Vacuum valve

Abstract

To provide a low-cost vacuum valve which accurately and easily centers an arc shield and maintains a voltage resistance performance almost equal to that of an existing arc shield without enlarging a cantilever shield.SOLUTION: A vacuum valve comprises a support section 1t provided in one end 1a of an insulation container 1 and a junction section 5t provided in one end 5a of an arc shield 5. The junction section includes a junction plane 5f, which is capable of being in contact with the support section and smoothed, and the junction plane is formed in an annular shape, which is continued in a circumferential direction, and inclined in a tapered shape. The support section includes a support plane 1f, which is capable of being in contact with the junction plane and smoothed, and the support plane is formed in an annular shape, which is continued in a circumferential direction, and tilted in a tapered shape. The junction plane is supported by the support plane.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] As a switching device for receiving and distributing electricity installed in a building or a large facility, for example, a switchgear equipped with a switch such as a circuit breaker or a disconnecting switch is known. A vacuum valve is applied to the switchgear as a component of the switch. The inside 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 as to be connectable and disconnectable. In this case, by connecting and disconnecting the pair of electrodes, a fault current is interrupted and a load current is opened and closed, and power is stably supplied from the switchgear. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-091211 A [Patent Document 2] JP 2002-319341 A [Patent Document 3] Patent No. 2941682 [Patent Document 4] Patent No. 5116538 [Patent Document 5] Japanese Patent Application Publication No. 59-154721 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, a hollow cylindrical metallic arc shield is provided inside the vacuum valve (i.e., the insulating vessel) to surround the pair of electrodes. The arc shield is arranged close to and along the inner surface of the insulating vessel, and prevents metal particles (metal vapor) generated from the electrode surfaces (arc region) by arc discharge from adhering to the inner surface of the insulating vessel when the electrodes are separated from each other to interrupt the current.

[0005] In recent years, in order to reduce the cost of vacuum interrupters, a cantilever-type arc shield (i.e., a cantilever shield) has been proposed, in which one end is supported by an insulating container and the other end is a free end. However, this cantilever shield is also required to maintain the same level of voltage resistance as existing arc shields.

[0006] The first measure to meet this demand is to increase the distance (spacing) between the cantilever shield and the pair of electrodes, in other words, to enlarge the cantilever shield.

[0007] However, since the cantilever shield is arranged close to the insulating container, the cantilever shield needs to be enlarged to expand the insulating container, which results in an increase in the size of the vacuum interrupter.

[0008] A second measure to meet the above requirements is to maintain a constant distance (spacing) between the cantilever shield and the pair of electrodes when the electrodes are spaced apart from each other to interrupt the current. In other words, the arc shield should be centered precisely.

[0009] However, to accurately center the arc shield, it is necessary to construct a centering jig or a complex structure according to the required centering accuracy. In this case, the number of parts must be increased to construct a complex structure. This increases the manufacturing cost of the vacuum valve by the amount of the increase in the number of parts and the manufacturing cost of the new centering jig.

[0010] An object of the present invention is to provide a low-cost vacuum valve which enables accurate and simple centering of the arc shield and maintains the same level of voltage resistance as existing arc shields without enlarging the cantilever shield. [Means for solving the problem]

[0011] According to an embodiment, the insulating container includes a support portion provided at one end thereof and a joint portion provided at one end thereof, the joint portion has a joint surface capable of contacting the support portion, the joint surface being configured to have a continuous annular shape in the circumferential direction and to be inclined in a tapered shape, the support portion has a support surface capable of contacting the joint surface, the support surface being configured to have a continuous annular shape in the circumferential direction and to be inclined in a tapered shape, and the joint surface is supported by the support surface. In this case, it is preferable that both the joint surface and the support surface are smoothed. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a cross-sectional view of a vacuum interrupter according to an embodiment. [Diagram 2] FIG. 4 is an enlarged cross-sectional view of a portion of the centered cantilever shield. [Diagram 3] FIG. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view of a vacuum interrupter according to a first modified example. [Diagram 5] FIG. 11 is a cross-sectional view of a vacuum interrupter according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] "One embodiment" 1 is a diagram showing the internal structure of a vacuum valve P according to this embodiment. The vacuum valve P has a movable electrode E1, a fixed electrode E2, an insulating container 1 (also called a vacuum container), a movable-side sealing member 2, a fixed-side sealing member 3, an airtightness maintaining mechanism 4, an arc shield 5, and a bellows cover 6. The movable electrode E1, the fixed electrode E2, the airtightness maintaining mechanism 4, the arc shield 5, and the bellows cover 6 are housed inside the insulating container 1.

[0014] 1, the insulating container 1 is formed into a hollow cylindrical shape from an insulating material such as alumina ceramic, etc. The movable side sealing member 2 and the fixed side sealing member 3 are made of a metal material mainly composed of stainless steel, for example.

[0015] 1, a hollow cylindrical insulating container 1 extends in a contact direction Dt of the pair of electrodes E1, E2 so as to accommodate the pair of electrodes E1, E2 in a contact-separation manner. The insulating container 1 has a cylindrical inner surface 1s that extends continuously in the circumferential direction around an imaginary axis Px that defines the center of the vacuum valve P. The contact direction Dt of the pair of electrodes E1, E2 and the extension direction of the imaginary axis Px are parallel to each other.

[0016] The insulating container 1 has both ends 1a and 1b open when viewed in the contact / separation direction Dt (the direction of the imaginary axis Px). Both openings (a movable-side opening K1 and a fixed-side opening K2) are covered by a movable-side sealing member 2 and a fixed-side sealing member 3.

[0017] Here, of both ends 1a, 1b of the insulating container 1, the movable side of the pair of electrodes E1, E2 is defined as one end 1a of the insulating container 1, and the fixed side of the pair of electrodes E1, E2 is defined as the other end 1b of the insulating container 1. In this case, the movable side opening K1 is opened at the one end 1a of the insulating container 1 and is closed by the movable side sealing member 2. The fixed side opening K2 is opened at the other end 1b of the insulating container 1 and is closed by the fixed side sealing member 3.

[0018] The arc shield 5 has a hollow cylindrical shape extending in the contact direction Dt so as to surround the pair of electrodes E1, E2, and is disposed inside the insulating container 1. The arc shield 5 is made of a metal material containing, for example, copper, stainless steel, or the like as a main component.

[0019] In the example of Figure 1, of the two ends 5a, 5b of the arc shield 5 as viewed in the separation and attachment direction Dt (direction of the virtual axis Px), one end 5a of the arc shield 5 is positioned on the movable side of the pair of electrodes E1, E2, and the other end 5b of the arc shield 5 is positioned on the fixed side of the pair of electrodes E1, E2.

[0020] In this case, only one end 5a of the arc shield 5 is supported to one end 1a of the insulating container 1 via a support part 1t and a joint part 5t described below, and the other end 5b is a free end that is not supported. As a result, inside the insulating container 1, the arc shield 5 is configured as a movable side cantilever shield of a type in which the movable side is cantilevered.

[0021] A pair of electrodes E1, E2 are housed and arranged inside (inside) a cantilever-type arc shield 5. Both electrodes E1, E2 are configured concentrically about a virtual axis Px, and extend in alignment with each other along the virtual axis Px.

[0022] The movable electrode E1 as one of the electrodes includes a movable contact 7 and a movable current-carrying shaft 8. The movable contact 7 is connected to one end of the movable current-carrying shaft 8, and the other end of the movable current-carrying shaft 8 is connected to an operation mechanism (not shown) via the movable-side sealing member 2.

[0023] The fixed electrode E2, which serves as the other electrode, includes a fixed contact 9 and a fixed current-carrying shaft 10. The fixed contact 9 is connected to one end of the fixed current-carrying shaft 10, and the other end of the fixed current-carrying shaft 10 is fixed to the vacuum valve P via the fixed-side sealing member 3 so as to be immovable along the imaginary axis Px.

[0024] 1, the movable current-carrying shaft 8 is moved along the imaginary axis Px by the operating mechanism. This allows the movable contact 7 to be brought into contact with and separated from the fixed contact 9. As a result, the vacuum valve P can be opened and closed (i.e., the pair of electrodes E1, E2 can be brought into contact with and separated from each other).

[0025] In addition, an airtightness maintaining mechanism 4 is disposed between the movable current-carrying shaft 8 and the movable-side sealing member 2. The airtightness maintaining mechanism 4 is made of a bellows having elasticity, and the bellows (airtightness maintaining mechanism) 4 is made of a thin metal such as stainless steel. The bellows 4 is shaped like a bellows that is expandable and contractible in the direction of the imaginary axis Px, and covers the outside of the movable current-carrying shaft 8 without any gaps.

[0026] One end of the bellows 4 is tightly joined to the movable sealing member 2, and the other end is tightly joined to the movable current-carrying shaft 8. 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 8 is being moved along the imaginary axis Px.

[0027] Furthermore, a bellows cover 6 is disposed inside the insulating container 1 so as to cover the airtightness maintenance mechanism 4. The bellows cover 6 is made of a metal material mainly composed of, for example, copper or stainless steel. As a result, the bellows cover 6 keeps the airtightness maintenance mechanism 4 in a state where it is prevented from directly facing the fixed contact 7 and the movable contact 9. As a result, when an arc generated from the electrode surface (arc region) by arc discharge strikes the airtightness maintenance mechanism 4 during current interruption, a defect such as a hole being made in the airtightness maintenance mechanism 4 depending on the degree of the strike is prevented from occurring, thereby preventing the intrusion of air into the insulating container 1.

[0028] However, a vacuum valve P employing the cantilever-type arc shield 5 as described above requires a structure that enables the arc shield 5 to be centered easily and accurately, while also firmly supporting one end 5a of the centered arc shield 5 relative to the insulating container 1.

[0029] To meet this demand, the vacuum valve P of this embodiment has a centering structure F for the arc shield 5, and a support structure T for the arc shield 5 relative to the insulating container 1. The centering structure F is applied in the manufacturing and assembly process of the vacuum valve P, and one end 5a of the centered arc shield 5 is firmly supported to the insulating container 1 by the support structure T.

[0030] In addition, centering refers to positioning one end 5a of the arc shield 5 with respect to the insulating container 1 so that the positional relationship between the arc shield 5 and the imaginary axis Px, the positional relationship between the arc shield 5 and the pair of electrodes E1, E2, or the positional relationship between the arc shield 5 and the inner surface 1s of the insulating container 1 is maintained constant.

[0031] The support structure T has a support part 1t, a joint part 5t, and a joint material 11. The joint material 11 is interposed between the support part 1t and the joint part 5t, and bonds the support part 1t and the joint part 5t to each other. Details of the joint material 11 will be described later with reference to FIG. 3.

[0032] 1, the support part 1t is provided at one end 1a of the insulating container 1 and is configured to be able to support one end 5a (i.e., the joint part 5t) of the arc shield 5. The support part 1t is provided at one end 1a of the insulating container 1 so as to protrude inward from the inner surface 1s of the insulating container 1 toward the inside of the insulating container 1. The support part 1t forms a hollow ring shape that is continuous in the circumferential direction about the imaginary axis Px.

[0033] On the other hand, the joint portion 5t is provided at one end 5a of the arc shield 5, and is configured so as to be able to be joined to one end 1a (i.e., the support portion 1t) of the insulating container 1. The joint portion 5t is provided at one end 5a of the arc shield 5 so as to protrude outward from the one end 5a of the arc shield 5 toward the inner surface 1s of the insulating container 1. The joint portion 5t forms a hollow annular shape that is continuous in the circumferential direction about the imaginary axis Px.

[0034] The degree of protrusion (amount of protrusion) of the support portion 1t and the joint portion 5t is set depending on, for example, the type and size of the vacuum valve P, the size of the internal space of the insulating container 1, the type and size of the arc shield 5, etc., and is not particularly limited here.

[0035] The centering structure F is constructed by being included in the support structure T, and has a support surface 1f and a joint surface 5f. The joint material 11 is interposed between the support surface 1f and the joint surface 5f, and bonds the support surface 1f and the joint surface 5f to each other. Details of the joint material 11 will be described later with reference to FIG. 3.

[0036] 1, the support surface 1f is provided at one end 1a (i.e., the support portion 1t) of the insulating container 1, and is configured to be able to come into contact with one end 5a (i.e., the joint portion 5t, joint surface 5f) of the arc shield 5. The support surface 1f is smoothed and flat without any irregularities so as to achieve surface contact with the joint surface 5f of the arc shield 5. The flat support surface 1f forms a hollow ring shape that is continuous in the circumferential direction about the imaginary axis Px.

[0037] The annular support surface 1f is configured to be inclined in a tapered shape toward the imaginary axis Px when viewed from one end 1a toward the other end 1b of the insulating container 1. In other words, the annular support surface 1f is configured to be inclined in a divergent shape toward the direction away from the imaginary axis Px when viewed from the other end 1b toward one end 1a of the insulating container 1.

[0038] On the other hand, the joint surface 5f is provided at one end 5a (i.e., joint portion 5t) of the arc shield 5, and is configured to be able to come into contact with one end 1a (i.e., support portion 1t, support surface 1f) of the insulating container 1. The joint surface 5f is smoothed and flat without any irregularities so as to achieve surface contact with the support surface 1f of the insulating container 1. The flat joint surface 5f forms a hollow ring shape that is continuous in the circumferential direction around the imaginary axis Px.

[0039] The annular joint surface 5f is inclined in a tapered manner toward the imaginary axis line Px when viewed from one end 5a toward the other end 5b of the arc shield 5. In other words, the annular joint surface 5f is inclined in a divergent manner toward the direction away from the imaginary axis line Px when viewed from the other end 5b toward the one end 5a of the arc shield 5.

[0040] In this case, when viewed in a direction parallel to the imaginary axis Px, the support surface 1f of the insulating container 1 and the joint surface 5f of the arc shield 5 are always set in a positional relationship in which they face each other in parallel. This makes it possible to easily center the arc shield 5 with high accuracy in the manufacturing and assembly process of the vacuum valve P.

[0041] In the manufacturing and assembly process of the vacuum valve P, assuming the insulating container 1 before the above-mentioned movable and fixed sealing members 2, 3 are attached, this single insulating container 1 is placed in a position in which both ends 1a, 1b are aligned in the direction of gravity. At this time, the insulating container 1 is placed so that one end 1a is located on the lower side in the direction of gravity and the other end 1b is located on the upper side in the direction of gravity.

[0042] Then, the arc shield 5 is inserted into the insulating container 1 from the fixed side opening K2 opened at the other end 1b on the upper side in the gravity direction. At this time, the arc shield 5 is inserted into the insulating container 1 from its one end 5a through the fixed side opening K2.

[0043] Then, the joint surface 5f of one end 5a (joint portion 5t) of the arc shield 5 faces and approaches the support surface 1f of one end 1a (support portion 1t) of the insulating container 1, and eventually the joint surface 5f is seated on the support surface 1f. At this time, the joint surface 5f of the arc shield 5 and the support surface 1f of the insulating container 1 come into contact with each other.

[0044] 2 is a diagram showing a state in which the joint surface 5f and the support surface 1f are in contact with each other. In this state, the joint surface 5f of the arc shield 5 is moved along the support surface 1f of the insulating container 1 to center the arc shield 5. Possible centering methods include, for example, a gravity centering method and a forced centering method.

[0045] According to the gravity centering method, one end 5a (joint portion 5t) of the arc shield 5 is pressed against one end 1a (support portion 1t) of the insulating container 1 by the weight of the arc shield 5 itself acting in the direction of gravity. The pressing force at this time causes the joint surface 5f of the arc shield 5 to slide and move along the support surface 1f of the insulating container 1. As a result, the centering of the arc shield 5 is automatically performed.

[0046] According to the forced centering method, one end 5a (joint portion 5t) of the arc shield 5 is pressed against one end 1a (support portion 1t) of the insulating container 1 by an external force. The pressing force at this time causes the joint surface 5f of the arc shield 5 to slide and move along the support surface 1f of the insulating container 1. As a result, the centering of the arc shield 5 is forcibly performed.

[0047] 2, after the above-mentioned centering is performed, the joint surface 5f of the arc shield 5 and the support surface 1f of the insulating container 1 are in contact with each other, and the joint surface 5f and the support surface 1f are in planar contact with each other without any gaps. Then, a joining process is performed between the joint portion 5t (joining surface 5f) of the arc shield 5 and the support portion 1t (support surface 1f) of the insulating container 1.

[0048] Fig. 3 is a diagram showing a state of the joining process. Fig. 3 shows a configuration example of a centering structure F for smoothly and reliably performing the joining process between the joining portion 5t (joining surface 5f) of the arc shield 5 and the supporting portion 1t (supporting surface 1f) of the insulating container 1.

[0049] 3, a bonding material 11 is applied in the bonding process, and the bonding material 11 is interposed between the bonding portion 5t (bonding surface 5f) and the supporting portion 1t (supporting surface 1f). The bonding material 11 includes a metal material 11a for bonding and a metallized thin film 11b.

[0050] The metallized thin film 11b is formed by coating the support surface 1f of the support part 1t, thereby metallizing the support surface 1f. On the other hand, as the metal material 11a, for example, a metallic brazing material may be applied. Note that since the metallized thin film 11b is coated to be extremely thin, it is not shown in FIG. 3 with a thickness that allows a cross-sectional view.

[0051] In the joining process, the molten metal material 11a is interposed between the joining portion 5t (joining surface 5f) and the supporting portion 1t (metallized supporting surface 1f). After this, the metal material 11a cools and solidifies, and the joining portion 5t (joining surface 5f) and the supporting portion 1t (metallized supporting surface 1f) can be joined together. As a result, one end 5a of the arc shield 5 is firmly supported by one end 1a of the insulating container 1.

[0052] Furthermore, the inclination angle of the joint surface 5f of the arc shield 5 with respect to a virtual plane Vs perpendicular to the virtual axis Px and the inclination angle of the support surface 1f of the insulating container 1 with respect to the virtual plane Vs are set to be the same as each other. In this case, it is preferable that the inclination angle θ of the joint surface 5f of the arc shield 5 and the inclination angle θ of the support surface 1f of the insulating container 1 are set to be the same as each other within the range of 2°≦θ≦15°.

[0053] Here, if the inclination angle θ is 15° or more (15°<θ), the molten metal material 11a will flow along the inclination direction of the support surface 1f and will no longer be able to be uniformly interposed between the joint 5t (joint surface 5f) and the support portion 1t (metallized support surface 1f). As a result, it will become difficult to maintain a constant joint strength between the joint 5t (joint surface 5f) and the support portion 1t (metallized support surface 1f).

[0054] On the other hand, if the inclination angle θ is 2° or less (θ<2°), it becomes difficult to slide the joint surface 5f of the arc shield 5 along the support surface 1f of the insulating container 1 when centering the arc shield 5 as described above, and as a result, it becomes difficult to center smoothly.

[0055] As described above, according to this embodiment, the joint surface 5f of the arc shield 5 and the support surface 1f of the insulating container 1 have an annular centering structure F having the same inclination angle. According to the centering structure F, the joint surface 5f slides along the support surface 1f during centering. This allows the centering of the arc shield 5 to be performed smoothly. As a result, the centering of the arc shield 5 can be performed accurately and easily without constructing a centering jig or a complex structure according to the centering accuracy, and further without increasing the number of parts.

[0056] According to this embodiment, after centering is performed by the centering structure F, in a state in which the joint surface 5f of the arc shield 5 and the support surface 1f of the insulating container 1 are in contact with each other, the joint surface 5f and the support surface 1f are in planar contact with each other without any gap. This makes it possible to keep the posture and direction (angle) of the centered arc shield 5 constant. As a result, it is possible to improve the centering accuracy despite the simple structure.

[0057] According to this embodiment, there is a support structure T including the above-mentioned centering structure F. The support structure T allows an existing arc shield 5 to be used as is, and one end 5a of the arc shield 5 is firmly supported at one end 1a of the insulating container 1. This makes it possible to realize a low-cost vacuum valve P that maintains the same level of withstand voltage performance as an existing arc shield.

[0058] According to this embodiment, in the bonding process, the metallized thin film 11b is coated on the support surface 1f of the support part 1t to be metallized, and the molten metal material 11a is interposed between the metallized support surface 1f and the bonding surface 5f and solidified. This allows the one end 5a of the arc shield 5 to be firmly supported on the one end 1a of the insulating container 1.

[0059] "First Modification" Fig. 4 is an enlarged cross-sectional view of a displacement prevention member 12 according to the first modified example. In the example of Fig. 4, the displacement prevention member 12 is additionally provided on the support part 1t of the insulating container 1, and prevents displacement of the arc shield 5 supported on the support part 1t (i.e., the arc shield 5 that is centered by the centering structure F and firmly supported on the insulating container 1 by the support structure T).

[0060] 4, the displacement prevention member 12 extends from one end 1a to the other end 1b of the insulating container 1 and has a hollow cylindrical shape that is continuous in the circumferential direction about the imaginary axis Px. The displacement prevention member 12 is in continuous contact in the circumferential direction with a nearby region including one end 5a of the arc shield 5. Specifically, the displacement prevention member 12 is in contact with the inner circumferential surface 5s of the arc shield 5 and extends along the inner circumferential surface 5s. Note that the contact state between the displacement prevention member 12 and the inner circumferential surface 5s of the arc shield 5 includes not only the above-mentioned variation in which they are in continuous contact with each other, but also a variation in which a small gap is provided between them, for example, which is included in the technical scope of the present invention.

[0061] The length of the anti-shift member 12 is set so as not to exceed the connection position R1 between the contacts 7, 9 and the conductive shafts 8, 10 when the pair of electrodes E1, E2 are in contact with each other (i.e., in a closed state or in a conductive state with the power turned on) as viewed in the contact / separation direction Dt (direction of the virtual axis Px).

[0062] Specifically, when viewed in the contact / disconnection direction Dt in a state in which a pair of electrodes E1, E2 are in contact with each other (closed electrode state, current-carrying state), if the length from a connection position R2 where the inner surface 1s of the insulating container 1 and the support surface 1f of the support portion 1t are connected to each other in a circular ring shape to the connection position R1 is L1, and the length (total length) of the anti-shift member 12 from the connection position R2 is L2, it is preferable that the relationship L1 / 2≦L2≦L1 is satisfied.

[0063] Here, when the total length L2 of the misalignment prevention member 12 is L1 or more (L1 < L2), at the time of current interruption, metal particles (metal vapor) generated from the electrode surface (arc generation region) due to arc discharge adhere to the misalignment prevention member 12. As a result, the surface insulation performance is deteriorated.

[0064] On the other hand, when the total length L2 of the misalignment prevention member 12 is L1 / 2 or less (L2 < L1 / 2), the region in contact with the inner peripheral surface 5s of the arc shield 5 becomes short. As a result, it becomes difficult to stably support the arc shield 5.

[0065] Furthermore, the misalignment prevention member 12 is set to have a constant thickness over its entire length. In this case, when viewed in the direction orthogonal to the virtual axis Px, the misalignment prevention member 12 is preferably set to be thicker than the arc shield 5.

[0066] Note that the thickness of the misalignment prevention member 12 is not particularly limited here because it is set according to, for example, the type and size of the vacuum valve P, the size of the internal space of the insulating container 1, the type and size of the arc shield 5, and the like.

[0067] As described above, according to the first modification example, the arc shield 5 is in a state where its inner peripheral surface 5s is supported from the inside by the misalignment prevention member 12. As a result, regardless of the usage environment of the vacuum valve P, the positional relationship between the virtual axis Px and the arc shield 5 can always be maintained constant.

[0068] According to the first modification example, the total length L2 of the misalignment prevention member 12 is set so as to satisfy the relationship of L1 / 2 ≤ L2 ≤ L1. As a result, while minimizing the amount of insulating material required for manufacturing, it is possible to realize, at low cost, the misalignment prevention member 12 having a length sufficient to make it difficult to cause surface breakdown when, for example, surface discharge occurs. Note that other configurations and effects are the same as those of the above-described embodiment, and thus the description thereof is omitted.

[0069] "Second Modification Example" 5 is a layout configuration diagram of an arc shield 5 according to a second modified example. The layout of the arc shield 5 according to the second modified example is configured by inverting the layout of the above-described embodiment upside down.

[0070] In the first embodiment, of the two ends 1a, 1b of the insulating container 1, the movable side of the pair of electrodes E1, E2 is defined as one end 1a of the insulating container 1, and the fixed side of the pair of electrodes E1, E2 is defined as the other end 1b of the insulating container 1, whereas in the second modified example, of the two ends 1a, 1b of the insulating container 1, the fixed side of the pair of electrodes E1, E2 is defined as one end 1a of the insulating container 1, and the movable side of the pair of electrodes E1, E2 is defined as the other end 1b of the insulating container 1. One end 5a of the arc shield 5 is positioned on the fixed side of the pair of electrodes E1, E2, and the other end 5b of the arc shield 5 is positioned on the movable side of the pair of electrodes E1, E2.

[0071] In this case, only one end 5a of the arc shield 5 is supported to one end 1a of the insulating container 1 via the above-mentioned supporting portion 1t and joint portion 5t, and the other end 5b is a free end that is not supported. As a result, inside the insulating container 1, the arc shield 5 is configured as a fixed-side cantilever shield of a type in which the fixed side is cantilevered. The other configurations and effects are similar to those of the above-described embodiment, and therefore will not be described further.

[0072] "Other Modifications" In the above-described embodiment, the support surface 1f (joint surface 5f) is configured to be inclined in a tapered manner toward the imaginary axis line Px when viewed in the direction from one end 1a (5a) to the other end 1b (5b) of the insulating container 1 (arc shield 5). In contrast, in this modified example, the direction of inclination of the joint surface 5f and the support surface 1f is reversed from that of the embodiment.

[0073] Although not particularly shown, in this modified example, the support surface 1f (joint surface 5f) is inclined in a tapered shape toward the direction away from the imaginary axis Px when viewed in the direction from one end 1a (5a) toward the other end 1b (5b) of the insulating container 1 (arc shield 5). In other words, the support surface 1f (joint surface 5f) is inclined in a tapered shape toward the direction approaching the imaginary axis Px when viewed in the direction from the other end 1b (5b) toward the one end 1a (5a) of the insulating container 1 (arc shield 5). The other configurations and effects are similar to those of the above-described embodiment, and therefore will not be described further.

[0074] Although one embodiment of the present invention and some modified examples have been described above, these embodiments and modified examples are presented as examples and are not intended to limit the scope of the invention. These embodiments and modified examples can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and modified examples are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0075] 1...insulating container, 1a...one end, 1b...other end, 1f...support surface, 1s...inner surface, 1t...support portion, 2...movable side sealing member, 3...fixed side sealing member, 4...airtightness maintaining mechanism, 5...arc shield, 5a...one end, 5b...other end, 5f...joint surface, 5t...joint portion, 6...bellows cover, 7...movable contact, 8...movable current-carrying shaft, 9...fixed contact, 10...fixed current-carrying shaft, 11...joint material, 12...position displacement prevention member, P...vacuum valve, Px...virtual axis, Vs...virtual plane, Dt...contact and separation direction, E1...movable electrode, E2...fixed electrode, K1...movable side opening, K2...fixed side opening, F...centering structure, T...support structure.

Claims

1. a cylindrical insulating container extending in a direction in which the pair of electrodes are brought into contact with each other so as to accommodate the pair of electrodes in a releasable manner; a cylindrical arc shield disposed inside the insulating container and extending in the contact / separation direction so as to surround the pair of electrodes; a support portion provided at one end of the insulating container out of both ends of the insulating container as viewed in the contact and separation direction and capable of supporting the arc shield; a joint portion provided at one end of the arc shield out of both ends of the arc shield as viewed in the contact direction and capable of being joined to the support portion of the insulating container; a vacuum valve in which only one end of the arc shield is supported by the insulating container when the joint portion is joined to the support portion, the joint portion of the arc shield is continuous in a circumferential direction around an imaginary axis that defines a center of the vacuum valve, and has a joint surface that can come into contact with the support portion of the insulating container, the joining surface forms a circular ring shape that is continuous in a circumferential direction around the imaginary axis line, and is configured to be tapered in a direction approaching the imaginary axis line when viewed in a direction from the one end toward the other end of the arc shield, the support portion of the insulating container is continuous in a circumferential direction around the imaginary axis line and has a support surface capable of contacting the joint surface of the arc shield, the support surface forms a circular ring shape that is continuous in a circumferential direction around the imaginary axis line, and is configured to be tapered in a direction approaching the imaginary axis line when viewed in a direction from the one end to the other end of the insulating container, The joining surface is supported by the support surface.

2. Assuming a virtual plane perpendicular to the virtual axis, 2. The vacuum valve according to claim 1, wherein an inclination angle of the joining surface of the arc shield relative to the imaginary plane and an inclination angle of the support surface of the insulating container relative to the imaginary plane are set so that the joining surface and the support surface are positioned opposite each other.

3. 3. The vacuum valve according to claim 2, wherein the inclination angle of the joint surface of the arc shield and the inclination angle of the support surface of the insulating container are set to be the same as each other.

4. the insulating container has a cylindrical inner surface that extends continuously in a circumferential direction around the imaginary axis, The support portion is provided at the one end of the insulating container so as to protrude from the inner surface toward the inside, 2. The vacuum valve according to claim 1, wherein the joint is provided at the one end of the arc shield so as to protrude toward the inner surface of the insulating container.

5. 4. The vacuum valve according to claim 3, wherein the inclination angle θ of the joining surface of the arc shield and the inclination angle θ of the support surface of the insulating container are set to the same inclination angle within a range of 2°≦θ≦15°.

6. The joining surface of the arc shield is smooth and flat without any irregularities, The support surface of the insulating container is smooth and flat without any irregularities, 2. The vacuum valve according to claim 1, wherein when the joint surface of the arc shield and the support surface of the insulating container are in contact with each other, the joint surface and the support surface are in planar contact with each other without any gap.

7. a bonding material is interposed between the support surface of the support portion and the bonding surface of the bonding portion in order to bond the bonding portion of the arc shield and the support portion of the insulating container to each other; The bonding material includes: A metal material for joining; 2. The vacuum valve according to claim 1, further comprising: a metallized thin film formed on the support surface of the support portion, metallizing the support surface.

8. a positional deviation prevention member for preventing a positional deviation of the arc shield supported by the support portion is provided on the support portion of the insulating container; The vacuum valve as described in claim 1, wherein the anti-shift member extends from one end of the insulating container toward the other end, forms a cylindrical shape that is continuous in the circumferential direction about the imaginary axis, and continuously contacts a nearby area including the one end of the arc shield in the circumferential direction, thereby maintaining a constant positional relationship between the imaginary axis and the arc shield.

9. Each of the pair of electrodes includes a contact and a current-carrying shaft connected to the contact and extending in the contact / separation direction, 9. A vacuum valve as described in claim 8, wherein the length of the anti-shift member is set so as not to exceed the connection position between the contacts and the conductive shaft when the pair of electrodes are in contact with each other, as viewed in the connection / disconnection direction.

10. 10. A vacuum valve as described in claim 9, wherein, when viewed in the contact and separation direction, the length from a connecting position where the inner surface of the insulating container and the support surface of the support portion are connected to each other to the connection position is L1, and the length of the positional deviation prevention member from the connecting position is L2, satisfying the relationship L1 / 2≦L2≦L1.

11. The displacement prevention member has a constant thickness over its entire length, 9. The vacuum valve according to claim 8, wherein the displacement prevention member is set to be thicker than the arc shield when viewed in a direction perpendicular to the imaginary axis.

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