Vacuum interrupter and manufacturing method thereof

Abstract

To provide a technology that makes it possible to obtain desired characteristics such as dielectric strength and electric field relaxation effects in a vacuum interrupter, and with which it is possible to contribute to simplifying and downsizing an assembling structure.SOLUTION: Arc shields 4a, 4b are supported on the inner circumferential side of an intermediate tank part 2 of a vacuum interrupter A at a position that is apart in the axial direction of a cylindrical body 10. Each arc shield 4a, 4b is annular in shape extending in the circumferential direction along the inner circumferential side of the intermediate tank part 2 and is constituted to include an arc shiel base end part 41 that supports the arc shield on the inner circumferential side of the intermediate tank part and an arc shield body part 42 which is cylindrical coaxially with the arc shield base end part 41 and extends in the axial direction from the inner circumferential side of the arc shield base end part 41. The arc shield base end part 41 is constituted to support a cylindrical auxiliary shield 5 which is coaxial with and is larger in diameter than the arc shield body part 42 so as to extend in the same direction as the arc shield body part 42.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vacuum interrupter that is applied to, for example, various electric power facilities and a method for manufacturing the vacuum interrupter. [Background technology]

[0002] Among the vacuum circuit breakers used in electric power facilities, there are known ones that incorporate a vacuum interrupter as a current interrupting component. In recent years, it is expected that the application of vacuum interrupters will be expanded to higher voltage power systems, and various improvements are being considered for each, for example, so that desired characteristics (insulation performance, etc.) can be obtained.

[0003] 6 indicates a commonly known vacuum interrupter, which uses a vacuum vessel 91 in which a fixed side, which is one end side in the axial direction (hereinafter simply referred to as the axial direction) of an insulating cylindrical body 90, is sealed with a fixed side flange 91a, and a movable side, which is the other end side in the axial direction, is sealed with a movable side flange 91b. The cylindrical body 90 has a cylindrical intermediate tank portion 9c, a fixed side insulating portion 9a, and a movable side insulating portion 9b, and is configured such that the intermediate tank portion 9c is sandwiched between the fixed side insulating portion 9a and the movable side insulating portion 9b and is connected coaxially.

[0004] A fixed-side current-carrying shaft 92a is provided on the fixed-side flange 91a inside the vacuum vessel 91 so as to extend in the axial direction from the inside of the vacuum vessel 91, and a fixed electrode 93a is supported on the end of the fixed-side current-carrying shaft 92a. A movable-side current-carrying shaft 92b is provided on the movable-side flange 91b so as to penetrate the movable-side flange 91b in the axial direction and extend in the axial direction.

[0005] The movable current-carrying shaft 92b is supported on the inside of the vacuum vessel 91 of the movable flange 91b via bellows 92c that is expandable and contractible in the axial direction, and is movable in the axial direction. A movable electrode 93b is supported on the end of the movable current-carrying shaft 92b, and moves toward and away from a fixed electrode 93a in accordance with the movement of the movable current-carrying shaft 92b.

[0006] In the vacuum interrupter described above, various shields are used to improve various characteristics such as dielectric strength, electric field relaxation effect, etc. For example, a shield is used that takes into consideration the electric field relaxation at a location called a triple point (a boundary location between three materials with different relative dielectric constants), and examples of such a shield include arc shields 94a, 94b and electric field relaxation shields 95a, 95b as shown in Fig. 6.

[0007] For example, Patent Documents 1 and 2 disclose a configuration (hereinafter simply referred to as the conventional configuration) in which an arc shield (references 2 and 3 in Patent Documents 1 and 2) provided in the intermediate tank section of a vacuum vessel has an extension portion that protrudes toward the outer periphery of the vacuum vessel, and an external shield (references 15 and 16 in Patent Document 1, reference 14 in Patent Document 2) is provided to surround the outer periphery of the protruding extension portion. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 5641944 [Patent Document 2] JP 2003-272492 A Summary of the Invention [Problem to be solved by the invention]

[0009] In a vacuum interrupter, each component of the vacuum interrupter is assembled while being appropriately sealed (for example, vacuum sealed off by brazing or the like) so that a desired vacuum state can be maintained inside the vacuum container. However, if an arc shield or an external shield having an extension is used as in the conventional configuration, the number of sealed parts increases, which may lead to a complicated assembly configuration and an increase in size.

[0010] The present invention has been made in consideration of these technical problems, and aims to provide a technology that enables desired characteristics, such as dielectric strength and electric field relaxation effect, to be obtained in a vacuum interrupter, and that can contribute to simplifying the assembly configuration and reducing the size. [Means for solving the problem]

[0011] The vacuum interrupter and manufacturing method of the vacuum interrupter according to the present invention can contribute to solving the above-mentioned problems, and one aspect of the vacuum interrupter comprises a vacuum vessel having an insulating cylindrical body, in which a fixed side, which is one axial end of the cylindrical body, is sealed by a fixed side flange and a movable side, which is the other axial end, is sealed by a movable side flange, a fixed side current-carrying shaft extending in the axial direction from the inside of the vacuum vessel of the fixed side flange, a fixed electrode supported by an end of the fixed side current-carrying shaft on the extending side side, a movable side current-carrying shaft penetrating the movable side flange in the axial direction, extending in the axial direction, supported inside the vacuum vessel of the movable side flange via a bellows which is expandable and contractible in the axial direction and movable in the axial direction, and a movable electrode supported by an end of the movable side current-carrying shaft inside the vacuum vessel, facing the fixed electrode, and moving towards and away from the fixed electrode in response to movement of the movable side current-carrying shaft.

[0012] The cylindrical main body has a cylindrical intermediate tank portion surrounding the outer circumferential sides of the fixed electrode and the movable electrode, a cylindrical fixed side insulating portion coaxially connected to the intermediate tank portion on the fixed side of the intermediate tank portion in the axial direction, and a cylindrical movable side insulating portion coaxially connected to the intermediate tank portion on the movable side of the intermediate tank portion in the axial direction.

[0013] The inner circumference of the intermediate tank is fixed from the inner circumference of the intermediate tank. side insulation Department An arc shield extending along the inner periphery of the intermediate tank section to the fixed side in the axial direction, and an arc shield extending from the inner periphery of the intermediate tank section to the movable side in the axial direction along the inner periphery of the movable insulating section, are supported at positions spaced apart from each other in the axial direction.

[0014] And each arc shield is: The end of the intermediate tank portion that is supported on the inner periphery of the intermediate tank portion is bent radially outward of the cylindrical main body. An annular groove extending circumferentially along the inner periphery of the intermediate tank portion of The arc shield has an arc shield base end and an arc shield main body that is cylindrical and coaxial with the arc shield base end and extends from the inner side of the arc shield base end in the axial direction, and is characterized in that a coaxial cylindrical auxiliary shield having a larger diameter than the arc shield main body is supported at each arc shield base end of the arc shield so as to extend in the same direction as the arc shield main body.

[0015] In one embodiment of the vacuum interrupter, each arc shield has its own To The tip of the arc shield main body extends so as to protrude in the axial direction beyond the tip of the supported auxiliary shield, and the linear expansion coefficient of each arc shield is To It may be characterized in that the coefficient of linear expansion is greater than that of the auxiliary shield that it supports.

[0016] Each arc shield may be characterized in that a terminal end of a tip portion in an extension direction of the arc shield main body is curved outward in a radial direction of the cylindrical main body.

[0017] The tip portion of the auxiliary shield supported by each arc shield may be curved toward the terminal end side of the arc shield main body.

[0018] Further, the intermediate tank portion may include a cylindrical tank main body portion and a pair of cylindrical adapters coaxially connected to a fixed side and a movable side of the cylindrical tank main body portion, and each connecting surface of the connected cylindrical tank main body portion and the connected cylindrical adapters facing each other has a stepped shape extending in the radial direction, and the base end of the auxiliary shield supported by each arc shield has a shape bent outward in the radial direction, and both the base end of the auxiliary shield and the base end of the arc shield are supported in a stacked position in the axial direction, and the both are supported between radially extending surfaces of the connected surfaces that extend in the radial direction on the radially inner side.

[0019] The auxiliary shield may be characterized in that it is made of titanium or an alloy containing titanium as a main component.

[0020] In one embodiment of the method for manufacturing the vacuum interrupter, each arc shield comprises: Each The auxiliary shield is supported, and then supported on the inner peripheral side of the intermediate tank portion. Effect of the Invention

[0021] As described above, according to the present invention, it is possible to obtain desired characteristics such as dielectric strength and electric field relaxation effect in a vacuum interrupter, and this can contribute to simplifying the assembly structure and reducing the size. [Brief description of the drawings]

[0022] [Figure 1] 1 is a schematic diagram for explaining the schematic configuration of a vacuum interrupter A according to a first embodiment (a vertical cross-sectional view taken along the axial direction (left-right direction in the figure) of a vacuum vessel 1). [Diagram 2] 2 is a schematic diagram illustrating the arc shield 4 (arc shield 4b in FIG. 2) and auxiliary shield 5 in FIG. 1, and their surroundings (an enlarged view of the main parts). FIG. [Diagram 3] 10 is a schematic diagram for explaining the schematic configuration of a modified example of the vacuum interrupter A according to the second embodiment (an enlarged view of the main part similar to FIG. 2). FIG. [Figure 4]FIG. 11 is a schematic diagram for explaining the schematic configuration of a modified example of the vacuum interrupter A according to the third embodiment (a vertical cross-sectional view taken along the axial direction of the vacuum vessel 1 (left-right direction in the figure)). [Diagram 5] 5A and 5B are schematic diagrams illustrating the arc shield 4 (arc shield 4b in FIG. 4) and auxiliary shield 5 in FIG. 4, and the surrounding area ((A) is an enlarged view of the main parts similar to FIG. 2, and (B) is a further enlarged view). [Figure 6] FIG. 1 is a schematic diagram illustrating an example of a general vacuum interrupter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The vacuum interrupter according to the embodiment of the present invention is completely different from the conventional configuration in which an arc shield or an external shield having an extension portion is applied.

[0024] That is, in the vacuum interrupter of this embodiment, a vacuum container is provided in which an intermediate tank portion is sandwiched between a fixed insulating portion and a movable insulating portion and arranged coaxially. side insulation Department The arc shield extends along the inner periphery of the intermediate tank section to the fixed side in the axial direction, and the arc shield extends from the inner periphery of the intermediate tank section to the movable side in the axial direction along the inner periphery of the movable insulating section, in a configuration in which the arc shield is supported at positions spaced apart from each other in the axial direction.

[0025] For each arc shield, The end of the intermediate tank portion that is supported on the inner periphery of the intermediate tank portion is bent radially outward of the cylindrical main body. An annular groove extending circumferentially along the inner periphery of the intermediate tank portion of The arc shield has an arc shield base end, and an arc shield main body that is cylindrical and coaxial with the arc shield base end and extends from the inner periphery of the arc shield base end in the axial direction. A coaxial cylindrical auxiliary shield having a larger diameter than the arc shield main body is supported at each of the arc shield base ends so as to extend in the same direction as the arc shield main body.

[0026] According to this configuration, it is possible to obtain desired characteristics such as dielectric strength and electric field relaxation effect in the vacuum interrupter without applying an arc shield or external shield having an extension portion as in the conventional configuration. Furthermore, compared with the conventional configuration, it is possible to reduce the number of sealed parts for maintaining the desired vacuum state of the vacuum container, which contributes to simplifying the assembly configuration of the vacuum interrupter and making it smaller. The simplified assembly configuration makes it easier to position and assemble each component of the vacuum interrupter (for example, it is easier to prevent misalignment of each component), which can also contribute to improving product precision, reliability, durability, etc.

[0027] This embodiment is a vacuum interrupter having an auxiliary shield supported at each base end of the arc shield as described above, and can be modified in design by appropriately applying common technical knowledge in various fields (such as the field of vacuum circuit breakers) and by appropriately referring to prior art documents, etc., as necessary. Note that in the following Examples 1 to 3, detailed explanations are omitted as appropriate, for example, by referring to the same reference numerals to similar contents.

[0028] Example 1 1 and 2 are diagrams for explaining the schematic configuration of a vacuum interrupter A according to Example 1. This vacuum interrupter A uses a vacuum vessel 1 in which the axial fixed side of an insulating cylindrical body 10 is sealed by a fixed side flange 11a and the axial movable side is sealed by a movable side flange 11b.

[0029] In this vacuum vessel 1, a columnar fixed-side current-carrying shaft 12a is provided on the inside of the vacuum vessel 1 of the fixed-side flange 11a so as to extend from the inside of the vacuum vessel 1 to the axially movable side. A fixed electrode 13a, for example, in the shape of a flat plate, is supported on the end of the fixed-side current-carrying shaft 12a on the axially movable side (extending direction side).

[0030] A columnar movable-side current-carrying shaft 12b is provided in the movable-side flange 11b so as to penetrate the movable-side flange 11b in the axial direction and extend in the axial direction. The movable-side current-carrying shaft 12b is supported inside the vacuum vessel 1 of the movable-side flange 11b via a cylindrical bellows 14 that is axially extendable and contractible and arranged coaxially with the movable-side current-carrying shaft 12b. This allows the movable-side current-carrying shaft 12b to move in the axial direction.

[0031] In the case of the movable current-carrying shaft 12b shown in FIG. 1, a cylindrical bellows shield 15 is provided so as to cover and surround the outer periphery of the bellows .

[0032] In addition, a movable electrode 13b, for example a flat plate, is supported on the end of the movable current shaft 12b inside the vacuum vessel 1, and is adapted to move towards and away from the fixed electrode 13a in accordance with the movement of the movable current shaft 12b in the axial direction.

[0033] The cylindrical main body 10 mainly comprises a cylindrical intermediate tank portion 2 surrounding the outer circumferential sides of the fixed electrode 13a and the movable electrode 13b (the outer circumferential side of the contact 13), a fixed side insulating portion 3a coaxially connected to the axial fixed side of the intermediate tank portion 2, and a movable side insulating portion 3b coaxially connected to the axial movable side of the intermediate tank portion 2.

[0034] A fixed side arc shield 4a is provided on the axial fixed side of the inner periphery of the intermediate tank portion 2, extending toward the axial fixed side along the inner periphery of the fixed side insulating portion 3a, and a movable side arc shield 4b is provided on the axial movable side of the intermediate tank portion 2, extending toward the axial movable side along the inner periphery of the movable side insulating portion 3b.

[0035] Both the fixed arc shield 4a and the movable arc shield 4b (hereinafter collectively and simply referred to as the arc shield 4) can be supported appropriately at desired positions spaced apart from each other in the axial direction on the inner periphery side of the intermediate tank section 2. For example, in the case of the arc shields 4a and 4b shown in Fig. 1 and Fig. 2, they are supported so as to engage with step portions 20a and 20b (hereinafter collectively and simply referred to as the step portion 20) formed on the inner periphery side of the intermediate tank section 2, which contributes to facilitating the positioning and assembly of the arc shields 4a and 4b.

[0036] Each arc shield 4 is annular and extends circumferentially along the inner periphery of the intermediate tank portion 2. of The arc shield has an arc shield base end 41 supported on the inner side of the intermediate tank portion 2, and an arc shield main body portion 42 that is cylindrical and coaxial with the arc shield base end 41 and extends axially from the inner side of the arc shield base end 41.

[0037] Coaxial cylindrical auxiliary shields 5a, 5b (hereinafter collectively referred to simply as auxiliary shield 5) having a diameter larger than that of the arc shield main body 42 are supported at the arc shield base end 41 of each arc shield 4 so as to extend in the same direction as the arc shield main body 42 (for example, in the case of the auxiliary shield 5a supported by the fixed side arc shield 4a, it is supported so as to extend to the fixed side). In the case of the auxiliary shield 5 shown in Figs. 1 and 2, it is supported at a position on the outer circumferential side of the arc shield main body 42 at the arc shield base end 41.

[0038] A cylindrical fixed electric field reduction shield 16a extending from the inside of the vacuum vessel 1 to the movable side in the axial direction is provided on the outer peripheral edge side of the fixed flange 11a on the inside of the vacuum vessel 1. A cylindrical movable electric field reduction shield 16b extending from the inside of the vacuum vessel 1 to the fixed side in the axial direction is provided on the outer peripheral edge side of the movable flange 11b on the inside of the vacuum vessel 1.

[0039] The shapes, materials, etc. of each component of the vacuum interrupter A shown above, as well as the processing methods and assembly methods of each component, can be appropriately applied in various forms depending on the intended use of the vacuum interrupter A, etc.

[0040] 1 and 2, the tip 43 in the extension direction of the arc shield 4 and the tip parts 17a, 17b in the extension direction of the electric field mitigation shields 16a, 16b may be curved so that their diameters decrease as they approach the extension direction, or the tip part 52 in the extension direction of the auxiliary shield 5 (the end 53 side of the tip part 52 in the drawing) may be bent inward in the radial direction (hereinafter simply referred to as the radial direction) of the cylindrical main body 10. Such curved or bent shapes may be formed by, for example, drawing or pressing.

[0041] Of the various components of the vacuum interrupter A, the fixed insulating portion 3a and the movable insulating portion 3b are made of insulating materials (e.g., alumina ceramics), and the remaining components are made of metallic materials (e.g., stainless steel (SUS304), oxygen-free copper, titanium). It is preferable to select the appropriate materials taking into account the possibility of expansion (thermal expansion) and residual stress that may occur when the components are assembled.

[0042] For example, between the arc shield main body 42 of the arc shield 4 and the auxiliary shield 5 (hereinafter simply referred to as between the shields), and between the arc shield 4 and the auxiliary shield 5 and the fixed side insulating part 3a and the movable side insulating part 3b (hereinafter simply referred to as between the shields), it is necessary to be able to maintain a non-contact state after assembly, so it is preferable to select the materials for each part appropriately.

[0043] As a general example, the fixed side insulating part 3a and the movable side insulating part 3b are made of alumina ceramics (for example, a linear expansion coefficient of 8×10 -6 / °C) is used, and stainless steel (SUS304; e.g., linear expansion coefficient 18.7×10 -6 / ℃) or oxygen-free copper (for example, linear expansion coefficient 17.7×10-6 1. / °C oxygen-free copper) can be used, but when these are assembled by welding, brazing or the like, the arc shield 4 and auxiliary shield 5 tend to expand more easily than the fixed insulating part 3a and the movable insulating part 3b.

[0044] Considering this tendency to expand, if the distance between the shields or the distance between the shield insulation is simply increased too much, the electric field at the triple junction will also increase. One way to suppress the electric field at the triple junction is to increase the dimensions of the arc shield 4 and auxiliary shield 5 in the extension direction, but in this case, it is thought that misalignment will easily occur during assembly.

[0045] Therefore, in order to maintain the non-contact state after assembly, it is preferable to appropriately select the linear expansion coefficient of the material applied to the auxiliary shield 5, which may come close to the fixed side insulating part 3a and the movable side insulating part 3b, so that the linear expansion coefficient of the material applied to the arc shield 4 is smaller than that of the material applied to the arc shield 4, or so that the linear expansion coefficient is close to that of the material applied to the fixed side insulating part 3a and the movable side insulating part 3b.

[0046] Specifically, the fixed insulating portion 3a and the movable insulating portion 3b have a linear expansion coefficient of, for example, 8×10 -6 When alumina ceramics with a linear expansion coefficient of 8.4×10 / °C is used, the auxiliary shield 5 has a linear expansion coefficient of 8.4×10 -6 / ℃ titanium or an alloy mainly composed of said titanium. To One example of such a measure is to extend the tip portion 43 of the arc shield main body 42 so as to protrude in the axial direction beyond the tip portion 52 of the supported auxiliary shield 5 .

[0047] By appropriately setting the shape and material of each component in this manner, the distance between the shields and the distance between the shield insulators can be reduced, and the length of the arc shield 4 and auxiliary shield 5 can be reduced, making it possible to maintain a non-contact state after assembly.

[0048] When the distance between the shields or the distance between the shield insulators is restricted as described above, it may be difficult to assemble the auxiliary shields after supporting each arc shield 4 to the intermediate tank portion 2. In such a case, it is preferable to support the auxiliary shield 5 to the arc shield 4 in advance and then support the arc shield 4 to the intermediate tank portion 2.

[0049] Example 2 FIG. 3 shows a modified example of the vacuum interrupter A according to the second embodiment.

[0050] As shown in Fig. 3, the arc shield 4 of the vacuum interrupter A of the second embodiment has a shape in which the central portion 44 side, which is the arc-shield base end portion 41 side of the tip portion 43 of the arc shield main body 42, is reduced in diameter as it approaches the extension direction (terminal end 45 side). Also, the terminal end 45 side of the tip portion 43 of the arc shield main body 42 is curved and expanded in diameter outward in the radial direction (hereinafter simply referred to as a terminal expanded curved shape). Specifically, the terminal expanded curved shape shown in Fig. 3 has a shape in which the terminal end 45 side of the tip portion 43 is expanded in diameter outward in the radial direction, warped back to the opposite side of the extension direction, and approaches the central portion 44 side.

[0051] According to the arc shield 4 having such a curved shape with an expanded diameter at the end, the electric field relaxation effect can be more easily obtained compared to the arc shield 4 shown in Figs.

[0052] The tip portion 52 of the auxiliary shield 5 has a curved shape toward the terminal end 45 of the arc shield main body 42. Specifically, in the case of the tip portion 52 of the auxiliary shield 5 shown in FIG. 3, the terminal end 53 of the tip portion 52 has a curved shape so as to be close to the terminal end 45 of the arc shield main body 42.

[0053] The expanded curved shape at the end of the arc shield main body 42 can be processed using a mold or the like. However, since the mold needs to be removed after the processing, there is a possibility that a gap 46 may be formed between the center 44 and the end 45 at the tip 43, as shown in Figure 3.

[0054] If a gap 46 is formed as described above, discharge may occur from the end 45 of the arc shield main body 42. However, if the tip 52 of the auxiliary shield 5 is curved toward the end 45 as shown in FIG. 3, this discharge can be sufficiently suppressed.

[0055] Therefore, according to the vacuum interrupter A of Example 2, the electric field relaxation effect of the arc shield 4 is more easily obtained than in Example 1, and it is also possible to suppress discharge that may occur from the end 45 of the arc shield main body 42.

[0056] Example 3 4 and 5 show a modified example of the vacuum interrupter A according to the third embodiment.

[0057] As shown in Figures 4 and 5, the intermediate tank portion 2 of the vacuum interrupter A of Example 3 has a cylindrical tank main body portion 21 and a pair of cylindrical adapters 6a, 6b (hereinafter, collectively referred to simply as adapter 6) coaxially connected to the fixed side and movable side of the tank main body portion 21, respectively.

[0058] The connecting surfaces 7a, 7b (hereinafter collectively referred to simply as the connecting surface 7) formed by the mutually opposing surfaces 71, 72 of the tank main body 21 and the adapter 6 connected as described above have a stepped shape extending in the radial direction. Furthermore, the connecting surfaces 7 have surfaces 81, 82 (hereinafter collectively referred to simply as the radially extending surface 8) extending in the radial direction on the radially inner side thereof, which have shapes separated from each other in the axial direction, and are capable of clamping both the base end 41 of the arc shield and the base end 51 of the auxiliary shield 5 as described later.

[0059] A base end 51 of the auxiliary shield 5 supported by the arc shield 4 is bent radially outward. Both the arc shield base end 41 and the base end 51 of the auxiliary shield 5 (hereinafter simply referred to as the base ends) are supported on the inner peripheral side of the intermediate tank portion 2 so as to be sandwiched between the radially extending surfaces 8 in an axially stacked position.

[0060] According to the vacuum interrupter 3 of the third embodiment, the base ends can be sandwiched by the radially extending surfaces, which not only contributes to facilitating positioning and assembly when supporting the arc shield 4 and the auxiliary shield 5 on the inner periphery side of the intermediate tank portion 2, but also makes it possible to appropriately omit brazing or the like in the assembly process. On the other hand, when brazing or the like is applied in the assembly process, it is possible that the arc shield 4 and the auxiliary shield 5 can be more firmly supported on the inner periphery side of the intermediate tank portion 2.

[0061] Although the present invention has been described in detail above only with respect to the specific examples, it will be apparent to those skilled in the art that various modifications are possible within the scope of the technical concept of the present invention, and it is natural that such modifications fall within the scope of the claims.

[0062] For example, the configurations of the vacuum interrupter A according to Examples 1 to 3 can be appropriately used with each other. Specifically, in the intermediate tank section 2 of the vacuum interrupter A shown in Figures 1 to 3, a configuration having a tank main body section 21 and adapters 6a, 6b as shown in Figures 4 and 5 may be applied, and the arc shield 4 may be supported on the inner peripheral side of the intermediate tank section 2 so as to be sandwiched by the radially extending surface 8 of the connecting surface 7.

[0063] In addition, in the intermediate tank portion 2 of the vacuum interrupter A shown in Figures 4 and 5, a configuration having a step portion 20 as shown in Figures 1 to 3 may be applied, and the base ends may be supported on the inner side of the intermediate tank portion 2 so as to engage with the step portion 20. [Explanation of symbols]

[0064] A…Vacuum interrupter 1...Vacuum container 10…Cylindrical body 2. Intermediate tank section 21…Tank body 3a…Fixed side insulation part 3b…Movable side insulation part 4a, 4b…Arc shield 41...Arc shield base end 42…Arc shield main body 5a, 5b...Auxiliary shield 6a, 6b...Adapter 7a,7b…Continuous surface 8a, 8b...Radially extending surface

Claims

1. a vacuum vessel having an insulating cylindrical body, the cylindrical body having one axial end, that is, a fixed side, sealed by a fixed side flange, and the other axial end, that is, a movable side, sealed by a movable side flange; a fixed-side current-carrying shaft extending in the axial direction from the fixed-side flange inside the vacuum vessel; a fixed electrode supported on an end of the fixed current-carrying shaft in an extending direction; a movable-side current-carrying shaft that penetrates the movable-side flange in the axial direction, extends in the axial direction, is supported on an inside of the vacuum vessel of the movable-side flange via a bellows that is expandable and contractible in the axial direction, and is movable in the axial direction; a movable electrode supported on an end of the movable current-carrying shaft inside the vacuum vessel, facing the fixed electrode, and moving toward and away from the fixed electrode in response to movement of the movable current-carrying shaft; Equipped with The cylindrical body includes: a cylindrical intermediate tank portion surrounding the outer periphery of the fixed electrode and the movable electrode; a cylindrical fixed-side insulating portion that is coaxially connected to the intermediate tank portion on a fixed side of the intermediate tank portion in the axial direction; a cylindrical movable-side insulating portion that is coaxially connected to the intermediate tank portion on the movable side of the intermediate tank portion in the axial direction; having On the inner circumference of the intermediate tank, an arc shield extending from an inner circumferential side of the intermediate tank portion along an inner circumferential side of the fixed insulating portion toward the fixed side in the axial direction; an arc shield extending from an inner circumferential side of the intermediate tank portion along an inner circumferential side of the movable insulating portion toward the movable side in the axial direction; are supported at positions spaced apart from each other in the axial direction, Each arc shield is an annular arc shield base end portion, which is an end portion of the arc shield that is supported by the inner periphery of the intermediate tank portion, and which is bent radially outwardly of the cylindrical main body and extends circumferentially along the inner periphery of the intermediate tank portion; an arc shield main body portion having a cylindrical shape coaxial with a base end portion of the arc shield and extending in the axial direction from an inner peripheral side of the base end portion of the arc shield; having A coaxial cylindrical auxiliary shield having a diameter larger than that of the arc shield main body is supported at each of the arc shield base ends of the arc shields so as to extend in the same direction as the arc shield main body, Each arc shield extends such that a tip end portion of the arc shield main body protrudes in the axial direction beyond a tip end portion of the auxiliary shield supported by the arc shield, The linear expansion coefficient of each arc shield is greater than the linear expansion coefficient of the auxiliary shield supported by the arc shield.

1. A vacuum interrupter comprising:

2. a vacuum vessel having an insulating cylindrical body, the cylindrical body having one axial end, that is, a fixed side, sealed by a fixed side flange, and the other axial end, that is, a movable side, sealed by a movable side flange; a fixed-side current-carrying shaft extending in the axial direction from the fixed-side flange inside the vacuum vessel; a fixed electrode supported on an end of the fixed current-carrying shaft in an extending direction; a movable-side current-carrying shaft that penetrates the movable-side flange in the axial direction, extends in the axial direction, is supported on an inside of the vacuum vessel of the movable-side flange via a bellows that is expandable and contractible in the axial direction, and is movable in the axial direction; a movable electrode supported on an end of the movable current-carrying shaft inside the vacuum vessel, facing the fixed electrode, and moving toward and away from the fixed electrode in response to movement of the movable current-carrying shaft; Equipped with The cylindrical body includes: a cylindrical intermediate tank portion surrounding the outer periphery of the fixed electrode and the movable electrode; a cylindrical fixed-side insulating portion that is coaxially connected to the intermediate tank portion on a fixed side of the intermediate tank portion in the axial direction; a cylindrical movable-side insulating portion that is coaxially connected to the intermediate tank portion on the movable side of the intermediate tank portion in the axial direction; having On the inner circumference of the intermediate tank, an arc shield extending from an inner circumferential side of the intermediate tank portion along an inner circumferential side of the fixed insulating portion toward the fixed side in the axial direction; an arc shield extending from an inner circumferential side of the intermediate tank portion along an inner circumferential side of the movable insulating portion toward the movable side in the axial direction; are supported at positions spaced apart from each other in the axial direction, Each arc shield is an annular arc shield base end portion, which is an end portion of the arc shield that is supported by the inner periphery of the intermediate tank portion, and which is bent radially outwardly of the cylindrical main body and extends circumferentially along the inner periphery of the intermediate tank portion; an arc shield main body portion having a cylindrical shape coaxial with a base end portion of the arc shield and extending in the axial direction from an inner peripheral side of the base end portion of the arc shield; having A coaxial cylindrical auxiliary shield having a diameter larger than that of the arc shield main body is supported at each of the arc shield base ends of the arc shields so as to extend in the same direction as the arc shield main body, The auxiliary shield is made of titanium or an alloy mainly composed of titanium.

1. A vacuum interrupter comprising:

3. 2. The vacuum interrupter according to claim 1, wherein the auxiliary shield is made of titanium or an alloy containing titanium as a main component.

4. A vacuum interrupter as described in any one of claims 1 to 3, characterized in that each arc shield has a terminal end of a tip portion in the extension direction of the arc shield main body that is curved radially outwardly of the cylindrical main body.

5. 5. The vacuum interrupter according to claim 4, wherein the tip portion of the auxiliary shield supported by each arc shield is curved toward the terminal end side of the arc shield main body.

6. The intermediate tank section is The tank includes a cylindrical tank body and a pair of cylindrical adapters coaxially connected to a fixed side and a movable side of the cylindrical tank body, Each connecting surface of the cylindrical tank main body and the cylindrical adapter that face each other has a stepped shape extending in the radial direction, a base end portion of the auxiliary shield supported by each arc shield is bent outward in the radial direction, and the base end portion of the auxiliary shield and the base end portion of the arc shield are supported in a stacked position in the axial direction, A vacuum interrupter as described in any one of claims 1 to 5, characterized in that the two are supported between each of the radially extending surfaces that extend radially inwardly of the respective connecting surfaces.

7. 7. A method for manufacturing a vacuum interrupter according to any one of claims 1 to 6, characterized in that each arc shield is supported on the inner periphery of the intermediate tank portion after supporting its respective auxiliary shield.

Images