided. In addition to being provided integrally, a recess 5a is also provided on the end surface of the connecting member 5 on the side of the connection with the operation rod 6b, and the movable electrode 6a and the connecting member 5 include the connecting member 5 in the recess 6d. In addition, the connecting member 5 and the operating rod 6b are joined in such a manner that the end of the operating rod 6b is included in the recess 5a.

  According to this configuration, the opposite side of the connecting member 5 to the main circuit switch is covered with the electrode member 6c, and the peripheral edge of the recess 6d functions as a ridge, so that the peripheral surface of the connecting member 5 and the operating rod 6b The adhesion of the metal vapor to the end surface on the connection side is suppressed, these surfaces are kept clean, and the length along the inner surface of the recess 5a provided in the connection member 5 is the insulation creepage distance, so that the small diameter The connecting member 5 can be used. Also in this embodiment, the movable electrode 6a and the electrode member 6c can be configured as an integrally processed product.

Embodiment 3
FIG. 4 is a side sectional view showing the configuration of the main part of the third embodiment of the switchgear according to the present invention. In this switchgear, the connecting member 5 that connects the movable electrode 6a and the operating rod 6b includes a plurality of projecting portions 5b, 5c, and 5d arranged in parallel in the axial direction on the outer periphery of the cylindrical body as shown in the figure. It becomes the composition. As in the first embodiment, the connecting member 5 is included in a recess (not shown) provided at the end of the movable electrode 6a.

  According to this configuration, the surfaces of the plurality of projecting portions 5b, 5c, 5d connected to the respective operation rods 6b remain as clean surfaces with less adhesion of metal vapor generated by the main circuit arc. As a result, a sufficient insulation creepage distance is secured, and good insulation characteristics can be obtained over a long period of time.

Embodiment 4
FIG. 5 is a side sectional view showing a configuration of a main part of the switchgear according to the fourth embodiment of the present invention. In this switchgear, the connecting member 5 that connects the movable electrode 6a and the operating rod 6b is configured as a cylindrical member having substantially the same diameter as the movable electrode 6a and the operating rod 6b. A plurality of projecting portions 5e, 5f arranged in parallel in the axial length direction are formed by joining the insulators forming the above. The connecting member 5 having the overhang portions 5e and 5f is included in a recess (not shown) provided at the end of the movable electrode 6a, as in the first embodiment.

  According to this configuration, the surfaces of the plurality of projecting portions 5e and 5f on the side connected to the respective operation rods 6b remain as clean surfaces with little adhesion of metal vapor generated by the main circuit arc, and these surfaces are more sufficient. Insulation creepage distance is ensured, good insulation characteristics can be obtained over a long period of time, and the projecting portions 5e and 5f are constituted by separate members from the connecting member 5, so that a combination of members having a simple shape can be used. The desired effect is obtained. It should be noted that high strength is not required for the joint between the insulator forming the protruding portions 5e and 5f and the connecting member 5, and this joining can be realized by an appropriate means such as adhesion.

Reference form 1
FIG. 6 is a side cross-sectional view showing the configuration of the main part of the switchgear of Reference Embodiment 1. 2 shows the configuration of the portion A shown in the vicinity of the connecting member 5, that is, surrounded by a broken line in FIG. 1, as in FIG. 2, and the configuration and operation of other portions not shown in FIG. This is the same, and a description thereof will be omitted. In this switchgear, the connecting member 5 for connecting the movable electrode 6a and the operating rod 6b is configured as a cylindrical member having substantially the same diameter as the movable electrode 6a and the operating rod 6b. As shown in FIG. 5, the outer surface of the core material 5g is covered with a surface material 5h, and has a layer structure.

  The core material 5g is an insulator mainly composed of aluminum oxide (alumina), and the surface material 5h is, for example, an insulator mainly composed of silicon oxide, etc., which is rougher than the alumina constituting the core material 5g. Is formed with a thickness of 1 mm or less by an insulator having a small dense surface.

  According to this configuration, the metal vapor generated by the main circuit arc adheres to the surface material 5h of the connecting member 5, and the surface material 5h is an insulator having a small surface roughness as described above, and creeping failure The voltage is high and the amount of gas released from the inside is small. Therefore, the main circuit current can be effectively prevented from flowing into the operating rod 6b, and good insulation characteristics can be obtained. Further, since the roughness of the surface material 5h is small, the fouling substances adhering to the surface of the surface material 5h can be easily removed during the production, and the surface fouling accompanying the production can be reliably restored. As a result, an additional effect of reducing the incidence of defective products in the manufacturing stage and obtaining a highly reliable switch gear can be obtained.

Reference form 2
FIG. 7 is a side cross-sectional view showing the configuration of the main part of the switchgear of Reference Embodiment 2. In this figure, unlike FIGS. 2-6, although the structure of the substantially the same range as FIG. 1 is shown, each other than the periphery of the connection member 5, ie, the B section enclosed with the broken line in the figure, is shown. The structure of the members is the same as that of the switch gear shown in FIG.

  The characteristic structure of this switchgear is that the outside of the connecting member 5 is connected between the connecting member 5 that connects the movable electrode 6a and the operating rod 6b and the main circuit switch that is opened and closed by the movement of the movable electrode 6a. The shielding member 14 is arranged in a surrounding manner. This shielding member 14 is a thin cylindrical body whose diameter is reduced on the side facing the main circuit switch, and is supported on the peripheral wall of the vacuum vessel 11 via a support rod 13, and a metal portion inside the vacuum vessel 11 There is no direct contact with them.

  According to this configuration, the metal vapor generated by the main circuit arc and directed to the connecting member 5 is caught by the shielding member 14 before reaching the connecting member 5, and the connecting member 5 is attached due to the adhesion of the metal vapor. It is possible to effectively suppress the temporal degradation of the creeping withstand voltage characteristic. The shielding member 14 may be made of either a conductor or an insulator, but when made of an insulator, the separation distance from the movable electrode 6b maintained at a high potential can be reduced, Metal vapor can be captured more effectively.

Reference form 3
FIG. 8 is a side cross-sectional view showing the configuration of the main part of the switchgear of Reference Embodiment 3. This figure shows the configuration of part B in FIG. 7, and the configuration of other parts not shown in the figure is the same as in FIG.

  In the same manner as in FIG. 7, this switchgear is provided between the connecting member 5 that connects the movable electrode 6a and the operating rod 6b and the main circuit switch that is opened and closed by the movement of the movable electrode 6a. The shielding member 14 is arranged in such a manner as to surround the outer side without contact with the metal part inside the vacuum vessel 11. The support rod 13 for supporting the shielding member 14 extends through the insulating support member 10c fixed to the peripheral wall of the vacuum vessel 11 and extends to the outside. Has been.

  According to this configuration, the metal vapor generated by the main circuit arc and directed to the connecting member 5 is captured by the shielding member 14 before reaching the connecting member 5. At this time, the shielding member 14 is maintained at the ground potential via the support rod 13, while a part of the metal vapor generated by the main circuit arc is generally ionized with a positive potential. The metal vapor is attracted to the shielding member 14 maintained at the ground potential, and is reliably captured on the surface thereof. Therefore, the amount of metal vapor attached to the connecting member 5 surrounded by the shielding member 14 can be more effectively reduced, and the temporal deterioration of the creeping pressure resistance characteristics can be effectively suppressed. Although the configuration in which the shielding member 14 is grounded via the support rod 13 has been described, it may be connected to a constant potential portion having a negative potential via the support rod 13, and in this case, ionized metal vapor is Further, it can be captured effectively.

1 fixed contact, 2 movable contact, 3 bus side conductor, 4 load side conductor, 5 connecting member, 5a recess, 5b-5f overhang, 5g core material, 5h surface material, 6a movable electrode,
6b Operation rod, 6c electrode member, 6d recess, 14 shielding member.

Claims (4)

A main circuit switch that opens and closes a bus-side conductor and a load-side conductor by contacting and separating a movable contact provided at one end of the movable electrode with respect to a fixed electrode, and an operation member that transmits an operation force for the contact and separation to the movable electrode And a connecting member made of an insulator for connecting the operation member and the movable electrode inside a common vacuum vessel,
The movable electrode includes a projecting portion that projects from the outer periphery of the connecting member over the entire circumference in a direction intersecting the axis of the movable electrode , and the projecting portion covers the connecting member at the outer peripheral portion. switchgear according to claim Oh isosamples extend in the axial direction of the operating member.   The switch gear according to claim 1, wherein the connecting member includes an overhanging portion that extends over the entire circumference in a direction crossing the axis of the connecting member. Wherein the movable electrode and the said connecting member is joined, overhang of the movable electrode, the bonding surface of the movable electrode in a direction crossing the axis of the movable electrode, the outer periphery of the coupling member over its entire circumference The switchgear according to claim 1 or 2, wherein the switchgear is formed so as to protrude further. The switchgear according to any one of claims 1 to 3 , wherein the projecting portion of the movable electrode is formed integrally with the movable electrode.

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