Vacuum valve and switch gear

Abstract

To provide a low-cost vacuum valve excellent in recyclability and reusability while maintaining high insulation performance (current cut-off performance).SOLUTION: A vacuum valve P comprises a plurality of metal components E1, E2, 2, 3, 4 and 5 that are made of a predetermined metallic material. Some 2, 3, and 5 of the plurality of metal components are externally exposed as metal exposure parts at a plurality of locations. The vacuum valve has insulation shields 10 and 11 that are provided to cover at least some of all the plurality of metal exposure parts. The insulation shield has a conductive part 12 that is constituted in an energizable manner, and a nonconductive part 13 that is constituted in an unenergizable manner.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a vacuum valve and a switchgear. [Background technology]

[0002] Switchgears equipped with switches such as circuit breakers and disconnectors are known as electrical distribution devices installed in buildings and large facilities. A vacuum valve is used as a component of the switchgear. The interior of the vacuum valve is maintained in a constant insulating state by an insulating container, and a pair of electrodes are housed inside the insulating container so that they can be connected and disconnected. By connecting and disconnecting the pair of electrodes, a fault current can be interrupted or a load current can be connected and disconnected, ensuring a stable supply of power from the switchgear. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4004012 Publication [Patent Document 2] Patent No. 5015845 [Patent Document 3] International Publication No. 2018 / 138754 Summary of the Invention [Problem to be solved by the invention]

[0004] Vacuum interrupters are required to have high insulating performance (current interruption performance), and one way to meet this is to use molding technology in which the entire exterior of the vacuum interrupter is molded with insulating material without any gaps.

[0005] However, with this molding technology, the insulating material must be molded so that no gas (gaps) are present between it and the vacuum valve, and the molding process is time-consuming and labor-intensive, which increases the manufacturing costs of the vacuum valve.

[0006] Furthermore, the molded insulating material is firmly attached to the outside of the vacuum interrupter and is difficult to separate, so it is not possible to meet the demand, for example, to recycle only the insulating material and reuse the other parts.

[0007] An object of the present invention is to provide a low-cost vacuum interrupter that is highly recyclable and reusable while maintaining high insulation performance (current interruption performance). [Means for solving the problem]

[0008] According to one embodiment, the vacuum valve comprises a plurality of metal parts made of a predetermined metal material, some of which are exposed to the outside at multiple locations as exposed metal parts, and has an insulating shield arranged to cover at least a portion of the entire plurality of exposed metal parts, and the insulating shield comprises a conductive part configured to be able to conduct electricity and a non-conductive part configured to not conduct electricity. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a cross-sectional view of a vacuum interrupter according to an embodiment. [Figure 2] FIG. 4 is a cross-sectional view of a vacuum interrupter according to a first modified example. [Figure 3] FIG. 10 is a cross-sectional view of a vacuum interrupter according to a second modified example. [Figure 4] FIG. 10 is a cross-sectional view of a vacuum interrupter according to a third modified example. [Figure 5] FIG. 10 is a cross-sectional view of a vacuum interrupter according to a fourth modified example. [Figure 6] FIG. 10 is a cross-sectional view of a vacuum interrupter according to a fifth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] "One embodiment" 1 is a diagram showing the internal structure of a vacuum valve P according to this embodiment. The vacuum valve P includes a plurality of metal parts made of a predetermined metal material and insulating parts made of an insulating material.

[0011] The metal components include, for example, a fixed electrode E1, a movable electrode E2, a fixed sealing member 2, a movable sealing member 3, an airtightness maintaining mechanism 4, and an arc shield 5. The insulating components include, for example, an insulating container 1 (also called a vacuum container). The fixed electrode E1, the movable electrode E2, the airtightness maintaining mechanism 4, and the arc shield 5 are housed inside the insulating container 1.

[0012] 1, the insulating container 1 has a composite hollow cylindrical shape in which a fixed-side insulating porcelain tube 1a and a movable-side insulating porcelain tube 1b are connected to each other along an imaginary axis Px (described later), and is made of an insulating material such as alumina ceramic. The fixed-side sealing member 2 and the movable-side sealing member 3 are made of a metal material whose main component is, for example, stainless steel.

[0013] 1, the hollow cylindrical insulating container 1 is concentric with an imaginary axis Px that defines the center of the vacuum valve P. A vacuum atmosphere is maintained inside the insulating container 1, and a pair of electrodes E1, E2 are housed in this vacuum atmosphere so that they can be brought into contact with each other. The insulating container 1 has a cylindrical inner surface 1s that extends in the direction in which the electrodes E1, E2 are brought into contact with each other (in other words, in the direction of the imaginary axis Px) and that extends continuously along the circumferential direction.

[0014] Furthermore, the insulating container 1 has openings at both ends when viewed in the direction of the imaginary axis Px. Both openings (fixed-side opening K1 and movable-side opening K2) are covered by the fixed-side sealing member 2 and the movable-side sealing member 3. Specifically, the fixed-side sealing member 2 is supported by the fixed-side insulating porcelain tube 1a and closes one of the fixed-side openings K1 of the insulating container 1. The movable-side sealing member 3 is supported by the movable-side insulating porcelain tube 1b and closes the other movable-side opening K2 of the insulating container 1.

[0015] At this time, the metal fixed-side sealing member 2 is exposed to the outside from the insulating container 1 (vacuum valve P) as a so-called exposed metal portion, except for the portion supported by the fixed-side insulating porcelain tube 1a (insulating container 1). The metal movable-side sealing member 3 is exposed to the outside from the insulating container 1 (vacuum valve P) as a so-called exposed metal portion, except for the portion supported by the movable-side insulating porcelain tube 1b (insulating container 1).

[0016] The arc shield 5 has a hollow cylindrical shape that extends in the direction in which the pair of electrodes E1, E2 contact each other so as to surround the pair of electrodes E1, E2 while facing the inner surface 1s of the insulating container 1, and is made of a metal material whose main components are, for example, copper or stainless steel. The arc shield 5 is supported by the insulating container 1 so as to accommodate therein a fixed contact 6 of the fixed electrode E1 and a movable contact 7 of the movable electrode E2, which will be described later.

[0017] 1 shows an example of a method for supporting the arc shield 5. Specifically, the arc shield 5 has an annular flange portion 5f. The arc shield 5 has a cylindrical outer surface 5s facing the inner surface 1s of the insulating container 1. The flange portion 5f protrudes from the outer surface 5s of the arc shield 5 toward the inner surface 1s of the insulating container 1 and extends continuously or intermittently along the circumferential direction.

[0018] Then, with the flange portion 5f interposed between the fixed-side insulating porcelain tube 1a and the movable-side insulating porcelain tube 1b, the flange portion 5f is sandwiched between the insulating porcelain tubes 1a and 1b. As an example of a sandwiching method, the flange portion 5f is joined to the insulating porcelain tubes 1a and 1b by silver brazing. As a result, the arc shield 5 is supported on the insulating container 1 via the flange portion 5f.

[0019] At this time, a part of the metal flange portion 5t (i.e., the metal flange end surface 5t) is exposed to the outside from the insulating container 1 (vacuum valve P) as a so-called exposed metal portion. As described above, when the flange portion 5f extends continuously along the circumferential direction, the flange end surface 5t is exposed continuously along the circumferential direction. On the other hand, when the flange portion 5f extends discontinuously along the circumferential direction, the flange end surface 5t is exposed discontinuously along the circumferential direction.

[0020] The fixed electrode E1 and the movable electrode E2 are arranged concentrically around the imaginary axis Px and extend in alignment along the imaginary axis Px. In this state, the fixed electrode E1 and the movable electrode E2 are positioned so as to face each other in parallel.

[0021] The fixed electrode E1 includes a fixed contact 6 and a fixed current-carrying shaft 8. The movable electrode E2 includes a movable contact 7 and a movable current-carrying shaft 9. The fixed contact 6 and the movable contact 7 are disk-shaped and have the same diameter, and are made of an alloy of a current-carrying material such as Cu or Ag with an arc-resistant material such as chromium (Cr), tungsten (W), or tungsten carbide (WC). The fixed current-carrying shaft 8 and the movable current-carrying shaft 9 are cylindrical and have the same diameter, and are made of a highly conductive material (for example, Cu).

[0022] The fixed contact 6 is connected to one end of a fixed current-carrying shaft 8, and the other end of the fixed current-carrying shaft 8 is fixed to the vacuum valve P so as not to be movable along the imaginary axis Px via a fixed-side sealing member 2. The movable contact 7 is connected to one end of a movable current-carrying shaft 9, and the other end of the movable current-carrying shaft 9 is connected to an operating mechanism (not shown) via a movable-side sealing member 3.

[0023] 1, the movable current-carrying shaft 9 is moved along the imaginary axis Px by an operating mechanism (not shown). This causes the movable contact 7 to move in contact with or away from the fixed contact 6. As a result, the vacuum interrupter P can be opened or closed (i.e., the electrodes E1, E2 can be moved in contact with or away from each other).

[0024] Furthermore, an airtightness maintaining mechanism 4 is disposed between the movable current-carrying shaft 9 and the movable-side sealing member 3. The airtightness maintaining mechanism 4 is made of a flexible bellows. The bellows (airtightness maintaining mechanism) 4 is made of a thin metal such as stainless steel. The bellows 4 is shaped like a bellows and is flexible in the direction of the imaginary axis Px, and covers the outside of the movable current-carrying shaft 9 without any gaps.

[0025] One end of the bellows 4 is tightly joined to the movable sealing member 3, and the other end is tightly joined to the movable current-carrying shaft 9. This ensures that the inside of the insulating container 1 is always kept airtight (i.e., vacuum state). As a result, when the vacuum valve P is opened or closed, the atmosphere (air) does not enter the inside of the insulating container 1, even while the movable current-carrying shaft 9 is being moved along the imaginary axis Px.

[0026] The above-mentioned vacuum valve P is mounted inside a switchgear (not shown) filled with an insulating gas such as dry air (compressed air from which moisture has been removed) or SF6 gas (sulfur hexafluoride gas). In this case, the vacuum valve P is required to have improved insulation performance (current interruption performance) while maintaining the existing size of the switchgear panel, and an insulating shield, which will be described later, is used as a measure to meet this requirement.

[0027] 1, in the vacuum valve P, a part of the above-mentioned metal parts (for example, the fixed electrode E1, the movable electrode E2, the fixed-side sealing member 2, the movable-side sealing member 3, the airtightness maintaining mechanism 4, and the arc shield 5) is exposed to the outside at a plurality of locations as exposed metal parts. The exposed metal parts correspond to the parts of the fixed-side sealing member 2, the movable-side sealing member 3, and the arc shield 5 that are exposed to the outside from the insulating container 1.

[0028] In Figure 1, examples of exposed metal portions are assumed to be the entire fixed side sealing member 2 excluding the portion supported by the fixed side insulating porcelain tube 1a (insulating container 1), the entire movable side sealing member 3 excluding the portion supported by the movable side insulating porcelain tube 1b (insulating container 1), and the flange end surface 5t of the flange portion 5f of the arc shield 5 clamped by the insulating container 1 (insulating porcelain tubes 1a, 1b).

[0029] For such a vacuum valve P, the insulating shield is provided to cover at least a portion of the above-mentioned plurality of exposed metal portions. In this case, for example, a full covering variation in which the insulating shield covers all of the exposed metal portions, or a partial covering variation in which the insulating shield covers some of the exposed metal portions, is conceivable.

[0030] In the full covering variation, the insulating shield covers both sealing members 2 and 3 and the flange end face 5t in its entirety. In the partial covering variation, the insulating shield covers only both sealing members 2 and 3, only the flange end face 5t, or only one of the sealing members 2 and 3.

[0031] 1 shows, as an example, a state in which only the sealing members 2 and 3, which are the exposed metal portions, are covered by insulating shields 10 and 11. In this state, the vacuum valve P has a fixed-side insulating shield 10 for covering the entire exposed portion of the fixed-side sealing member 2, and a movable-side insulating shield 11 for covering the entire exposed portion of the movable-side sealing member 3.

[0032] Both insulating shields 10, 11 have the same configuration and include a conductive portion 12 configured to be electrically conductive and a non-conductive portion 13 configured to be electrically non-conductive. Note that the non-conductive portion 13 can be defined as an insulating portion, and the insulating portion (non-conductive portion 13) is configured to have high electrical resistance so that no current flows even when a voltage is applied.

[0033] The conductive portion 12 is disposed opposite the sealing members 2 and 3 (exposed metal portions). The conductive portion 12 faces the sealing members 2 and 3 with a certain gap therebetween. The conductive portion 12 is set to a shape and size that extends over a wider area than the sealing members 2 and 3 so as to evenly cover the entire sealing members 2 and 3. The conductive portion 12 is set to be thinner than the non-conductive portion 13, which will be described later.

[0034] The conductive portion 12 can be formed from a metal material such as gold, silver, or copper. For example, according to a deposition method using a metal material such as gold or copper, molecules of the vaporized metal material are deposited on the surface of the substrate (i.e., the non-conductive portion 13) to form a film. Alternatively, according to a coating method using a metal material such as silver, a liquefied metal material is applied to the surface of the substrate (i.e., the non-conductive portion 13) with a brush to form a film.

[0035] The non-conductive portion 13 is disposed adjacent to the conductive portion 12 on the opposite side of the sealing members 2, 3 (exposed metal portion) with the conductive portion 12 in between. The non-conductive portion 13 is in contact with the conductive portion 12 without any gaps. The non-conductive portion 13 is set to have at least the same shape and size as the conductive portion 12 so that the entire conductive portion 12 is evenly covered. The non-conductive portion 13 is set to be thicker than the conductive portion 12.

[0036] It is preferable that the non-conductive portion 13 has a relative dielectric constant of 3.0 or less. For example, if the relative dielectric constant of the non-conductive portion 13 is set to 3.0 or more, it becomes difficult to further improve the insulation performance (current interruption performance) of the vacuum valve P while using the existing panel-sized switchgear as is.

[0037] At least one of the conductive portion 12 and the non-conductive portion 13 may be made of a thermoplastic resin. With this configuration, it is possible to manufacture the insulating shields 10, 11 using existing injection molding methods such as injection molding and compression molding. This significantly reduces the effort and time required to manufacture the insulating shields 10, 11. As a result, the manufacturing costs of the insulating shields 10, 11 can be significantly reduced.

[0038] In this case, examples of thermoplastic resins that can be used for the non-conductive portion 13 include polyethylene (PE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), acrylic resin (PMMA), polyvinyl alcohol (PVAL), polyimide (PI), polyamide-imide (PAI), polyetherimide (PEI), polysulfone (PSU), polyethersulfone (PES), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), and the like.

[0039] These thermoplastic resins may be used alone or as mixtures or composite materials. When used as mixtures or composite materials, for example, by kneading a powdered, solid fused silica or alumina filler or a fibrous glass fiber filler with the thermoplastic resin, the mechanical strength of the thermoplastic resin can be improved and the linear expansion coefficient can be reduced. Furthermore, by kneading a hollow, powdered fused silica filler with the thermoplastic resin, the relative dielectric constant of the thermoplastic resin can be reduced.

[0040] By using a filler in this way, it is possible to inexpensively produce a thermoplastic resin that satisfies the insulating performance (current interruption performance) required for the insulating shields 10, 11. This makes it possible to further reduce the overall manufacturing cost of the insulating shields 10, 11 that use this thermoplastic resin.

[0041] In addition, it is preferable that the glass transition temperature of the non-conductive portion 13 made of the above-mentioned thermoplastic resin is set to be equal to or higher than 90° C. Note that materials made of polymers such as thermoplastic resins exist in four states: liquid, rubber, glass, and crystalline (solid), and the boundary between the soft rubber state and the hard glass state is the glass transition point, and the boundary temperature at which the rubber state changes to the glass state is called the glass transition temperature.

[0042] In existing switchgear, it is specified that the temperature rise of the conductor is limited to 50°C when the ambient temperature is 40°C or below. Taking this into consideration, it is expected that the conductive parts 12 of the insulating shields 10, 11 will also reach a similar temperature. In order for the non-conductive parts 13 made of thermoplastic resin to fully demonstrate their inherent insulating performance (current-breaking performance) at this temperature, they must be set to above the glass transition temperature of 90°C, at which the physical properties of thermoplastic resin change. This makes it possible to improve the insulating performance (current-breaking performance) of the vacuum valve P while maintaining the current size of the switchgear panel that houses the vacuum valve P without increasing it.

[0043] On the other hand, a thermoplastic resin applicable to the conductive portion 12 can be, for example, a thermoplastic resin applicable to the non-conductive portion 13 described above to which an appropriate amount of conductive material (conductive filler) has been mixed (added) depending on the purpose of use and the environment of use.

[0044] Here, when both the conductive portion 12 and the non-conductive portion 13 are made of thermoplastic resin, it becomes possible to manufacture the insulating shields 10, 11 by two-color (double) molding using an existing injection molding machine, without using a complicated molding process. This makes it possible to significantly reduce the labor and time required to manufacture the insulating shields 10, 11. As a result, the manufacturing cost of the insulating shields 10, 11 can be significantly reduced.

[0045] Furthermore, the insulating shields 10, 11 are required to be easily attached to and detached from the vacuum valve P, and as a means to meet this requirement, the vacuum valve P has an electrical connection support means.

[0046] The electrical connection support means electrically connects the conductive portions 12 of the insulating shields 10 and 11 to metal components (for example, the fixed electrode E1, the movable electrode E2, the fixed-side sealing member 2, the movable-side sealing member 3, and the arc shield 5). At this time, the conductive portions 12 and the metal components are configured to have the same potential (equal potential) with each other.

[0047] The electrical connection support means detachably supports the insulating shields 10, 11 on the vacuum valve P. At this time, a gap 14 that allows a gas to be present is formed between the insulating shields 10, 11 and the vacuum valve P, except for the portion where the conductive portion 12 of the insulating shields 10, 11 is electrically connected to the metal component by the electrical connection support means.

[0048] In FIG. 1, a fixed current-carrying shaft 8 of the fixed electrode E1 and a movable current-carrying shaft 9 of the movable electrode E2 are used as an example of the electrical connection support means.

[0049] The other end of the fixed current-carrying shaft 8 (the end opposite to the end connected to the fixed contact 6) is connected to the fixed insulating shield. At this time, the conductive portion 12 of the fixed insulating shield 10 and the fixed current-carrying shaft 8 are electrically connected to each other and are at the same potential. At the same time, the fixed insulating shield 10 is supported by the vacuum valve P via the fixed current-carrying shaft 8.

[0050] In this state, a gap 14 that allows gas to be present is formed between the fixed side insulating shield 10 and the vacuum valve P, except for the connection portion between the fixed current-carrying shaft 8 and the conductive portion 12 of the fixed side insulating shield 10.

[0051] The other end of the movable current-carrying shaft 9 (the end opposite to the end connected to the fixed contact 7) is connected to the movable-side insulating shield 11. At this time, the conductive portion 12 of the movable-side insulating shield 11 and the movable current-carrying shaft 9 are electrically connected to each other and are at the same potential. At the same time, the movable-side insulating shield 11 is supported by the vacuum valve P via the movable current-carrying shaft 9.

[0052] In this state, a gap 14 that allows gas to be present is formed between the movable side insulating shield 11 and the vacuum valve P, except for the connection portion between the movable current-carrying shaft 9 and the conductive portion 12 of the movable side insulating shield 11.

[0053] 1, gap 14, which allows gas to be present, is formed between insulating shields 10 and 11 (i.e., conductive portion 12) and sealing materials 2 and 3 (exposed metal portions). The size (width) of gap 14 is not particularly limited here, as long as it allows gas to be present, and is set arbitrarily depending on, for example, the type and shape of vacuum valve P.

[0054] According to this embodiment, the insulating shields 10, 11 are provided to cover at least a portion of the entire exposed metal portion of the vacuum valve P. This electrically covers the portions of the vacuum valve P where the electric field is emphasized. As a result, it is possible to realize a vacuum valve P that maintains high insulating performance (current interruption performance) without having to mold the entire exterior of the vacuum valve P with insulating material without any gaps.

[0055] According to this embodiment, the electrical connection support means electrically covers the portions of the vacuum valve P where the electric field was emphasized with the insulating shields 10, 11, and electrically connects the conductive portions 12 of the insulating shields 10, 11 to the metal components, making them at the same potential. At this time, for example, a triple junction generated at the connection portion between the insulating container 1 and the sealing members 2, 3 is covered with the same potential. This makes it possible to alleviate (reduce) the electric field around the vacuum valve P. As a result, it is possible to reduce the size of the vacuum valve P while improving the insulation performance (current interruption performance).

[0056] According to this embodiment, the electrically connecting and supporting means causes the conductive portions 12 of the insulating shields 10, 11 and the metal component to have the same potential, and simultaneously forms a gap 14 that allows gas to be present between the insulating shields 10, 11 and the vacuum valve P, excluding the connection portion between them. In this case, the insulating shields 10, 11 are configured as separate bodies from the vacuum valve P. In other words, the insulating shields 10, 11 are configured to be easily attached and detached (separated) from the vacuum valve P. This meets the need to recycle only the insulating material used in the non-conductive portions 13 of the insulating shields 10, 11 and reuse the other parts of the vacuum valve P, for example. As a result, a low-cost vacuum valve P with excellent recyclability and reusability can be realized.

[0057] According to this embodiment, the non-conductive portions 13 of the insulating shields 10, 11 are set to have a relative dielectric constant of 3.0 or less. This makes it possible to reduce the electric field in the gap 14 (i.e., the portion where gas can be present) between the insulating shields 10, 11 and the vacuum interrupter P. As a result, it is possible to further improve the insulation performance (current interruption performance) of the vacuum interrupter P while maintaining the current panel size of the switchgear in which the vacuum interrupter P is mounted without increasing it (in other words, while using the existing panel size of the switchgear as is).

[0058] According to this embodiment, the vacuum interrupter P having the insulating shields 10 and 11 is mounted inside a switchgear filled with an insulating gas, such as dry air or SF6 gas. In this state, the vacuum interrupter P is compositely insulated by the insulating shields 10 and 11 (i.e., solid insulating portion) and the insulating gas (i.e., gas insulating portion). Using a material with a low dielectric constant for the insulating shields 10 and 11 (solid insulating portion) increases the electric field contribution ratio of the non-conductive portion 13 and decreases the electric field contribution ratio of the insulating gas (gas insulating portion). For example, assuming that dry air is used as the insulating gas, using a material with a dielectric constant of 3.0 or less for the insulating shields 10 and 11 (non-conductive portion 13) reduces the electric field applied to the gas insulating portion (i.e., dry air), thereby suppressing the occurrence of partial discharge. A switchgear employing such an insulation system can further improve insulation performance (current interruption performance) while maintaining the same panel size as existing switchgears that are currently insulated solely with SF6 gas.

[0059] "First Variation" 2 is a diagram showing the internal structure of a vacuum interrupter P according to this modification. In the above-described embodiment, the current-carrying shafts 8, 9 of both electrodes E1, E2 are used as the electrical connection support means, but instead, in this modification, a bolt 15 and a screw hole structure 16 into which the bolt 15 can be screwed are used as an example of the electrical connection support means. Of the bolt 15 and the screw hole structure 16, at least the screw hole structure 16 is made of a metallic material and is electrically conductive.

[0060] 2, the plurality of screw hole structures 16 are made of a metal material. The plurality of screw hole structures 16 are disposed between the conductive portion 12 of the fixed-side insulating shield 10 and the fixed-side sealing member 2 (exposed metal portion), and between the conductive portion 12 of the movable-side insulating shield 11 and the movable-side sealing member 3 (exposed metal portion).

[0061] The arrangement of the multiple screw hole structures 16 is not particularly limited here, as it can be set arbitrarily depending on, for example, the type and size of the vacuum valve P. In Figure 2, as an example, the multiple screw hole structures 16 are arranged concentrically around an imaginary axis Px that defines the center of the vacuum valve P.

[0062] 2, the non-conductive portion 13 of the insulating shields 10, 11 is recessed to provide a plurality of bolt insertion grooves 17. The number of bolt insertion grooves 17 is set to be the same as that of the above-described threaded hole structures 16. The bolt insertion grooves 17 are arranged so as to be aligned in a straight line with the threaded hole structures 16 when viewed in the direction along the imaginary axis Px.

[0063] Here, in the fixed-side insulating shield 10, the bolt 15 is inserted into the bolt insertion groove 17, passes through the non-conductive portion 13, and is screwed into the threaded hole structure 16. At this time, the conductive portion 12 of the fixed-side insulating shield 10 and the fixed-side sealing member 2 (exposed metal portion) are electrically connected to each other and have the same potential. At the same time, the fixed-side insulating shield 10 is supported by the vacuum valve P via the bolt 15 and the threaded hole structure 16.

[0064] In this state, a gap 14 that allows gas to be present is formed between the fixed side insulating shield 10 and the vacuum valve P, except for the connection portion between the fixed side sealing member 2 and the conductive portion 12 of the fixed side insulating shield 10.

[0065] In the movable-side insulating shield 11, bolts 15 are inserted into the bolt insertion grooves 17, passed through the non-conductive portions 13, and screwed into the threaded hole structures 16. At this time, the conductive portions 12 of the movable-side insulating shield 11 and the movable-side sealing member 3 (exposed metal portions) are electrically connected to each other and have the same potential. At the same time, the movable-side insulating shield 11 is supported by the vacuum valve P via the bolts 15 and the threaded hole structures 16.

[0066] In this state, a gap 14 that allows gas to be present is formed between the movable side insulating shield 11 and the vacuum valve P, except for the connection portion between the movable side sealing member 3 and the conductive portion 12 of the movable side insulating shield 11.

[0067] According to this modification, the insulating shields 10, 11 can be quickly and easily separated from the vacuum valve P simply by removing the bolts 15 from the threaded hole structure 16. This makes it possible to meet the demand for recycling only the non-conductive portion 13 (insulating material) and reusing the other parts (vacuum valve P). Note that the other configurations and effects are the same as those of the above-described embodiment, and therefore will not be described here.

[0068] "Second Variant" 3 is a diagram showing the internal structure of the vacuum interrupter P according to this modification. In the above-described embodiment, the current-carrying shafts 8, 9 of both electrodes E1, E2 are used as the electrical connection support means, but instead, in this modification, an adhesive 18 is used as an example of the electrical connection support means.

[0069] In the example of Figure 3, adhesive 18 is arranged between the conductive portion 12 of the fixed side insulating shield 10 and the fixed side sealing member 2 (exposed metal portion), and between the conductive portion 12 of the movable side insulating shield 11 and the movable side sealing member 3 (exposed metal portion).

[0070] The arrangement of the adhesive 18 is not particularly limited here, as it can be arbitrarily set depending on, for example, the type and size of the vacuum valve P. In FIG. 3, as an example, the adhesive 18 is arranged concentrically around an imaginary axis Px that defines the center of the vacuum valve P.

[0071] The adhesive 18 may be made of either conductive or non-conductive material. In this case, if the other ends of the current-carrying shafts 8, 9 (the opposite ends to the ends connected to the fixed contacts 6, 7) are electrically connected to the conductive portions 12 of the insulating shields 10, 11, either conductive or non-conductive adhesive 18 can be used. As a result, similar to the above-described embodiment, the conductive portions 12 of the insulating shields 10, 11 and the sealing members 2, 3 (exposed metal portions) are electrically connected to each other and have the same potential.

[0072] On the other hand, if the other ends of the current-carrying shafts 8, 9 (opposite the ends connected to the fixed contacts 6, 7) are not electrically connected to the conductive parts 12 of the insulating shields 10, 11, it is necessary to apply a conductive adhesive. This electrically connects the conductive parts 12 of the insulating shields 10, 11 and the sealing members 2, 3 (exposed metal parts) to each other and makes them have the same potential.

[0073] At the same time, the insulating shields 10, 11 are supported by the vacuum valve P by the adhesive 18, as in the above-described embodiment. In this state, a gap 14 is formed between the insulating shields 10, 11 and the vacuum valve P, allowing a gas to be present therein.

[0074] According to this modification, for example, by applying heat or other stimuli to weaken the adhesive strength of the adhesive 18, the insulating shields 10, 11 can be quickly and easily separated from the vacuum valve P. This makes it possible to meet the demand for recycling only the non-conductive portion 13 (insulating material) and reusing the other parts (vacuum valve P). Note that the other configurations and effects are the same as those of the above-described embodiment, and therefore will not be described here.

[0075] "Third Variation" 4 is a diagram showing the internal structure of a vacuum interrupter P according to this modification. In the above-described embodiment, the insulating shields 10, 11 are configured to cover the entire exposed portions of both sealing members 2, 3. Instead, in this modification, the insulating shields 10, 11 are configured to cover only part of the exposed portions of both sealing members 2, 3.

[0076] 4, as an example, the insulating shields 10 and 11 are configured so that only the portions perpendicular to the imaginary axis Px that defines the center of the vacuum valve P are arranged concentrically around the imaginary axis Px. Note that the other configurations and effects are the same as those of the above-described embodiment, and therefore a description thereof will be omitted.

[0077] "Fourth Variation" 5 is a diagram showing the internal structure of a vacuum interrupter P according to this modification. In the above-described embodiment, the insulating shields 10 and 11 are arranged to cover both sealing members 2 and 3 (exposed metal portions), but instead, in this modification, the insulating shield 19 is arranged to cover the flange end surface 5t (exposed metal portion) of the flange portion 5f of the arc shield 5, which is sandwiched between the insulating container 1 (insulated porcelain bushings 1a and 1b).

[0078] 5, the insulating shield 19 is disposed facing the outside of the insulating container 1 (the fixed-side insulating porcelain tube 1a and the movable-side insulating porcelain tube 1b). In this state, as will be described later, a gap 14 capable of containing a gas is formed between the insulating shield and the insulating container 1 when viewed in a direction perpendicular to an imaginary axis Px that defines the center of the vacuum valve P.

[0079] 5, the insulating shield 19, like the above-described embodiment, includes a conductive portion 12 configured to be electrically conductive and a non-conductive portion 13 configured to be electrically non-conductive. The conductive portion 12 is disposed facing the flange end surface 5t (exposed metal portion). The non-conductive portion 13 is disposed adjacent to the conductive portion 12 on the opposite side of the flange end surface 5t (exposed metal portion) with the conductive portion 12 in between.

[0080] In this modification, a conductive hollow ring member 20 is used as an example of an electrical connection support means. The hollow ring member 20 is disposed in the gap 14 between the insulating shield 19 and the insulating container 1, and is configured to be able to electrically connect the conductive portion 12 and the flange end surface 5t.

[0081] Possible methods for arranging the hollow ring member 20 include, for example, a post-assembly manufacturing method in which the hollow ring member 20 is manufactured separately from the insulating shield 19 and then attached to the conductive portion 12, or an integrated manufacturing method in which the hollow ring member 20 is manufactured integrally with the conductive portion 12.

[0082] In the post-assembly manufacturing method, the hollow ring member 20 may be made of the same material as the arc shield 5, or may be made of the same material as the conductive portion 12 of the insulating shield 19. In either case, the separately manufactured hollow ring member 20 may be joined between the conductive portion 12 and the flange end surface 5t without any gaps. One example of the joining method is silver brazing.

[0083] In the integral manufacturing method, the hollow ring member 20 is manufactured simultaneously with the manufacturing process of the insulating shield 19 (conductive portion 12), and is therefore made of the same material as the conductive portion 12. The hollow ring member 20 manufactured integrally with the conductive portion 12 can be joined to the flange end surface 5t without any gaps. One example of the joining method is silver brazing.

[0084] In this way, by interposing the hollow ring member 20 in the gap between the insulating shield 19 and the insulating container 1, the conductive portion 12 of the insulating shield 19 and the flange end surface 5t (exposed metal portion) of the arc shield 5 are electrically connected to each other and have the same potential.

[0085] At the same time, as in the above-described embodiment, the insulating shield 19 is supported by the vacuum valve P by the hollow ring member 20. In this state, as described above, a gap 14 is formed between the insulating shield 19 and the vacuum valve P, allowing gas to be present therein.

[0086] According to this modification, the insulating shield 19 can be quickly and easily separated from the vacuum valve P simply by removing the hollow ring member 20. This makes it possible to meet the demand for recycling only the non-conductive portion 13 (insulating material) and reusing the other parts (vacuum valve P). Note that the other configurations and effects are the same as those of the above-described embodiment, and therefore a description thereof will be omitted.

[0087] "Fifth Variation" 6 is a diagram showing the internal structure of a vacuum interrupter P according to this modification. In the above-described embodiment, the conductive portions 12 of the insulating shields 10, 11 are arranged so that their entirety faces the sealing materials 2, 3 (exposed metal portions). However, in this modification, the conductive portions 12 of the insulating shields 10, 11 are arranged so that part of them extends inside the non-conductive portion 13.

[0088] 6, the conductive portion 12 is disposed with its outer edge 12t recessed inside the non-conductive portion 13 and the rest exposed toward the vacuum valve P (not shown). In this state, the shape of the outer edge 12t of the conductive portion 12 may be curved, or the outer edge tip 12e may be chamfered.

[0089] According to this modification, by disposing part of the conductive portion 12 inside the non-conductive portion 13, which has no conductivity, it is possible to prevent high electric field areas from occurring outside the insulating shields 10 and 11. At the same time, inside the non-conductive portion 13, the shape of the conductive portion 12 (outer edge 12t) can be set arbitrarily, thereby improving the degree of freedom in designing the insulating shields 10 and 11.

[0090] Furthermore, one method for disposing the outer edge 12t of the conductive portion 12 inside the non-conductive portion 13 is to, for example, mold the non-conductive portion 13 by injection molding, then carve out the shape of the conductive portion 12 and pour liquid conductive paint into the carved-out portion. This reduces defects during manufacturing, making it possible to manufacture the insulating shields 10, 11 at low cost. Note that the other configurations and effects are the same as those of the above-described embodiment, and therefore a description thereof will be omitted.

[0091] Although one embodiment of the present invention and several modifications thereof have been described above, these embodiments and modifications are presented as examples and are not intended to limit the scope of the invention. These embodiments and modifications may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0092] P...vacuum valve, Px...imaginary axis, K1...fixed side opening, K2...movable side opening, E1...fixed electrode, E2...movable electrode, 1...insulating container, 1a...fixed side insulating tube, 1b...movable side insulating tube, 1s...inner surface, 2...fixed side sealing member, 3...movable side sealing member, 4...airtightness maintaining mechanism, 5...arc shield, 5f...flange portion, 5t...flange end face, 6...fixed contact, 7...movable contact, 8...fixed current-carrying shaft, 9...movable current-carrying shaft, 10...fixed side insulating shield, 11...movable side insulating shield, 12...conductive portion, 12t...outer edge, 13...non-conductive portion, 14...gap, 15...bolt, 16...screw hole structure, 17...bolt insertion groove, 18...adhesive, 19...insulating shield, 20...hollow ring member.

Claims

1. A vacuum valve comprising a plurality of metal parts made of a predetermined metal material, some of the metal parts being exposed to the outside at a plurality of locations as exposed metal portions, an insulating shield provided so as to cover at least a portion of the plurality of exposed metal portions; The insulating shield is a conductive portion configured to be electrically conductive; A vacuum valve comprising: a non-conductive part configured to be unable to conduct electricity.

2. the conductive portion is disposed opposite the exposed metal portion, 2. The vacuum interrupter according to claim 1, wherein the non-conductive portion is disposed adjacent to the conductive portion on the opposite side of the conductive portion from the exposed metal portion.

3. 2. The vacuum interrupter according to claim 1, wherein the conductive portion is disposed so that a portion of the conductive portion is embedded inside the non-conductive portion.

4. 2. The vacuum interrupter according to claim 1, wherein at least one of the conductive portion and the non-conductive portion is made of a thermoplastic resin.

5. 5. The vacuum interrupter according to claim 4, wherein the non-conductive portion made of the thermoplastic resin has a glass transition temperature set to 90° C. or higher.

6. the vacuum interrupter has an electrical connection support means for electrically connecting the conductive portion of the insulating shield to the metal component and for detachably supporting the insulating shield on the vacuum interrupter; 2. The vacuum valve according to claim 1, wherein a gap allowing a gas to be present is formed between the insulating shield and the vacuum valve, except for the portion where the conductive portion is electrically connected to the metal component by the electrical connection support means.

7. The metal part includes: a metal sealing member for closing openings at both ends of an insulating container that accommodates a pair of electrodes in a releasable manner; a metallic arc shield supported by the insulating container and extending to surround the pair of electrodes; 2. The vacuum valve according to claim 1, wherein the exposed metal portion corresponds to a portion of the sealing material and the arc shield that is exposed to the outside from the insulating container.

8. 2. The vacuum interrupter according to claim 1, wherein the non-conductive portion has a relative dielectric constant set to 3.0 or less.

9. A switchgear using the vacuum valve according to any one of claims 1 to 8, The switchgear is filled with insulating gas, The vacuum valve is compositely insulated by the insulating shield and the insulating gas when mounted inside the switchgear.

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