JP7566657B2 - Vacuum valve - Google Patents

Description

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

Switchgear equipped with switches such as circuit breakers and disconnectors is known as a switching device for receiving and distributing electricity installed in buildings and large facilities. A vacuum valve is used as a component of the switchgear. The inside of the vacuum valve is maintained in a constant insulating state by an insulating container (vacuum container), and a pair of electrodes are housed inside this insulating container so that they can be connected and disconnected. In this case, fault currents are interrupted and load currents are opened and closed by connecting and disconnecting the pair of electrodes, and power is supplied stably from the switchgear.

JP 2006-318795 A

However, for example, when a vacuum valve is opened (i.e., a pair of electrodes is separated) while a current is flowing, an arc discharge (hereafter referred to as an arc) occurs between the electrodes, heating the opposing surfaces of the electrodes and raising the surface temperature. This can cause a part of the electrode surface to melt, resulting in a high-temperature molten material (molten metal) that flows toward the outer edge of the electrode.

Here, the outer edge of the electrode has a structure in which the electric field strength is the highest. In this case, when the high-temperature molten material described above reaches the outer edge of the electrode, the high-temperature molten material and the part with the highest electric field strength overlap at the same location, making the outer edge of the electrode prone to dielectric breakdown (in other words, prone to becoming the starting point of dielectric breakdown). This reduces the insulation performance when the vacuum valve is opened, and as a result, there is a risk that it may become difficult to interrupt the current.

The objective of the present invention is to provide a vacuum valve that uses technology that prevents the high-temperature molten material generated on the electrode surface by the arc and the area of high electric field strength from overlapping at the same location on the outer edge of the electrode.

According to an embodiment, a vacuum valve has a pair of electrodes arranged with their electrode surfaces facing each other and capable of being brought into contact with and separated from each other, and is equipped with a molten material flow suppression means provided on each of the electrode surfaces of the pair of electrodes for suppressing high-temperature molten material generated on the electrode surface by the arc between the electrodes from flowing and reaching the outer edge of the electrodes, and an arc generation position control means provided on each of the electrode surfaces of the pair of electrodes for controlling the generation position of the arc , wherein the molten material flow suppression means is configured to be continuous in the circumferential direction around the periphery of the electrode surface and inside the outer edge of the electrode , and the arc generation position control means is provided inside the molten material flow suppression means and is configured to form a contour shape that protrudes beyond the electrode surface and has a surface bulge structure that protrudes maximum only at the center of at least one of the electrode surfaces, and the center of the electrode surface coincides with a single imaginary axis that defines the center of the vacuum valve.

FIG. 2 is a cross-sectional view showing the internal configuration of a vacuum valve according to one embodiment. FIG. 2 is a plan view of the electrode surface of FIG. 1 . FIG. 2 is a perspective view of the electrode surface of FIG. 1 . FIG. 4 is a cross-sectional view taken along line F4-F4 in FIG. 3 . FIG. 11 is a cross-sectional view showing a state in which a pair of electrodes are in straight contact with each other. FIG. 13 is a cross-sectional view showing a state in which a pair of electrodes are in contact with each other at an angle. FIG. FIG. 4 is a schematic diagram showing the electric field distribution on the electrode surface. FIG. 11 is a cross-sectional view showing another configuration of the damming structure. FIG. 11 is a cross-sectional view showing another configuration of the damming structure. FIG. 11 is a cross-sectional view of an electrode surface portion of a vacuum interrupter according to a modified example. FIG. 11 is a cross-sectional view of an electrode surface portion of a vacuum interrupter according to a modified example. FIG. 11 is a cross-sectional view of an electrode surface portion of a vacuum interrupter according to a modified example. FIG. 11 is a cross-sectional view of an electrode surface portion of a vacuum interrupter according to a modified example.

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

In the example shown in FIG. 1, the insulating container 1 is made of an insulating material such as alumina ceramic and has a hollow cylindrical shape. The fixed sealing member 2 and the movable sealing member 3 are made of a metal material whose main component is stainless steel, for example.

As shown in FIG. 1, the hollow cylindrical insulating container 1 is concentric with an imaginary axis Px that defines the center of the vacuum valve P. When viewed in the direction of the imaginary axis Px, the insulating container 1 is open at both ends. Both openings (fixed side opening K1, movable side opening K2) are covered by a fixed side sealing member 2 and a movable side sealing member 3. Specifically, the fixed side sealing member 2 closes one of the fixed side openings K1 of the insulating container 1 via a fixed side sealing metal fitting 6. The movable side sealing member 3 closes the other movable side opening K2 of the insulating container 1 via a movable side sealing metal fitting 7.

The arc shield 5 is made of a metal material whose main components are, for example, copper or stainless steel. The arc shield 5 has a hollow cylindrical shape and is fixed to the insulating container 1. The arc shield 5 is arranged so as to accommodate the fixed contact 8 of the fixed electrode E1 and the movable contact 10 of the movable electrode E2 within its interior (inside).

The fixed electrode E1 and the movable electrode E2 are aligned and extend along the imaginary axis Px. The fixed electrode E1 has a fixed contact 8 and a fixed current-carrying shaft 9. The movable electrode E2 has a movable contact 10 and a movable current-carrying shaft 11. The fixed contact 8 and the movable contact 10 are made of copper chromium (CuCr) material, and the fixed current-carrying shaft 9 and the movable current-carrying shaft 11 are made of copper (Cu) material.

In the example of FIG. 1, the fixed contact 8 is disk-shaped, and the fixed current-carrying shaft 9 is cylindrical. The fixed contact 8 and the fixed current-carrying shaft 9 have the same diameter. Therefore, the fixed electrode E1 equipped with the fixed contact 8 and the fixed current-carrying shaft 9 is configured with a straight cylindrical contour as a whole. The fixed contact 8 has surfaces with a circular contour on both sides, with one surface defined as the fixed electrode surface 8a described below, and the other surface (opposite the fixed electrode surface 8a) defined as the back surface 8b.

On the other hand, the movable contact 10 is disk-shaped, and the movable current-carrying shaft 11 is cylindrical. The movable contact 10 and the movable current-carrying shaft 11 have the same diameter. Therefore, the movable electrode E2 equipped with the movable contact 10 and the movable current-carrying shaft 11 is configured with a straight cylindrical contour as a whole. The movable contact 10 has surfaces with a circular contour on both sides, with one surface defined as the movable electrode surface 10a described below, and the other surface (opposite the movable electrode surface 10a) defined as the back surface 10b.

The fixed contact 8 and the movable contact 10 are arranged opposite each other so that their circular electrode surfaces (fixed electrode surface 8a, movable electrode surface 10a) face each other in parallel. The fixed contact 8 has its back surface 8b connected to one end of the fixed current-carrying shaft 9, the other end of which is fixed to the vacuum valve P via the fixed sealing member 2 so as not to be able to move along the imaginary axis Px. The movable contact 10 has its back surface 10b connected to one end of the movable current-carrying shaft 11, the other end of which is connected to an operating mechanism (not shown) via the movable sealing member 3.

The movable current-carrying shaft 11 is then moved along the imaginary axis Px by the operating mechanism. This allows the movable contact 10 to be brought into contact with and separated from the fixed contact 8. 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 and separated from each other).

Furthermore, an airtightness maintaining mechanism 4 is disposed between the movable current-carrying shaft 11 and the movable-side sealing member 3. 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 can expand and contract in the direction of the imaginary axis Px, and covers the outside of the movable current-carrying shaft 11 without any gaps.

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 11. This ensures that the inside of the insulating container 1 is always kept airtight (i.e., vacuum state). As a result, when opening and closing the vacuum valve P, the atmosphere (air) does not enter the inside of the insulating container 1, even while the movable current-carrying shaft 11 is being moved along the imaginary axis Px.

When the vacuum valve P is opened, an arc generated between the electrodes E1 and E2 may cause a portion of the opposing surfaces of the electrodes E1 and E2 (the fixed electrode surface 8a, the movable electrode surface 10a) to melt. In this case, the plasma pressure during arc generation is high at the center (coincident with the imaginary axis Px) of the electrodes E1 and E2 (electrode surfaces 8a and 10a) and low at the periphery (i.e., the annular electrode outer edges 8f and 10f) of the electrodes E1 and E2 (electrode surfaces 8a and 10a). As a result, the molten high-temperature material (molten metal) flows along the plasma pressure gradient toward the electrode outer edges (the fixed electrode outer edge 8f, the movable electrode outer edge 10f).

The outer edges 8f and 10f of the electrodes are structurally designed to be areas where the electric field strength is high. Therefore, when the high-temperature molten material reaches the outer edges 8f and 10f of the electrodes, the high-temperature molten material and the area with high electric field strength overlap at the same location, creating a condition in which insulation breakdown is likely to occur starting from the overlapping point. This reduces the insulation performance when the vacuum valve P is opened.

Therefore, in order to improve the insulation performance when the vacuum valve P is opened (in other words, when an arc is generated), the vacuum valve P according to this embodiment is provided with a means (hereinafter referred to as a molten material flow suppression means 12) for suppressing the flow of the high-temperature molten material from reaching the outer edges 8f and 10f of the electrodes.

In the example shown in FIG. 1, the molten material flow suppression means 12 is configured as a continuous ring around the periphery of the electrodes E1, E2 (electrode surfaces 8a, 10a) and immediately before the annular electrode outer edges 8f, 10f.

Furthermore, when an arc is generated, the opposing surfaces of the electrodes E1 and E2 (the fixed electrode surface 8a and the movable electrode surface 10a) are heated and the surface temperature increases. Such a high-temperature region is formed corresponding to the position where the arc is generated. In this case, it is preferable to control the high-temperature region to a position that avoids the electrode outer edges 8f and 10f (in other words, the position furthest from the electrode outer edges 8f and 10f). The position furthest from the annular electrode outer edges 8f and 10f is the center of the electrodes E1 and E2 (electrode surfaces 8a and 10a), i.e., the part that coincides with the virtual axis Px.

Therefore, the vacuum valve P according to this embodiment is provided with a means for controlling the arc generation position (hereinafter referred to as arc generation position control means 13) at the center of the electrodes E1, E2 (electrode surfaces 8a, 10a) that coincide with the imaginary axis Px, as well as the area including the vicinity and periphery (hereinafter referred to as electrode center Es).

In the example of FIG. 1, the arc generation position control means 13 is configured to have a contour shape that is inside the above-mentioned annular molten material flow suppression means 12 and protrudes beyond the electrode surfaces 8a, 10a at the electrode center Es. The arc generation position control means 13 protrudes most at the center (coincident with the imaginary axis Px) of the electrodes E1, E2 (electrode surfaces 8a, 10a) in the electrode center Es.

Figure 2 is a diagram of the electrode surfaces (fixed electrode surface 8a, movable electrode surface 10a) of electrodes E1 and E2, Figure 3 is a diagram of the external configuration of the fixed contact 8 and the movable contact 10, and Figure 4 is a cross-sectional view of the fixed contact 8 and the movable contact 10.

In the examples of Figures 2 to 4, a damming structure 12p is used as the melt flow suppression means 12, which has the function of blocking the high-temperature melt flowing toward the annular electrode outer edges 8f, 10f just before the electrode outer edges 8f, 10f. The damming structure 12p is provided on the electrode surfaces 8a, 10a of the electrodes E1, E2 facing each other, respectively, and includes a storage mechanism 14 (also called a storage mechanism), a damming mechanism 15, and a guide mechanism 16.

The storage mechanism 14 is provided continuously around the electrodes E1, E2 (electrode surfaces 8a, 10a) immediately before the annular electrode outer edges 8f, 10f. The storage mechanism 14 is configured by continuously recessing a portion of the electrode surfaces 8a, 10a along the circumferential direction. The cross-sectional shape of the storage mechanism 14 can be various shapes, such as a rectangular shape, a triangular shape, or a circular arc shape. This creates a storage groove that can store high-temperature molten material immediately before the electrode outer edges 8f, 10f. In this case, the high-temperature molten material that flows toward the electrode outer edges 8f, 10f is stored (stored) in the storage mechanism 14 (storage groove) without leakage. As a result, the high-temperature molten material does not exceed the storage mechanism 14 (storage groove) and reach the electrode outer edges 8f, 10f.

The damming mechanism 15 is provided adjacent to the storage mechanism 14 (storage groove). The damming mechanism 15 can be envisioned as an annular barrier section that is raised along the virtual axis Px described above inside the storage mechanism 14 (storage groove). This causes the flow range of the high-temperature molten material stored (stored) in the storage mechanism 14 (storage groove) to be restricted by the damming mechanism 15 (barrier section). As a result, the high-temperature molten material does not pass over the damming mechanism 15 (barrier section) and reach the electrode outer edges 8f, 10f.

The guide mechanism 16 is provided adjacent to the storage mechanism 14 (storage groove) so as to face the damming mechanism 15 (barrier portion). The guide mechanism 16 can be envisioned as an annular slope portion that approaches the damming mechanism 15 (barrier portion) and forms a downward slope inside the storage mechanism 14 (storage groove). As a result, the high-temperature molten material that flows toward the electrode outer edges 8f, 10f is guided by the guide mechanism 16 (slope portion) to the storage mechanism 14 (storage groove) without leakage. As a result, the molten material remains in front of the storage mechanism 14 (storage groove), and thereafter, the inflow of new molten material into the storage mechanism 14 (storage groove) is not hindered.

The arc generation position control means 13 uses a surface bulge structure 13p that has the function of controlling the arc generation position to a position that avoids the electrode outer edges 8f, 10f. The surface bulge structure 13p bulges in an arc shape from the electrode surfaces 8a, 10a, and forms a contour shape that protrudes most at the center of the electrode surfaces 8a, 10a (coincident with the imaginary axis Px).

In this case, the radius of curvature of the arc-shaped surface bulge structure 13p is set to be larger than the radius of curvature of the electrode outer edges 8f, 10f. In other words, the curvature of the surface bulge structure 13p is set to be smaller than the curvature of the electrode outer edges 8f, 10f. This makes it possible to increase the electric field at the electrode outer edges 8f, 10f while simultaneously keeping the electric field low in areas other than the electrode outer edges 8f, 10f, as shown in FIG. 8 described below.

As for the amount of protrusion (height, length, distance) of the surface bulge structure 13p, it is possible to envisage a method of determining the amount of protrusion of the surface bulge structure 13p based on the electrode surfaces 8a and 10a described above, or a method of determining the amount of protrusion of the surface bulge structure 13p based on the bottom surface 14s (reservoir groove) of the storage mechanism 14 (see Figure 4).

For example, when the bottom surface 14s is used as a reference, if the height from the bottom surface 14s to the electrode surfaces 8a, 10a (the depth of the storage mechanism 14 (storage groove)) in a direction parallel to the virtual axis Px is a, and the height from the bottom surface 14s to the maximum protruding position of the surface bulging structure 13p (i.e., the center of the electrode surfaces 8a, 10a) is b, the protrusion amount of the surface bulging structure 13p is specified to satisfy the relationship a<b.

Figures 5 and 6 are diagrams showing the contact state of electrode surfaces 8a, 10a (electrodes E1, E2) having a surface bulge structure 13p. As shown in Figure 5, when the vacuum valve P is in the closed state, both electrodes E1, E2 come into contact with each other at the location where the surface bulge structure 13p protrudes most (i.e., the center of the electrode surfaces 8a, 10a). Here, as shown in Figure 6, even if both electrodes E1, E2 are slightly tilted, both electrode surfaces 8a, 10a come into contact with each other near their centers.

This allows the position where the arc occurs when the vacuum valve P is opened to be controlled to a position that avoids the electrode outer edges 8f, 10f (in other words, the position furthest from the electrode outer edges 8f, 10f), specifically, to the center of the electrodes E1, E2 (electrode surfaces 8a, 10a) (coincident with the virtual axis Px).

Figure 7 is a cross-sectional diagram of the damming structure 12p. In the example of Figure 7, the damming mechanism 15 (barrier portion) is raised parallel to the virtual axis Px described above. In this case, the angle θ between the damming mechanism 15 (barrier portion) and the electrode surfaces 8a, 10a is set to 90°. This allows the damming mechanism 15 (barrier portion) to function as a breakwater against the high-temperature molten material stored (stored) in the storage mechanism 14 (storage groove).

Figure 8 is a diagram showing the distribution of electric field strength on the electrode surfaces 8a, 10a. As shown in Figure 8, by making the surface bulge structure 13p bulge in an arc shape from the electrode surfaces 8a, 10a, the electric field strength can be kept low except at the electrode outer edges 8f, 10f. In other words, the electric field strength at the electrode outer edges 8f, 10f can be made the highest. This improves the insulation performance when the vacuum valve P is opened.

Figure 9 is a cross-sectional diagram of the damming structure 12p. In the example of Figure 9, the damming mechanism 15 (barrier portion) is inclined and raised in a direction intersecting the virtual axis Px described above, i.e., in a direction approaching the guide mechanism 16 (slope portion). In this case, the angle θ between the damming mechanism 15 (barrier portion) and the electrode surfaces 8a, 10a is set to less than 90°. This allows the damming mechanism 15 (barrier portion) to function to prevent the high-temperature molten material contained (stored) in the storage mechanism 14 (storage groove) from overflowing, in other words, to hold the molten material in the storage mechanism 14 (storage groove).

Figure 10 is a cross-sectional diagram of the damming structure 12p. In the example of Figure 10, the damming mechanism 15 (barrier portion) is configured with a ring-shaped flange portion 12f. The flange portion 12f is provided continuously in the circumferential direction along the upper end of the damming mechanism 15 (barrier portion) in the same plane as the electrode surfaces 8a, 10a, while protruding so as to partially cover the storage mechanism 14 (reservoir groove). This makes it possible to more effectively prevent the outflow of the molten material.

As described above, according to this embodiment, the molten material flow suppression means 12 (dam structure 12p) is configured continuously in the circumferential direction around the electrode surfaces 8a, 10a and immediately before the electrode outer edges 8f, 10f. This makes it possible to suppress the high-temperature molten material generated on the electrode surfaces 8a, 10a by the arc between the electrodes E1, E2 from flowing and reaching the electrode outer edges 8f, 10f. As a result, it is possible to prevent the high-temperature molten material generated on the electrode surfaces 8a, 10a by the arc and the part with high electric field strength from overlapping at the same point on the electrode outer edges 8f, 10f, in other words, to prevent the formation of a state in which insulation breakdown is likely to occur starting from the overlapping point. Thus, it is possible to maintain or improve the insulation performance when the vacuum valve P is opened.

According to this embodiment, a storage mechanism 14 (also called a storage mechanism) is provided on each of the electrode surfaces 8a, 10a as the damming structure 12p. The storage mechanism 14 is configured by continuously recessing a portion of the electrode surfaces 8a, 10a in the circumferential direction. This allows the high-temperature molten material that flows toward the electrode outer edges 8f, 10f to be stored (stored) without leakage in the storage mechanism 14 (storage groove). As a result, the high-temperature molten material can be prevented from exceeding the storage mechanism 14 and reaching the electrode outer edges 8f, 10f.

According to this embodiment, on the electrode surfaces 8a, 10a, a damming mechanism 15 is provided adjacent to the storage mechanism 14 (reservoir groove) as a damming structure 12p. The damming mechanism 15 is configured as an annular barrier portion raised inside the storage mechanism 14. As a result, the flow range of the high-temperature molten material stored (stored) in the storage mechanism 14 is restricted by the damming mechanism 15 (barrier portion). As a result, the high-temperature molten material can be prevented from passing over the damming mechanism 15 and reaching the outer edges 8f, 10f of the electrodes.

According to this embodiment, on the electrode surfaces 8a, 10a, the guide mechanism 16 is provided as the damming structure 12p adjacent to the storage mechanism 14 (reservoir groove) so as to face the damming mechanism 15 (barrier portion). The guide mechanism 16 is configured as an annular slope portion that forms a downward slope as it approaches the damming mechanism 15 inside the storage mechanism 14. As a result, the high-temperature molten material that flows toward the electrode outer edges 8f, 10f is guided to the storage mechanism 14 without leakage by the guide mechanism 16 (slope portion). As a result, it is possible to prevent the molten material from remaining in front of the storage mechanism 14 and subsequently obstructing the flow of new molten material into the storage mechanism 14.

According to this embodiment, the arc generation position control means 13 (surface bulging structure 13p) is provided inside the melt flow suppression means 12, and is configured to have a contour shape that protrudes beyond the electrode surfaces 8a, 10a at the electrode center Es. As a result, when the vacuum valve P is in a closed state, both electrode surfaces 8a, 10a always contact each other near their centers. As a result, the position at which the arc is generated when the vacuum valve P is open can be controlled to a position that avoids the electrode outer edges 8f, 10f. In other words, the part that is likely to generate an arc can be set in advance to any position on the electrode surfaces 8a, 10a (for example, the center of electrodes E1, E2).

According to this embodiment, by making the surface bulging structure 13p bulge from the electrode surfaces 8a, 10a, the electric field strength can be kept low except at the electrode outer edges 8f, 10f. This makes it possible to maximize the electric field strength at the electrode outer edges 8f, 10f. As a result, the insulation performance when the vacuum valve P is opened can be dramatically improved.

"Variations"
In the above embodiment, the surface bulging structures 13p of both electrodes E1, E2 are bulged in an arc shape, but instead, as shown in Fig. 11, the periphery of the center (virtual axis Px) of either one of the surface bulging structures 13p may be flat. In the example of Fig. 11, a flat surface 13m is formed on the surface bulging structure 13p of the movable electrode E2. In this case, the periphery of the center (virtual axis Px) of both surface bulging structures 13p may be flat. Note that other configurations and effects are similar to those of the above embodiment, and therefore description thereof will be omitted.

In the above embodiment, the surface bulge structure 13p of both electrodes E1 and E2 is bulged in an arc shape. Alternatively, as shown in FIG. 12, a surface bulge structure 13p that bulges in a rectangular shape may be used. In this case, it is preferable to apply a chamfer R along the periphery of the rectangular surface bulge structure 13p. Note that other configurations and effects are similar to those of the above embodiment, and therefore description thereof will be omitted.

In the above embodiment, electrodes E1 and E2 are assumed to have the electrode outer edges 8f and 10f and the surface bulging structure 13p integrated together. Alternatively, as shown in FIG. 13, the electrode outer edges 8f and 10f and the surface bulging structure 13p may be configured separately. In this case, it is preferable that the surface bulging structure 13p is formed from a material that can withstand high temperatures (e.g., copper chrome material), and the electrode outer edges 8f and 10f are formed from a material that can withstand high electric fields (e.g., pure chrome, SUS, tungsten).

In addition, as shown in FIG. 14, for example, the storage mechanism 14 (reservoir groove) may be configured to penetrate the fixed contact 8 and the movable contact 10. With this configuration, the high-temperature molten material that flows into the storage mechanism 14 (reservoir groove) comes into contact with one end face 9s, 11s of the fixed current-carrying shaft 9 (movable current-carrying shaft 11), but since the copper fixed current-carrying shaft 9 (movable current-carrying shaft 11) has high thermal conductivity, it is possible to achieve the effect of being cooled in a short time. Note that the other configurations and effects are the same as those of the above-mentioned embodiment, and therefore their description will be omitted.

In the above embodiment, one damming structure 12p is provided in front of the electrode outer edges 8f, 10f, but multiple damming structures 12p may be provided. Although not specifically shown, for example, the storage mechanism 14 (reservoir groove) is provided around two or more circumferences. This can further improve the storage capacity for high-temperature molten material. Note that other configurations and effects are the same as those of the above embodiment, so their description is omitted.

Although one embodiment of the present invention and several variations have been described above, these embodiments and variations are presented as examples and are not intended to limit the scope of the invention. These embodiments and variations 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 variations are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents as set forth in the claims.

E1, E2...electrode, Es...center of electrode, 8a, 10a...electrode surface, 8b, 10b...back surface, 8f, 10f...outer edge of electrode, 12...molten material flow suppression means, 13...arc generation position control means, 13p...surface bulge structure, 14...accommodation mechanism (reservoir groove), 15...dam mechanism (barrier section), 16...guide mechanism (slope section).

Claims (7)

A vacuum valve having a pair of electrodes arranged with their electrode surfaces facing each other and capable of being brought into and out of contact with each other,
a melt flow suppressing means provided on each of the electrode surfaces of the pair of electrodes to suppress a high-temperature melt generated on the electrode surface by an arc between the electrodes from flowing and reaching an outer edge of the electrodes ;
and an arc generation position control means provided on each of the pair of electrodes on the electrode surface for controlling an arc generation position ,
the melt flow suppressing means is formed continuously in a circumferential direction on the periphery of the electrode surface and inside the outer edge of the electrode ,
the arc generation position control means is provided inside the molten material flow suppression means, has a contour shape that protrudes beyond the electrode surfaces, and has a surface bulge structure that protrudes maximally only at the center of at least one of the electrode surfaces;
A vacuum valve , wherein the center of the electrode surface coincides with an imaginary axis that defines the center of the vacuum valve . The vacuum valve according to claim 1, wherein the melt flow suppression means has a blocking structure that blocks the high-temperature melt flowing toward the outer edge of the electrode just before the outer edge of the electrode. The blocking structure includes a receiving mechanism in which a part of the electrode surface is continuously recessed along a circumferential direction,
3. The vacuum valve according to claim 2, wherein the high-temperature molten material that has flowed toward the outer edge of the electrode is contained in the containing mechanism. The damming structure includes a damming mechanism provided adjacent to the containing mechanism,
4. The vacuum valve according to claim 3, wherein a flow range of the high-temperature molten material contained in the containing mechanism is restricted by the blocking mechanism. The damming structure includes a guide mechanism provided adjacent to the storage mechanism,
4. The vacuum valve according to claim 3, wherein the high-temperature molten material that has flowed toward the outer edge of the electrode is guided to the containing mechanism by the guide mechanism. the surface swelling structure has a contour shape that protrudes in an arc shape from the electrode surface,
2. The vacuum valve according to claim 1 , wherein the radius of curvature of the arc-shaped surface bulge structure is set to be larger than the radius of curvature of the outer edge of the electrode. The outer edge of the electrode and the surface swelling structure are formed separately,
The surface swelling structure is formed of a material that can withstand high temperatures;
2. The vacuum valve according to claim 1 , wherein the outer edge of the electrode is made of a material that can withstand a high electric field.

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