JP7814177B2 - Vacuum valve - Google Patents

Description

An embodiment of the present invention relates to a vacuum valve.

Conventionally, vacuum valves have been known that include a pair of electrodes that can be connected or disconnected and an arc shield that surrounds the pair of electrodes. Vacuum valves have a sealed vacuum insulating container.

Japanese Patent Application Laid-Open No. 2021-89828

In conventional vacuum valves, the arc shield is located close to the insulating container, so if the arc shield has a potential, the electric field strength of the arc shield becomes high. This makes it easier for partial discharges to occur inside the insulating container in a vacuum, which can have a negative impact on the performance of the vacuum valve.

One example of the problem solved by this invention is to obtain a vacuum valve that reduces the electric field strength of the arc shield and suppresses the occurrence of partial discharge.

The vacuum valve according to this embodiment includes, for example, a cylindrical container, a first electrode, a second electrode, a shielding member, and a conductive portion. The first electrode is housed in the container. The second electrode is housed in the container facing the first electrode. The shielding member is fixedly housed in the container and surrounds the first and second electrodes. The conductive portion is electrically connected to the shielding member and is provided on at least one of the inner and outer surfaces of the container.

FIG. 1 is a cross-sectional view of a vacuum interrupter according to a first embodiment. FIG. 2 is an enlarged cross-sectional view of a part of the vacuum interrupter of the second embodiment. FIG. 3 is a diagram comparing the electric field strength at the triple point when the container does not have a protrusion, when the conductive portion is in contact with the side surface of the protrusion, and when the conductive portion is not in contact with the side surface of the protrusion. FIG. 4 is an enlarged cross-sectional view of a part of the vacuum interrupter of the third embodiment. FIG. 5 is a diagram comparing the electric field strength at the triple point when the conductive portion is applied up to the tip of the protrusion and when the conductive portion is not applied up to the tip of the protrusion. FIG. 6 is an enlarged cross-sectional view of a part of the vacuum interrupter of the fourth embodiment. FIG. 7 is an enlarged cross-sectional view of a part of the vacuum interrupter of the fifth embodiment. FIG. 8 is an enlarged cross-sectional view of a portion of a shield member according to a modified example.

(Embodiment)
The vacuum interrupter 1 according to the embodiment will be described below with reference to the drawings. The configuration of the embodiment described below, and the actions and results (effects) brought about by the configuration, are merely examples and are not limited to the following description.

Furthermore, the multiple embodiments disclosed below include similar components. Therefore, in the following, these similar components will be given common reference numerals, and duplicate explanations will be omitted. Note that in this specification, ordinal numbers are used only to distinguish between parts and components, and do not indicate order or priority.

First Embodiment
Fig. 1 is a cross-sectional view of a vacuum interrupter 1 according to a first embodiment. As shown in Fig. 1, the vacuum interrupter 1 includes an insulating container 2, a fixed electrode 3, a movable electrode 4, an arc shield 5, a conductive layer 6, and a bellows 7. The insulating container 2 is an example of a container, and the fixed electrode 3 is an example of a first electrode. The movable electrode 4 is an example of a second electrode, and the arc shield 5 is an example of a shielding member. The conductive layer 6 is an example of a conductive portion.

In the following figures, for convenience, three mutually orthogonal directions are defined. The radial direction with the axis Ax of the insulating container 2 as the center of rotation is simply referred to as the radial direction, and the circumferential direction with the axis Ax of the insulating container 2 as the center of rotation is simply referred to as the circumferential direction. The Z direction is the direction along the axis Ax of the insulating container 2 and can also be referred to as the up-down direction. Note that the expressions indicating directions such as front-back, left-right, up-down, etc. in this embodiment are used for convenience and do not limit the position, posture, or usage of the vacuum valve 1. The Z direction is an example of a first direction. Furthermore, the radial direction is an example of a second direction, and the circumferential direction is an example of a third direction.

The insulating container 2 is made of an insulating material such as ceramic and is formed in a cylindrical shape. However, the shape of the insulating container 2 is not limited to a cylindrical shape. The shape of the insulating container 2 may be, for example, a polygonal tube.

As shown in FIG. 1, the insulating container 2 has a first opening 21 and a second opening 22 at both ends in the vertical direction (Z direction).

The first opening 21 opens in the vertical direction (Z direction) from the upper end 2a, which is the end of the insulating container 2 in the upward direction (+Z direction).

The upper end 2a is joined to a first metal fitting 2a1 extending in the vertical direction (Z direction). In this embodiment, the surface of the upper end 2a that joins with the first metal fitting 2a1 is metalized.

Metallization is a process that turns the surface of a non-metallic material into a metal film. In this embodiment, for example, a Mn/Mn layer (metallization layer) is provided on the upper end 2a of the insulating container 2, and a Ni-plated layer (plating layer) is further applied on top of the Mn/Mn layer.

In this embodiment, the Ni-plated layer on the upper end portion 2a and the first metal fitting 2a1 are joined using silver solder. However, the metal materials forming each layer are not limited to these.

The second opening 22 opens in the vertical direction (Z direction) from the lower end 2b, which is the end of the insulating container 2 in the downward direction (-Z direction). In other words, the second opening 22 is located on the opposite side of the first opening 21.

The lower end 2b is joined to a second metal fitting 2b1 that extends in the vertical direction (Z direction). Similar to the upper end 2a, the surface of the lower end 2b that joins with the second metal fitting 2b1 is metallized.

Also, as shown in FIG. 1, the insulating container 2 has a first sealing plate 23 and a second sealing plate 24.

The first sealing plate 23 is a disk-shaped plate that closes the first opening 21 and is joined to the first metal fitting 2a1. Furthermore, the first sealing plate 23 has a first hole 231.

The first hole portion 231 opens in the vertical direction (Z direction) from the center of the first sealing plate 23.

The second sealing plate 24 is a disk-shaped plate that closes the second opening 22 and is joined to the second metal fitting 2b1. Furthermore, the second sealing plate 24 has a second hole 241.

The second hole portion 241 opens in the vertical direction (Z direction) from the center of the second sealing plate 24.

The first sealing plate 23 and the first metal fitting 2a1, and the second sealing plate 24 and the second metal fitting 2b1 are each joined with silver solder. This seals the inside of the insulating container 2.

In addition, the area outside the outer surface 2d of the insulating container 2 facing the outside is formed of epoxy resin. In other words, the vacuum valve 1 is covered with epoxy resin. However, the material covering the vacuum valve 1 is not limited to epoxy resin.

The fixed electrode 3 is a disk made of a metal such as aluminum or chromium copper. However, the fixed electrode 3 may also be made of other metals. The fixed electrode 3 passes through the first opening 21 and is housed in the insulating container 2.

As shown in FIG. 1, the fixed electrode 3 has a fixed current-carrying shaft 31. The fixed current-carrying shaft 31 is a cylinder that passes through the first hole portion 231 and extends in the vertical direction (Z direction) from the outside toward the fixed electrode 3. The fixed electrode 3 is attached to the lower end 31a, which is the end of the fixed current-carrying shaft 31 on the fixed electrode 3 side (downward) in the vertical direction, by silver brazing. Furthermore, the method of attaching the fixed electrode 3 to the lower end 31a is not limited to silver brazing.

The outer diameter of the fixed current-carrying shaft 31 is approximately the same as the inner diameter of the first hole 231. The fixed current-carrying shaft 31 is joined to the first hole 231 with silver solder, thereby being fixed to and supported by the first sealing plate 23. In other words, the fixed current-carrying shaft 31 is inserted into and fixed in the first hole 231.

Like the fixed electrode 3, the movable electrode 4 is a disk made of a metal such as aluminum or chromium copper. However, the movable electrode 4 may also be made of other metals. The movable electrode 4 passes through the second opening 22 and is housed in the insulating container 2. In other words, the movable electrode 4 faces the fixed electrode 3. The fixed electrode 3 and the movable electrode 4 are positioned in the vertical direction (Z direction) so that they do not come into contact when the current in the vacuum valve 1 is interrupted.

As shown in FIG. 1, the movable electrode 4 has a movable current-carrying shaft 41. The movable current-carrying shaft 41 is a cylinder that passes through the second hole portion 241 and extends in the vertical direction (Z direction) from the outside toward the movable electrode 4. The movable electrode 4 is attached to the upper end portion 41a, which is the end portion of the movable current-carrying shaft 41 on the movable electrode 4 side (upward direction) in the vertical direction, by silver brazing. Furthermore, the method of attaching the movable electrode 4 to the upper end portion 41a is not limited to silver brazing.

The outer diameter of the movable current-carrying shaft 41 is smaller than the inner diameter of the second hole portion 241. The end opposite the upper end portion 41a of the movable current-carrying shaft 41 is connected to, for example, an advance/retract mechanism. This allows the movable current-carrying shaft 41 to move up and down (Z direction). Note that the outer diameter of the movable current-carrying shaft 41 only needs to be small enough to allow the movable current-carrying shaft 41 to move up and down (Z direction).

As shown in FIG. 1, the arc shield 5 is made of, for example, metal, and is housed in the insulating container 2, fixed to the inner surface 2c of the insulating container 2 facing the fixed electrode 3 and movable electrode 4. The arc shield 5 extends from the inner surface 2c of the insulating container 2 toward the fixed electrode 3 and movable electrode 4, and then extends toward the first sealing plate 23 and second sealing plate 24. In other words, the arc shield 5 has a cylindrical shape with both ends open in the vertical direction (Z direction).

The arc shield 5 is located radially between the inner surface 2c of the insulating container 2 and the fixed electrode 3 and movable electrode 4, and prevents metal particles generated from the fixed electrode 3 and movable electrode 4 from adhering to the inner surface 2c of the insulating container 2 when the current in the vacuum valve 1 is interrupted.

The length of the arc shield 5 in the vertical direction (Z direction) is at least equal to or greater than the sum of the thickness of the fixed electrode 3 and the movable electrode 4 in the vertical direction and the distance between the fixed electrode 3 and the movable electrode 4 in the current-blocking state. In other words, the arc shield 5 is positioned so as to surround the fixed electrode 3 and the movable electrode 4.

The conductive layer 6 is made of, for example, metal, and is applied continuously to the inner surface 2c of the insulating container 2 without being scattered. In other words, the conductive layer 6 is applied around the entire periphery of the inner surface 2c of the insulating container 2.

In this embodiment, the conductive layer 6 is applied continuously and not scattered on the inner surface 2c of the insulating container 2. However, it is sufficient that the conductive layer 6 is applied continuously and not scattered on at least one of the inner surface 2c and outer surface 2d of the insulating container 2.

When the conductive layer 6 is applied to the outer surface 2d of the insulating container 2, the conductive layer 6 is applied so as to contact the end 5a, which is the radial end of the arc shield 5.

Furthermore, as shown in FIG. 1, the conductive layer 6 is applied to an area that does not extend beyond both ends 5b of the arc shield 5 in the vertical direction. In other words, the length of the conductive layer 6 in the vertical direction is shorter than the length of the arc shield 5 in the vertical direction.

The conductive layer 6 also contacts the portion of the arc shield 5 that extends from the inner surface 2c of the insulating container 2 toward the fixed electrode 3 and the movable electrode 4. This gives the conductive layer 6 the same potential as the arc shield 5. In other words, the conductive layer 6 is electrically connected to the arc shield 5.

The surface of the conductive layer 6 that comes into contact with the inner surface 2c of the insulating container 2 is metallized, just like the upper end 2a and lower end 2b of the insulating container 2.

In this embodiment, the thickness of the conductive layer 6 is substantially equal to the thickness of the metallization applied to the surface of the conductive layer 6 that comes into contact with the insulating container 2.

As shown in FIG. 1, the bellows 7 is a bellows-shaped expandable tube housed in the insulating container 2 that can expand and contract in the vertical direction (Z direction), and is made of, for example, metal. A movable current-carrying shaft 41 passes through the interior of the bellows 7.

The upper end 7a, which is the end of the bellows 7 in the upward direction (+Z direction), is joined to the side of the movable current-carrying shaft 41.

The lower end 7b of the bellows 7, which is the end in the downward direction (-Z direction), covers the second hole 241 and is bonded to the second sealing plate 24. In other words, the outer diameter of the bellows 7 is larger than the inner diameter of the second hole 241.

As a result, the bellows 7 keeps the air that flows in through the gap between the movable current-carrying shaft 41 and the second hole portion 241 inside the bellows 7.

A cover that covers the bellows 7 may be provided at the upper end 7a of the bellows 7. This can, for example, prevent molten metal scattered by the arc from adhering to the bellows 7.

In the vacuum interrupter 1 of this embodiment, a fixed electrode 3 is fixed to the first sealing plate 23 via a fixed current-carrying shaft 31, and a movable electrode 4, which can move in the vertical direction (Z direction) via a movable current-carrying shaft 41, comes into contact with or separates from the fixed electrode 3, thereby passing or interrupting current. When the current is interrupted, metal particles are generated from the surfaces of the fixed electrode 3 and the movable electrode 4.

The arc shield 5 is positioned radially between the insulating container 2 and the fixed and movable electrodes 3 and 4, preventing metal particles generated from the surfaces of the fixed and movable electrodes 3 and 4 from adhering to the inner surface 2c of the insulating container 2.

On the other hand, the arc shield 5 is located very close to the insulating container 2. When the arc shield 5 has a potential, a potential difference occurs between the arc shield 5 and the insulating container 2, increasing the electric field strength of the arc shield 5.

The conductive layer 6 is applied to the inner surface 2c of the insulating container 2, which faces the arc shield 5, and is in contact with the arc shield 5. As a result, the conductive layer 6 has the same potential as the arc shield 5, eliminating the potential difference between the arc shield 5 and the insulating container 2. This reduces the electric field strength of the arc shield 5 and suppresses the occurrence of partial discharges.

As described above, the vacuum interrupter 1 comprises a cylindrical insulating container 2, a fixed electrode 3, a movable electrode 4, an arc shield 5, and a conductive layer 6. The fixed electrode 3 is housed in the insulating container 2. The movable electrode 4 is housed in the insulating container 2 facing the fixed electrode 3. The arc shield 5 is fixedly housed in the insulating container 2 and surrounds the fixed electrode 3 and the movable electrode 4. The conductive layer 6 is electrically connected to the arc shield 5 and is provided on at least one of the inner surface 2c and outer surface 2d of the insulating container 2.

When the vacuum interrupter 1 interrupts current, metal particles are generated on the surfaces of the fixed electrode 3 and the movable electrode 4. To prevent metal particles from adhering to the inner surface 2c of the insulating container 2, the arc shield 5 surrounds the fixed electrode 3 and the movable electrode 4 and is located between the fixed electrode 3 and the movable electrode 4 and the inner surface 2c of the insulating container 2. Therefore, the arc shield 5 is located near the inner surface 2c of the insulating container 2. When a voltage is applied and the arc shield 5 has a potential, a potential difference is created between the arc shield 5 and the insulating container 2, increasing the electric field strength of the arc shield 5. However, by providing a conductive layer 6 with the same potential as the arc shield 5 on at least one of the inner surface 2c or outer surface 2d of the insulating container 2, the potential difference between the arc shield 5 and the insulating container 2 is eliminated.

As a result, the conductive layer 6 reduces the electric field strength of the arc shield 5. Therefore, the vacuum interrupter 1 can reduce the electric field strength of the arc shield 5 and suppress the occurrence of partial discharge.

In addition, in this embodiment, the conductive layer 6 is provided continuously on the inner surface 2c or outer surface 2d of the insulating container 2, rather than being scattered throughout. The inner surface 2c or outer surface 2d of the insulating container 2 is covered with the conductive layer 6 all around. As a result, the electric field strength of the arc shield 5 is reduced all around the insulating container 2. This makes it difficult for electrons to accelerate. Therefore, the vacuum valve 1 can further suppress the occurrence of partial discharge.

In addition, in this embodiment, the conductive layer 6 does not extend beyond both ends 5b of the arc shield 5 in the vertical direction (Z direction). The arc shield 5 makes it difficult for the equipotential lines near the triple point A formed by the insulating container 2, vacuum, and conductive layer 6 to penetrate into the area near the triple point A. This reduces the electric field at the triple point A, making it difficult for electrons to be emitted from the triple point A. Therefore, the vacuum valve 1 can further suppress the occurrence of partial discharge.

Furthermore, in the vacuum interrupter 1, metal particles generated from the surfaces of the fixed electrode 3 and movable electrode 4 when the current is interrupted are blocked by the arc shield 5, preventing them from adhering to the conductive layer 6. This makes it difficult for the conductive layer 6 to become at the same potential as the high-voltage side or the ground side.

In addition, in this embodiment, the surface of the conductive layer 6 that comes into contact with the insulating container 2 is metallized. This makes it easier for the insulating container 2 and the conductive layer 6, which are made of different materials, to bond together. This prevents the conductive layer 6 from peeling off from the insulating container 2.

In addition, in this embodiment, the thickness of the conductive layer 6 is equal to the thickness of the metallization applied to the surface of the conductive layer 6 that comes into contact with the insulating container 2. Therefore, the thickness of the metallized conductive layer 6 is not thicker than necessary. This prevents the conductive layer 6 from peeling off from the insulating container 2 due to its own weight.

In addition, in this embodiment, the area outside the outer surface 2d of the insulating container 2 is formed from epoxy resin. This allows the vacuum valve 1 to be used, for example, as a molded vacuum valve in which the exterior of the vacuum valve is filled with epoxy resin.

Second Embodiment
The vacuum valve 1 of the second embodiment shown in Figure 2 has the same configuration as the vacuum valve 1 of the first embodiment, except for the configuration described below. Therefore, the second embodiment also provides the same effects as the first embodiment.

In the second embodiment, as shown in Figure 2, the vacuum valve 1 includes an insulating container 2A that is different from the insulating container 2 of the first embodiment.

Figure 2 is an enlarged cross-sectional view of a portion of the vacuum valve 1 according to the second embodiment. As shown in Figure 2, the insulating container 2A has a protrusion 25.

The protrusions 25 are part of the insulating container 2A and are provided above and below the portion of the arc shield 5 that extends from the inner surface 2c of the insulating container 2 toward the fixed electrode 3 and the movable electrode 4.

The protrusions 25 protrude from the inner surface 2c of the insulating container 2A toward the fixed electrode 3 and the movable electrode 4. Note that in this embodiment, the protrusions 25 protrude from the inner surface 2c of the insulating container 2A toward the fixed electrode 3 and the movable electrode 4, but they may also protrude from the outer surface 2d of the insulating container 2A toward the outside. In other words, the protrusions 25 protrude radially from the inner surface 2c or outer surface 2d of the insulating container 2A.

Furthermore, the protrusions 25 are provided continuously in the circumferential direction on the inner surface 2c of the insulating container 2A, rather than being scattered around. In other words, the protrusions 25 are provided around the entire circumferential circumference of the inner surface 2c of the insulating container 2A.

In this embodiment, the protrusions 25 are provided in a continuous, non-scattered manner on the inner surface 2c of the insulating container 2A in the circumferential direction. However, the protrusions 25 may also be provided in a continuous, non-scattered manner on the outer surface 2d of the insulating container 2A in the circumferential direction.

In this embodiment, the radial length of the protrusion 25 is longer than the thickness of the conductive layer 6 applied to the inner surface 2c of the insulating container 2A. However, the radial length of the protrusion 25 may be changed as appropriate, as long as it is equal to or greater than the thickness of the conductive layer 6 applied to the insulating container 2A.

The conductive layer 6 is applied to the inner surface 2c of the insulating container 2A and is in contact with the first opening 21 or the second opening 22 of the protrusion 25 and the side surface 25a facing the arc shield 5, which is the surface facing the arc shield 5.

The surface of the conductive layer 6 that comes into contact with the side surface 25a of the protrusion 25 facing the arc shield 5 is metallized.

Figure 3 is a graph comparing the electric field strength at the triple point A when the insulating container 2A does not have a protrusion 25, when the conductive layer 6 is in contact with the side surface 25a of the protrusion 25, and when the conductive layer 6 is not in contact with the side surface 25a of the protrusion 25.

Figure 3 shows the electric field strength at the triple point A when the insulating container 2A does not have a protrusion 25 (first embodiment) (G1), when the conductive layer 6 is in contact with the side surface 25a of the protrusion 25 (G2), and when the conductive layer 6 is not in contact with the side surface 25a of the protrusion 25 (G3).

As shown in Figure 3, the electric field strength at the triple point A is reduced by approximately one-fifth when the insulating container 2A has the protrusion 25. Furthermore, the electric field strength at the triple point A is reduced by approximately two-fifths when the conductive layer 6 is in contact with the side surface 25a of the protrusion 25.

As described above, the insulating container 2A has a protrusion 25. The protrusion 25 protrudes radially from the inner surface 2c or outer surface 2d of the insulating container 2A. Therefore, as shown in FIG. 3, by providing the protrusion 25 on the inner surface 2c or outer surface 2d of the insulating container 2A, the insulating container 2A reduces the electric field strength at the triple point A formed by the insulating container 2A, the vacuum, and the conductive layer 6. This allows the vacuum valve 1 to reduce the electric field at the triple point A formed by the insulating container 2A, the vacuum, and the conductive layer 6.

In addition, in this embodiment, the conductive layer 6 is in contact with the side surface 25a of the protrusion 25. Therefore, as shown in FIG. 3, the insulating container 2A reduces the electric field strength at the triple point A formed by the insulating container 2A, the vacuum, and the conductive layer 6 by bringing the conductive layer 6 into contact with the side surface 25a of the protrusion 25. This allows the vacuum valve 1 to further reduce the electric field at the triple point A formed by the insulating container 2A, the vacuum, and the conductive layer 6.

In addition, in this embodiment, the radial length of the protrusion 25 is equal to or greater than the thickness of the conductive layer 6. Therefore, the conductive layer 6 does not protrude beyond the protrusion 25. This allows the vacuum valve 1 to suppress an increase in the electric field strength at the triple point A caused by the insulating container 2A, the vacuum, and the conductive layer 6.

Furthermore, in this embodiment, the protrusions 25 are provided continuously in the circumferential direction, not scattered on the inner surface 2c or outer surface 2d of the insulating container 2. Therefore, the protrusions 25 are provided continuously in the circumferential direction around the entire inner surface 2c or outer surface 2d of the insulating container 2A. This allows the vacuum valve 1 to suppress the occurrence of partial discharges caused by the conductive layer 6 applied to the inner surface 2c or outer surface 2d of the insulating container 2. Therefore, the vacuum valve 1 can further suppress the occurrence of partial discharges.

Third Embodiment
The vacuum valve 1 of the third embodiment shown in Figure 4 has the same configuration as the vacuum valve 1 of the first and second embodiments, except for the configuration described below. Therefore, the third embodiment also provides the same effects based on the configuration as the first and second embodiments.

In the third embodiment, as shown in FIG. 4, the vacuum valve 1 includes an insulating container 2B that is different from the insulating containers 2, 2A of the first and second embodiments.

Figure 4 is an enlarged cross-sectional view of a portion of the vacuum valve 1 according to the third embodiment. As shown in Figure 4, the protruding portion 25 has a projection 26.

The protrusions 26 protrude toward the arc shield 5 from the side surface 25a of the protruding portion 25 facing the arc shield 5. The amount of protrusion of the protrusions 26 may be changed as appropriate, provided that they do not come into contact with the arc shield 5. The protrusions 26 also protrude radially from the ends of the protruding portion 25 toward the arc shield 5. However, they may protrude, for example, from near the center of the protruding portion 25, provided that they do not come into contact with the inner surface 2c of the insulating container 2B.

One end of the conductive layer 6 contacts the arc shield 5, and the other end of the conductive layer 6 extends along the side surface 25a of the protrusion 25 up to the tip 26a of the projection 26. In other words, the conductive layer 6 does not extend beyond the tip 26a of the projection 26. In this embodiment, the conductive layer 6 is applied up to the tip 26a of the projection 26, but it is sufficient if it is applied at least up to the tip 26a of the projection 26.

Figure 5 is a graph comparing the electric field strength at the triple point A when the conductive layer 6 is applied up to the tip 26a of the protrusion 26 and when the conductive layer 6 is not applied up to the tip 26a of the protrusion 26. Figure 5 shows the electric field strength at the triple point A when the conductive layer 6 is applied up to the tip 26a of the protrusion 26 (G4) and when the conductive layer 6 is not applied up to the tip 26a of the protrusion 26 (G5).

As shown in Figure 5, the electric field strength at the triple point A is reduced by more than nine-tenths because the conductive layer 6 is applied up to the tip 26a of the protrusion 26.

As described above, the protruding portion 25 has a protrusion 26 that protrudes toward the arc shield 5 from the surface facing the arc shield 5. The conductive layer 6 extends at least to the tip 26a of the protrusion 26. Therefore, as shown in FIG. 5, the insulating container 2B has the protrusion 26 and the conductive layer 6 extends to the tip 26a of the protrusion 26, thereby reducing the electric field strength at the triple point A formed by the insulating container 2B, the vacuum, and the conductive layer 6. This allows the vacuum interrupter 1 to further reduce the electric field at the triple point A formed by the insulating container 2B, the vacuum, and the conductive layer 6.

Fourth Embodiment
The vacuum valve 1 of the fourth embodiment shown in Figure 6 has the same configuration as the vacuum valves 1 of the first, second, and third embodiments, except for the configuration described below. Therefore, the fourth embodiment also provides the same effects based on the configurations of the first, second, and third embodiments.

In the fourth embodiment, as shown in FIG. 6, the vacuum valve 1 includes an insulating container 2C that is different from the insulating containers 2, 2A, and 2B of the first, second, and third embodiments.

Figure 6 is an enlarged cross-sectional view of a portion of the vacuum interrupter 1 according to the fourth embodiment. As shown in Figure 6, the insulating container 2C does not have a protrusion 26, unlike the configuration of the third embodiment. Instead, the protrusion 25 has an electric field mitigation shield 27. Note that the electric field mitigation shield 27 is an example of a shield.

The electric field mitigation shield 27 is made of, for example, an insulating material and is provided on the side surface 25a of the protrusion 25 that faces the arc shield 5. In other words, the electric field mitigation shield 27 is located between the side surface 25a of the protrusion 25 that faces the arc shield 5 and the conductive layer 6.

The electric field mitigation shield 27 covers the side surface 25a of the protrusion 25 facing the arc shield 5 and is L-shaped and protrudes toward the arc shield 5. In this embodiment, the electric field mitigation shield 27 protrudes radially from the end of the protrusion 25 toward the arc shield 5. However, it may protrude, for example, from near the center of the protrusion 25 as long as it does not come into contact with the inner surface 2c of the insulating container 2C.

One end of the conductive layer 6 contacts the arc shield 5, and the other end of the conductive layer 6 is applied up to the tip 27a of the electric field mitigation shield 27. In other words, the conductive layer 6 does not extend beyond the tip 27a of the electric field mitigation shield 27. In this embodiment, the conductive layer 6 is applied up to the tip 27a of the electric field mitigation shield 27, but it is sufficient if the conductive layer 6 is applied at least up to the tip 27a of the electric field mitigation shield 27.

In addition, in this embodiment, for example, the surface of the conductive layer 6 that comes into contact with the electric field mitigation shield 27 may be metallized to facilitate bonding between the conductive layer 6 and the electric field mitigation shield 27.

As described above, the protrusion 25 has an insulating electric field mitigation shield 27 between the surface facing the arc shield 5 and the conductive layer 6. The electric field mitigation shield 27 covers the surface facing the arc shield 5 and protrudes toward the arc shield 5. The conductive layer 6 extends at least to the tip 27a of the electric field mitigation shield 27.

As a result, the space between the arc shield 5 and the conductive layer 6 is blocked by the electric field mitigation shield 27. As a result, the electric field mitigation shield 27 mitigates the electric field at the triple point A formed by the insulating container 2C, vacuum, and conductive layer 6. Therefore, the vacuum interrupter 1 can mitigate the electric field at the triple point A formed by the insulating container 2C, vacuum, and conductive layer 6 without providing a protrusion 26.

Fifth Embodiment
The vacuum valve 1 of the fifth embodiment shown in Figure 7 has the same configuration as the vacuum valves 1 of the first to fourth embodiments, except for the configuration described below. Therefore, the fifth embodiment also provides the same effects based on the configurations of the first to fourth embodiments.

In the fifth embodiment, as shown in FIG. 7, the vacuum valve 1 includes an insulating container 2D that differs from the insulating containers 2, 2A, 2B, and 2C of the first to fourth embodiments.

Figure 7 is an enlarged cross-sectional view of a portion of the vacuum interrupter 1 according to the fifth embodiment. As shown in Figure 7, the insulating container 2D does not have a protrusion 25, unlike the configuration of the second embodiment. Instead, the insulating container 2D has a convex portion 28.

The convex portions 28 are provided above and below the portion extending from the inner surface 2c of the insulating container 2D of the arc shield 5 toward the fixed electrode 3 and the movable electrode 4.

The protrusion 28 extends at an angle from the inner surface 2c of the insulating container 2D toward the fixed electrode 3 or the movable electrode 4, and then extends at an angle toward the arc shield 5.

One end of the conductive layer 6 contacts the arc shield 5, and the other end of the conductive layer 6 is applied up to the apex 28a of the convex portion 28. In other words, the conductive layer 6 is applied down to a point below the apex 28a of the convex portion 28.

In this embodiment, the conductive layer 6 is applied up to the apex 28a of the convex portion 28, but it may also be applied up to the tip 28b of the convex portion 28.

As described above, the insulating container 2D has a protrusion 28. The protrusion 28 extends at an angle from the inner surface 2c or outer surface 2d of the insulating container 2D toward the fixed electrode 3 or movable electrode 4, and then extends at an angle toward the arc shield 5. The conductive layer 6 is provided below the apex 28a of the protrusion 28 and is metallized. This allows the vacuum interrupter 1 to reduce the electric field at the triple point A formed by the insulating container 2D, the vacuum, and the conductive layer 6 without having a protrusion 25.

<Modification>
8 is an enlarged cross-sectional view of a portion of the arc shield 5A of the modified example. As shown in FIG. 8, the vacuum interrupter 1 of the modified example includes an arc shield 5A having a shape different from the arc shields 5 of the first to fifth embodiments.

The arc shield 5A has a bent portion 51. The arc shield 5A extends from the center in the vertical direction (Z direction) along the axis Ax of the insulating container 2 and connects to the bent portion 51.

The bent portion 51 extends in the vertical direction (Z direction) and is bent toward the fixed electrode 3 and the movable electrode 4. In other words, the bent portion 51 bends radially inward and then extends in the vertical direction (Z direction) along the axis Ax of the insulating container 2.

One end of the conductive layer 6 contacts the arc shield 5, and the other end of the conductive layer 6 is applied down to both end portions 5b of the arc shield 5. In other words, the conductive layer 6 is applied up to an area that does not exceed both end portions 5b of the arc shield 5 in the vertical direction. Note that in this modified example, the conductive layer 6 is applied down to both end portions 5b of the arc shield 5, but it is sufficient that the conductive layer 6 is applied at least between the bend 51 and both end portions 5b of the arc shield 5.

When the conductive layer 6 is applied only between the bent portion 51 and both ends 5b of the arc shield 5, the conductive layer 6 does not come into contact with the arc shield 5. As a result, the conductive layer 6 and the arc shield 5 do not have the same potential. To prevent this, when the conductive layer 6 is applied only between the bent portion 51 and both ends 5b of the arc shield 5, it is preferable that the conductive layer 6 be made of a metal that has the same potential as the arc shield 5.

As described above, the arc shield 5A has a bent portion 51. The bent portion 51 extends in the vertical direction (Z direction) and is bent toward the fixed electrode 3 and the movable electrode 4. The conductive layer 6 is provided at least between the bent portion 51 and both end portions 5b of the arc shield 5.

When a voltage is applied, the electric field strength at the bent portion 51 of the arc shield 5A increases. Electrons accelerated by the electric field tend to collide with the area opposite the bent portion 51. In other words, they tend to collide between the bent portion 51 of the arc shield 5A and both end portions 5b of the arc shield 5A.

Therefore, by providing a conductive layer 6 between the bent portion 51 and both ends 5b of the arc shield 5, the electric field strength of the arc shield 5 can be alleviated with the minimum necessary conductive layer 6. This allows the vacuum interrupter 1 to reduce the cost of the conductive layer 6.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope of the invention and its equivalents as set forth in the claims, as well as within the scope and spirit of the invention.

1 Vacuum valve 2, 2A, 2B, 2C, 2D Insulating container (container)
2c Inner surface 2d Outer surface 25 Protrusion 25a Side surface 26 Protrusion 26a Tip 27 Electric field mitigation shield (shield)
27a Tip 28 Convex portion 28a Vertex 3 Fixed electrode (first electrode)
4 Movable electrode (second electrode)
5, 5A Arc shield (shield material)
5b both end portions 51 bending portion 6 conductive layer (conductive portion)

Claims (12)

A cylindrical container;
a first electrode accommodated in the container;
a second electrode accommodated in the container and facing the first electrode;
a shield member fixedly housed in the container and surrounding the first electrode and the second electrode;
a conductive portion electrically connected to the shielding member and provided on at least one of an inner surface and an outer surface of the container;
Equipped with
a triple point where the container, the vacuum, and the conductive portion contact does not extend beyond both ends of the shielding member in a first direction in which the first electrode and the second electrode face each other;
Vacuum valve. The conductive portion is provided continuously on the inner surface or the outer surface of the container without being scattered.
2. The vacuum valve according to claim 1. the shielding member extends in the first direction and has a bent portion bent toward the first electrode and the second electrode,
The conductive portion is provided at least between the bent portion and both end portions of the shielding member.
3. The vacuum valve according to claim 1 or 2. The container has a protrusion that protrudes from the inner surface or the outer surface in a second direction perpendicular to the first direction.
The vacuum interrupter according to any one of claims 1 to 3. The conductive portion is in contact with a side surface of the protrusion.
5. The vacuum valve according to claim 4. a length of the protrusion in the second direction is equal to or greater than a thickness of the conductive portion;
6. The vacuum valve according to claim 4 or 5. The protrusion is provided continuously and not scattered on the inner surface or the outer surface of the container in a third direction perpendicular to the first direction.
The vacuum interrupter according to any one of claims 4 to 6. the protruding portion has a projection that protrudes from a surface facing the shielding member toward the shielding member,
The conductive portion is provided at least up to the tip of the protrusion.
The vacuum interrupter according to any one of claims 4 to 7. the protrusion has an insulating shield between a surface facing the shield member and the conductive portion,
the shield covers a surface facing the shield member and protrudes toward the shield member,
The conductive portion is provided at least up to the tip of the shield.
The vacuum interrupter according to any one of claims 4 to 7. The surface of the conductive portion that comes into contact with the container is metallized.
A vacuum interrupter according to any one of claims 1 to 9. The thickness of the conductive portion is equal to the thickness of the metallization treatment.
11. The vacuum valve according to claim 10. the container has a protrusion that extends obliquely from the inner surface or the outer surface toward the first electrode or the second electrode, and then extends obliquely toward the shielding member,
The conductive portion is provided below the apex of the convex portion and is subjected to the metallization treatment.
12. A vacuum valve according to claim 10 or 11.