JPH10233145A - Vacuum valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum valve such that damage to contact surfaces caused by an arc generated at the input of power can be prevented and, even if it is damaged, a decrease in insulation characteristic can be prevented. SOLUTION: An approximately truncated-cone-shaped projection 12a is formed at the center of the contact surface of the contact 12 of an electrode on one side, and in the center of the contact surface of the contact 11 of an electrode on the other side, a recess 11a is formed into which the projection 12a is fitted when both of the contacts come into contact, with the top surface of the projection 12a making contact with the bottom surface of the recess 11a. The outer periphery of the top surface of the projection 12a is chamfered, and the outer periphery of the entrance of the recess 11a is also chamfered, so that an electric current is carried by way of the top surface of the projection 12a and the bottom surface of the recess 11a. For the contact material of the recess 11a, a material having a higher tensile strength than the contact material of the projection 12a is used, so that even if the contacts are fused together, the fused parts are allowed to remain in the recess 12a, preventing insulation characteristic from decreasing at the gap between the contacts when a circuit is broken and when it is made again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a vacuum valve.

[0002]

2. Description of the Related Art A vacuum valve incorporated in a vacuum circuit breaker is approximately
By separating a pair of contacts in a high vacuum of 10 ^-2 Pa or less, the current is interrupted by utilizing the excellent arc-extinguishing and insulating properties of the vacuum.

FIG. 9 is a longitudinal sectional view showing an example of this. The openings at both ends of an insulating cylinder 1 generally made of ceramics or glass are sealed with a fixed end plate 2 and a movable end plate 3, respectively, so as to be airtight. A simple container.

[0004] A fixed-side energized shaft 4 is fixedly penetrated to the fixed-side end plate 2, and a fixed-side electrode 5 is brazed to the tip of the fixed-side energized shaft 4. A movable-side electrode 6 is opposed to the fixed-side electrode 5 and has a movable-side energized shaft 7 connected to an operation mechanism (not shown).
It is brazed to. Further, on the opposing surfaces of the fixed side electrode 5 and the movable side electrode 6, contacts 8 made of various alloy materials are brazed to the respective electrodes according to the use of the vacuum circuit breaker.

On the other hand, the opening of the movable energizing shaft 7 and the opening of the movable end plate 3 are air-tightly brazed by a bellows 9, thereby maintaining the vacuum inside the insulating cylinder 1 and operating the movable energizing shaft 7. This allows contact opening and closing.

Further, in order to prevent a phenomenon in which metal vapor or metal splatter scattered from the contacts and electrodes at the time of current interruption adheres to the inner surface of the insulating cylinder 1 and the insulation performance on the creeping surface is deteriorated, a cylindrical shield 10 is provided. Have been.

[0007]

When a large current is opened and closed by a vacuum circuit breaker incorporating a vacuum valve having such a structure,
Depending on the switching conditions, the withstand voltage performance may be reduced. The reason is that the surface state of the contact changes due to the arc generated by opening and closing.

The reasons for the change of the surface state are mainly as follows. First, when the vacuum circuit breaker is turned on and the contacts of the vacuum valve are closed, insulation is broken by the voltage applied between the contacts immediately before the contacts come into contact, and a pre-arc (preceding discharge) is ignited.

FIG. 10 is an enlarged view of the vicinity of the contact point of the vacuum valve.
As shown in (a), an arc 22 fired at a narrow contact gap
Since the diffusion is suppressed, the density of the energy injected into the contact 8 is increased, and the surface is melted.

When the fused portion 8a solidifies after the contact of the contacts, the mutual contacts are welded. As shown in FIG.
The welded portion 8a1 has different characteristics from the base material as a result of being rapidly heated and quenched, and particularly has a high tensile strength (tensile strength). Therefore, in the next opening operation, the contact base material portion immediately below the welded portion 8a1 is peeled off to form a larger projection 8b.

Since the electric field is high at the tip of the projection 8b, the insulation is easily broken. In particular, when the load is a capacitor, the charge charged in the capacitor flows as an inrush current of a high-frequency large current, and the above-mentioned damage to the contacts is further increased.

Further, in the opening and closing of the capacitor, no reactor is connected between the capacitor and the circuit breaker.
With so-called back-to-back opening and closing,
Inrush currents can be as high as thousands of Hz-tens of kiloamps. When such a high-frequency high current is ignited as a pre-arc, a phenomenon different from the above-described damage caused by welding and peeling of the contacts occurs. That is, as shown in FIG. 11, a thin burred projection 8c may be formed at the contact end.

According to the experiment of the inventor, 20 kA-4,200 H
After conducting 10,000 open / close tests with an inrush current of z, the vacuum valve was dismantled and observed. The thickness t of the protrusion 8c was about 0.6 mm, and the protrusion length L reached a maximum of 2.5 mm. There were also things.

The reason why the protruding portion 8c is formed is that the injection energy density into the contact with a large current is high,
Not only does the amount of evaporation increase, but the higher the frequency, the higher the rate of change of current.As a result, the amount of metal vapor supplied from the contacts increases, exceeding the diffusion speed of the arc. Is estimated to be blown outward. By repeating this phenomenon many times,
The burrs 8c are formed as described above.

Incidentally, as a damage of a contact caused by an arc, the surface of the contact may be melted due to local concentration of the arc when a large current is interrupted. For this reason, various electrode structures mainly utilizing the interaction between the arc and the magnetic field have been proposed and implemented, and an arc control technique at the time of interruption has been established to some extent.

On the other hand, there is no effective means for controlling the arc generated at the time of closing as described above. Therefore, an object of the present invention is to provide a vacuum valve that can suppress damage to a contact surface due to an arc generated at the time of injection, and can prevent a decrease in insulation performance even if it is damaged.

[0017]

According to a first aspect of the present invention, a fixed-side electrode is provided at the tip of a fixed-side energizing shaft protruding from one side of the vacuum vessel to the inside thereof, and moves forward and backward from the other side of the vacuum vessel. A movable valve is provided at the end of a movable-side energized shaft freely penetrated, and a contact is fixed to a surface opposite to the movable-side electrode and the fixed-side electrode. Is formed, and a convex portion is fitted to the opposing surface of the contact on the other side by the operation of inputting the movable side conducting shaft, and a concave portion is formed in which the top surface of the convex portion contacts the bottom surface, and the tensile strength of the contact material of this concave portion is reduced. It is characterized in that it is larger than the tensile strength of the projection.

A vacuum valve according to a second aspect of the invention is characterized in that a convex portion and a concave portion are formed at the center of the contact, and the vacuum valve according to the third aspect of the present invention has a convex portion and a concave portion. Are formed at a plurality of locations around the center of the contact.

According to a fourth aspect of the present invention, there is provided a vacuum valve, wherein a combination of a contact material for a concave portion and a contact material for a convex portion is formed by an infiltration method and a solid phase sintering method or an arc melting method and a solid phase sintering method. Alternatively, a copper chromium alloy manufactured by an arc melting method and an infiltration method is used.

According to a fifth aspect of the present invention, a fixed-side electrode is provided at the tip of a fixed-side energizing shaft protruding from one side of the vacuum vessel to the inside thereof, and penetrates freely from the other side of the vacuum vessel. The movable-side electrode is provided at the tip of the movable-side energized shaft,
7. The vacuum valve according to claim 6, wherein a non-contact outer peripheral surface is formed on an outer periphery of a contact surface of the contact in the vacuum valve in which a contact is fixed on a side opposite to the movable-side electrode and the fixed-side electrode. Is characterized in that when the contact surface of the contact is D1 and the diameter of the non-contact surface is D2, D2−D1> 5 mm.

According to a seventh aspect of the present invention, a fixed-side electrode is provided at the tip of a fixed-side energizing shaft protruding from one side of the vacuum valve into the inside thereof, and penetrates freely from the other side of the vacuum vessel. A movable electrode is provided at the tip of the movable-side energized shaft, and a contact is fixed on the opposite side of the movable-side electrode and the fixed-side electrode. The vacuum valve according to the invention of claim 8 is characterized in that the groove is concentric, and the vacuum valve of the invention corresponding to claim 9 is characterized in that the groove is radial.

Further, according to a tenth aspect of the present invention, a fixed-side electrode is provided at a tip of a fixed-side energizing shaft protruding from one side of the vacuum vessel into the inside, and penetrates freely from the other side of the vacuum vessel. A movable electrode is provided at the tip of the movable-side energized shaft, and a plurality of small holes penetrating the contact and the electrode are formed in a vacuum valve in which the contact is fixed on the opposite side of the movable-side electrode and the fixed-side electrode. It is characterized by the following.

According to the invention corresponding to the first, second and third aspects, when the contact surface is melted by the arc generated between the contacts, the solidified portion after the melting is formed on the concave side. Thus, a decrease in withstand voltage characteristics at the time of contact opening is prevented.

Further, in the invention corresponding to claim 4, the tensile strength of the contact material on the concave side is made larger than the tensile strength of the contact material on the convex side. In the inventions corresponding to claims 5 and 6, the increase in the electric field strength when the contact surface of the contact melts and projects to the outer peripheral side is reduced by the flat non-contact outer peripheral surface.

Further, in the inventions corresponding to claims 7, 8 and 9, the pressure increased by the arc generated between the contacts is reduced by the gas released from the groove.

Further, in the invention corresponding to claim 10, the pressure raised by the arc generated between the contacts is
Decreased by gas evolving behind the electrode through a plurality of small holes.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the vacuum valve of the present invention will be described below with reference to the drawings. FIG. 1 is a partially enlarged detailed view showing a first embodiment of the vacuum valve of the present invention, and is a view corresponding to claims 1 and 2, and FIG. 2 is an enlarged vertical sectional view of a contact portion of FIG. . FIG. 1 shows a state before charging, FIG. 2 shows an opening state after charging and partial melting, and the same parts as those in FIG. 9 shown in the prior art are denoted by the same reference numerals. .

In FIG. 1, a concave portion 11a is formed at the center of one contact 11 and a convex portion 12a is formed at the other contact 12 at a position corresponding to the concave portion 11a. Here, the relationship between the depth d1 of the concave portion 11a and the height h1 of the convex portion 12a is slightly h1> d1.

The reason is that the bottom surface of the concave portion 11a and the convex portion
This is because the top surface of the contact 12a comes into contact with the flat portions 11b and 12b of the contact and does not make contact. Further, as a characteristic of the material of the contact, the tensile strength of the concave contact 11 is made higher than the tensile strength of the convex contact 12.

For example, in the case of a copper chromium alloy which is used worldwide as a contact material for a vacuum valve in terms of arc extinguishing performance and withstand voltage performance, the concave contact 11 and the convex contact 12 are formed by arc melting. There are combinations of respective contacts by the method and the infiltration method, the arc melting method and the solid phase sintering method, and the infiltration method and the solid phase sintering method.

Of these, the solid phase sintering method, the infiltration method and the arc melting method are typical, and the tensile strength is generally highest by the arc melting method and lowest by the solid phase sintering method. Among these manufacturing methods, first, the solid phase sintering method is a method of sintering a material obtained by stirring and mixing copper and chromium powder materials at high temperature and high pressure, and has the highest productivity. However, the porosity is relatively high, the density of the material is about 90 to 95% of the theoretical density, and the content of the impurity gas is relatively high.

Next, the infiltration method is a method in which molten copper is infiltrated into a material called a skeleton obtained by sintering chromium powder at a high temperature and a low pressure, and has few defects and a material density close to 100%. In order to ensure sufficient wettability, it is important to control the chromium raw material, the production cost is relatively high, and the productivity is low.

The arc melting method is a method in which an arc is ignited between electrode rods manufactured by a solid phase sintering method or an infiltration method to solidify a molten material of the electrode rods. Although the density is almost 100%, the production cost is the highest and the productivity is low.

As described above, the material defect differs depending on the production method, and mainly because of the amount of the impurity gas, the breaking performance of the arc melting method is the best and that of the solid phase sintering method is the poorest. According to such a combination of the contact shape and the material, the following phenomenon occurs.

First, when the pre-arc firing portion is welded, the contact is peeled off from the base material of the contact having a low tensile strength when the electrode is opened, and a projection is formed on the contact side having a high tensile strength. Therefore, in the present embodiment, as shown in FIG.
a is formed inside. However, due to the periphery of the concave portion 11a, electrolysis at the tip of the projection 13 is relaxed, and does not affect the insulation performance. On the other hand, in the welded portion of the convex contact 12, a concave portion 14 after being peeled is formed as shown in FIG. 2A, but the electric field intensity does not increase.

By forming a concave portion having a high tensile strength and a convex portion having a low tensile strength on the surface of the contact as described above, the projection can always be formed in the concave portion even if welding and peeling occur. Can prevent an increase in the electric field strength, and can prevent a decrease in insulation performance.

By the way, in the electrodes shown in FIGS. 1 and 2, there are three combinations of the copper-chromium contact materials of the three manufacturing methods as described above, each having the following features.

First, when a copper chromium contact is used for the concave side contact by the infiltration method and for the convex side contact by the solid phase sintering method, not only is the contact inexpensive, but also the welding power is the lowest.
This is because when they are welded, they are peeled off on the copper chromium side in the solid-phase sintering method having low tensile strength. Therefore, the operating force of the mechanism that drives the movable-side energized shaft can be reduced, and even if frequent opening and closing are performed, there is little deformation of the electrode and shrinkage of the shaft. And a highly reliable vacuum valve without the risk of leakage.

Next, when an arc melting method is used for the concave contact and a solid state sintering copper chromium contact is used for the convex contact, the infiltration method is used for the concave contact and the solid state sintering method is used for the convex contact. The breaking performance can be improved due to the characteristics of the arc melting contact as compared with the case of using a chrome contact. Since the welding force is determined by the characteristics of the copper chrome contacts in the solid-phase sintering method, in this case, the mechanism operation force is low and a highly reliable vacuum valve that does not cause deformation or leakage of each part is required. Can be.

Further, when a copper chromium contact of an arc melting method is used for the concave side contact and an infiltration method of the copper chromium contact is used for the convex side contact, the concave and infiltration copper chromium contact, which has a relatively small content of defects and impurity gas, is used. The breaking performance can be further improved as compared with the case where an arc melting method is used for the side contact and a copper chrome contact is used for the convex side contact by the solid phase sintering method, and it can be applied to a system having a large short-circuit breaking capacity.

By the way, the contact is generally processed by a lathe and the productivity is excellent, but in this regard, in the first embodiment, the contact body and the centers of the concave portion 11a and the convex portion 12a coincide with each other. , Easy to process.

However, this embodiment is suitable for a vacuum valve having a relatively small input capacity, and when the input capacity is increased and the welding force of the contacts is increased, the operating force for opening the electrode must be increased. Then, the electrode may be deformed or the shaft may be shrunk, or the stress of the opening / closing impact applied to the airtight brazing portion may be increased, so that the reliability may be reduced.

FIG. 3 shows a structure of an electrode portion as a second embodiment of the vacuum valve according to the present invention. In FIG. 3, at least two concave portions 15 having a depth d1 are formed in one peripheral portion other than the center portion of one contact 15, and the other contact 16 has a height h at a position facing the concave portion 15 a.
One projection 16a is formed.

Also in this case, similarly to the first embodiment, the recess 15a and the projection 16a of the contact always come into contact with each other at the time of closing, and the flat portions 15b and 16b of the contact do not come into contact with each other.
> D1. Further, as a material of the contact, a material in which the tensile strength of the concave contact 15 is higher than the tensile strength of the convex contact 16 is used.

According to the second embodiment, the welding portion can be set at a position deviated from the center axis, so that when the movable portion is turned on and opened on the movable current-carrying shaft, the moment applied to the welding portion causes a low operation. The weld can be peeled off by force.

In this case as well, as a result of peeling, the projection is formed on the contact side having a high tensile strength. However, the concave portion 15 can prevent an increase in the electric field due to the projection, and there is no possibility that the insulation performance is reduced.

Next, FIG. 4 is a partially enlarged detailed view showing a third embodiment of the electrode portion of the vacuum valve of the present invention, which corresponds to claims 5 and 6, and FIG. It is the longitudinal cross-sectional view which expanded the vicinity of one end of the contact.

[0048] In Figure 4, are formed the contact face 17a of the diameter D ₁ in the contact 17, on the outside of the contact surface 17a, the non-contact flat surface 17b only step h2 lower diameter D ₂ is formed . The outer peripheral portion 17c of the contact is chamfered in an arc shape to prevent concentration of an electric field.

With this electrode, the inrush current Ba
When the ck to back is opened and closed, the portion melted by the pre-arc ignited at the contact portion 17a of the contact 17 projects in a thin bur shape, but as shown in FIG. 5, the non-contact flat surface 17b immediately below the projection 17d. As a result, the electric field at the tip of the protruding portion 17d is reduced, and there is no possibility that the insulation performance is reduced.

If the step h2 is too high, the effect of alleviating the electric field by the non-contact flat surface 17b is reduced. In the experiment of the inventor, the thickness of the protruding portion 17d is about 0.6 mm.
In order to effectively reduce the electric field, it is desirable to set approximately 1 <h2 <1.5 mm. In back-to-back opening and closing, the damage to the contacts is large, so the vacuum valve has been replaced in the past several thousand times.

Although it depends on the value and frequency of the rush current and the number of switching operations, the above-mentioned experimental conditions of the inventor of 20 kA-4,200 Hz
Is a severe condition, and if it can be opened and closed 10,000 times under these conditions, it is sufficient for frequent opening and closing.

Therefore, if the influence of the projecting portion formed by the inrush current and the number of times of switching can be suppressed, it can be applied for frequent switching. According to the experiment of the inventor, the height of the maximum protruding portion under the open / close condition was 2.5 mm, so that the width of the non-contact flat surface may be any more. Therefore, D ₂ −
If D ₁ > 5 mm, frequent back-to-back opening and closing can be performed.

FIG. 6 shows a fourth embodiment of the vacuum valve according to the present invention, and corresponds to claims 7 and 8.
(A) is a plan view, and (b) is a sectional view taken along the line AA of (a). In FIG. 6, even if the contact 18 is locally melted by the pre-arc firing, the molten material flows into the groove 18a, so that it is possible to prevent the contact from protruding to the outer peripheral portion and to increase the electric field at the contact end. There is no reduction in insulation performance due to

Since the cutting by the lathe is excellent in the productivity of the contacts, it is better to form the grooves in a concentric shape. However, since the concentric grooves are closed, the effect of suppressing an increase in the pressure of the arc column during pre-arc firing is low.

Therefore, as shown in the plan view of FIG. 7A corresponding to claim 9 and the fifth embodiment of FIG. 7B in the section BB of FIG. If formed, the groove is opened at the contact outer peripheral portion 19b, so that the pressure of the arc column can be released. For this reason, it is possible to prevent the melted contact from protruding. Therefore, when the inrush current is large, a radial groove is preferable.

FIG. 8 is a partially enlarged detailed view showing a sixth embodiment of the vacuum valve of the present invention.
(A) is a partial plan view, (b) is a CC sectional view of (a). In FIG. 8, a small hole extends through the contact 20 and the electrode 21.
A large number 20a are formed in the axial direction.

In this embodiment, since the plasma of the arc generated at the time of the pre-arc firing is discharged backward through the small holes 20a, the pressure of the arc column is increased more than in the radially grooved embodiment of FIG. It can be more effectively suppressed. As a result, the protrusion of the melted contact can be prevented, so that a decrease in insulation performance can be prevented.

[0058]

As described above, according to the first aspect of the present invention, the fixed-side electrode is provided at the tip of the fixed-side energizing shaft protruding from one side of the vacuum vessel, and moves forward and backward from the other side of the vacuum vessel. A movable valve is provided at the end of a movable-side energized shaft freely penetrated, and a contact is fixed to a surface opposite to the movable-side electrode and the fixed-side electrode. Is formed, and a convex portion is fitted to the opposing surface of the contact on the other side by the operation of inputting the movable side conducting shaft, and a concave portion is formed in which the top surface of the convex portion contacts the bottom surface, and the tensile strength of the contact material of this concave portion is reduced. When the contact surface is melted by the arc generated between the contacts by making it larger than the tensile strength of the convex portion, a solidified portion after melting is formed on the concave side to reduce the withstand voltage characteristics at the time of contact opening. This prevents damage to the contact surface due to arcs generated during Also, it is possible to obtain a vacuum valve which can prevent a decrease in insulating properties.

According to the invention corresponding to claim 2,
According to the third aspect of the present invention, the protrusion and the recess are formed at a plurality of locations around the center of the contact, so that the protrusion and the recess are formed at the center of the contact. When the contact surface melts due to the arc, the solidified part after melting is formed on the concave side, preventing the deterioration of the withstand voltage characteristic at the time of contact opening, suppressing damage to the contact surface due to the arc generated at the time of injection Thus, even if damaged, a vacuum valve that can prevent the insulation characteristics from being deteriorated can be obtained.

According to a fourth aspect of the present invention,
The combination of the contact material of the concave portion and the contact material of the convex portion should be a copper chromium alloy manufactured by infiltration method and solid phase sintering method, arc melting method and solid phase sintering method, or arc melting method and infiltration method. Since the tensile strength of the contact material on the concave side is higher than the tensile strength of the contact material on the convex side, it is possible to suppress damage to the contact surface due to the arc generated at the time of injection, and to prevent the deterioration of insulation properties even if it is damaged. The vacuum valve which can be obtained can be obtained.

According to the invention corresponding to claim 5,
A fixed-side electrode is provided at the end of a fixed-side energizing shaft protruding from one side of the vacuum vessel to the inside, and a movable-side electrode is provided at the end of a movable-side energizing shaft penetrating from the other side of the vacuum vessel so as to freely advance and retreat. According to the invention corresponding to claim 6, a non-contact outer peripheral surface is formed on the outer periphery of the contact surface of the contact in the vacuum valve having the contact fixed on the opposite side of the movable side electrode and the fixed side electrode. For example, when the contact surface of the contact is D1 and the diameter of the non-contact surface is D2, by setting D2−D1> 5 mm,
An increase in electric field strength when the contact surface of the contact melts and protrudes to the outer peripheral side is mitigated by the flat non-contact outer peripheral surface. It is possible to obtain a vacuum valve capable of preventing the characteristic from deteriorating.

According to a seventh aspect of the present invention,
A fixed-side electrode is provided at the tip of a fixed-side energizing shaft protruding from one side of the vacuum valve to the inside, and a movable-side electrode is provided at the tip of a movable-side energizing shaft penetrating from the other side of the vacuum vessel so as to be able to advance and retreat. In the vacuum valve in which the contact is fixed on the opposite side of the movable-side electrode and the fixed-side electrode, a groove is formed on the opposite surface of the contact, and in the invention corresponding to claim 8, the groove is concentric. According to the invention corresponding to claim 9, the pressure raised by the arc generated between the contacts is reduced by the gas released from the groove by making the groove radial, It is possible to obtain a vacuum valve capable of preventing an increase in pressure between the contacts due to an arc generated between the contacts and improving the breaking performance.

Further, according to the tenth aspect of the present invention, a fixed-side electrode is provided at the tip of a fixed-side energizing shaft projecting from one side of the vacuum vessel to the inside thereof, so that the fixed-side electrode can advance and retreat from the other side of the vacuum vessel. A movable electrode is provided at the tip of the penetrated movable-side conducting shaft, and a plurality of small holes penetrating the contact and the electrode are provided in a vacuum valve in which the contact is fixed on the opposite side of the movable-side electrode and the fixed-side electrode. By forming, the pressure that was raised by the arc generated between the contacts was reduced by the gas released behind the electrode from the multiple holes, preventing the pressure between the contacts from being increased by the arc generated between the contacts. Thus, a vacuum valve capable of improving the shut-off performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially enlarged view showing a first embodiment of a vacuum valve according to the present invention, wherein (a) shows a fixed side of an electrode portion, and (b) shows a movable side.

FIG. 2 is a partially enlarged view showing an operation of the first embodiment of the vacuum valve of the present invention, wherein (a) shows a fixed side of a contact;
(B) shows the movable side.

FIGS. 3A and 3B are partially enlarged views showing a second embodiment of the vacuum valve of the present invention, wherein FIG. 3A shows a fixed side of an electrode portion, and FIG. 3B shows a movable side.

FIGS. 4A and 4B are partially enlarged views showing a third embodiment of the vacuum valve of the present invention, wherein FIG. 4A shows a fixed side of an electrode portion, and FIG. 4B shows a movable side.

FIG. 5 is a partially enlarged sectional view showing the operation of a third embodiment of the vacuum valve of the present invention.

FIGS. 6A and 6B are partially enlarged views showing a fourth embodiment of the vacuum valve of the present invention, wherein FIG. 6A is a plan view and FIG. 6B is a sectional view taken along line AA of FIG.

FIGS. 7A and 7B are partially enlarged views showing a fifth embodiment of the vacuum valve of the present invention, wherein FIG. 7A is a plan view and FIG. 7B is a sectional view taken along line BB of FIG.

8A and 8B are partially enlarged views showing a sixth embodiment of the vacuum valve of the present invention, wherein FIG. 8A is a plan view, and FIG. 8B is a cross-sectional view taken along the line CC of FIG.

FIG. 9 is a longitudinal sectional view showing an example of a conventional vacuum valve.

FIGS. 10A and 10B are partially enlarged views showing the operation of a conventional vacuum valve, in which FIG. 10A shows a state immediately before closing, and FIG. 10B shows a contact after opening.

11 is a partially enlarged view showing the operation of the conventional vacuum valve different from that of FIG. 10, where (a) shows the fixed side of the electrode and (b) shows the movable side.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating cylinder, 2 ... Fixed end plate, 3 ... Movable end plate, 4 ...
Fixed-side conducting shaft, 5: fixed-side electrode, 6, 21: movable-side electrode,
7: movable side conducting shaft, 8, 17, 18, 19: contact, 9: bellows, 10: shield, 11, 15: concave contact, 11a: concave, 1
2, 16 ... convex side contact, 12a ... convex part, 13 ... protrusion, 14 ... hole, 17
b: non-contact flat portion, 17d: projecting portion, 18a, 19a: groove, 20
a ... Small hole.

Claims (10)

[Claims] 1. A fixed-side electrode is provided at the tip of a fixed-side energizing shaft protruding from one side of the vacuum vessel to the inside thereof, and a tip of a movable-side energizing shaft penetrated from the other side of the vacuum vessel so as to be able to advance and retreat. A movable side electrode is provided, and a vacuum valve in which a contact is fixed to a surface facing the movable side electrode and the fixed side electrode,
A convex portion is formed on the opposing surface of the contact on one side, and the convex portion is fitted to the opposing surface of the contact on the other side by the operation of turning on the movable-side energizing shaft, and the top surface of the convex portion contacts the bottom surface. Forming a recess,
The tensile strength of the contact material in the concave portion is larger than the tensile strength of the convex portion. 2. The vacuum valve according to claim 1, wherein the convex portion and the concave portion are formed at a center of the contact. 3. The vacuum valve according to claim 1, wherein the convex portion and the concave portion are formed at a plurality of positions around a central portion of the contact. 4. A combination of the contact material of the concave portion and the contact material of the convex portion is manufactured by an infiltration method and a solid phase sintering method, an arc melting method and a solid phase sintering method, or an arc melting method and an infiltration method. The vacuum valve according to any one of claims 1 to 3, wherein the copper chromium alloy is formed. 5. A fixed-side electrode is provided at a tip of a fixed-side energizing shaft protruding from one side of the vacuum vessel to the inside, and a tip of a movable-side energizing shaft penetrated from the other side of the vacuum vessel so as to be able to advance and retreat. A movable side electrode is provided in a vacuum valve in which a contact is fixed on a side opposite to the movable side electrode and the fixed side electrode,
A non-contact outer peripheral surface is formed on the outer periphery of the contact surface of the contact, wherein the vacuum valve is provided. 6. The vacuum valve according to claim 5, wherein D2−D1> 5 mm, where D1 is a contact surface of the contact and D2 is a diameter of the non-contact surface. 7. A fixed-side electrode is provided at a tip of a fixed-side energized shaft protruding from one side of the vacuum valve to the inside thereof, and a tip of a movable-side energized shaft penetrated from the other side of the vacuum vessel so as to be able to advance and retreat. A movable electrode, and a contact is fixed on the opposite side of the movable electrode and the fixed electrode, wherein a groove is formed on a surface facing the contact. 8. The vacuum valve according to claim 7, wherein said groove is concentric. 9. The vacuum valve according to claim 7, wherein said groove is radial. 10. A fixed-side electrode is provided at the tip of a fixed-side energizing shaft protruding from one side of the vacuum vessel to the inside, and a tip of a movable-side energizing shaft penetrated from the other side of the vacuum vessel so as to be able to advance and retreat. The movable side electrode is provided, and a plurality of small holes penetrating the contact point and the electrode are formed in a vacuum valve in which a contact is fixed on a side opposite to the movable side electrode and the fixed side electrode. Vacuum valve.