Vacuum valve and production method therefor

Abstract

A vacuum valve according to the present disclosure comprises: a pair of electrodes (1) composed of a fixed-side electrode (2) and a movable-side electrode (3) disposed facing each other in one direction; a cylindrical insulating container (10) disposed around the electrodes (1); a pair of end plates (20) joined to end surfaces of the insulating container (10) and vacuum-sealing the inside of the insulating container (10); and a metallized layer (40) formed on a joint portion (30) where the insulating container (10) and the end plates (20) are joined. At least one among the insulating container (10) and the end plates (20) is formed with a contact portion (50) that covers an inner edge portion (41) of the metallized layer (40) by bringing the insulating container (10) and the end plates (20) into contact with each other in order to mitigate an electric field at the inner edge portion (41).

Description

Vacuum valve and method for manufacturing the same

[0001] This disclosure relates to a vacuum valve and a method for manufacturing the same.

[0002] A vacuum valve is known in which a fixed end plate and a movable end plate are attached to each end of a cylindrical insulating container made of alumina ceramics or the like, so as to be coaxial with the insulating container, and a fixed electrode rod and a movable electrode rod are positioned inside the insulating container, passing through the center of each end plate. In such a vacuum valve, each end plate and the insulating container are joined by brazing, mainly using silver-based brazing material, so a metallized layer is formed at the end of the insulating container.

[0003] The metallized layer is extremely thin, and its edge is a triple point where the conductor, insulator, and vacuum or external atmosphere intersect. Therefore, when a high voltage is applied to a vacuum valve, the electric field at the metallized layer edge becomes higher than at other parts, making it prone to becoming the starting point for surface discharge. Such metallized layer edges exist both inside and outside the vacuum valve. However, for the metallized layer edge on the outside of the vacuum valve, surface discharge originating from the metallized layer edge can be prevented by using high-pressure gas as the external atmosphere, covering it with a solid insulator such as resin, or installing a corona ring to mitigate the electric field.

[0004] On the other hand, regarding the edge of the metallized layer inside the vacuum valve, since the occurrence of surface discharge cannot be prevented by the countermeasures from the outside of the vacuum valve as described above, it is necessary to use a vacuum valve having a structure capable of suppressing the occurrence of surface discharge starting from the edge of the metallized layer inside the vacuum valve. As an example of a vacuum valve having such a structure, in Patent Document 1, a vacuum valve is disclosed in which an electric field relaxation shield having the same potential as the metallized layer is provided in the vicinity of the edge of the metallized layer to relax the electric field of the edge of the metallized layer inside the vacuum valve. However, in such a vacuum valve, there is a risk that the tip of the electric field relaxation shield becomes a high electric field and becomes a starting point for new surface discharge. Therefore, in Patent Document 2, a vacuum valve is disclosed in which a layer having a low secondary electron emission coefficient is provided on the inner surface of the insulating container in the vicinity of the metallized layer to prevent partial discharge generated in the metallized layer or the electric field relaxation shield from reaching surface discharge.

[0005] Japanese Unexamined Patent Application Publication No. 2013 - 80647 Japanese Unexamined Patent Application Publication No. 2019 - 110010

[0006] In the vacuum valve disclosed in Patent Document 1 described above, since a new electric field relaxation shield is provided to suppress the occurrence of surface discharge starting from the edge of the metallized layer, there are problems that the number of parts increases and the tip of the electric field relaxation shield becomes a high electric field and becomes a starting point for surface discharge. Further, in the vacuum valve disclosed in Patent Document 2, by newly providing a layer having a low secondary electron emission coefficient on the inner surface of the insulating container, the progression from partial discharge starting from the edge of the metallized layer and the tip of the electric field relaxation shield to surface discharge is suppressed, but there is a problem that the processing steps for forming a film of a material having a low secondary electron emission coefficient increase and the vacuum valve becomes expensive.

[0007] The present disclosure has been made to solve the above problems, and provides an inexpensive vacuum valve capable of improving the withstand voltage performance while suppressing an increase in cost.

[0008] The vacuum valve according to this disclosure comprises a pair of electrodes consisting of a fixed electrode and a movable electrode arranged facing each other in one direction, a cylindrical insulating container arranged around the electrodes, a pair of end plates joined to the end face of the insulating container to seal the inside of the insulating container with a vacuum, and a metallized layer formed at the joint where the insulating container and the end plates are joined, wherein at least one of the insulating container and the end plates has a contact portion formed thereon that covers the inner edge portion by bringing the insulating container and the end plate into contact in order to mitigate the electric field at the inner edge portion of the metallized layer.

[0009] In the vacuum valve according to this disclosure, a contact portion is formed by bringing the insulating container and the end plate into contact to cover the inner edge portion of the metallized layer in order to mitigate the electric field at the inner edge portion, thereby suppressing the occurrence of surface discharge inside the vacuum valve. As a result, it is possible to manufacture an inexpensive vacuum valve while suppressing an increase in cost and improving the withstand voltage performance.

[0010] This is a cross-sectional view of a vacuum valve according to Embodiment 1. This is an enlarged view of the2. This is an enlarged view of the vacuum valve according to Embodiment 2. This is an enlarged view of the vacuum valve according to Embodiment 3. This is an enlarged view of the vacuum valve according to Embodiment 3. This is an enlarged view of the vacuum valve according to Embodiment 4.

[0011] The embodiments will be described in detail below with reference to the drawings. Note that the embodiments described below are illustrative examples. Furthermore, each embodiment can be combined as appropriate.

[0012] Embodiment 1. A vacuum valve according to Embodiment 1 will be described using Figures 1 to 6. First, an example of the configuration of the vacuum valve according to Embodiment 1 shown in Figures 1 and 2 will be described. Figure 1 is a cross-sectional view of the vacuum valve, and Figure 2 is an enlarged view of the area X shown by the dashed line in Figure 1. The vacuum valve comprises an insulating container 10, an electrode 1, an end plate 20, a metallized layer 40, and a contact portion 50.

[0013] The electrode 1 is a pair of electrodes consisting of a fixed electrode 2 and a movable electrode 3 arranged opposite each other in one direction A. Here, the fixed electrode 2 is provided at the end of the fixed electrode rod, and the movable electrode 3 is provided at the end of the movable electrode rod, with the fixed electrode 2 and movable electrode 3 provided at the ends of each electrode rod being arranged opposite each other. The direction perpendicular to the one direction A in which the pair of electrodes 1 are arranged opposite each other is called the radial direction, and in Figure 1, the radial direction is the direction indicated by arrow B. The insulating container 10 is a cylindrical member arranged around the electrode 1 and is made of alumina ceramics or the like. An arc shield 5 is provided on the inner surface of the insulating container 10 so as to cover the fixed electrode 2 and the movable electrode 3.

[0014] The end plate 20 is a pair of end plates 20 consisting of a fixed end plate 21 and a movable end plate 22, which are joined to the end faces of the insulating container 10 to seal the inside of the insulating container 10 with a vacuum. The end plate 20 consists of a cylindrical portion 23 and a disc portion 24 connected to the inside of the cylindrical portion 23, and for example, a deep dish shape may be used. In the cylindrical portion 23, the end plate 20 is joined to the insulating container 10. In addition, a hole is formed in the center of the disc portion 24 of the end plate 20 for passing the fixed electrode rod and the movable electrode rod, and the fixed electrode rod and the movable electrode rod, which are positioned to pass through this hole, are joined to the end plate 20, respectively.

[0015] Brazing is primarily used to join the insulating container 10 to the end plate 20, and to join the electrode rod to the end plate 20, using silver-based brazing material. When joining the insulating container 10 to the end plate 20, the central axis of the cylindrical insulating container 10 and the central axis of the cylindrical portion 23 of the end plate 20 are arranged to be coaxial, and the end plate 20 is brazed to the end face of the insulating container 10. When joining the electrode rod to the end plate 20, the fixed electrode rod is brazed to the disc portion 24 of the fixed end plate 21, and the movable electrode rod is brazed to the disc portion 24 of the movable end plate 22 via a bellows 4. Furthermore, the electrodes 1 provided at the ends of the fixed electrode rod and the movable electrode rod are also brazed to the fixed electrode rod and the movable electrode rod, respectively.

[0016] At the end of the insulating container 10, a joint 30 is provided on the outer circumference of the end face of the insulating container 10, where the insulating container 10 and the cylindrical portion 23 of the end plate 20 are brazed together, and a first projection 11 protruding in one direction A is formed on the inner circumference of the end face of the insulating container 10. Here, the end face of the insulating container 10 refers to the surface extending radially B formed at the end of the insulating container 10. A metallized layer 40 is formed on the joint 30 in order to braze the insulating container 10 and the end plate 20 together. Inside the vacuum valve, the metallized layer 40 is formed so as to extend radially B inward from the joint 30 on the outer circumference of the end face of the insulating container 10.

[0017] When the inner edge portion, which is the inner end of the metallized layer 40, is provided on the outer end face of the insulating container 10, it is difficult to bring the inner edge portion and the outer surface of the first projection 11 into close contact, resulting in a gap between them, and the inner edge portion of the metallized layer 40 and the insulating first projection 11 face each other at close range. In this case, the inner edge portion, which is the end of the extremely thin metallized layer 40, is formed to protrude toward the electrode 1, and it faces the first projection 11 of the insulating container 10, which is a dielectric made of alumina ceramics, so there is a risk that the electric field of the inner edge portion will become strong. Therefore, as shown in Figure 2, by forming the inner edge portion 41 on the outer surface of the first projection 11, the inner edge portion 41 is in close contact with the outer surface of the first projection 11, the inner edge portion 41 does not face toward the electrode 1, and the inner edge portion 41 and the dielectric first projection 11 do not face each other, so the electric field of the inner edge portion 41 can be mitigated. Therefore, in order for the inner edge portion 41 to be formed on the outer surface of the first projection 11, it is preferable that the metallized layer 40 is formed to extend from the joint portion 30 to the outer surface of the first projection 11.

[0018] When a high voltage is applied to electrode 1, there is a risk of surface discharge occurring on the inner surface of the insulating container 10 between the fixed end plate 21 and the movable end plate 22, which are a pair of end plates 20, and the inner edge portion 41 of the metallized layer 40 is likely to be the starting point for such surface discharge. Surface discharge occurs when desorbed gas generated from the surface of the insulating container 10, which is an insulator, becomes plasma and forms a conductive channel. In the vacuum valve according to this embodiment, the first projection 11, which is an insulator, rises up like a wall from the inner edge portion 41 or the second projection 25 of the metallized layer 40, which is the starting point for discharge. Therefore, when attempting to form a conductive channel from the inner surface of the first projection 11 through the top surface to the outer surface, the conductive channel becomes an unnatural shape with two bends of approximately 90°, making it difficult to form. Furthermore, even if it is temporarily formed, it is likely to break at the bent corner, making it impossible to stably form a conductive channel. Accordingly, this first projection 11 inhibits the formation of a conductive channel from the inner surface through the top surface to the outer surface, thereby suppressing the occurrence of surface discharge.

[0019] As such a contact portion 50, the end plate 20 shown in Figure 2 has a second projection 25 that protrudes from the inner surface of the cylindrical portion 23 toward the first projection 11, contacts the outer surface of the first projection 11, and covers the inner edge portion 41 of the metallized layer 40. Since the second projection 25, which is at the same potential as the metallized layer 40, is positioned to cover the inner edge portion 41 of the metallized layer 40, the electric field on the inner edge portion 41 of the metallized layer 40 can be mitigated, thereby suppressing the occurrence of creepage discharge. Furthermore, compared to the case where the end face of the insulating container and the contact portion of the end plate are in contact without the first projection 11 being formed on the insulating container 10, since the contact portion 50 is provided on the outer surface of the first projection 11, the creepage distance of the creepage discharge path becomes longer by approximately the length of the protruding first projection 11, and the occurrence of creepage discharge can be further suppressed.

[0020] The second projection 25 may be provided around the entire circumference of the inner surface of the end plate 20 and may be formed to fit with the first projection 11. The second projection 25 may also be formed, for example, by press working, or by splitting and tearing the end of the cylindrical portion 23 into two parts. Since the second projection 25 can be formed in this way, integral molding of the cylindrical portion 23 and the disc portion 24 of the end plate 20 is possible, and no extra processing steps are required.

[0021] In this way, the formation of the second projection 25 on the end plate 20 provides a contact portion 50 where the inner surface of the cylindrical portion 23 of the end plate 20, which is at the same potential as the metallized layer 40, and the outer surface of the first projection 11 of the insulating container 10 come into contact, thereby suppressing the occurrence of creepage discharge. Furthermore, in Figure 2, since the contact portion 50 is located below the uppermost part of the outer surface of the first projection 11, the creepage distance can be increased compared to the case where the contact portion is located at the uppermost part of the outer surface of the first projection 11, thereby further suppressing the occurrence of creepage discharge.

[0022] When the first projection 11 is formed on the insulating container 10, in order to mitigate the electric field at the inner edge portion 41 of the metallized layer 40, it is sufficient that the contact portion between the outer surface of the first projection 11 and the inner surface of the cylindrical portion 23 is provided above the metallized layer 40 in Figure 2, and the shape of the end plate 20 is not limited to that shown in Figure 2.

[0023] An example in which a contact portion of a different shape from that shown in Figure 2 is provided on the end plate will be explained using Figures 3 to 6. As shown in Figure 3, the end plate 20a has a curved portion 26 in which the second projection 25a curves inside the cylindrical portion 23, and a part of the curved portion 26 that contacts the outer surface of the first projection 11 may be provided as a contact portion 50a. That is, the curved portion 26 is in contact with the outer surface of the first projection 11 at its innermost part and is formed to fit onto the first projection 11. In Figure 3, the curved portion 26 is drawn as having a constant radius of curvature, but it is not necessarily limited to this shape, and the radius of curvature may change. Because the electric field concentration is mitigated in the curved portion 26, the electric field at the contact portion 50a can be mitigated.

[0024] As shown in Figure 4, the end plate 20b has a bent portion 27 formed by bending the end of the cylindrical portion 23a inward, and the end of the cylindrical portion 23a that contacts the outer surface of the first projection 11 may be provided as a contact portion 50b. Here, a joint portion 30a is provided at the bent portion 27 where the end plate 20 and the insulating container 10 are joined. Since such an end plate 20b with a bent portion 27 and a contact portion 50b can be formed by bending, a vacuum valve can be manufactured at a lower cost.

[0025] As shown in Figure 5, the end plate 20c may also be provided with a small-diameter portion 28 as a contact portion 50c, which is formed so that the cylindrical portion 23b contacts the outer surface of the first projection 11. The inner diameter of the small-diameter portion 28 is formed to be smaller than the inner diameter of the joint portion 30 of the cylindrical portion 23b. Since such an end plate 20c equipped with a small-diameter portion 28 and a contact portion 50c can be formed by press working, a vacuum valve can be manufactured at a lower cost.

[0026] As described above, in the vacuum valve according to this embodiment, the inner surfaces of the end plates 20, 20a, 20b, and 20c, which are at the same potential as the metallized layer 40, and the outer surface of the insulating container 10 are in contact at the contact portions 50, 50a, 50b, and 50c. The second protrusions 25, 25a, bent portion 27, and small diameter portion 28, which are at the same potential as the metallized layer 40, are arranged to cover the inner edge portion of the metallized layer 40, thereby mitigating the electric field at the inner edge portion 41 of the metallized layer 40. As a result, by suppressing the occurrence of surface discharge inside the vacuum valve without increasing the number of parts, the withstand voltage performance can be improved while suppressing an increase in cost, thus enabling the manufacture of an inexpensive vacuum valve.

[0027] Furthermore, brazing material is present in the joint 30 and the metallized layer 40 for joining the insulating container 10 to the end plates 20, 20a, 20b, and 20c. When brazing is performed to join the insulating container 10 to the end plates 20, 20a, 20b, and 20c, the assembled vacuum valve is placed in a heating furnace to melt the brazing material. At this time, some of the brazing material evaporates and diffuses into the vacuum valve, potentially contaminating the inner surface of the vacuum valve and reducing its withstand voltage performance. Also, when a high voltage is applied to the electrode 1 of the vacuum valve and a discharge occurs starting from the inner edge 41 of the metallized layer 40, the brazing material on the metallized layer 40 may evaporate and contaminate the inner surface of the vacuum valve, potentially reducing its withstand voltage performance.

[0028] In this embodiment, the vacuum valve is separated inside the vacuum valve from the space containing the joint 30 and the metallized layer 40 by the contact portions 50, 50a, 50b, and 50c, where the outer surface of the insulating container 10 and the inner surfaces of the end plates 20, 20a, 20b, and 20c are in contact. Therefore, even if the brazing material present in the joint 30 and the metallized layer 40 evaporates, the diffusion of the evaporated brazing material is suppressed by the contact portions 50, 50a, 50b, and 50c, preventing contamination of the inner surface of the vacuum valve and improving its withstand voltage performance. By improving the withstand voltage performance of the vacuum valve, it becomes possible to miniaturize vacuum valves with the same rated voltage, thus enabling the manufacture of vacuum valves at a lower cost.

[0029] Furthermore, since the outer surface of the insulating container 10 and the inner surfaces of the end plates 20, 20a, 20b, and 20c are in contact at the contact portions 50, 50a, 50b, and 50c, the insulating container 10 and the end plates 20 can be positioned with good coaxiality without using positioning jigs or the like when assembling the vacuum valve. Therefore, the assembly of the vacuum valve becomes easier, the assembly time is shortened, and the vacuum valve can be manufactured at a low cost.

[0030] Furthermore, the number of contact points is not limited to those shown in Figures 2 to 5; for example, as shown in Figure 6, multiple contact points 50 may be provided. In Figure 6, the end plate 20d has multiple second protrusions 25 formed in a unidirectional direction A on the inner surface of the cylindrical portion 23, which serve as contact points 50. By providing multiple contact points 50 in this way, the diffusion of the brazing material evaporated from the joint portion 30 and the metallized layer 40 can be further suppressed. In addition, the number of contact points between the insulating container 10 and the end plate 20 increases, making the assembled vacuum valve more stable before joining, thus making the assembly of the vacuum valve even easier.

[0031] Furthermore, the end plates 20, 20a, 20b, 20c and the insulating container 10 may be formed such that the inner surfaces of the end plates 20, 20a, 20b, 20c and the outer surface of the first projection 11 of the insulating container 10 fit together at the contact portions 50, 50a, 50b, 50c. In addition, the vacuum valve structure described above, in which the outer surface of the insulating container 10 and the inner surfaces of the end plates 20, 20a, 20b, 20c contact each other at the contact portions 50, 50a, 50b, 50c, can be applied to either the fixed end plate 21 or the movable end plate 22 that are joined to the insulating container 10, and the same effect can be obtained in either case.

[0032] Next, the manufacturing method for the vacuum valve described above will be explained. In the manufacturing method for the vacuum valve, the insulating container 10 and the end plates 20, 20a, 20b, 20c, and 20d are brought into contact at the contact portions 50, 50a, 50b, and 50c, thereby positioning the end plates 20, 20a, 20b, 20c, and 20d relative to the insulating container 10. In this process, the outer surface of the insulating container 10 and the inner surfaces of the end plates 20, 20a, 20b, and 20c come into contact at the contact portions 50, 50a, 50b, and 50c without the use of positioning jigs or the like, allowing the insulating container 10 and the end plates 20, 20a, 20b, 20c, and 20d to be positioned with good coaxiality. Therefore, the assembly of the vacuum valve becomes easier, the assembly time is shortened, and the vacuum valve can be manufactured at a low cost.

[0033] As described above, the vacuum valve according to Embodiment 1 comprises a pair of electrodes 1 consisting of a fixed electrode 2 and a movable electrode 3 arranged facing each other in one direction, a cylindrical insulating container 10 arranged around the electrodes 1, a pair of end plates 20, 20a, 20b, 20c, 20d joined to the end face of the insulating container 10 to seal the inside of the insulating container 10 with a vacuum, and a metallized layer 40 formed on the joint portion 30 where the insulating container 10 and the end plates 20, 20a, 20b, 20c, 20d are joined. At least one of the insulating container 10 and the end plates 20, 20a, 20b, 20c, 20d has contact portions 50, 50a, 50b, 50c formed on it to cover the inner edge portion 41 by bringing the insulating container 10 into contact with the end plates 20, 20a, 20b, 20c, 20d in order to mitigate the electric field at the inner edge portion 41 of the metallized layer 40.

[0034] With this configuration, in order to mitigate the electric field at the inner edge portion 41 of the metallized layer 40, contact portions 50, 50a, 50b, and 50c are formed by bringing the insulating container 10 into contact with the end plates 20, 20a, 20b, 20c, and 20d to cover the inner edge portion 41, thereby suppressing the occurrence of surface discharge inside the vacuum valve. As a result, it is possible to improve the withstand voltage performance while suppressing an increase in cost, and to manufacture an inexpensive vacuum valve.

[0035] Furthermore, in Embodiment 1, the outer surface of the insulating container 10 and the inner surfaces of the end plates 20, 20a, 20b, 20c come into contact at the contact portions 50, 50a, 50b, 50c. When the brazing material present in the joint portion 30 and the metallized layer 40 inside the vacuum valve evaporates, the diffusion of the evaporated brazing material is suppressed, preventing contamination of the inner surface of the vacuum valve and improving the withstand voltage performance. Moreover, by improving the withstand voltage performance of the vacuum valve, vacuum valves with the same rated voltage can be made smaller, thus enabling the manufacture of vacuum valves at a lower cost.

[0036] Furthermore, in Embodiment 1, the outer surface of the insulating container 10 and the inner surfaces of the end plates 20, 20a, 20b, and 20c are in contact at the contact portions 50, 50a, 50b, and 50c. With this configuration, when assembling the vacuum valve, the insulating container 10 and the end plates 20 can be positioned with good coaxiality without using positioning jigs or the like, thus simplifying the assembly of the vacuum valve. As a result, assembly time is reduced, and the vacuum valve can be manufactured at a lower cost.

[0037] Furthermore, in Embodiment 1, the insulating container 10 of the vacuum valve has a joint portion 30 on the outer circumference of the end face and a first projection 11 protruding in one direction A on the inner circumference of the end face. The end plates 20, 20a, 20b, 20c, 20d of the vacuum valve consist of cylindrical portions 23, 23a, 23b and disc portions 24 connected to the inside of the cylindrical portions 23, 23a, 23b. The cylindrical portions 23, 23a, 23b are joined to the insulating container 10 and have contact portions 50, 50a, 50b, 50c where the inner surfaces of the cylindrical portions 23, 23a, 23b and the outer surfaces of the first projection 11 come into contact. With this configuration, since the contact portions 50, 50a, 50b, 50c are provided on the outer surfaces of the first projection 11, the creepage distance is not shortened and the occurrence of creepage discharge inside the vacuum valve can be further suppressed.

[0038] Furthermore, in Embodiment 1, the metallized layer 40 of the vacuum valve is formed to extend from the joint portion 30 to the outer surface of the first projection 11. With this configuration, the inner edge portion 41 of the metallized layer 40 is formed on the outer surface of the first projection 11, and the inner edge portion 41 and the first projection 11 do not face each other at close range, so the electric field of the inner edge portion 41 can be mitigated. As a result, the occurrence of creepage discharge can be further suppressed.

[0039] Furthermore, in Embodiment 1, the end plates 20, 20a of the vacuum valve are provided with second protrusions 25, 25a that project from the inner surface of the cylindrical portion 23 toward the first projection 11 and contact the outer surface of the first projection 11, forming contact portions 50, 50a. With this configuration, electrons are prevented from being supplied from the inner edge portion 41 of the metallized layer 40 by the contact portions 50, 50a, thereby suppressing the occurrence of surface discharge inside the vacuum valve.

[0040] Furthermore, in Embodiment 1, the end plate 20a of the vacuum valve has a curved portion 26 in which the second projection 25a curves inside the cylindrical portion 23, and a part of the curved portion 26 that contacts the outer surface of the first projection 11 is provided as a contact portion 50a. With this configuration, electric field concentration is mitigated in the curved portion 26, and therefore the electric field at the contact portion 50a can be mitigated. As a result, the occurrence of creepage discharge originating from the contact portion 50a can be suppressed.

[0041] Furthermore, in Embodiment 1, the end plate 20d of the vacuum valve is provided with a plurality of second protrusions 25 formed in a unidirectional direction A on the inner surface of the cylindrical portion 23, which serve as contact portions 50. With this configuration, since multiple contact portions 50 are provided, the diffusion of the brazing material evaporated from the joint portion 30 and the metallized layer 40 can be further suppressed, and the vacuum valve can be assembled more stably.

[0042] Furthermore, in the first embodiment, the end plate 20b of the vacuum valve has a bent portion 27 formed by bending the end of the cylindrical portion 23a inward from the cylindrical portion 23a, and the end of the cylindrical portion 23a that is joined to the insulating container 10 at the bent portion 27 and contacts the outer surface of the first projection 11 is provided as a contact portion 50b. With this configuration, since the end plate 20b with the bent portion 27 and the contact portion 50b can be formed by bending, a vacuum valve with improved voltage resistance performance by providing the contact portion 50b can be manufactured at a lower cost.

[0043] Furthermore, in the first embodiment, the end plate 20c of the vacuum valve is provided with a small-diameter portion 28 formed such that the cylindrical portion 23b contacts the outer surface of the first protrusion 11 as a contact portion 50c. According to such a configuration, since the end plate 20c provided with the small-diameter portion 28 and the contact portion 50c can be formed by pressing, a vacuum valve with improved withstand voltage performance can be manufactured at a lower cost by providing the contact portion 50c.

[0044] Furthermore, in the first embodiment, the method for manufacturing a vacuum valve includes a step of positioning the insulating container 10 and the end plates 20, 20a, 20b, 20c, 20d by bringing them into contact at the contact portions 50, 50a, 50b, 50c. According to such a configuration, without using a positioning jig or the like, the outer surface of the insulating container 10 and the inner surfaces of the end plates 20, 20a, 20b, 20c contact at the contact portions 50, 50a, 50b, 50c, so that the insulating container 10 and the end plates 20, 20a, 20b, 20c, 20d can be arranged with good coaxiality. Therefore, the assembly of the vacuum valve becomes easy, the assembly work time is shortened, and the vacuum valve can be manufactured at a low cost.

[0045] Embodiment 2. The vacuum valve according to Embodiment 2 will be described with reference to FIGS. 7 and 8. In Embodiment 2, the same reference numerals are assigned to the same components as in the above Embodiment 1, and the configuration different from that of Embodiment 1 will be mainly described.

[0046] FIGS. 7 and 8 are enlarged views showing a configuration example of the vacuum valve according to Embodiment 2. In Embodiment 1, a configuration example is shown in which contact portions 50, 50a, 50b, 50c are provided on the end plates 20, 20a, 20b, 20c to bring the outer surface of the first protrusion 11 of the insulating container 10 into contact with the inner surface of the cylindrical portion 23 of the end plates 20, 20a, 20b, 20c. In Embodiment 2, however, a configuration example is shown in which contact portions 50d, 50e are provided on the first protrusions 11 of the insulating containers 10a, 10b to bring the outer surface of the first protrusion 11 of the insulating containers 10a, 10b into contact with the inner surface of the cylindrical portion 23 of the end plate 20e.

[0047] In FIG. 7, the insulating container 10a includes a third protrusion 12 that protrudes from the outer surface of the first protrusion 11 toward the cylindrical portion 23 of the end plate 20e and contacts the inner surface of the cylindrical portion 23 to cover the inner edge portion 41 of the metallized layer 40 as a contact portion 50d. Thus, the cylindrical portion 23 of the end plate 20e having the same potential as the metallized layer 40 is arranged to cover the inner edge portion 41 of the metallized layer 40, so that the electric field at the inner edge portion 41 of the metallized layer 40 can be relaxed. As a result, without increasing the number of parts, by suppressing the occurrence of creeping discharge inside the vacuum valve, it is possible to improve the withstand voltage performance while suppressing an increase in cost.

[0048] Also, when the brazing material present in the joint portion 30 and the metallized layer 40 evaporates, the outer surface of the first protrusion 11 of the insulating container 10a and the inner surface of the cylindrical portion 23 of the end plate 20e contact each other at the contact portion 50d, suppressing the diffusion of the evaporated brazing material, preventing the inner surface of the vacuum valve from being contaminated, and improving the withstand voltage performance.

[0049] Further, since the outer surface of the first protrusion 11 of the insulating container 10a and the inner surface of the cylindrical portion 23 of the end plate 20e contact each other at the contact portion 50d, when assembling the vacuum valve, the insulating container 10a and the end plate 20e can be arranged with good coaxiality without using a positioning jig or the like. Therefore, the assembly of the vacuum valve becomes easy, the assembly work time is shortened, and the vacuum valve can be manufactured at a low cost.

[0050] Furthermore, as shown in FIG. 8, in the insulating container 10b, a tapered portion 13 that connects the outer surface of the third protrusion 12 and the inner peripheral end of the joint portion 30 is formed, so that the corner of the outer surface of the third protrusion 12 connected to the tapered portion 13 becomes an obtuse angle. By forming such a tapered portion 13, the thickness in the radial direction B of the portion protruding from the end surface of the insulating container 10b increases and it becomes difficult to break, and the corner of the third protrusion 12 of the insulating container 10b at the contact portion 50e becomes an obtuse angle, preventing chipping. Therefore, in the manufacture of the vacuum valve, it is possible to prevent a part of the insulating container 10b from breaking or chipping and becoming a defective product, so that the vacuum valve can be manufactured at a low cost.

[0051] Furthermore, the end plate 20e and the insulating containers 10a and 10b may be formed such that the inner surface of the cylindrical portion 23 of the end plate 20e and the outer surface of the third projection 12 of the insulating containers 10a and 10b fit together at the contact portions 50d and 50e.

[0052] The vacuum valve structure described above, in which the outer surfaces of the insulating containers 10a and 10b and the inner surface of the end plate 20e are in contact via contact portions 50d and 50e, can be applied to either the fixed end plate 21 or the movable end plate 22 that are joined to the insulating containers 10a and 10b, and the same effect can be obtained regardless of which one is applied to.

[0053] As described above, in the vacuum valve according to Embodiment 2, the insulating containers 10a and 10b are provided with third projections 12 as contact portions 50d and 50e, which protrude from the outer surface of the first projection 11 toward the cylindrical portion 23 and contact the inner surface of the cylindrical portion 23. With this configuration, by providing the insulating containers 10a and 10b with third projections 12 as contact portions 50d and 50e that contact the inner surface of the cylindrical portion 23 of the end plate 20e, surface discharge can be suppressed inside the vacuum valve without increasing the number of parts, thereby improving the withstand voltage performance while suppressing an increase in cost. Furthermore, if the brazing material present in the joint portion 30 and the metallized layer 40 evaporates, the diffusion of the evaporated brazing material is suppressed by the contact portions 50d and 50e, preventing contamination of the inner surface of the vacuum valve and improving the withstand voltage performance. In addition, the contact portions 50d and 50e make it easier to assemble the vacuum valve, making it possible to manufacture the vacuum valve at a low cost.

[0054] Furthermore, in the second embodiment, the insulating container 10b has a tapered portion 13 formed thereon that connects the outer surface of the third projection 12 to the inner circumferential end of the joint portion 30. With this configuration, the tapered portion 13 is formed, which increases the radial thickness B of the portion protruding from the end face of the insulating container 10b, making it less prone to breakage, and the corner of the outer surface of the third projection 12 connected to the tapered portion 13 becomes obtuse, preventing chipping. As a result, in the manufacturing of vacuum valves, it is possible to prevent defective products from being made due to breakage or chipping of a part of the insulating container 10b, making it possible to manufacture vacuum valves at a low cost.

[0055] Embodiment 3. The vacuum valve according to Embodiment 3 will be described with reference to Figures 9 and 10. In Embodiment 3, the same reference numerals are used for components that are the same as those in Embodiments 1 and 2, and the description will mainly focus on the configurations that differ from Embodiments 1 and 2.

[0056] Figures 9 and 10 are enlarged views showing an example of the configuration of a vacuum valve according to Embodiment 3. In Embodiment 1, contact portions 50, 50a, 50b, and 50c were provided on the end plates 20, 20a, 20b, and 20c to bring the outer surface of the first projection 11 of the insulating container 10 into contact with the inner surface of the cylindrical portion 23 of the end plates 20, 20a, 20b, and 20c. However, in Embodiment 3, spacers 60 and 60a, which are separate components from the insulating container 10 and the end plate 20e, are provided as contact portions 50f, 50g, 50h, and 50i, and the spacers 60 and 60a are brought into contact with both the outer surface of the first projection 11 of the insulating container 10 and the inner surface of the cylindrical portion 23 of the end plate 20e, thereby bringing the insulating container 10 and the end plate 20e into indirect contact.

[0057] In Figure 9, the spacer 60 is provided between the first projection 11 of the insulating container 10 and the cylindrical portion 23 of the end plate 20e, and is a member that contacts the outer surface of the first projection 11 and the inner surface of the cylindrical portion 23. The spacer 60 is brazed together with the end plate 20e in the metallized layer 40 formed on the outer end surface of the insulating container 10.

[0058] The spacer 60 has a hole formed in the center of the deep dish-shaped member through which the first projection 11 passes. At the contact portion 50f in Figure 9, which is above the inner edge portion 41 of the metallized layer 40, the inner surface of the spacer 60 contacts the outer surface of the first projection 11. Also, at the contact portion 50g, the outer surface of the spacer 60 contacts the inner surface of the cylindrical portion 23 of the end plate 20e. In this way, the spacer 60 contacts both the outer surface of the first projection 11 of the insulating container 10 and the inner surface of the cylindrical portion 23 of the end plate 20e, so that the insulating container 10 and the end plate 20e are indirectly in contact via the spacer 60. When the insulating container 10 and the end plate 20e are indirectly in contact using the spacer 60, the number of parts increases compared to when the insulating container and the end plate are in direct contact as shown in Embodiments 1 and 2. However, the spacer 60 has a simple structure and can be easily manufactured.

[0059] Therefore, the cylindrical portion 23 of the end plate 20e, which is at the same potential as the metallized layer 40, is in contact with the outer surface of the first projection 11 of the insulating container 10 above the inner edge portion 41 of the metallized layer 40 in Figure 9 via the spacer 60. Since the spacer 60, which is at the same potential as the metallized layer 40, is positioned to cover the inner edge portion 41 of the metallized layer 40, the electric field at the inner edge portion 41 of the metallized layer 40 can be mitigated. As a result, surface discharge inside the vacuum valve can be suppressed by adding only very simple components, thereby improving the withstand voltage performance while suppressing cost increases.

[0060] Furthermore, if the brazing material present in the joint 30 and the metallized layer 40 evaporates, the outer surface of the first projection 11 of the insulating container 10 and the inner surface of the spacer 60 come into contact at the contact portion 50f, thereby suppressing the diffusion of the evaporated brazing material, preventing contamination of the inner surface of the vacuum valve, and improving the dielectric strength.

[0061] Furthermore, since the outer surface of the first projection 11 of the insulating container 10 and the inner surface of the spacer 60 are in contact at the contact portion 50f, and the outer surface of the spacer 60 and the inner surface of the cylindrical portion 23 of the end plate 20e are in contact at the contact portion 50g, the insulating container 10 and the end plate 20e can be positioned with good coaxiality without using a separate positioning jig or the like when assembling the vacuum valve. Therefore, the assembly of the vacuum valve becomes easier, the assembly time is shortened, and the vacuum valve can be manufactured at a low cost.

[0062] The shape of the spacer 60 is not limited to that shown in Figure 9. Any shape that can indirectly bring the insulating container 10 and the end plate 20e into contact with each other, in order to contact both the outer surface of the insulating container 10 and the inner surface of the end plate 20e, covering the inner edge portion 41 of the metallization layer 40 and mitigating the electric field at the inner edge portion 41 of the metallization layer 40, and that can be easily manufactured with a simple structure is acceptable.

[0063] An example of another spacer shape is shown in Figure 10. In Figure 10, the inner surface of the spacer 60a contacts the outer surface of the insulating container 10 at contact portion 50h, and the outer surface of the spacer 60a contacts the inner surface of the end plate 20e at contact portion 50i, forming a ring-shaped member. That is, since the spacer 60a contacts both the insulating container 10 and the end plate 20e, the spacer 60a functions as contact portions 50h and 50i that indirectly bring the insulating container 10 and the end plate 20e into contact. In Figure 10, the portion of the spacer 60a below the contact portion 50g with the outer surface of the insulating container 10 is chamfered and is formed to cover the metallized layer 40.

[0064] Furthermore, the insulating container 10a, end plate 20e, and spacers 60, 60a may be formed such that the inner surfaces of the spacers 60, 60a fit with the outer surface of the first projection 11 of the insulating container 10 at contact portions 50f, 50h, and the outer surfaces of the spacers 60, 60a fit with the inner surface of the cylindrical portion 23 of the end plate 20e at contact portions 50g, 50i.

[0065] The vacuum valve structure described above, in which the outer surface of the insulating container 10 and the inner surface of the end plate 20e are in contact via spacers 60 and 60a through contact portions 50f, 50g, 50h, and 50i, can be applied to either the fixed end plate 21 or the movable end plate 22 joined to the insulating container 10, and the same effect can be obtained regardless of which one is applied to.

[0066] Next, the manufacturing method for the vacuum valve described above will be explained. In the manufacturing method for the vacuum valve, the inner surfaces of the spacers 60 and 60a are brought into contact with the outer surface of the first projection 11 of the insulating container 10 to position the spacers 60 and 60a relative to the insulating container 10, and the inner surface of the cylindrical portion 23 of the end plate 20e is brought into contact with the outer surface of the spacers 60 and 60a to position the end plate 20e relative to the insulating container 10. In these steps, without using any other positioning jig, the outer surface of the first projection 11 of the insulating container 10 and the inner surfaces of the spacers 60 and 60a come into contact at contact portions 50f and 50h, and the outer surfaces of the spacers 60 and 60a come into contact with the inner surface of the cylindrical portion 23 of the end plate 20e at contact portions 50g and 50i, thereby enabling the insulating container 10 and the end plate 20e to be positioned with good coaxiality. Therefore, the assembly of the vacuum valve becomes easier, the assembly time is shortened, and the vacuum valve can be manufactured at a low cost.

[0067] As described above, the vacuum valve according to Embodiment 3 is provided with spacers 60, 60a as contact portions 50f, 50g, 50h, and 50i, which are provided between the first projection 11 and the cylindrical portion 23 and are in contact with the outer surface of the first projection 11 and the inner surface of the cylindrical portion 23 to cover the inner edge portion 41 of the metallized layer 40. With this configuration, by providing spacers 60, 60a as contact portions 50f, 50g, 50h, and 50i that indirectly bring the insulating container 10 and the end plate 20e into contact, it is possible to suppress the occurrence of surface discharge inside the vacuum valve and improve the withstand voltage performance while suppressing cost increases by adding only very simple parts. Furthermore, if the brazing material present in the joint portion 30 and the metallized layer 40 evaporates, the diffusion of the evaporated brazing material is suppressed by the contact portions 50f and 50h, preventing contamination of the inner surface of the vacuum valve and improving the withstand voltage performance. Furthermore, the contact parts 50f, 50g, 50h, and 50i facilitate the assembly of the vacuum valve, making it possible to manufacture the vacuum valve at a low cost.

[0068] Furthermore, in Embodiment 3, the method for manufacturing the vacuum valve includes the steps of: positioning the spacers 60 and 60a relative to the insulating container 10 by bringing the inner surfaces of the spacers 60 and 60a into contact with the outer surface of the first projection 11 of the insulating container 10; and positioning the end plate 20e relative to the insulating container 10 by bringing the inner surface of the cylindrical portion 23 of the end plate 20e into contact with the outer surface of the spacers 60 and 60a. With this configuration, the insulating container 10 and the end plate 20e can be positioned with good coaxiality without using another positioning jig or the like. Therefore, the assembly of the vacuum valve becomes easier, the assembly time is shortened, and the vacuum valve can be manufactured at low cost.

[0069] Embodiment 4. The vacuum valve according to Embodiment 4 will be described with reference to Figure 11. In Embodiment 4, the same reference numerals are used for the same components as in Embodiments 1 to 3, and the description will mainly focus on the configuration that differs from Embodiments 1 to 3.

[0070] Figure 11 is an enlarged view showing an example of the configuration of a vacuum valve according to Embodiment 4. In Embodiment 1, a first projection 11 was provided on the inner circumference side of the end face of the insulating container 10, and an example of a configuration in which the outer surface of the first projection 11 is in contact with the inner surface of the cylindrical portion 23 of the end plates 20, 20a, 20b, and 20c was shown. However, in Embodiment 4, an example of a configuration in which the inner surface of the insulating container 10c is in contact with the outer surface of the cylindrical portion 23b of the end plate 20f is shown.

[0071] In Figure 11, the insulating container 10c has a fourth projection 14 that protrudes in one direction A on the outer circumference of the end face of the insulating container 10c. The end plate 20f consists of a cylindrical portion 23b and a disc portion 24a connected to the inside of the cylindrical portion 23b, and has a connecting portion 29 that extends radially outward from the cylindrical portion 23b and is joined at the joint portion 30b to the end face that extends radially B and is formed at the end of the fourth projection 14 of the insulating container 10c. A metallized layer 40a is formed at this joint portion 30b.

[0072] At the contact portion 50j in Figure 11, below the inner edge portion 41a of the metallized layer 40a, the outer surface of the cylindrical portion 23b of the end plate 20f, which is at the same potential as the metallized layer 40a, contacts the inner surface of the fourth projection 14 of the insulating container 10c, covering the inner edge portion 41a of the metallized layer 40a. Since the cylindrical portion 23b, which is at the same potential as the metallized layer 40, is positioned to cover the metallized layer 40a, the electric field at the inner edge portion 41 of the metallized layer 40 can be mitigated. As a result, by suppressing the occurrence of creepage discharge inside the vacuum valve without increasing the number of parts, the dielectric strength can be improved while suppressing an increase in cost.

[0073] Furthermore, the formation of the fourth projection 14 on the insulating container 10c creates a step on the inner surface of the insulating container 10c that protrudes inward in the radial direction B. This step is formed on the surface of the insulating container 10c from the contact portion 50j downwards in Figure 11, increasing the creepage distance of the creepage discharge path, thereby further suppressing the occurrence of creepage discharge.

[0074] In the configuration example shown in Figure 11, the inner surface of the fourth projection 14 of the insulating container 10c and the outer surface of the cylindrical portion 23b of the end plate 20f are shown to be in contact. However, even if the fourth projection 14 is not formed on the insulating container 10c, if the outer surface of the cylindrical portion 23b of the end plate 20f and the inner surface of the insulating container are in contact, the cylindrical portion 23b, which is at the same potential as the metallization layer 40, is positioned to cover the metallization layer 40a, thereby mitigating the electric field at the inner edge portion 41 of the metallization layer 40. As a result, the occurrence of surface discharge inside the vacuum valve can be suppressed.

[0075] Furthermore, if the brazing material present in the joint 30b and the metallized layer 40a evaporates, the contact between the inner surface of the insulating container 10c and the outer surface of the cylindrical portion 23b of the end plate 20f at the contact portion 50j suppresses the diffusion of the evaporated brazing material, preventing contamination of the inner surface of the vacuum valve and improving the dielectric strength.

[0076] Furthermore, since the inner surface of the insulating container 10c and the outer surface of the cylindrical portion 23b of the end plate 20f are in contact at the contact portion 50j, the insulating container 10c and the end plate 20f can be positioned with good coaxiality without using positioning jigs or the like when assembling the vacuum valve. Therefore, the assembly of the vacuum valve becomes easier, the assembly time is shortened, and the vacuum valve can be manufactured at a low cost.

[0077] Furthermore, since the end plate 20f having such a cylindrical portion 23b, disc portion 24a, and connecting portion 29 is a shape that can be formed by press working, a vacuum valve can be manufactured at a lower cost. In addition, the insulating container 10c and the end plate 20f may be formed such that the inner surface of the fourth projection 14 of the insulating container 10c and the outer surface of the cylindrical portion 23b of the end plate 20f fit together at the contact portion 50j.

[0078] The metallized layer 40a is formed at the joint portion 30b, but if the metallized layer extends to the contact portion 50j, there is a risk that the brazing material will spread to the outer surface of the cylindrical portion 23b of the end plate 20f. Furthermore, there is a risk that the space enclosed by the cylindrical portion 23b and the connecting portion 29 of the end plate 20f and the metallized layer will be sealed and gas will accumulate. Therefore, in order to prevent these problems, it is preferable that the metallized layer 40a does not come into contact with the contact portion 50j where the inner surface of the insulating container 10c and the outer surface of the cylindrical portion 23b of the end plate 20f come into contact. In order to prevent the metallized layer 40a from coming into contact with the contact portion 50j, for example, as shown in Figure 11, the corners of the fourth projection 14 of the insulating container 10c on which the metallized layer 40a is provided may be chamfered.

[0079] The vacuum valve structure described above, in which the inner surface of the insulating container 10c and the outer surface of the end plate 20f are in contact via a contact portion 50j, can be applied to either the fixed end plate 21 or the movable end plate 22 joined to the insulating container 10c, and the same effect can be obtained regardless of which one is applied to.

[0080] As described above, the vacuum valve according to Embodiment 4 is characterized in that the end plate 20f consists of a cylindrical portion 23b and a disc portion 24a connected to the inside of the cylindrical portion 23b, and has a contact portion where the outer surface of the cylindrical portion 23b and the inner surface of the insulating container come into contact. With this configuration, by providing the end plate 20f with the cylindrical portion 23b that comes into contact with the inner surface of the insulating container as a contact portion, surface discharge can be suppressed inside the vacuum valve without increasing the number of parts, thereby improving the withstand voltage performance while suppressing an increase in cost. Furthermore, if the brazing material present in the joint portion 30b and the metallized layer 40a evaporates, the diffusion of the evaporated brazing material is suppressed by the contact portion, preventing contamination of the inner surface of the vacuum valve and improving the withstand voltage performance. In addition, since the assembly of the vacuum valve is made easier by the contact portion, it becomes possible to manufacture the vacuum valve at a low cost.

[0081] Furthermore, in the fourth embodiment, the insulating container 10c has a fourth projection 14 that protrudes in one direction A on the outer circumference of the end face of the insulating container 10c, and the end plate 20f has a contact portion 50j where the outer surface of the cylindrical portion 23b and the inner surface of the fourth projection 14 come into contact. With this configuration, the fourth projection 14 forms a step on the inner surface of the insulating container 10c that protrudes inward in the radial direction B, so the creepage distance of the creepage discharge path formed on the surface of the insulating container 10c from the contact portion 50j becomes longer, and the occurrence of creepage discharge can be further suppressed.

[0082] Furthermore, in Embodiment 4, the metallized layer 40a does not come into contact with the contact portion 50j. With this configuration, it is possible to prevent the brazing material present in the metallized layer 40a from spreading to the outer surface of the cylindrical portion 23b of the end plate 20f at the contact portion 50j, and furthermore, to prevent gas from accumulating by sealing the space surrounded by the cylindrical portion 23b and connecting portion 29 of the end plate 20f and the metallized layer.

[0083] While this disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable individually or in various combinations to the embodiments. Accordingly, countless variations not illustrated are envisioned within the scope of the art disclosed in this specification. For example, these include modifying, adding or omitting at least one component, or extracting at least one component and combining it with a component from another embodiment.

[0084] 1 Electrode, 2 Fixed electrode, 3 Movable electrode, 4 Bellows, 5 Arc shield, 10, 10a, 10b, 10c Insulating container, 11 First projection, 12 Third projection, 13 Tapered section, 14 Fourth projection, 20, 20a, 20b, 20c, 20d, 20e, 20f End plate, 21 Fixed end plate, 22 Movable end plate, 23, 23a, 23b Cylindrical section, 24, 24a Disc section, 25, 25a Second projection, 26 Curved section, 27 Bent section, 28 Small diameter section, 29 Connecting section, 30, 30a, 30b Joint section, 40, 40a Metallized layer, 41, 41a Inner edge portion, 50, 50a, 50b, 50c, 50d, 50e, 50f, 50g, 50h, 50i, 50j Contact portion, 60, 60a Spacer

Claims

1. A vacuum valve comprising: a pair of electrodes consisting of a fixed electrode and a movable electrode arranged opposite to each other in one direction; a cylindrical insulating container arranged around the electrodes; a pair of end plates joined to the end face of the insulating container to seal the inside of the insulating container with a vacuum; and a metallized layer formed at the joint where the insulating container and the end plates are joined, wherein at least one of the insulating container and the end plates has a contact portion formed thereon that covers the inner edge portion by bringing the insulating container and the end plate into contact in order to mitigate the electric field at the inner edge portion of the metallized layer.

2. The vacuum valve according to claim 1, wherein the insulating container has the joining portion on the outer circumference of the end face and the first projection protruding in one direction on the inner circumference of the end face, and the end plate consists of a cylindrical portion and a disc portion connected to the inside of the cylindrical portion, and is joined to the insulating container at the cylindrical portion and has a contact portion in which the inner surface of the cylindrical portion and the outer surface of the first projection come into contact.

3. The vacuum valve according to claim 2, wherein the metallized layer is formed to extend from the joint to the outer surface of the first projection.

4. The vacuum valve according to claim 2 or 3, wherein the end plate is provided with a second projection that protrudes from the inner surface of the cylindrical portion toward the first projection and contacts the outer surface of the first projection as the contact portion.

5. The vacuum valve according to claim 4, wherein the end plate has a curved portion in which the second projection curves inside the cylindrical portion, and a part of the curved portion that contacts the outer surface of the first projection is provided as the contact portion.

6. The vacuum valve according to claim 4 or 5, wherein the end plate is provided with a plurality of second protrusions formed in a unidirectional direction on the inner surface of the cylindrical portion as the contact portion.

7. The vacuum valve according to claim 2 or 3, wherein the end plate has a bent portion formed by bending the end of the cylindrical portion toward the inside of the cylindrical portion, and is joined to the insulating container at the bent portion, and the end of the cylindrical portion that contacts the outer surface of the first projection is provided as the contact portion.

8. The vacuum valve according to claim 2 or 3, wherein the end plate is provided with a small-diameter portion formed such that the cylindrical portion contacts the outer surface of the first projection, as the contact portion.

9. The vacuum valve according to claim 2 or 3, wherein the insulating container is provided with a third projection that protrudes from the outer surface of the first projection toward the cylindrical portion and contacts the inner surface of the cylindrical portion, the third projection being the contact portion.

10. The vacuum valve according to claim 9, wherein the insulating container has a tapered portion formed to connect the outer surface of the third projection and the inner circumferential end of the joint.

11. The vacuum valve according to claim 2 or 3, wherein a spacer is provided between the first projection and the cylindrical portion, and the spacer is provided as the contact portion, and the spacer contacts the outer surface of the first projection and the inner surface of the cylindrical portion.

12. The vacuum valve according to claim 11, wherein the inner surface of the spacer fits with the outer surface of the first projection, and the outer surface of the spacer fits with the inner surface of the cylindrical portion.

13. The vacuum valve according to claim 1, wherein the end plate comprises a cylindrical portion and a disc portion connected to the inside of the cylindrical portion, and has a contact portion in which the outer surface of the cylindrical portion and the inner surface of the insulating container come into contact.

14. The vacuum valve according to claim 13, wherein the insulating container has a fourth projection that protrudes in one direction on the outer circumference of the end face, and the end plate has a contact portion in which the outer surface of the cylindrical portion and the inner surface of the fourth projection come into contact.

15. The vacuum valve according to claim 13 or claim 14, wherein the metallized layer does not come into contact with the contact portion.

16. The vacuum valve according to any one of claims 1 to 10 and 13 to 15, wherein the end plate is fitted with the insulating container at the contact portion.

17. A method for manufacturing a vacuum valve, comprising the step of bringing the insulating container and the end plate of the vacuum valve according to any one of claims 1 to 16 into contact at the contact portion, thereby positioning the end plate relative to the insulating container.

18. A method for manufacturing a vacuum valve, comprising the steps of: positioning the spacer with respect to the insulating container by bringing the inner surface of the spacer into contact with the outer surface of the first projection of the insulating container of the vacuum valve according to claim 11 or claim 12; and positioning the end plate with respect to the insulating container by bringing the inner surface of the cylindrical portion of the end plate into contact with the outer surface of the spacer.

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