JP2010040347A - Vacuum switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum switch having a high insulation performance and covered with a solid insulation resin. <P>SOLUTION: The vacuum switch is provided with a vacuum container 2 which is constructed of a fixed electrode 6A, a movable electrode 6B opposed to the fixed electrode 6A, an end plate, and an insulated cylinder having a metal baked face on the jointing face with the end plate, a solid insulation resin 21 which is molded at the outside of the vacuum container 2, a first coil spring 30 which contacts the end plate and the metal baked face of the insulated cylinder and is arranged at the outer circumference of the end plate, and a second coil spring 31 which contacts the first coil spring and is arranged at the outer circumference of the insulated cylinder so as to cover the corner part of the metal baked face of the insulated cylinder. The end plate, the metal baked face of the insulated cylinder, and the first and the second coil springs are electrically connected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vacuum switch and a vacuum insulation switchgear, and more particularly to a vacuum switch and a vacuum insulation switchgear suitable for an insulating mold around a vacuum vessel that houses an opening / closing part.

  The vacuum switch is a switch that uses high vacuum insulation performance, and can achieve downsizing and gasless.

  In some vacuum switches, in addition to the vacuum insulation, there is one in which the insulation performance is enhanced by covering the periphery of the switch container with a solid insulating resin to form a double insulation structure.

  However, when the periphery of the switch case of the vacuum switch is covered with a solid insulating resin, the electric field concentrates on the end of the insulating cylinder constituting the switch case, and dielectric breakdown tends to occur.

  Therefore, there is one described in Patent Document 1 as a vacuum switch in which the periphery of the switch container is covered with a solid insulating resin and the electric field concentration at the end of the insulating cylinder is reduced.

  In Patent Document 1, a fixed electrode and a movable electrode are housed inside, and both ends of a spiral spring formed of a conductive metal or resin are connected to the end of an insulating cylinder constituting a vacuum vessel. There is disclosed a vacuum switch in which electric field relaxation shields having a shape are disposed and these are covered with a mold to reduce electric field concentration on the end of an insulating cylinder.

Japanese Patent Laying-Open No. 2005-197061

  However, in the structure disclosed in Patent Document 1, the doughnut-shaped electric field relaxation shield is disposed at the end of the insulating cylinder, but because it is a donut shape in which both ends of one spiral spring are connected, There is a problem that the corner portion of the end portion of the insulating cylinder where the electric field is most concentrated cannot be covered, and the electric field is concentrated on the corner portion of the end portion of the insulating cylinder, which may cause dielectric breakdown.

  Therefore, an object of the present invention is to provide a vacuum switch and a vacuum insulated switchgear that prevent the electric field from concentrating on the corners of the end of the insulating cylinder and prevent breakdown.

  In order to achieve the above object, a vacuum switch according to the present invention includes a fixed electrode, a movable electrode facing the fixed electrode, an insulating cylinder, and an end plate that covers both ends of the insulating cylinder in the axial direction. A vacuum vessel that houses the electrode and the movable electrode therein, a solid insulating resin molded on the outside of the vacuum vessel, and an end plate that is in contact with the end face of the end plate and the insulating cylinder and disposed on the outer periphery of the end plate. A first coil spring and a second coil spring that is bound to the first coil spring and is disposed on an outer periphery of the insulating cylinder so as to cover a corner of the end surface of the insulating cylinder, and the end plate and the insulating cylinder The first end face and the first and second coil springs are electrically connected.

  In order to achieve the above object, a vacuum insulated switchgear according to the present invention includes a vacuum switch having the above-described configuration, an operating mechanism for operating the vacuum switch, and a bus for supplying power to the vacuum switch. And a power cable connected to the vacuum switch and supplying power to the load side.

  According to the vacuum switch and the vacuum insulated switchgear of the present invention, since the corner portion of the end of the insulating cylinder can be covered with the second coil spring, the electric field is not concentrated on this portion, so that the insulation breakdown does not occur. The effect that reliability becomes high is acquired.

  A first embodiment of a vacuum switch according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the vacuum switch 1 of the present embodiment includes a vacuum vessel 2, fixed and movable electrodes 6 </ b> A and 6 </ b> B disposed in the vacuum vessel 2, and a solid insulating resin 21 that covers the periphery of the vacuum vessel 2. And is roughly composed of

  The vacuum vessel 2 is connected to the fixed side ceramic insulating cylinder 2A, the movable side ceramic insulating cylinder 2B connected to the fixed side ceramic insulating cylinder 2A, and the axially fixed side end of the fixed side ceramic insulating cylinder 2A. The metal fixed side end plate 3A, which is thinner than 2A and 2B, and the metal movable side end plate 3B connected to the axially movable side end of the movable side ceramic insulating cylinder 2B, the interior is high. Keep in vacuum. Metal bonding (metallization) with good compatibility with metal is applied to the joining surfaces of both insulating cylinders 2A and 2B with both end plates 3A and 3B in order to join with both metallic end plates 3A and 3B. ing.

  Inside the vacuum vessel 2, a fixed electrode 6A and a movable electrode 6B that is movable in the axial direction facing the fixed electrode 6A are arranged. The fixed electrode 6A is a fixed-side end plate 3A that constitutes the vacuum vessel 2. The movable electrode 6B is held at the tip of the movable electrode rod 7B communicating in the axial direction with the movable side end plate 3B constituting the vacuum vessel 2, respectively. . A movable side conductor 10 is connected to an end of the movable side electrode rod 7B opposite to the one where the movable electrode 6B is held in the axial direction, and is electrically connected to one of the bus side or the load side. Connected to. A fixed-side conductor 11 whose periphery is covered with a solid insulating resin 22 is connected to an end of the fixed-side electrode rod 7A opposite to the one where the fixed electrode 6A is held. It is electrically connected to the other load side. The movable-side electrode rod 7B is moved up and down in the axial direction in the drawing by an operating device (not shown) to move the movable electrode 6B to realize an open / closed / disconnected position with the fixed electrode 6A.

  A bellows 9 supported by the movable side end plate 3B is disposed around the movable side electrode rod 7B so that the vacuum state in the vacuum vessel 2 can be maintained even when the movable side electrode rod 7B moves up and down in the axial direction. ing. A bellows shield 8 is movable around the bellows 9 to prevent the metal particles scattered by the arc generated between the electrodes during the opening / closing operation from adhering to the bellows 9 and to reduce the electric field concentration at the end of the bellows 9. The side electrode rod 7B is supported and arranged. In addition, an arc shield 5 is provided around the fixed and movable electrodes 6A and 6B so as to prevent metal fine particles scattered in the arc generated during the opening / closing operation or the like from adhering to the inner surface of the vacuum vessel 2 and deteriorating the insulation performance. Arranged and supported by a ceramic insulating cylinder. Moreover, in order to relieve the electric field concentrated on the ends of the metal baking surfaces of the fixed and movable ceramic insulating cylinders 2A and 2B inside the vacuum vessel 2, the metal baking surfaces of the fixed and movable ceramic insulating cylinders 2A and 2B. The fixed-side electric field relaxation shield 4A and the movable-side electric field relaxation shield 4B are disposed in the vicinity of the inner peripheral surface of the end of the first and second ends, and are supported by the fixed-side and movable-side end plates 3A and 3B.

  The outside of the vacuum vessel 2 configured as described above is covered with a solid insulating resin 21 such as epoxy. Further, on the outer periphery of the fixed-side and movable-side ceramic insulating cylinders 2A and 2B, heat between the ceramic and the solid-insulating resin is provided on the outer periphery of the ceramic-insulating resin 2 in order to mitigate stress concentration based on the difference in thermal shrinkage between the ceramic and the solid insulating resin 21. A cushioning material 20 having a shrinkage rate and softer than ceramics and resin that is solid-insulated is disposed.

  And in this embodiment, in order to relieve the electric field concentrated on the outer corner of the metal baking, which is the joint between the fixed and movable ceramic insulating cylinders 2A and 2B and the fixed and movable end plates 3A and 3B. A metal first coil spring 30 and a second coil spring 31 are arranged so as to cover the corners.

  The arrangement of the first coil spring 30 and the second coil spring 31 will be described with reference to FIGS.

  As shown in FIG. 2, the first coil spring 30 is formed by spirally winding a metal wire-like member into a donut shape, and its end is bound by winding a binding wire 40 as shown in FIG. ing. FIG. 4 shows a state in which the first coil spring 30 is bundled with a second coil spring 31 having a larger natural radius than the first coil spring 30. As shown in FIG. By carrying out in 4 places, the solid bundling is realized.

  Here, the circumferential length of the first coil spring 30 defined in the drawing of FIG. 2 is shorter than the outer circumferential length of the end plate in the natural state, and the circumferential length of the second coil spring 31 is natural. In this state, it is shorter than the outer circumferential length of the ceramic insulating cylinder.

  Next, how to attach the bound first coil spring 30 and second coil spring 31 will be described with reference to FIG. FIG. 5 is an enlarged view of the end of the fixed ceramic insulating cylinder 2A in FIG.

  First, before the solid insulation is performed and the cushioning material 20 is disposed on the outer periphery of the fixed-side ceramic insulating cylinder 2A, the first coil spring 31 having a large natural state radius from the fixed side is first placed. When the coil spring 30 and the second coil spring 31 are pushed into the fixed side end plate 3A, the circumferential length of the second coil spring 31 is shorter than the length of the outer periphery of the fixed ceramic insulating cylinder 2A in the natural state. Since the circumferential length of the first coil spring 30 is naturally shorter than the outer circumference of the fixed-side end plate 3A, the second coil spring 31 is positioned on the outer circumference of the fixed-side ceramic insulating cylinder 2A, and the first coil spring 30 is When positioned on the outer periphery of the fixed-side end plate 3A, the first coil spring 30 and the second coil spring 31 are expanded.

  Finally, the first coil spring 30 comes into contact with the outer peripheral surface of the fixed-side end plate 3A and the metal baking surface at the end of the fixed-side ceramic insulating cylinder 2A, and the first coil spring 30 and the second coil spring 31 The fixed ceramic insulating cylinder 2A is stopped at a position where the corner is covered. At this time, since the first coil spring 30 and the second coil spring 31 are fixed in an expanded state from the natural length, a contraction force works and does not easily move from the position. At that position, the conductive adhesive 36 is applied and fixed. As a result, the fixed end plate 3 </ b> A and the first coil spring 30, and the second coil spring 31 bound to the first coil spring 30 are electrically connected.

  Also on the movable side, the first coil spring 30 and the second coil spring 31 are arranged and fixed in the same procedure, and the first coil spring 30 and the second coil spring 31 are fixed, and then molded with the solid insulating resin 21.

  According to the vacuum switch of the present embodiment described above, the first coil spring 30 is in contact with the outer peripheral surface of the fixed-side end plate 3A and the metal baking surface at the end of the fixed-side ceramic insulating cylinder 2A. The fixed ceramic insulating cylinder 2 </ b> A is covered with a first coil spring 30 and a second coil spring 31 bound to the first coil spring 30.

  As a result, the fixed side end plate 3A equal to the system potential, the first coil spring 30 and the second coil spring 31 covering the corners of the end portion of the fixed side ceramic insulating cylinder 2A, and metal baking of the fixed side ceramic insulating cylinder 2A are performed. They are electrically connected and each equals the system potential.

  Therefore, the electric field concentration at the corner of the end portion of the fixed ceramic insulating cylinder 2A can be alleviated, and even when a high voltage is applied, partial discharge is less likely to occur and dielectric breakdown does not occur. Further, the first coil spring 30 and the second coil spring 31 are spiral metal wire members, which have many gaps and do not form a continuous narrow gap. Therefore, the first coil spring 30 and the second coil spring 31 are molded with the solid insulating resin 21. At this time, the flow of the resin is not hindered, so that voids are not easily formed, and deterioration of the insulation performance can be prevented.

  In addition, since a metal coil spring is used in the present embodiment, it has higher heat resistance and can withstand the high temperature during molding, for example, compared to the case where a conductive resin is disposed.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the second embodiment shown in FIG. 6, in addition to the first coil spring 30 and the second coil spring 31 used in the first embodiment, a new third coil spring 32 made of metal is newly added to the second coil spring 31. They are provided above and are bound together in the same manner as in FIG. Since the first coil spring 30 is electrically connected to the fixed side end plate 3A, the first coil spring 30, the second coil spring 31, the third coil spring 32, the fixed side end plate 3A and the fixed side ceramic insulation are used. The metal baking surface at the end of the cylinder 2A is electrically connected.

  As a result, the distribution of equipotential lines can be broadened at the corners of the end portion of the fixed ceramic insulating cylinder 2A to reduce the density of equipotential lines compared to the first embodiment. This can be further relaxed compared to the examples.

  Although the description has been given by taking the fixed side as an example here, the third coil spring 32 can be similarly bound to the second coil spring 31 on the movable side, and the above-described effects can be achieved.

  A third embodiment of the present invention will be described with reference to FIG.

  In the third embodiment shown in FIG. 7, instead of the fixed side end plate 3A in the vacuum switch 1 described in the first embodiment, a fixed side end plate 103A having a recess 104A is used.

  That is, the fixed-side end plate 103A is formed with a concave portion 104A recessed inward in the vicinity of the connection position with the fixed-side ceramic insulating cylinder 2A, and the first coil spring 30 is disposed in the concave portion 104A.

  The axial width of the recess 104A is preferably equal to or smaller than the axial thickness of the first coil spring 30, and the depth is preferably sufficient to fit the first coil spring 30.

  In the present embodiment, the same effects as those of the first embodiment described above can be obtained, and the concave portion 104A is formed in the fixed end plate 103A, so that the first coil spring 30 is fitted into the concave portion. The first coil spring 30 can be reliably fixed.

  Although only the fixed side has been described here, the first coil spring 30 can be reliably fixed by forming a similar concave portion on the movable side end plate 103B.

  A fourth embodiment of the present invention will be described with reference to FIG.

  In the fourth embodiment shown in FIG. 8, instead of the fixed side end plate 103A described in the third embodiment, a fixed side end plate 203A in which a thin portion 204A is partially formed is used.

  That is, the fixed-side end plate 203A is formed by forming a portion where the concave portion 104A in the third embodiment is formed by a thin-walled portion 204A that is thinner than the other fixed-side end plate 203, and the thin-walled portion 204A has a first portion. The coil spring 30 is arranged.

  The axial width of the thin wall portion 204A is preferably equal to or less than the axial thickness of the first coil spring 30 in order to dispose the first coil spring 30.

  In the present embodiment, the same effects as those of the first embodiment described above can be obtained, and the first coil spring 30 is fitted to the thin portion 204A by forming the thin portion 204A on the fixed side end plate 203A. The first coil springs 30 can be reliably fixed together.

  Although only the fixed side has been described here, the first coil spring 30 can be reliably fixed by forming the same thin portion also on the movable side end plate 203B.

  A fifth embodiment of the present invention will be described with reference to FIG.

  In the fifth embodiment shown in FIG. 9, the outer side of the fixed-side end plate 3A in the first embodiment does not contact the metal baking surface of the fixed-side ceramic insulating cylinder 2A, but overlaps with other portions. A spring fixing plate 37 is disposed, and the first coil spring 30 is disposed in a portion where the spring fixing plate 37 does not overlap the fixed side end plate 3A. The first coil spring 30 is hooked on the outer peripheral end of the spring fixing plate 37, and is strongly fixed between the spring fixing plate 37 and the metal baking surface of the fixed ceramic insulating cylinder 2A. By using the spring fixing plate 37 having a length that the spring fixing plate 37 covers the axial direction of the fixed side end plate 3A and a thickness at a point where the spring fixing plate 37 is in contact with the first coil spring 30, the degree of catching of the first coil spring 30 can be increased. Can be adjusted.

  That is, the length in which the spring fixing plate 37 covers the axial direction of the fixed side end plate 3A is made equal to or less than the axial length of the first coil spring 30 to make contact with the first coil spring 30 in the spring fixing plate 37. The first coil spring 30 can be strongly fixed by increasing the thickness at the point to be performed. At this time, the distance between the spring fixing plate 37 to which the first coil spring 30 is hooked and the fixed side end plate 3 </ b> A is preferably equal to or less than the axial thickness of the first coil spring 30.

  A sixth embodiment of the present invention will be described with reference to FIG.

  In the second embodiment described above, the circumferential lengths of the first coil spring 30 to the third coil spring 32 are changed. In the present embodiment shown in FIG. 10, the first coil spring 30 to the third coil spring 30 are changed. The circumferential lengths of the coil springs 32 are all made equal. Thereby, it is not necessary to distinguish between the first coil spring 30 to the third coil spring 32, and it is sufficient to manufacture only one type of coil spring, so that the manufacturing cost is reduced. Moreover, when attaching a coil spring, there is no restriction | limiting by which coil spring of the 1st coil spring 30 or the 3rd coil spring 32 puts first, and an assembly property improves.

  In the present embodiment, the case where there are three coil springs has been described. However, even if there are two coil springs, the same effect can be achieved by making the circumferential lengths equal.

  A seventh embodiment of the present invention will be described with reference to FIG.

  In the first to sixth embodiments, the end portions of the coil springs are bound by using the binding wire 40. However, in this embodiment, the end portions of the first coil spring 30 are bound and welded together. ing. By end-to-end welding, the terminal end of the coil spring does not exist in the binding portion 42 and the binding wire 40 does not need to be used, so electric field concentration such as the end portion of the coil spring or the end portion of the binding wire is likely to occur. A site does not occur and electric field concentration can be relaxed.

  Although the first coil spring 30 has been described as an example, it is needless to say that the first coil spring 30 can also be applied to the second and third coil springs 31 and 32.

  An eighth embodiment of the present invention will be described with reference to FIG.

  In the eighth embodiment shown in FIG. 12, hooks 35X and 35Y are formed at the end of the first coil spring 30, and the two hooks 35X and 35Y are bound together. Further, the binding positions of the first coil spring 30 to the third coil spring 32 are shifted.

  According to the present embodiment, the end portions can be bound by hooking the coil spring with the hook, so that the assemblability is improved. Further, by shifting the binding position of the plurality of coil springs, other than the ends of the other coil springs are located in the vicinity of the end of the hook where the electric field tends to concentrate, and the electric field concentration at the end of the hook can be mitigated. .

  Next, an embodiment in which the vacuum switch described in the first embodiment is mounted on a vacuum insulated switchgear will be described with reference to FIG.

  As shown in FIG. 13, the vacuum insulation switch gear 66 of this embodiment supplies power to the switch unit 50, operation mechanisms 53 and 54 for operating the switches in the switch unit 50, and the switch unit 50. A three-phase bus 60, a load cable 61 connected to the switch unit 50 and supplying power to the load side, a current transformer 62 installed on the load cable 61, and an upper part in the vacuum insulated switchgear. Main instrument room 67.

  The switch unit 50 is provided with two contact points for interrupting / disconnecting (two-point cut) in a single vacuum vessel, and is connected to the load side via the vacuum switch 51 and a conductor. And a solid insulating resin 21 in which these are integrally molded. First and second coil springs 30 and 31 are disposed in the vacuum switch 51 and the ground switch 52, respectively. Among the operation mechanisms, the operation mechanism 53 is an operation mechanism for a blocking / disconnection unit, and the operation mechanism 54 is an operation mechanism for a ground opening / closing unit.

  According to the present embodiment, a vacuum insulated switchgear having high insulation reliability is provided by using the switch unit 50 having improved insulation performance by arranging the first coil spring 30 and the second coil spring 31. can do.

  In addition, it cannot be overemphasized that any structure of each embodiment mentioned above can be employ | adopted for the vacuum insulation switchgear which concerns on this embodiment.

  In each of the above embodiments, only two or three coil springs have been described. However, the present invention can be applied to a case where four or more coil springs are bound. In such a case, the interval between the equipotential lines at the corners of the insulating cylinder can be widened, and the electric field concentration at the corners of the insulating cylinder can be reduced.

  Next, an embodiment different from the above-described embodiment in which the vacuum switch described in the first embodiment is mounted on a vacuum insulated switchgear will be described with reference to FIG. Since the vacuum insulation switchgear 166 according to the present embodiment has the same configuration except for the above-described embodiment and the switch unit 150 described with reference to FIG. 13, detailed description thereof is omitted here.

  The switch unit 150 is provided with two contact points for interrupting / disconnecting (two-point cut), and the vacuum switches 151A and 151B in which the contacts are housed in separate vacuum containers for each contact, the vacuum switches 151A and 151B, and the conductor The earthing switch 52 is connected to the load side via a solid insulating resin 21 molded integrally with these. In the vacuum switches 151A and 151B and the ground switch 52, first and second coil springs 30 and 31 are arranged for the respective switches.

  The switch unit 150 may have, for example, a two-point cut configuration as in this embodiment, and a vacuum container may be provided for each contact. In such a case, there is an advantage that the degree of freedom of production increases.

  Similar to the above-described vacuum insulated switchgear embodiment, in this embodiment, the first coil spring 30 and the second coil spring 31 are disposed, and the switch unit 50 with improved insulation performance is used, so that the insulation reliability is improved. High vacuum insulation switchgear can be provided.

  Needless to say, any of the configurations of the above-described embodiments can be employed in the vacuum-insulated switchgear according to the present embodiment as in the above-described embodiments of the vacuum-insulated switchgear.

  In each of the above embodiments, only two or three coil springs have been described. However, the present invention can be applied to a case where four or more coil springs are bound. In such a case, the interval between the equipotential lines at the corners of the insulating cylinder can be widened, and the electric field concentration at the corners of the insulating cylinder can be reduced.

It is an axial sectional view showing a first embodiment of a vacuum switch of the present invention. It is a figure which shows the coil spring employ | adopted as the 1st Embodiment of this invention. FIG. 4 is a partial enlarged view showing a binding state at the coil spring end portion shown in FIG. 3. It is a figure which shows the state which bound two coil springs from which the circumference length employ | adopted as the 1st Embodiment of this invention differs. It is the fragmentary sectional view which expanded the stationary-side ceramic insulation cylinder in FIG. It is the fragmentary sectional view which expanded the stationary side ceramic insulation cylinder which shows the 2nd Embodiment of this invention. It is the fragmentary sectional view which expanded the stationary ceramic insulation cylinder which shows the 3rd Embodiment of this invention. It is the fragmentary sectional view which expanded the stationary side ceramic insulation cylinder which shows the 4th Embodiment of this invention. It is the fragmentary sectional view which expanded the stationary side ceramic insulation cylinder which shows the 5th Embodiment of this invention. It is a figure which shows the 6th Embodiment of this invention and shows the state which bound three coil springs with equal circumferential length. It is the elements on larger scale which show the other example of the binding of the coil spring which is the 7th Embodiment of this invention. It is the elements on larger scale which show the other example in which the three coil springs which are the 8th Embodiment of this invention are bundled. It is a figure which shows the vacuum insulation switchgear carrying the vacuum switch in the 1st Embodiment of this invention partially partially, and shows it. It is a figure which partially shows another vacuum insulation switchgear carrying the vacuum switch in the 1st Embodiment of this invention.

Explanation of symbols

1, 51, 151A, 151B Vacuum switch 2A Fixed ceramic insulating cylinder 2B Movable ceramic insulating cylinder 3A, 103A, 203A Fixed end plate 3B, 103B, 203B Movable end plate 4A Fixed side electric field relaxation shield 4B Movable electric field Relaxation shield 5 Arc shield 6A Fixed electrode 6B Movable electrode 7A Fixed side electrode rod 7B Movable side electrode rod 8 Bellows shield 9 Bellows 10 Movable side conductor 11 Fixed side conductor 20 Buffer material 21, 22 Solid insulating resin 30 First coil spring 31 First coil spring 31 Second coil spring 32 Third coil spring 35X, 35Y Hook 36 Conductive adhesive 37 Spring fixing plate 40, 41 Bundling wire 42 Bundling section 50, 150 Switch unit 52 Grounding switch 53, 54 Operation mechanism 60 Bus 61 Load cable 62 Change Fluidizer 66,166 Vacuum insulation switchgear 67 Instrument room 1 04 Recessed portion 204 Thin portion

Claims (14)

  A fixed electrode; a movable electrode facing the fixed electrode; an insulating cylinder; and an end plate that covers both axial ends of the insulating cylinder; a vacuum vessel that houses the fixed electrode and the movable electrode; and the vacuum A solid insulating resin molded on the outside of the container; a first coil spring disposed on an outer periphery of the end plate in contact with the end plate and an end surface of the insulating cylinder; A second coil spring disposed on the outer periphery of the insulating cylinder so as to cover a corner portion of the end face of the cylinder, and the end plate, the end face of the insulating cylinder, and the first and second coil springs are electrically connected. A vacuum switch characterized by   In Claim 1, metal baking is given to the axial direction end face of the insulating cylinder, and the end plate thinner than the insulating cylinder is joined to the end face of the insulating cylinder subjected to the metal baking. A featured vacuum switch.   3. The third coil spring bound to the second coil spring is disposed on the outer periphery of the insulating cylinder according to claim 1, and the third coil spring is electrically connected to the second coil spring. A vacuum switch characterized by   The vacuum switch according to claim 1 or 2, wherein a concave portion recessed inward is formed in the vicinity of a joint surface of the end plate with the insulating tube, and the first coil spring is disposed in the concave portion. .   3. The thin plate according to claim 1, wherein a thin portion having a thickness smaller than other portions is formed in the vicinity of the insulating tube of the end plate, and the first coil spring is disposed in the thin portion of the end plate. Vacuum switch to be used.   3. The end plate according to claim 1, wherein a spring fixing plate is arranged outside the end plate so as not to overlap in the vicinity of the end surface of the insulating cylinder but to overlap in other portions, and the spring fixing plate does not overlap. A vacuum switch having the first coil spring fixed thereon.   7. The vacuum switch according to claim 1, wherein a circumferential length of the first coil spring is shorter than a circumferential length of the second and third coil springs.   7. The vacuum switch according to claim 1, wherein circumferential lengths of the respective coil springs are made equal.   9. The vacuum switch according to claim 1, wherein each of the coil springs is formed in a donut shape by spirally winding a metal wire-like member, and an end portion thereof is bound by a binding wire. .   9. The vacuum switch according to claim 1, wherein each of the coil springs is formed in a donut shape by spirally winding a metal wire-like member, and ends thereof are joined by welding.   9. Each of the coil springs according to claim 1, wherein each of the coil springs is formed by spirally winding a metal wire-like member into a donut shape, and an end thereof is bound by a hook, and at least the first coil spring and the first coil spring are combined. 2. A vacuum switch characterized in that the coil spring of 2 is displaced in the binding position by the hook.   The vacuum switch according to any one of claims 1 to 11, an operating mechanism for operating the vacuum switch, a busbar for supplying power to the vacuum switch, and the vacuum switch connected to the load side. A vacuum insulated switchgear comprising a power cable for supplying power.   13. The vacuum insulated switchgear according to claim 12, wherein the vacuum switch is provided with a contact point between a fixed electrode and a movable electrode in one vacuum vessel.   13. The vacuum insulated switchgear according to claim 12, wherein the vacuum switch is provided with a contact point between the fixed electrode and the movable electrode in a separate vacuum container for each contact point.

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