VACUUM VALVE

A vacuum valve includes: an insulation container; a fixed-side electrode including a fixed-side contact, a fixed-side longitudinal magnetic-field coil generating a magnetic field on a surface of the fixed-side contact in an axial direction, and a fixed-side spacer; and a movable-side electrode including a movable-side contact, a movable-side longitudinal magnetic-field coil generating a magnetic field on a surface of the movable-side contact in the axial direction, and a movable-side spacer. The fixed-side longitudinal magnetic-field coil and the movable-side longitudinal magnetic-field coil each include an outer ring portion having an arc shape and a power feeding portion protruding from an end of the outer ring portion. The fixed-side or movable-side contact is brazed to the power feeding portion. The fixed-side and movable-side spacers are made of a material with lower conductivity than materials of the fixed-side and movable-side longitudinal magnetic-field coils, or made of an insulator.

FIELD

The present disclosure relates to a vacuum valve to be used for arc-extinguishing chambers of a vacuum circuit breaker and a vacuum switch.

BACKGROUND

A vacuum valve is used for arc-extinguishing chambers of a vacuum circuit breaker and a vacuum switch. The vacuum valve has a fixed electrode and a movable electrode accommodated within a cylindrical insulation container. Each of the fixed electrode and the movable electrode includes a contact, a longitudinal magnetic-field coil, a support, and an electrode rod. Both end portions of the insulation container are closed by end plates, and the electrode rod of the movable electrode penetrates the end plate and extends to the outside of the insulation container. A bellows is provided for the electrode rod of the movable electrode, so that an opening action and a closing action can be performed while the inside of the insulation container is maintained under vacuum.

When the vacuum valve is assembled, a foil-like or wire-like brazing material is disposed between parts for each of the fixed electrode and the movable electrode, and the brazing material is heated, melted, and solidified to perform partial brazing. The fixed electrode and the movable electrode having been partially brazed are coaxially disposed inside the insulation container, and final brazing is performed in a vacuum furnace, whereby the fixed electrode and the movable electrode are disposed in a vacuum.

Patent Literature 1 discloses a vacuum valve that includes a longitudinal magnetic-field coil including an inner ring portion, a spoke portion, and an outer ring portion. The inner ring portion is fixed to a fixed shaft. The spoke portion extends in a radial direction from the inner ring portion. The outer ring portion extends in an arc shape in a circumferential direction from an end of the spoke portion. A protrusion called a power feeding portion is provided at an end of the outer ring portion, and a contact is brazed to the power feeding portion. The longitudinal magnetic-field coil generates en axial magnetic field on a surface of the contact when an electric current flows through the outer ring portion. Since magnetic fields generated on surfaces of the contacts trap and diffuse electrons forming an arc generated between the contacts, a local rise in temperature of the contact is prevented, and electric current interruption performance is improved.

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

The vacuum valve disclosed in Patent Literature 1 includes a plurality of outer ring portions separated from each other by a slit, extending in a radial direction, and the outer ring portions are arranged in form of a ring that is partially missing. Therefore, around the slit, the axial magnetic field is weakened on the surface of the contact, so that arc becomes difficult to diffuse. It is possible to reduce the number of portions in each of which the axial magnetic field is weakened on the surface of the contact, by providing a single outer ring portion to reduce the number of slits. However, since the power feeding portion is provided only at one place, the contact cannot be stably supported by the longitudinal magnetic-field coil, and assemblability is deteriorated accordingly.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a vacuum valve having a smaller number of portions in each of which an axial magnetic field is weakened on a surface of a contact and being easier to assemble.

Solution to Problem

In order to solve the above-described problem and achieve the object, the present disclosure provides a vacuum valve comprising: an insulation container with a cylindrical shape; and a fixed-side electrode and a movable-side electrode installed on a central axis of the insulation container in such a way as to face each other, wherein the fixed-side electrode includes a fixed-side contact, a fixed-side longitudinal magnetic-field coil, and a fixed-side spacer, the fixed-side longitudinal magnetic-field coil generating a magnetic field on a surface of the fixed-side contact in an axial direction of the insulation container, the fixed-side spacer filling a gap between the fixed-side contact and the fixed-side longitudinal magnetic-field coil, the movable-side electrode includes a movable-side contact, a movable-side longitudinal magnetic-field coil, and a movable-side spacer, the movable-side longitudinal magnetic-field coil generating a magnetic field on a surface of the movable-side contact in the axial direction of the insulation container, the movable-side spacer filling a gap between the movable-side contact and the movable-side longitudinal magnetic-field coil, the fixed-side longitudinal magnetic-field coil and the movable-side longitudinal magnetic-field coil each include an inner ring portion, a spoke portion, an outer ring portion, and a power feeding portion, the inner ring portion being disposed at a central part of the insulation container in a radial direction, the spoke portion extending from the inner ring portion in the radial direction of the insulation container, the outer ring portion extending in an arc shape in a circumferential direction of the insulation container, an end of the outer ring portion being separated from the spoke portion by a slit extending along the radial direction of the insulation container, the power feeding portion protruding from the end in the axial direction of the insulation container, the fixed-side contact or the movable-side contact being brazed to the power feeding portion, and the fixed-side spacer and the movable-side spacer are made of a material having a lower electric conductivity than a material of the fixed-side longitudinal magnetic-field coil and a material having a lower electric conductivity than a material of the movable-side longitudinal magnetic-field coil, respectively, or made of an insulator, each of the fixed-side spacer and the movable-side spacer being installed on at least one portion of the outer ring portion.

Advantageous Effects of Invention

The present disclosure achieves an advantageous effect that it can provide a vacuum valve having a smaller number of portions where axial magnetic fields are weakened on surfaces of contacts and being easier to assemble.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a vacuum valve according to each embodiment will be described in detail with reference to the drawings.

First Embodiment

FIG.1is a cross-sectional view of a vacuum valve according to a first embodiment.FIG.2is a cross-sectional view of an electrode unit of the vacuum valve according to the first embodiment.FIG.3is a perspective view of the electrode unit of the vacuum valve according to the first embodimentFIG.4is an exploded perspective view of the electrode unit of the vacuum valve according to the first embodiment. A vacuum valve10includes an insulation container1with a tubular shape, and a fixed side electrode2and a movable-side electrode3that are coaxially arranged on a central axis of the insulation container1. Hereinafter, unless otherwise specified, an “axial direction” refers to an axial direction of the insulation container1, a “radial direction” refers to a radial direction of the insulation container1, and a “circumferential direction” refers to a circumferential direction of the insulation container1.

The fixed-side electrode2includes a fixed-side contact21, a fixed-side longitudinal magnetic-field coil2.2, fixed-side spacers23, a fixed-side support24, a fixed-side electrode rod25, and a fixed-side end plate26. The fixed-side longitudinal magnetic-field coil22generates an axial magnetic field on a surface of the fixed-side contact21. The fixed-side spacers23fill a gap between the fixed-side contact21and the fixed-side longitudinal magnetic-field coil22The fixed-side support24supports the fixed-side contact21, The fixed-side end plate26closes one end portion of the insulation container1. The movable-side electrode3includes a movable-side contact31, a movable-side longitudinal magnetic-field coil32movable-side spacers33, a movable-side support34, a movable-side electrode rod35, a bellows cover36, a bellows37, and a movable-side end plate38. The movable-side longitudinal magnetic-field coil32generates an axial magnetic field on a surface of the movable-side contact31. The movable-side spacers33fill a gap between the movable-side contact31and the movable-side longitudinal magnetic-field coil32. The movable-side support34supports the movable-side contact31. The movable-side electrode rod35moves along the axial direction during an opening action and a closing action under power transmitted from an open and closing device (not illustrated). The movable-side end plate38closes another end portion of the insulation container1.

The bellows cover36with a disk shape is attached to the movable-side electrode rod35. The movable-side end plate38and the bellows cover36are connected by the bellows37. The bellows37covers the movable-side electrode rod35from the radial direction. The bellows37is capable of expanding and contracting in the axial direction, and expands and contracts in accordance with the movement of the movable-side electrode rod35during the opening action and the closing action. A guide4for guiding the movable-side electrode rod35is set on the movable-side end plate38.

An electrode unit2athat is an end portion of the fixed-side electrode2and an electrode unit3athat is an end portion of the movable-side electrode3are opposed to each other. The fixed-side electrode2and the movable-side electrode3have their equal structures. However, since the fixed-side longitudinal magnetic-field coil22and the movable-side longitudinal magnetic-field coil32have their different orientations in the circumferential direction, the illustrated cross-sectional shapes of the fixed-aide longitudinal magnetic-field coil22and the movable-side longitudinal magnetic-field coil32are also different inFIG.1. The vacuum valve10performs an opening action and a closing action. In the opening action, the movable-side contact31that has been in contact with the fixed-side contact21is separated from the fixed-side contact21. In the closing action, the movable-side contact31that has been separated from the fixed-side contact21is brought into contact with the fixed-side contact21.

One end of the fixed-side electrode rod25is fixed to the fixed-side end plate26. The fixed-side support24is attached to another end of the fixed-side electrode rod25. The fixed-side support24includes a circular disk portion41and a shaft portion42protruding from one surface of the circular disk portion41. The fixed-side support24is surrounded by the fixed-side longitudinal magnetic-field coil22from the outer peripheral side. The fixed-side contact21is brazed to a surface opposite to a surface of the circular disk portion41of the fixed-side support24from which the shaft portion42protrudes.

FIG.5is a plan view of the fixed-side longitudinal magnetic-field coil and the movable-side longitudinal magnetic-field coil of the vacuum valve according to the first embodiment. The fixed-side longitudinal magnetic-field coil22includes an inner ring portion58, a spoke portion51, and an outer ring portion52. The inner ring portion58is disposed at a central part of the insulation container1in the radial direction. The spoke portion S1extends in the radial direction from the inner ring portion58. The outer ring portion52extends in an arc shape in the circumferential direction from a leading end of the spoke portion51. An end of the outer ring portion52is separated from the spoke portion51by a slit57extending along the radial direction. A power feeding portion53is provided at the end of the outer ring portion52, and the fixed-side contact21is braced to the power feeding portion53. The power feeding portion53protrudes in the axial direction from the end of the outer ring portion52. A groove54is formed in an end surface of the fixed-side longitudinal magnetic-field coil22facing the fixed-side contact21, The inner ring portion58is fixed to the fixed-side electrode rod25.

The fixed-side longitudinal magnetic-field coil22is made of copper, and the fixed-side support24is made of a material having a lower electric conductivity than the fixed-side longitudinal magnetic-field coil22. The fixed-side longitudinal magnetic-field coil22has a higher electric conductivity than the fixed-side support24, so that an electric current more easily flows through the fixed-side longitudinal magnetic-field coil22than through the fixed-side support24. Therefore, an electric current flowing between the fixed-side electrode rod25and the fixed-side contact21more easily flows through a path via the fixed-side longitudinal magnetic-field coil22than through a path via the fixed-side support24.

FIG.6is a diagram illustrating a state in which the fixed-side spacers have been attached to the fixed-side longitudinal magnetic-field coil of the vacuum valve according to the first embodiment and a state in which the movable-side spacers have been attached to the movable-side longitudinal magnetic-field coil of the same. The fixed-side spacers23are fitted into the groove54. Each of the fixed-side spacers23has an H-shaped cross section, which is made of an insulator such as ceramic, or of metal having a lower electric conductivity than copper, such as austenitic stainless steel. The fixed-side spacers23fill axial gaps between the fixed-side longitudinal magnetic-field coil22and the fixed-side contact21, and are in contact with both of the fixed-side longitudinal magnetic-field coil22and the fixed-side contact21. Therefore, the fixed-side contact21is supported by the fixed-side longitudinal magnetic-field coil22not only via the power feeding portion53, but also via the fixed-side spacers23at locations where the fixed-side spacers23are set.

Furthermore, the fixed-side longitudinal magnetic-field coil22is provided with a ridge55formed on the outer peripheral side of the groove54. On the other hand, for the fixed-side contact21, the ridge56formed on the inner peripheral side of a portion with which the fixed-side spacer23is in contact. The ridges55and56are subjected to swaging in such a way as to have the fixed-side spacer23interposed between the ridges55and56. The fixed-side spacers23are not brazed, but are fixed to the fixed-side longitudinal magnetic-field coil22and the fixed-side contact21by the swaging of the ridges55and55.

The movable-side electrode rod35penetrates the movable-side end plate38, and one end of the movable-side electrode rod35protrudes out of the insulation container1. The movable-side support34is attached to another end of the movable-side electrode rod35. The movable-side support34includes a circular disk portion41and a shaft portion42protruding from one surface of the circular disk portion41. The movable-side support34is surrounded by the movable-side longitudinal magnetic-field coil32from the outer peripheral side. The movable-side contact31is brazed to a surface opposite to a surface of the circular disk portion41of the movable-side support34from which the shaft portion42protrudes.

As illustrated inFIG.5, the movable-side longitudinal magnetic-field coil32includes an inner ring portion58, a spoke portion51, and an outer ring portion52. The inner ring portion58is disposed at the central part of the insulation container1in the radial direction. The spoke portion51extends in the radial direction from the inner ring portion58. The outer ring portion52extends in, an arc shape in the circumferential direction from a leading end of the spoke portion51. An end of the outer ring portion52is separated from the spoke portion51by a slit57extending along the radial direction. A power feeding portion53is provided at the end of the outer ring portion52, and the movable-side contact31is brazed to the power feeding portion53. The power feeding portion53protrudes in the axial direction from the end of the outer ring portion52. That is, a groove54is formed in an end surface of the movable-side longitudinal magnetic-field coil32facing the movable-aide contact31. The inner ring portion58is fixed to the movable-aide electrode rod35.

The movable-side longitudinal magnetic-field coil32is made of copper, and the movable-side support34is made of a material having a lower electric conductivity than the movable-side longitudinal magnetic-field coil32. The movable-side longitudinal magnetic-field coil32has higher electric conductivity than the movable-side support34, so that an electric current more easily flows through the movable-side longitudinal magnetic-field coil32than through the movable-side support34. Therefore, an electric current flowing between the movable-side electrode rod35and the movable-side contact31more easily flows through a path via the movable-side longitudinal magnetic-field coil32than through a path via the movable-side support34.

A shield5is provided in the insulation container1. The shield5covers the fixed-side electrode2and the movable-side electrode3from the outer peripheral side. Metal vapor is generated from the fixed-side contact21or the movable-side contact31due to an arc generated between the fixed-side contact21and the movable-side contact31at the time of the opening action. The shield5prevents the metal vapor thus generated from adhering to the insulation container1thereby to deteriorate dielectric strength between the electrodes.

The movable-Bide longitudinal magnetic-field coil32, the movable-side spacer33, and the movable-side contact31have the same structures as the fixed-side longitudinal magnetic-field coil22, the fixed-side spacer23, and the fixed-side contact21, respectively. As illustrated inFIG.6, the movable-side spacers33each having an H-shaped cross section are fitted into the groove54. The movable-side spacers33fill gaps between the movable-side longitudinal magnetic-field coil32and the movable-side contact31, and the movable-side contact31is supported by the movable-side longitudinal magnetic-field coil32not only via the power feeding portion53, but also via the movable-side spacers33at locations where the movable-side spacers33are set.

In addition, ridges55S and56formed on the movable-side longitudinal magnetic-field coil32and the movable-side contact31, respectively, are subjected to swaging in such a way as to have the movable-side spacers33interposed between the ridges5S and56. The movable-side spacers33are not brazed, but are fixed to the movable-side longitudinal magnetic-field coil32and the movable-side contact31by the swaging of the ridges55and56.

When the vacuum valve is assembled, the fixed-side spacers23are fitted into the groove54of the fixed-side longitudinal magnetic-field coil22, and the ridge55on the outer peripheral portion of the fixed-side longitudinal magnetic-field coil22is subjected to swaging to fix the fixed-side spacers23to the fixed-side longitudinal magnetic-field coil22. Furthermore, the fixed-side longitudinal magnetic-field coil22and the fixed-side contact21are in butt-contact with each other, and the ridge56of the fixed-side contact21is subjected to swaging to fix the fixed-side contact21to the fixed-side spacers23. Likewise, for the movable-side longitudinal magnetic-field coil32, the movable-side spacers33, and the movable-side contact31, the movable-side spacers33are fitted into the groove54of the movable-side longitudinal magnetic-field coil32, and the ridges55and56are subjected to swaging to fix the movable-side longitudinal magnetic-field coil32, the movable-side spacers33, and the movable-side contact31. Thereafter, the fixed-side contact21, the fixed-side longitudinal magnetic-field coil22, the fixed-side support24, the fixed-side electrode rod25, and the fixed-side end plate26are partially brazed to form the fixed-side electrode2, and the movable-side contact31, the movable-side longitudinal magnetic-field coil32, the movable-side support34, the movable-side electrode rod35, the bellows cover36, the bellows37, and the movable-side end plate38are partially brazed to form the movable-side electrode3. Then, the shield5, the guide4, the fixed-side electrode and the movable-side electrode3are fitted in the insulation container1, and final brazing is performed thereon.

FIG.7is a cross-sectional view of an electrode unit of a vacuum valve according to a first modification of the first embodiment,FIG.8is an exploded perspective view of the electrode unit of the vacuum valve according to the first modification of the first embodiment. In the first modification of the first embodiment, the ridges55of the fixed-side longitudinal magnetic-field coil22and the movable-side longitudinal magnetic-field coil32are provided on the inner peripheral side of the grooves54. Even when the ridges55are provided on the inner peripheral side of the grooves54, it is possible to fix the fixed-aide spacers23to the fixed-side longitudinal magnetic-field coil22and fix the movable-side spacers33to the movable-side longitudinal magnetic-field coil32by means of swaging of the ridges55.

FIG.9is a cross-sectional view of an electrode unit of a vacuum valve according to a second modification of the first embodiment. In the second modification of the first embodiment, the ridge56of the fixed-side contact21and the ridge56of the movable-side contact31are provided on the outer peripheral side of a portion with which the fixed-side spacers23are in contact and a portion with which the movable-side spacers33are in contact, respectively. Even when the ridges56are provided on the outer peripheral side of the portions with which the fixed-side spacers23and the movable-side spacers33are in contact, it is possible to fix the fixed-side spacers23to the fixed-side contact21and fix the movable-side spacers33to the movable-side contact31by means of swaging of the ridges56.

FIG.10is a cross-sectional view of an electrode unit of a vacuum valve according to a third modification of the first embodiment. In the third modification of the first embodiment, the ridges55of the fixed-side longitudinal magnetic-field coil22and the movable-side longitudinal magnetic-field coil32are provided on the inner peripheral side of the grooves54. Furthermore, the ridge56of the fixed-side contact21and the ridge56of the movable-side contact31are provided on the outer peripheral side of portions with which the fixed-side spacers23and the movable-side spacers33are in contact, respectively. Even when the ridge55is provided on the inner peripheral side of the groove54and the ridge56is provided on the outer peripheral side of the portion with which the fixed-side spacer23or the movable-side spacer33is in contact, it is possible to fix the fixed-aide spacers23to the fixed-side longitudinal magnetic-field coil22and fix the movable-side spacers33to the movable-side longitudinal magnetic-field coil32by means of swaging of the ridges55, and is also possible to fix the fixed-side spacers23to the fixed-side contact21and fix the movable-side spacers33to the movable-side contact31by means of swaging of the ridges56.

In the vacuum valve10according to the first embodiment, the fixed-side contact21is supported by the fixed-aide longitudinal magnetic-field coil22not only via the power feeding portion53, but also via the fixed-side spacers23at the locations where the fixed-side spacers213are placed so that the fixed-side contact21can be stably supported. Similarly, in the vacuums valve10according to the first embodiment, the movable-side contact31is supported by the movable-side longitudinal magnetic-field coil32not only via the power feeding portion53, but also via the movable-side spacers33at the locations where the movable-aide spacers33are placed, so that the movable-side contact31can be stably supported. In the vacuum valve10according to the first, embodiment, the fixed-side contact21is stably supported by the fixed-side longitudinal magnetic-field coil22, and the movable-side contact31is stably supported by the movable-side longitudinal magnetic-field coil32. Therefore, the fixed-side contact21and the movable-side contact31do not tend to tilt at the time of assembly, so that assembly is easier.

In the vacuum valve10according to the first embodiment, the single slit57is provided for the fixed-side longitudinal magnetic-field coil22, and each of the fixed-aide spacers23is made of an insulator or metal material having a lover electric conductivity than the fixed-aide longitudinal magnetic-field coil22. Therefore, it is possible to generate a strong axial magnetic field on substantially the entire circumference of the fixed-side contact21except for a portion around the slit57. Similarly, in the vacuum valve10according to the first embodiment, the single slit57is provided for the movable-side longitudinal magnetic-field coil32, and each of the movable-side spacers33is made of an insulator or metal material having a lover electric conductivity than the movable-side longitudinal magnetic-field coil32. Therefore, it is possible to generate a strong axial magnetic field on substantially the entire circumference of the movable-side contact31except for a portion around the slit57. As a result, the vacuum valve10according to the first embodiment can enhance electric current interruption performance.

In the vacuum valve10according to the first embodiment the fixed-side contact21and the fixed-side longitudinal magnetic-field coil22are fixed via the fixed-side spacers23, and the movable-side contact31and the movable-side longitudinal magnetic-field coil32are fixed via the movable-side spacers33. Therefore, in the vacuum valve10according to the first embodiment, even if the brazing material joining the fixed-side contact21and the fixed-side longitudinal magnetic-field coil22or the brazing material joining the movable-side contact31and the movable-side longitudinal magnetic-field coil32is remelted at the time of final brazing, the fixed-side contact21does not come off the fixed-side longitudinal magnetic-field coil22, and the movable-side contact31does not come off the movable-side longitudinal magnetic-field coil32, so that yield can be improved.

Furthermore, in the vacuum valve10according to the first embodiment, the fixed-side spacers23and the movable-side spacers33are fixed by means of swaging of the ridges S5and56, not by means of brazing: Therefore, even when each of the fixed-side spacers23is made of metal with lower electric conductivity than the fixed-aide longitudinal magnetic-field coil22, or even when each of the movable-side spacers33is made of metal with lower electric conductivity than the movable-side longitudinal magnetic-field coil32, some contact resistance is generated between the fixed-side spacer23and the fixed-side longitudinal magnetic-field coil22, between the fixed-side spacer23and the fixed-side contact21, between the movable-side spacer33and the movable-side longitudinal magnetic-field coil32, and between the movable-side spacer33and the movable-side contact31. Consequently, the vacuum valve10according to the first embodiment can reduce a leakage current that passes through the fixed-side spacers23and a leakage current that passes through the movable-side spacers33, and improve electric current interruption performance.

In addition, since the fixed side contact21, the movable-side contact31, the fixed-side longitudinal magnetic-field coil22, and the movable-side longitudinal magnetic-field coil32are made by like-shaving processing such as rotary cutting and lathe turning, machining cost does not increase even if the ridges55and56are provided. In addition, since the fixed-side longitudinal magnetic-field coil22and the movable-side longitudinal magnetic-field coil32each include only one outer ring portion52, the fixed-side longitudinal magnetic-field coil22and the movable-side longitudinal magnetic-field coil32can be created with a small number of processing steps. Furthermore, it is possible to easily make the fixed-side spacers23and the movable-side spacers33just by dividing a ring having an H-shaped cross section.

Second Embodiment

FIG.11is a cross-sectional view of an electrode unit of a vacuum valve according to a second embodiment.FIG.12is an exploded perspective view of the electrode unit of the vacuums valve according to the second embodiment.FIG.13is a diagram illustrating a state in which a fixed-side spacer has been attached to a fixed-side longitudinal magnetic-field coil of the vacuum valve according to the second embodiment and a state in which a movable-side spacer has been attached to a movable-side longitudinal magnetic-field coil of the same. In the vacuum valve10according to the second embodiment, the fixed-side spacer23and, the movable-side spacer33have each the shape of a ring that is partially missing to form a single absent portion39in which the power feeding portion53is to be set. Except for this point, the vacuum valve10according to the second embodiment is substantially the same as the vacuum valve10according to the first embodiment.

In the vacuum valve10according to the second embodiment, it is possible to easily make the fixed-side spacer23and the movable-side spacer33by cutting a pipe material having been subjected to slit processing so that manufacturing cost can be reduced. In addition, since the fixed-side spacer23and the movable-side spacer33are each singularly provided, it is possible to reduce the number of man-hours for a work of fixing the fixed-side spacer23to the fixed-side longitudinal magnetic-field coil22and a work of fixing the movable-side spacer33to the movable-side longitudinal magnetic-field coil32. In addition, the vacuum valve10according to the second embodiment can achieve substantially the same effects as those of the vacuum valve10according to the first embodiment.

Third Embodiment

FIG.14is a cross-sectional view of an electrode unit of a vacuum valve according to a third embodiment.FIG.15is an exploded perspective view of the electrode unit of the vacuum valve according to the third embodiment.FIG.16is a diagram illustrating a state in which a fixed-side spacer has been attached to a fixed-side longitudinal magnetic-field coil of the vacuum valve according to the third embodiment and a state in which a movable-side spacer has been attached to a movable-side longitudinal magnetic-field coil of the same. In the vacuum valve10according to the third embodiment, the fixed-side spacer23and the movable-side spacer33each have a circular disk shape in which a cut-away portion61is formed, the power feeding portion53is to be set in the cut-away portion61. In the vacuum valve10according to the third embodiment, since the fixed-side spacer23is disposed between the fixed-side contact21and the fixed-side support24, the fixed-side support24and the fixed-side contact21are not in contact with each other. Furthermore, since the movable-side spacer33is disposed between the movable-side contact31and the movable-side support34, the movable-side support.34and the movable-side contact31are not in contact with each other Except for this point, the vacuum valve10according to this embodiment is substantially the same as the vacuum valve10according to the first embodiment.

In the vacuum valve10according to the third embodiment, it is possible to easily make the fixed-side spacer23and the movable-side spacer33by cutting a grooved bar material or by forming the cut-away portion61in a disk by press working, so that manufacturing cost can be reduced. In addition, since the fixed-side spacer23and the movable-side spacer33are each singularly provided, it is possible to reduce the number of man-hours for a work of fixing the fixed-side spacer23to the fixed-side longitudinal magnetic-field coil22and a work of fixing the movable-side spacer33to the movable-side longitudinal magnetic-field coil In addition, the vacuum valve10according to the third embodiment can achieve substantially the same effects as those of the vacuum valve10according to the first embodiment.

The configurations set forth in the above embodiments show just, examples of the contents of the present disclosure, and it is possible to combine each of these configurations with other publicly known techniques, and also possible to omit and/or modify a part of each of the configurations without departing from the scope of the present disclosure.

REFERENCE SIGNS LIST