Vacuum valve

Abstract

To provide a highly reliable vacuum valve.SOLUTION: A vacuum valve includes metal end plates (5, 11) having axial straight portions (5b, 11b) and radial straight portions (5a, 11a), and electric field relaxation flanges (6, 12) that are arranged between at least one of the metal end plates (5, 11) and an insulating container (1) and fixed to the insulating container (1). The electric field relaxation flanges (6, 12) include first bent portions (6b, 12b) bent in the axial direction from fixing portions (6a, 12a) with the insulating container (1), and the first bent portions (6b, 12b) of the electric field relaxation flanges (6, 12) are bonded and attached along the inner surfaces of the axial straight portions (5b, 11b) of the metal end plates (5, 11).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application relates to a vacuum valve.

Background Art

[0002] A vacuum valve mounted on a vacuum interrupter or a vacuum switch, etc., generally consists of an insulating container, a shield, a fixed-side contact, a fixed-side electrode bar, a fixed-side metal end plate, a movable-side contact, a movable-side electrode bar, a bellows cover, a bellows, and a movable-side metal end plate.

[0003] On both end faces of the aforementioned insulating container, a metallized layer for brazing is provided, and by brazing each metal end plate and the insulating container and hermetically sealing them, it becomes possible to maintain the vacuum state inside the insulating container.

[0004] Also, in the vacuum valve shown in Patent Document 1, in order to mitigate the electric field, a ring-shaped sealing member is provided between the insulating container and each metal end plate, thereby improving the withstand voltage performance.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the above-described conventional vacuum valve, in a configuration where a sealing member for electric field relaxation is not provided between each metal end plate and the insulating container, and in the case of a structure where the metallized layers on both end faces of the insulating container are exposed, the withstand voltage performance may deteriorate. Therefore, as shown in Patent Document 1, there is a vacuum valve in which the withstand voltage performance is improved by providing a sealing member.

[0007] However, in order to mitigate the electric field, if a ring-shaped sealing member is provided between the insulating container and each metal end plate, as shown in Patent Document 1, the dielectric strength is improved. However, when this vacuum valve is placed in a pressurized gas, there is a problem that each metal end plate may deform due to the pressure of the gas.

[0008] This application discloses a technology for solving the above-mentioned problems, and its purpose is to provide a highly reliable vacuum valve. [Means for solving the problem]

[0009] The vacuum valve disclosed herein comprises an insulating container having metallized layers on both end faces; a fixed-side metal end plate having an axially straight portion and a radially straight portion, disposed on one side of the insulating container; a fixed-side electrode rod fixed to the fixed-side metal end plate; a fixed-side contact provided on the fixed-side electrode rod; a movable-side metal end plate having an axially straight portion and a radially straight portion, disposed on the other side of the insulating container; a movable-side electrode rod provided on the movable-side metal end plate so as to be able to move back and forth via a bellows; and a movable-side contact provided on the movable-side electrode rod that moves toward and away from the fixed-side contact, wherein an electric field mitigation flange is provided disposed between at least one of the metal end plates, the fixed-side metal end plate or the movable-side metal end plate, and the insulating container, and is fixed to the insulating container, wherein the electric field mitigation flange has a first bent portion formed axially from the portion fixed to the insulating container, and the first bent portion of the electric field mitigation flange is joined and attached so as to be along the inner surface of the axially straight portion of the metal end plate. [Effects of the Invention]

[0010] According to the vacuum valve disclosed herein, an electric field mitigation flange is positioned between at least one of the metal end plates, either the fixed-side metal end plate or the movable-side metal end plate, and an insulating container. The electric field mitigation flange has a first bent portion formed axially from the portion fixed to the insulating container, and the first bent portion of the electric field mitigation flange is joined and attached along the inner surface of the axially straight portion of the metal end plate, thereby providing a highly reliable vacuum valve. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view showing a vacuum valve according to Embodiment 1. [Figure 2] This figure shows the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 1, where (a) is a cross-sectional view and (b) is a perspective view. [Figure 3] This figure shows the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 1, where (a) is a cross-sectional view and (b) is a perspective view. [Figure 4] This is a cross-sectional view showing the dimensional relationship of a vacuum valve according to Embodiment 1. [Figure 5] This figure shows the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 2, where (a) is a cross-sectional view and (b) is a perspective view. [Figure 6] This figure shows the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 2, where (a) is a cross-sectional view and (b) is a perspective view. [Figure 7] This figure shows the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 3, where (a) is a cross-sectional view and (b) is a perspective view. [Figure 8] This figure shows the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 3, where (a) is a cross-sectional view and (b) is a perspective view. [Figure 9] This is a cross-sectional view showing the dimensional relationship of the vacuum valve according to Embodiment 3. [Figure 10] FIG. is a diagram showing a fixed-side electric field relaxation flange in the vacuum valve according to Embodiment 4. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 11] FIG. is a diagram showing an assembled state of a fixed-side electric field relaxation flange, a fixed-side metal end plate, and an insulating container in the vacuum valve according to Embodiment 4. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 12] FIG. is a diagram showing a fixed-side electric field relaxation flange in the vacuum valve according to Embodiment 5. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 13] FIG. is a diagram showing an assembled state of a fixed-side electric field relaxation flange, a fixed-side metal end plate, and an insulating container in the vacuum valve according to Embodiment 5. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 14] FIG. is a cross-sectional view showing dimensional relationships in the vacuum valve according to Embodiment 5. [Figure 15] FIG. is a diagram showing a fixed-side electric field relaxation flange in the vacuum valve according to Embodiment 6. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 16] FIG. is a diagram showing an assembled state of a fixed-side electric field relaxation flange, a fixed-side metal end plate, and an insulating container in the vacuum valve according to Embodiment 6. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 17] FIG. is a diagram showing a fixed-side electric field relaxation flange in the vacuum valve according to Embodiment 7. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 18] FIG. is a diagram showing an assembled state of a fixed-side electric field relaxation flange, a fixed-side metal end plate, and an insulating container in the vacuum valve according to Embodiment 7. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 19] FIG. is a diagram showing a fixed-side electric field relaxation flange in the vacuum valve according to Embodiment 8. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 20] FIG. is a diagram showing an assembled state of a fixed-side electric field relaxation flange, a fixed-side metal end plate, and an insulating container in the vacuum valve according to Embodiment 8. (a) is a cross-sectional view, and (b) is a perspective view. [Figure 21]It is a cross-sectional view showing the dimensional relationship in the vacuum valve according to Embodiment 8.

Mode for Carrying Out the Invention

[0012] Embodiment 1. Hereinafter, Embodiment 1 of the present application will be described based on FIGS. 1 to 4. In each figure, the same or corresponding members and parts will be described with the same reference numerals. FIG. 1 is a cross-sectional view showing the vacuum valve according to Embodiment 1. FIG. 2 is a view showing the fixed-side electric field relaxation flange in the vacuum valve according to Embodiment 1, (a) is a cross-sectional view, and (b) is a perspective view. FIG. 3 is a view showing the assembled state of the fixed-side electric field relaxation flange, the fixed-side metal end plate, and the insulating container in the vacuum valve according to Embodiment 1, (a) is a cross-sectional view, and (b) is a perspective view. FIG. 4 is a cross-sectional view showing the dimensional relationship in the vacuum valve according to Embodiment 1.

[0013] As shown in FIG. 1, in the vacuum valve of Embodiment 1, a metallized layer 1a is provided on the fixed-side end face of the insulating container 1, a metallized layer 1b is provided on the movable-side end face, and a fixed-side electrode bar 4 having a fixed-side contact 3 located on the central side in the insulating container 1 passes through the fixed-side through hole 5c of the fixed-side metal end plate 5 and is arranged. A movable-side electrode bar 8 having a movable-side contact 7 that comes into contact with and separates from the fixed-side contact 3 located on the central side in the insulating container 1 passes through the movable-side through hole 11c of the movable-side metal end plate 11 and is arranged.

[0014] A shield 2 is provided to prevent an arc or the like associated with the contact and separation of the fixed-side contact 3 and the movable-side contact 7 from adhering to the inner surface of the insulating container 1 on the central side in the insulating container 1. The movable-side electrode bar 8 is provided with a bellows cover 9 and a bellows 10 to maintain the inside of the insulating container 1 in a vacuum state.

[0015] The fixed-side metal end plate 5 has a fixed-side axial straight portion 5b and a fixed-side radial straight portion 5a, which are located on one side of the insulating container 1. The thickness of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5 is shown to be smaller than the thickness of the fixed-side radial straight portion 5a. The movable-side metal end plate 11 has a movable-side axial straight portion 11b and a movable-side radial straight portion 11a, which are located on the other side of the insulating container 1. The thickness of the movable-side axial straight portion 11b of the movable-side metal end plate 11 is shown to be smaller than the thickness of the movable-side radial straight portion 11a.

[0016] A fixed-side electric field mitigation flange 6 is provided, which is positioned between the fixed-side metal end plate 5 and the insulating container 1, with a fixing portion 6a fixed to the metallized layer 1a of the insulating container 1. The fixed-side electric field mitigation flange 6 has a fixed-side first bent portion 6b formed by bending it axially from the fixed-side fixing portion 6a with the insulating container 1, and the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 is joined and attached so as to follow the inner surface of the fixed-side axially straight portion 5b of the fixed-side metal end plate 5.

[0017] A movable electric field mitigation flange 12 is provided, which is positioned between the movable metal end plate 11 and the insulating container 1, with the movable fixing portion 12a fixed to the metallized layer 1b of the insulating container 1. The movable electric field mitigation flange 12 has a movable first bent portion 12b formed by bending axially from the movable fixing portion 12a with the insulating container 1, and the movable first bent portion 12b of the movable electric field mitigation flange 12 is joined and attached along the inner surface of the movable axial straight portion 11b of the movable metal end plate 11.

[0018] The fixed-side metal end plate 5 and the movable-side metal end plate 11 are processed by pressing the plate material to increase the thickness of the radially straight portion 5a on the fixed side, the radially straight portion 11a on the movable side, and the curved portion. To prevent cracking of the insulating container 1 caused by a large difference in the average coefficient of linear expansion between the insulating container 1 and the fixed-side metal end plate 5 and the movable-side metal end plate 11, the axially straight portion 5b on the fixed side and the axially straight portion 11b on the movable side are machined to reduce their thickness.

[0019] Furthermore, Figures 2 and beyond will mainly explain the fixed-side metal end plate 5 and the fixed-side electric field mitigation flange 6. As shown in Figure 2, the fixed-side electric field mitigation flange 6 is shown as being made of a metal such as copper, which is close to the average coefficient of linear expansion of the insulating container 1. As shown in Figure 4, when the width of the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field mitigation flange 6 fixed to the insulating container 1 is a, and the thickness width of the insulating container 1 is b, the relationship between a and b is a≧b. When the length of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 is c, and the length of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5 is d, the relationship between c and d is c≦d. In other words, the width a of the bottom surface of the fixed-side fixing portion 6a of the fixed-side field-relieving flange 6 is greater than or equal to the thickness width b of the insulating container 1, and the fixed-side first bent portion 6b of the fixed-side field-relieving flange 6 is shorter than or equal to the length d of the axially straight portion 5b of the fixed-side metal end plate 5, and is formed by bending it so that c ≤ d.

[0020] Although not shown in detail in the illustration, the movable metal end plate 11 and the movable field mitigation flange 12 have the same structure as the fixed metal end plate 5 and the fixed field mitigation flange 6.

[0021] As described above, the vacuum valve according to this embodiment 1 has a structure in which the fixed-side electric field mitigation flange 6 is fixed so as to cover the metallized layer 1a of the insulating container 1, and the axial side surface of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 is joined and positioned along the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5. Furthermore, the movable-side electric field mitigation flange 12 is fixed so as to cover the metallized layer 1b of the insulating container 1, and the axial side surface of the movable-side first bent portion 12b of the movable-side electric field mitigation flange 12 is joined and positioned along the inner surface of the movable-side axial straight portion 11b of the movable-side metal end plate 11.

[0022] By shaping the fixed-side electric field mitigation flange 6 and the movable-side electric field mitigation flange 12 as described above, it becomes possible to mitigate the electric field of the metallized layers 1a and 1b on the end faces of the insulating container 1, thereby improving the dielectric strength. Furthermore, by joining the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 along the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and joining the axial side of the movable-side first bent portion 12b of the movable-side electric field mitigation flange 12 along the inner surface of the movable-side axial straight portion 11b of the movable-side metal end plate 11, it becomes possible to increase the axial thickness of the fixed-side metal end plate 5 and the movable-side metal end plate 11. This suppresses deformation of the fixed-side metal end plate 5 and the movable-side metal end plate 11 due to gas pressure, even when the vacuum valve is placed in pressurized gas, thereby improving mechanical strength.

[0023] Furthermore, although the case described above involves the fixed-side field mitigation flange 6 being placed on the fixed-side metal end plate 5 and the movable-side field mitigation flange 12 being placed on the movable-side metal end plate 11, the case is not limited to this. The fixed-side field mitigation flange 6 may be provided only on the fixed-side metal end plate 5, or the movable-side field mitigation flange 12 may be provided only on the movable-side metal end plate 11.

[0024] Embodiment 2. Embodiment 2 of the present application will be described with reference to Figures 5 and 6, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 5 is a diagram showing the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 2, where (a) is a cross-sectional view and (b) is a perspective view. Figure 6 is a diagram showing the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 2, where (a) is a cross-sectional view and (b) is a perspective view.

[0025] The vacuum valve of Embodiment 2 of the present invention has substantially the same configuration as that of Embodiment 1 described above. In Embodiment 2, as shown in Figure 5, for example, the tip of the first bent portion 6b on the fixed side of the fixed-side electric field mitigation flange 6 is bent to the same radius as the curved surface of the fixed-side metal end plate 5, thereby forming the fixed-side R-processed portion 6c.

[0026] To avoid the need for expensive machining (cutting) of the fixed metal end plate 5, the fixed metal end plate 5 is press-formed from a plate material of a thickness that prevents cracking of the insulating container caused by a large difference in the average coefficient of thermal expansion between the insulating container 1 and the fixed metal end plate 5.

[0027] Furthermore, as shown in Figure 5, the fixed-side electric field relaxation flange 6 is made of a metal such as copper, which has an average coefficient of thermal expansion close to that of the insulating container 1. As shown in Figure 4 above, when the width of the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field relaxation flange 6 is a and the thickness width of the insulating container 1 is b, the relationship between a and b is a≧b.

[0028] Furthermore, the fixed-side first bent portion 6b of the fixed-side field-relieving flange 6 is bent to follow the inner surface of the fixed-side axially straight portion 5b of the fixed-side metal end plate 5, and is joined and attached so that the bent portion extends beyond the fixed-side axially straight portion 5b of the fixed-side metal end plate 5 and follows the position of the R-shaped curved surface. In addition, the tip of the fixed-side first bent portion 6b of the fixed-side field-relieving flange 6 is bent to the same radius as the R-shaped curved surface of the fixed-side metal end plate 5 to form the fixed-side R-shaped portion 6c.

[0029] As described above, the vacuum valve according to this second embodiment is structured such that the fixed-side electric field mitigation flange 6 is fixed so as to cover the metallized layer 1a of the insulating container 1, the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 is joined to the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and the fixed-side R-processed portion 6c of the fixed-side electric field mitigation flange 6 is joined to the R-processed curved surface of the fixed-side metal end plate 5.

[0030] By shaping the fixed-side electric field mitigation flange 6 as described above, it becomes possible to mitigate the electric field of the metallized layers 1a and 1b on the end face of the insulating container 1, thereby improving the dielectric strength. Furthermore, by joining the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 to the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and joining the fixed-side R-processed portion 6c of the fixed-side electric field mitigation flange 6 to the R-processed curved surface of the fixed-side metal end plate 5, it becomes possible to increase the axial thickness of the fixed-side metal end plate 5, thereby suppressing deformation of the fixed-side metal end plate 5 due to gas pressure even when the vacuum valve is placed in pressurized gas, and improving mechanical strength.

[0031] Furthermore, as shown in Figure 6, the strength is increased by placing a reinforcing plate 13 along the radially straight portion of the fixed side metal end plate 5 on the fixed side of the R-shaped portion 6c of the fixed side electric field mitigation flange 6.

[0032] Furthermore, since it is not necessary to perform expensive machining (cutting) when processing the fixed metal end plate 5, processing costs can be reduced.

[0033] The above description concerns the fixed metal end plate 5 and the fixed field mitigation flange 6. Although not shown in detail in the illustrations, the movable metal end plate 11 and the movable field mitigation flange 12 have the same structure as the fixed metal end plate 5 and the fixed field mitigation flange 6.

[0034] Furthermore, although the case described above involves the fixed-side field mitigation flange 6 being placed on the fixed-side metal end plate 5 and the movable-side field mitigation flange 12 being placed on the movable-side metal end plate 11, the case is not limited to this. The fixed-side field mitigation flange 6 may be provided only on the fixed-side metal end plate 5, or the movable-side field mitigation flange 12 may be provided only on the movable-side metal end plate 11.

[0035] Embodiment 3. Embodiment 3 of the present application will be described with reference to Figures 7 to 9, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 7 is a diagram showing the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 3, where (a) is a cross-sectional view and (b) is a perspective view. Figure 8 is a diagram showing the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 3, where (a) is a cross-sectional view and (b) is a perspective view. Figure 9 is a cross-sectional view showing the dimensional relationship in a vacuum valve according to Embodiment 3.

[0036] As shown in Figure 7, the vacuum valve of Embodiment 3 of the present invention is characterized in that, for example, a fixed-side radial straight portion 6d is provided that is continuous from the tip of the fixed-side first bent portion 6b of the fixed-side electric field relaxation flange 6, and a fixed-side through hole 6e having the same diameter as the fixed-side through hole 5c of the fixed-side metal end plate 5 is formed in the center of the fixed-side radial straight portion 6d.

[0037] To avoid the need for expensive machining (cutting) of the fixed metal end plate 5, the fixed metal end plate 5 is press-formed from a plate material of a thickness that prevents cracking of the insulating container caused by a large difference in the average coefficient of thermal expansion between the insulating container 1 and the fixed metal end plate 5.

[0038] Furthermore, as shown in Figure 7, the fixed-side electric field relaxation flange 6 is made of a metal such as copper, which is close to the average coefficient of linear expansion of the insulating container 1, and as shown in Figure 4 above, when the width of the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field relaxation flange 6 is a and the thickness width of the insulating container 1 is b, the relationship between a and b is a≧b.

[0039] Furthermore, as shown in Figure 9, when the length of the radially straight portion 6d on the fixed side of the fixed-side field-relieving flange 6 is e, and the length of the radially straight portion 5a on the fixed side of the fixed-side metal end plate 5 is f, the relationship between e and f is e ≤ f.

[0040] Furthermore, the fixed-side first bent portion 6b of the fixed-side field-relieving flange 6 is joined to the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and the fixed-side radial straight portion 6d of the fixed-side field-relieving flange 6 is joined to the fixed-side radial straight portion 5a of the fixed-side metal end plate 5.

[0041] As described above, the vacuum valve according to this embodiment 3 is structured such that the fixed-side electric field mitigation flange 6 is fixed so as to cover the metallized layer 1a of the insulating container 1, the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 is joined to the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and the fixed-side radial straight portion 6d of the fixed-side electric field mitigation flange 6 is joined to the fixed-side radial straight portion 5a of the fixed-side metal end plate 5.

[0042] By shaping the fixed-side electric field mitigation flange 6 as described above, it becomes possible to mitigate the electric field of the metallized layers 1a and 1b on the end face of the insulating container 1, thereby improving the dielectric strength. Furthermore, by joining the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 along the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and by joining the fixed-side radial straight portion 6d of the fixed-side electric field mitigation flange 6 along the fixed-side radial straight portion 5a of the fixed-side metal end plate 5, it becomes possible to increase the axial thickness of the fixed-side metal end plate 5. This suppresses deformation of the fixed-side metal end plate 5 due to gas pressure even when the vacuum valve is placed in pressurized gas, thereby improving mechanical strength.

[0043] Furthermore, since it eliminates the need for expensive machining (cutting) when processing the fixed metal end plate 5, and also eliminates the need for a reinforcing plate to be placed on the fixed side radial straight portion 5a of the fixed metal end plate 5, processing costs and the number of parts can be reduced.

[0044] The above description concerns the fixed metal end plate 5 and the fixed field mitigation flange 6. Although not shown in detail in the illustrations, the movable metal end plate 11 and the movable field mitigation flange 12 have the same structure as the fixed metal end plate 5 and the fixed field mitigation flange 6.

[0045] Furthermore, although the case described above involves the fixed-side field mitigation flange 6 being placed on the fixed-side metal end plate 5 and the movable-side field mitigation flange 12 being placed on the movable-side metal end plate 11, the case is not limited to this. The fixed-side field mitigation flange 6 may be provided only on the fixed-side metal end plate 5, or the movable-side field mitigation flange 12 may be provided only on the movable-side metal end plate 11.

[0046] Embodiment 4. Embodiment 4 of the present application will be described with reference to Figures 10 and 11, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 10 is a diagram showing the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 4, where (a) is a cross-sectional view and (b) is a perspective view. Figure 11 is a diagram showing the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 4, where (a) is a cross-sectional view and (b) is a perspective view.

[0047] The vacuum valve of Embodiment 4 of the present application is characterized in that, for example, the fixed-side electric field relaxation flange 6 has a fixed-side second bent portion 6f which is bent in a direction perpendicular to the axial direction toward the inner circumference from the tip of the fixed-side first bent portion 6b, and a fixed-side third bent portion 6g which is bent from the fixed-side second bent portion 6f toward the fixed-side fixing portion 6a of the fixed-side electric field relaxation flange 6, and the fixed-side third bent portion 6g extends to a position beyond the metallized layer 1a of the insulating container 1.

[0048] To avoid the need for expensive machining (cutting) of the fixed metal end plate 5, the fixed metal end plate 5 is press-formed from a plate material of a thickness that prevents cracking of the insulating container caused by a large difference in the average coefficient of thermal expansion between the insulating container 1 and the fixed metal end plate 5.

[0049] Furthermore, as shown in Figure 10, the fixed-side electric field relaxation flange 6 is made of a metal such as copper, which is close to the average coefficient of linear expansion of the insulating container 1. As shown in Figure 4 above, when the width of the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field relaxation flange 6 is a and the thickness width of the insulating container 1 is b, the relationship between a and b is a≧b.

[0050] The fixed-side electric field relaxation flange 6 is made of a metal such as copper, which has an average coefficient of thermal expansion close to that of the insulating container 1. As shown in Figure 4 above, when the width of the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field relaxation flange 6 is a and the thickness width of the insulating container 1 is b, the relationship between a and b is a≧b.

[0051] As described above, the vacuum valve according to this embodiment 4 has a structure in which the fixed-side electric field mitigation flange 6 is fixed so as to cover the metallized layer 1a of the insulating container 1, the axial side surface of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 is joined to the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and the fixed-side third bent portion 6g of the fixed-side electric field mitigation flange 6 is extended to a position beyond the metallized layer 1a of the insulating container 1 so as to be located inside the insulating container 1.

[0052] By shaping the fixed-side electric field mitigation flange 6 as described above, it becomes possible to mitigate the electric field of the metallized layers 1a and 1b on the end face of the insulating container 1, thereby improving the dielectric strength. Furthermore, by joining the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 along the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and by extending the fixed-side third bent portion 6g of the fixed-side electric field mitigation flange 6 beyond the metallized layer 1a of the insulating container 1 so that it is located inside the insulating container 1, it becomes possible to increase the axial thickness of the fixed-side metal end plate 5, thereby suppressing deformation of the fixed-side metal end plate 5 due to gas pressure even when the vacuum valve is placed in pressurized gas, and improving mechanical strength.

[0053] Furthermore, by positioning a portion of the fixed-side third bend 6g of the fixed-side electric field relaxation flange 6 beyond the end face of the metallized layer 1a of the insulating container 1, it becomes possible to suppress the scattering of metal vapor or metal sputter generated when current is interrupted, thereby preventing contamination of the inner surface of the insulating container 1.

[0054] Furthermore, since it is not necessary to perform expensive machining (cutting) when processing the fixed metal end plate 5, processing costs can be reduced.

[0055] The above description concerns the fixed metal end plate 5 and the fixed field mitigation flange 6. Although not shown in detail in the illustrations, the movable metal end plate 11 and the movable field mitigation flange 12 have the same structure as the fixed metal end plate 5 and the fixed field mitigation flange 6.

[0056] Furthermore, although the case described above involves the fixed-side field mitigation flange 6 being placed on the fixed-side metal end plate 5 and the movable-side field mitigation flange 12 being placed on the movable-side metal end plate 11, the case is not limited to this. The fixed-side field mitigation flange 6 may be provided only on the fixed-side metal end plate 5, or the movable-side field mitigation flange 12 may be provided only on the movable-side metal end plate 11.

[0057] Embodiment 5. Embodiment 5 of the present application will be described with reference to Figures 12 to 14, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 12 is a diagram showing the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 5, where (a) is a cross-sectional view and (b) is a perspective view. Figure 13 is a diagram showing the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 5, where (a) is a cross-sectional view and (b) is a perspective view. Figure 14 is a cross-sectional view showing the dimensional relationship in a vacuum valve according to Embodiment 5.

[0058] The vacuum valve of Embodiment 5 of the present application is characterized in that, for example, the fixed-side electric field mitigation flange 6 has a fixed-side second bent portion 6f which is bent in a direction perpendicular to the axial direction toward the inner circumference from the tip of the fixed-side first bent portion 6b, and a fixed-side third bent portion 6g which is bent toward the fixed-side fixing portion 6a from the fixed-side second bent portion 6f, the fixed-side third bent portion 6g which extends to a position beyond the metallized layer 1a of the insulating container 1, and the outside of the fixed-side fixing portion 6a of the fixed-side electric field mitigation flange 6 has a fixed-side fourth bent portion 6h which is bent in the same direction as the fixed-side first bent portion 6b and joined and attached along the outer surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5. The fixed-side axial straight portion 5b of the fixed-side metal end plate 5 is located between the fixed-side first bent portion 6b and the fixed-side fourth bent portion 6h of the fixed-side electric field mitigation flange 6.

[0059] To avoid the need for expensive machining (cutting) of the fixed metal end plate 5, the fixed metal end plate 5 is press-formed from a plate material of a thickness that prevents cracking of the insulating container caused by a large difference in the average coefficient of thermal expansion between the insulating container 1 and the fixed metal end plate 5.

[0060] As shown in Figure 12, the fixed-side electric field relaxation flange 6 is made of a metal such as copper, which has an average coefficient of thermal expansion close to that of the insulating container 1. As shown in Figure 4 above, when the width of the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field relaxation flange 6 is a and the thickness width of the insulating container 1 is b, the relationship between a and b is a≧b.

[0061] Furthermore, as shown in Figure 14, when the length of the fourth bent portion 6h on the fixed side of the fixed-side electric field relaxation flange 6 is g, and the length of the straight axial portion 5b on the fixed side of the fixed-side metal end plate 5 is d, the relationship between g and d is g ≤ d.

[0062] As described above, the vacuum valve according to this embodiment 5 has a structure in which the fixed-side electric field mitigation flange 6 is fixed so as to cover the metallized layer 1a of the insulating container 1, the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 is joined to the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and the fixed-side third bent portion 6g of the fixed-side electric field mitigation flange 6 is extended to a position beyond the metallized layer 1a of the insulating container 1 so as to be located inside the insulating container 1. Furthermore, the fixed-side fourth bent portion 6h of the fixed-side electric field mitigation flange 6 is bent in the same direction as the fixed-side first bent portion 6b and joined to the outer surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5. As a result, the axially straight portion 5b of the fixed-side metal end plate 5 is positioned between the first fixed-side bend portion 6b and the fourth fixed-side bend portion 6h of the fixed-side electric field mitigation flange 6, thereby improving the mechanical strength between the fixed-side metal end plate 5 and the fixed-side electric field mitigation flange 6.

[0063] By shaping the fixed-side electric field mitigation flange 6 as described above, it becomes possible to mitigate the electric field of the metallized layers 1a and 1b on the end face of the insulating container 1, thereby improving the dielectric strength. Furthermore, by joining the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 along the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and by extending the fixed-side third bent portion 6g of the fixed-side electric field mitigation flange 6 beyond the metallized layer 1a of the insulating container 1 so that it is located inside the insulating container 1, and by bending the fixed-side fourth bent portion 6h of the fixed-side electric field mitigation flange 6 in the same direction as the fixed-side first bent portion 6b and joining and attaching it along the outer surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, it becomes possible to increase the axial thickness of the fixed-side metal end plate 5, and even when the vacuum valve is placed in pressurized gas, deformation of the fixed-side metal end plate 5 due to gas pressure can be suppressed, thereby improving mechanical strength.

[0064] Furthermore, by positioning a portion of the fixed-side third bend 6g of the fixed-side electric field relaxation flange 6 beyond the end face of the metallized layer 1a of the insulating container 1, it becomes possible to suppress the scattering of metal vapor or metal sputter generated when current is interrupted, thereby preventing contamination of the inner surface of the insulating container 1.

[0065] Furthermore, since it is not necessary to perform expensive machining (cutting) when processing the fixed metal end plate 5, processing costs can be reduced.

[0066] The above description concerns the fixed metal end plate 5 and the fixed field mitigation flange 6. Although not shown in detail in the illustrations, the movable metal end plate 11 and the movable field mitigation flange 12 have the same structure as the fixed metal end plate 5 and the fixed field mitigation flange 6.

[0067] Furthermore, although the case described above involves the fixed-side field mitigation flange 6 being placed on the fixed-side metal end plate 5 and the movable-side field mitigation flange 12 being placed on the movable-side metal end plate 11, the case is not limited to this. The fixed-side field mitigation flange 6 may be provided only on the fixed-side metal end plate 5, or the movable-side field mitigation flange 12 may be provided only on the movable-side metal end plate 11.

[0068] Embodiment 6. Embodiment 6 of the present application will be described with reference to Figures 15 and 16, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 15 is a diagram showing the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 6, where (a) is a cross-sectional view and (b) is a perspective view. Figure 16 is a diagram showing the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 6, where (a) is a cross-sectional view and (b) is a perspective view.

[0069] The vacuum valve of Embodiment 6 of the present application has substantially the same configuration as that of Embodiment 5 described above. In Embodiment 6, as shown in Figure 15, for example, a fixed-side screw hole 14 is formed in the fixed-side fourth bent portion 6h of the fixed-side field relaxation flange 6, and the fixed-side electrolytic relaxation ring 15 is screwed into the fixed-side screw hole 14 formed in the fixed-side fourth bent portion 6h of the fixed-side field relaxation flange 6 by screwing a fixed-side screw 16 into the fixed-side screw hole 14 formed in the fixed-side fourth bent portion 6h of the fixed-side field relaxation flange 6 and screwing it to the fixed-side fourth bent portion 6h of the fixed-side field relaxation flange 6.

[0070] To avoid the need for expensive machining (cutting) of the fixed metal end plate 5, the fixed metal end plate 5 is press-formed from a plate material of a thickness that prevents cracking of the insulating container caused by a large difference in the average coefficient of thermal expansion between the insulating container 1 and the fixed metal end plate 5.

[0071] As shown in Figure 15, the fixed-side field-relieving flange 6 is made of a metal such as copper, which has an average coefficient of linear expansion close to that of the insulating container 1. As shown in Figure 4 above, when the width of the bottom surface of the fixed-side fixing portion 6a of the fixed-side field-relieving flange 6 is a and the thickness width of the insulating container 1 is b, the relationship between a and b is a≧b. Also, as shown in Figure 14 above, when the length of the fixed-side fourth bend portion 6h of the fixed-side field-relieving flange 6 is g and the length of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5 is d, the relationship between g and d is g≦d.

[0072] The vacuum valve according to this embodiment 6 has, in addition to the configuration of embodiment 5 described above, a fixed-side electrolytic relaxation ring 15 screwed to the fixed-side fourth bent portion 6h of the fixed-side electric field relaxation flange 6 by a fixed-side screw 16.

[0073] By shaping the fixed-side electric field mitigation flange 6 as described above, it becomes possible to mitigate the electric field of the metallized layers 1a and 1b on the end face of the insulating container 1, thereby improving the dielectric strength. Furthermore, by joining the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 along the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and by extending the fixed-side third bent portion 6g of the fixed-side electric field mitigation flange 6 beyond the metallized layer 1a of the insulating container 1 so that it is located inside the insulating container 1, and by bending the fixed-side fourth bent portion 6h of the fixed-side electric field mitigation flange 6 in the same direction as the fixed-side first bent portion 6b and joining and attaching it along the outer surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, it becomes possible to increase the axial thickness of the fixed-side metal end plate 5, and even when the vacuum valve is placed in pressurized gas, deformation of the fixed-side metal end plate 5 due to gas pressure can be suppressed, thereby improving mechanical strength.

[0074] Furthermore, by positioning a portion of the fixed-side third bend 6g of the fixed-side electric field relaxation flange 6 beyond the end face of the metallized layer 1a of the insulating container 1, it becomes possible to suppress the scattering of metal vapor or metal sputter generated when current is interrupted, thereby preventing contamination of the inner surface of the insulating container 1.

[0075] Furthermore, by providing a fixed-side screw hole 14 on the side surface of the fixed-side fourth bent portion 6h of the fixed-side electric field mitigation flange 6, it becomes possible to retrofit a fixed-side electric field mitigation ring 15 to the outside of the vacuum valve, thereby mitigating the electric field outside the vacuum valve as well.

[0076] Furthermore, since it is not necessary to perform expensive machining (cutting) when processing the fixed metal end plate 5, processing costs can be reduced.

[0077] The above description concerns the fixed metal end plate 5 and the fixed field mitigation flange 6. Although not shown in detail in the illustrations, the movable metal end plate 11 and the movable field mitigation flange 12 have the same structure as the fixed metal end plate 5 and the fixed field mitigation flange 6.

[0078] Furthermore, although the case described above involves the fixed-side field mitigation flange 6 being placed on the fixed-side metal end plate 5 and the movable-side field mitigation flange 12 being placed on the movable-side metal end plate 11, the case is not limited to this. The fixed-side field mitigation flange 6 may be provided only on the fixed-side metal end plate 5, or the movable-side field mitigation flange 12 may be provided only on the movable-side metal end plate 11.

[0079] Embodiment 7. Embodiment 7 of the present application will be described with reference to Figures 17 and 18, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 17 is a diagram showing the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 7, where (a) is a cross-sectional view and (b) is a perspective view. Figure 18 is a diagram showing the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 7, where (a) is a cross-sectional view and (b) is a perspective view.

[0080] The vacuum valve of Embodiment 7 of the present application is characterized in that, in addition to the configuration of Embodiment 5 described above, it has a fixed-side fifth bent portion 6i that is bent from the fixed-side fourth bent portion 6h of the fixed-side electric field relaxation flange 6 toward the outer circumference in a direction perpendicular to the axial direction, and a fixed-side sixth bent portion 6j that is bent from the fixed-side fifth bent portion 6i toward the fixed-side fixing portion 6a, the fixed-side sixth bent portion 6j extends to a position beyond the metallized layer 1a of the insulating container 1, and a fixed-side confirmation hole 17 is provided in the fixed-side sixth bent portion 6j near the height position of the metallized layer 1a for checking the solder after brazing.

[0081] As shown in Figure 17, the fixed-side electric field relaxation flange 6 is made of a metal such as copper, which has an average coefficient of thermal expansion close to that of the insulating container 1. As shown in Figure 4 above, when the width of the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field relaxation flange 6 is a and the thickness width of the insulating container 1 is b, the relationship between a and b is a≧b.

[0082] The vacuum valve according to this embodiment 7, in addition to the configuration of embodiment 5 described above, is provided with a fixed-side fifth bent portion 6i at the tip of the fixed-side fourth bent portion 6h of the fixed-side electric field relaxation flange 6, and a fixed-side sixth bent portion 6j that is bent from the fixed-side fifth bent portion 6i toward the fixed-side fixing portion 6a, the fixed-side sixth bent portion 6j extending to a position beyond the metallized layer 1a of the insulating container 1, and a fixed-side confirmation hole 17 is provided in the fixed-side sixth bent portion 6j near the height position of the metallized layer 1a, so that the area around the brazing after brazing can be checked from the fixed-side confirmation hole 17.

[0083] By shaping the fixed-side electric field mitigation flange 6 as described above, it becomes possible to mitigate the electric field of the metallized layers 1a and 1b on the end face of the insulating container 1, thereby improving the dielectric strength. Furthermore, by joining the axial side of the fixed-side first bent portion 6b of the fixed-side electric field mitigation flange 6 along the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and by extending the fixed-side third bent portion 6g of the fixed-side electric field mitigation flange 6 beyond the metallized layer 1a of the insulating container 1 so that it is located inside the insulating container 1, and by bending the fixed-side fourth bent portion 6h of the fixed-side electric field mitigation flange 6 in the same direction as the fixed-side first bent portion 6b and joining and attaching it along the outer surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, it becomes possible to increase the axial thickness of the fixed-side metal end plate 5, and even when the vacuum valve is placed in pressurized gas, deformation of the fixed-side metal end plate 5 due to gas pressure can be suppressed, thereby improving mechanical strength.

[0084] Furthermore, by positioning a portion of the fixed-side third bend 6g of the fixed-side electric field relaxation flange 6 beyond the end face of the metallized layer 1a of the insulating container 1, it becomes possible to suppress the scattering of metal vapor or metal sputter generated when current is interrupted, thereby preventing contamination of the inner surface of the insulating container 1.

[0085] Furthermore, by positioning the fixed-side sixth bent portion 6j of the fixed-side electric field mitigation flange 6 to extend beyond the metallized layer 1a of the insulating container 1 so that it is located outside the insulating container 1, the electric field outside the vacuum valve can also be mitigated.

[0086] Furthermore, since it is not necessary to perform expensive machining (cutting) when processing the fixed metal end plate 5, processing costs can be reduced.

[0087] Furthermore, by providing a fixed-side confirmation hole 17 on the side surface of the fixed-side sixth bend portion 6j of the fixed-side electric field relaxation flange 6, the condition around the brazing material after brazing can be checked.

[0088] The above description concerns the fixed metal end plate 5 and the fixed field mitigation flange 6. Although not shown in detail in the illustrations, the movable metal end plate 11 and the movable field mitigation flange 12 have the same structure as the fixed metal end plate 5 and the fixed field mitigation flange 6.

[0089] Furthermore, although the case described above involves the fixed-side field mitigation flange 6 being placed on the fixed-side metal end plate 5 and the movable-side field mitigation flange 12 being placed on the movable-side metal end plate 11, the case is not limited to this. The fixed-side field mitigation flange 6 may be provided only on the fixed-side metal end plate 5, or the movable-side field mitigation flange 12 may be provided only on the movable-side metal end plate 11.

[0090] Embodiment 8. Embodiment 8 of the present application will be described with reference to Figures 19 to 21, in which the same or equivalent members and parts will be denoted by the same reference numerals in each figure. Figure 19 is a diagram showing the fixed-side electric field mitigation flange in a vacuum valve according to Embodiment 8, where (a) is a cross-sectional view and (b) is a perspective view. Figure 20 is a diagram showing the assembled state of the fixed-side electric field mitigation flange, the fixed-side metal end plate, and the insulating container in a vacuum valve according to Embodiment 8, where (a) is a cross-sectional view and (b) is a perspective view. Figure 21 is a cross-sectional view showing the dimensional relationship in a vacuum valve according to Embodiment 8.

[0091] The vacuum valve of Embodiment 8 of the present invention is characterized in that, in addition to the configuration of Embodiment 7 described above, for example, a fixed-side counterbore portion 18 that engages with the insulating container 1 is formed on the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field relaxation flange 6, as shown in Figure 21, when the thickness width of the insulating container 1 is b and the counterbore width of the fixed-side counterbore portion 18 is h, the relationship between b and h is b ≤ h.

[0092] As shown in Figure 19, the fixed-side electric field relaxation flange 6 is made of a metal such as copper, which has an average coefficient of thermal expansion close to that of the insulating container 1. By shaping the fixed-side electric field relaxation flange 6 as described above, it is possible to relax the electric field of the metallized layers 1a and 1b on the end faces of the insulating container 1, thereby improving the dielectric strength. Furthermore, by joining the axial side of the first fixed-side bent portion 6b of the fixed-side electric field mitigation flange 6 along the inner surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, and by extending the third fixed-side bent portion 6g of the fixed-side electric field mitigation flange 6 beyond the metallized layer 1a of the insulating container 1 so that it is located inside the insulating container 1, and by bending the fourth fixed-side bent portion 6h of the fixed-side electric field mitigation flange 6 in the same direction as the first bent portion 6b and joining and attaching it along the outer surface of the fixed-side axial straight portion 5b of the fixed-side metal end plate 5, it becomes possible to increase the axial thickness of the fixed-side metal end plate 5, and even when the vacuum valve is placed in pressurized gas, deformation of the fixed-side metal end plate 5 due to gas pressure can be suppressed and mechanical strength can be improved.

[0093] Furthermore, by positioning a portion of the fixed-side third bend 6g of the fixed-side electric field relaxation flange 6 beyond the end face of the metallized layer 1a of the insulating container 1, it becomes possible to suppress the scattering of metal vapor or metal sputter generated when current is interrupted, thereby preventing contamination of the inner surface of the insulating container 1.

[0094] Furthermore, by positioning the fixed-side sixth bent portion 6j of the fixed-side electric field mitigation flange 6 to extend beyond the metallized layer 1a of the insulating container 1 so that it is located outside the insulating container 1, the electric field outside the vacuum valve can also be mitigated.

[0095] Furthermore, since it is not necessary to perform expensive machining (cutting) when processing the fixed metal end plate 5, processing costs can be reduced.

[0096] Furthermore, by providing a fixed-side confirmation hole 17 on the side surface of the fixed-side sixth bend portion 6j of the fixed-side electric field relaxation flange 6, the condition around the brazing material after brazing can be checked.

[0097] Furthermore, by providing a fixed-side counterbore portion 18 that engages with the insulating container 1 on the bottom surface of the fixed-side fixing portion 6a of the fixed-side electric field mitigation flange 6, the fixed-side electric field mitigation flange 6 and the insulating container 1 can be positioned, and the vacuum valve can be easily assembled without using a dedicated positioning jig.

[0098] The above description concerns the fixed metal end plate 5 and the fixed field mitigation flange 6. Although not shown in detail in the illustrations, the movable metal end plate 11 and the movable field mitigation flange 12 have the same structure as the fixed metal end plate 5 and the fixed field mitigation flange 6.

[0099] Furthermore, although the case described above involves the fixed-side field mitigation flange 6 being placed on the fixed-side metal end plate 5 and the movable-side field mitigation flange 12 being placed on the movable-side metal end plate 11, the case is not limited to this. The fixed-side field mitigation flange 6 may be provided only on the fixed-side metal end plate 5, or the movable-side field mitigation flange 12 may be provided only on the movable-side metal end plate 11.

[0100] Although this application 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 can be applied individually or in various combinations to the embodiments. Accordingly, countless variations not illustrated are conceivable within the scope of the technology disclosed herein. These include, for example, modifications, additions, or omissions of at least one component, as well as the extraction of at least one component and its combination with components of other embodiments. [Industrial applicability]

[0101] This invention is suitable for realizing highly reliable vacuum valves. [Explanation of Symbols]

[0102] 1 Insulating container, 1a Metallized layer, 1b Metallized layer, 2 Shield, 3 Fixed side contact, 4 Fixed side electrode rod, 5 Fixed side metal end plate, 5a Fixed side radial straight section, 5b Fixed side axial straight section, 6 Fixed side electric field mitigation flange, 6a Fixed side fixing section, 6b Fixed side first bend section, 6c Fixed side R-processed section, 6d Fixed side radial straight section, 6f Fixed side second bend section, 6g Fixed side third bend section, 6h Fixed side fourth bend section, 6i Fixed side fifth bend section, 6j Fixed side sixth bend section, 7 Movable side contact, 8 Movable side electrode rod, 9 Bellows cover, 10 Bellows, 11 Movable side metal end plate, 11a Movable side radial straight section, 11b Movable side axial straight section, 12 Movable side electric field mitigation flange, 12a Movable side fixing section, 12b 13. Movable side first bending section, 15. Fixed side reinforcing plate, 16. Fixed side electric field mitigation ring, 17. Fixed side screw, 18. Fixed side confirmation hole, 19. Fixed side counterbore section

Claims

1. a movable side contact provided on the movable side electrode bar and adapted to move forward and backward through a bellows to the movable side metal end plate; and a movable side contact provided on the movable side electrode bar and adapted to come into contact with and be separated from the fixed side contact. The vacuum valve has an insulating container having metallized layers on both end surfaces, a fixed side metal end plate arranged on one side of the insulating container and having an axially straight portion and a radially straight portion, a fixed side electrode bar secured to the fixed side metal end plate, a fixed side contact provided on the fixed side electrode bar, a movable side metal end plate arranged on the other side of the insulating container and having an axially straight portion and a radially straight portion, a movable side electrode bar provided on the movable side metal end plate so as to be able to advance and retreat via a bellows, and a movable side contact provided on the movable side electrode bar and adapted to come into contact with and be separated from the fixed side contact, wherein an electric field relaxation flange is provided between at least one of the fixed side metal end plate and the movable side metal end plate and is secured to the insulating container,

2. 2. The vacuum valve according to claim 1, wherein the electric field relaxation flange is made of a metal having an average linear expansion coefficient equivalent to that of the insulating container.

3. 3. The vacuum valve according to claim 1, wherein the thickness of the axially straight portion of the metal end plate is smaller than the thickness of the radially straight portion of the metal end plate.

4. 3. The vacuum valve according to claim 1 or 2, characterized in that, when the width of the bottom surface of the fixing portion of the electric field relaxation flange is a and the thickness width of the insulating container is b, the relationship between a and b is a ≧ b, and when the length of the first bent portion of the electric field relaxation flange is c and the length of the axial straight portion of the metal end plate is d, the relationship between c and d is c ≦ d.

5. 3. The vacuum valve according to claim 1, wherein the first bent portion of the electric field relaxation flange has a rounded portion bent to the same radius as the rounded curved surface of the metal end plate.

6. 6. The vacuum valve according to claim 5, wherein a reinforcing plate is provided at the R-processed portion of the electric field relaxation flange.

7. 3. The vacuum valve according to claim 1, wherein the electric field relaxation flange has a straight portion extending from the first bent portion along the radial straight portion of the metal end plate.

8. The vacuum valve according to claim 7, characterized in that, when the length of the straight portion of the electric field relaxation flange is e and the length of the radial straight portion of the metal end plate is f, the relationship between e and f satisfies e≦f.

9. The vacuum valve described in claim 1 or 2, characterized in that the electric field mitigation flange has a second bent portion bent from the first bent portion toward the inner circumference in a direction perpendicular to the axial direction, and a third bent portion bent from the second bent portion toward the fixing portion, and the third bent portion extends to a position beyond the metallized layer of the insulating container.

10. The vacuum valve described in claim 1 or 2, characterized in that the electric field mitigation flange has a second bent portion bent from the first bent portion toward the inner circumference in a direction perpendicular to the axial direction, a third bent portion bent from the second bent portion toward the fixing portion, the third bent portion extending to a position beyond the metallized layer of the insulating container, and a fourth bent portion bent at the outer side of the fixing portion of the electric field mitigation flange in the same direction as the first bent portion and joined and attached so as to fit along the outer surface of the metal end plate.

11. The vacuum valve according to claim 10, characterized in that, when the length of the fourth bent portion of the electric field relaxation flange is g and the length of the axially straight portion of the metal end plate is d, the relationship between g and d satisfies g≦d.

12. 11. The vacuum valve according to claim 10, wherein an electric field relaxation ring is screwed to the fourth bent portion of the electric field relaxation flange.

13. The vacuum valve described in claim 10, characterized in that it has a fifth bend portion bent from the fourth bend portion of the electric field mitigation flange toward the outer periphery in a direction perpendicular to the axial direction, and a sixth bend portion bent from the fifth bend portion toward the fixing portion, the sixth bend portion extending to a position beyond the metallized layer of the insulating container, and a confirmation hole formed in the sixth bend portion at the height position of the metallized layer.

14. A vacuum valve as described in claim 10, characterized in that a countersunk portion that engages with the insulating container is formed on a bottom surface of the fixing portion of the electric field mitigation flange, and when the thickness width of the insulating container is b and the countersunk width of the countersunk portion is h, the relationship between b and h is b≦h.