JP2002133984A - Vacuum valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum valve with a high reliability which is improved in a property for refrigeration and allows a large current passage by forming a flowing path at least in a movable shaft or a fixed shaft, and prevents a refrigerating fluid in the flowing path from leaking to a vacuum container. SOLUTION: The fixed shaft or the movable shaft is formed from an end shaft with an end on the inside of the vacuum container and a bottom on the outside of the vacuum container, and a bottom shaft joined to the bottom of the end shaft on the outside of the vacuum container. A flowing path, which enters through an entrance at the bottom, goes to the end, is folded, and returns to an exit at the bottom, is formed in the end shaft. A path of the refrigerating fluid for flowing in and out, which is joined to the entrance and the exit opened at the bottom of the end shaft, is formed in the bottom shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve applied to, for example, an opening / closing device for opening / closing and protecting an electric circuit, and in particular, at least one of a fixed shaft and a movable shaft has a flow passage for cooling a contact. It relates to a vacuum valve.

[0002]

2. Description of the Related Art As shown in FIG. 14, for example, a vacuum valve comprises a cylindrical insulating container 1a, and end plates 1b and 1c which respectively close both open end surfaces of the insulating container 1a. A vacuum vessel 1 which is evacuated by a vacuum pump and whose inside is in a vacuum state, a fixed shaft 5 attached to an end plate 1c and provided with a contact 4 at a tip end inside the vacuum vessel 1, and a bellows 6 on an end plate 1b. And a movable shaft 3 having a contact 2 provided at a tip end inside the vacuum vessel 1.

The movable shaft 3 can be reciprocated in the axial direction by an operating mechanism (not shown), and the transition from the current interrupted state to the energized state is performed by pushing up the movable shaft 3 by the operating mechanism and changing the contact 2 to the contact 4 of the fixed shaft 5. This is done by contacting On the other hand, the transition from the energized state to the current cut-off state where an abnormal current occurs and the circuit needs to be protected is performed by lowering the movable shaft 3 by the operating mechanism connected to the movable shaft 3 and moving the contact 2 from the contact 4 of the fixed shaft 5. It is done by separating. In addition, the vacuum state in the vacuum vessel 1 during the reciprocating movement of the movable shaft 3 is favorably maintained because the bellows 6 is deformed and the displacement of the movable shaft 3 with respect to the end plate 1b is absorbed. Also, good shut-off performance is maintained.

[0004]

However, in the above-structured vacuum valve, the current flowing through the movable shaft 3 and the fixed shaft 5 via the contacts 2 and 4 during energization causes the electric current flowing through the contact surface between the contacts 2 and 4 to increase. Due to the high contact electric resistance, Joule heat is concentrated near the contact surfaces of the contacts 2 and 4.

Therefore, the temperature near the contacts 2 and 4 rises during energization, and when the energizing current further increases, the temperature of the contacts becomes higher than a specified temperature and reliability cannot be maintained. There is a drawback that a switching device using a vacuum valve cannot be applied to switching and protection of an electric circuit having a large current.

In order to solve the above-mentioned drawback, it is sufficient to forcibly cool the vicinity of the contacts 2 and 4 to suppress a temperature rise during energization. For this purpose, one or both of the movable shaft 3 and the fixed shaft 5 are provided. A flow path through which a cooling fluid such as water flows is formed by a path passing near the contact, and the cooling fluid is circulated to the flow path by an external cooling fluid circulation system to efficiently cool the vicinity of the contact. It is possible.

FIG. 15 is a side view of the movable shaft 3 in which a flow path for contact cooling is formed, and FIG.
FIG. 6 is a sectional view taken along line VI-XVI.

In these figures, the flow path 8 is
An inflow-side flow path that proceeds at right angles to the axial direction from an inlet 10 at the lower side of the movable shaft 3 and extends in the axial direction toward the vicinity of the contact 2 therefrom; An outflow-side flow path which advances from there and extends in the axial direction toward the vicinity of the contact 2 is configured to communicate in the vicinity of the contact 2.

In this way, the cooling performance is drastically improved by flowing a cooling fluid such as water into the movable shaft 3 so that the contact 2 of the movable shaft 3 and the fixed shaft 5 contacting the contact 2 are formed. Since a rise in the temperature of the contact 4 can be suppressed, a large current can be supplied.

However, it is difficult to form the flow path 8 having such a structure by excavation or the like without dividing the movable shaft 3. After shaving, it is necessary to fix and join and integrate by brazing or the like. On the other hand, since the movable shaft 3 has a lower part exposed outside the vacuum vessel 1 and an upper part exposed inside the vacuum vessel 1, a part of the joint 9 by brazing or the like is also exposed inside the vacuum vessel 1 in a vacuum state. Will do.

For this reason, there is a possibility that a gap may be left in the fixed portion of the joining portion 9 due to aging or the like, and a cooling fluid such as water may leak from the flow channel 8 into the vacuum vessel 1. Leaks, there is a problem that the vacuum state is destroyed and the shut-off performance of the vacuum valve cannot be maintained, thereby lowering the reliability. In addition, not only the movable shaft 3 but also the same flow path 8 formed in the fixed shaft 5 has a similar problem.

The present invention solves the above-mentioned problems and improves the cooling performance by a flow path formed in at least one of a movable shaft and a fixed shaft, thereby suppressing a rise in the temperature of a contact and enabling a large current to flow. It is another object of the present invention to provide a highly reliable vacuum valve capable of maintaining a shut-off performance for a long period of time without leakage of a cooling fluid in a flow path into a vacuum vessel.

[0013]

In order to solve the above problems,
The vacuum valve according to claim 1, wherein the contact provided at the tip of the fixed shaft and the contact provided at the tip of the movable shaft are separated or contacted in the vacuum vessel in accordance with the movement of the movable shaft. In a vacuum valve that opens and closes a circuit, at least one of the fixed shaft and the movable shaft has a distal end inside the vacuum vessel and a distal end provided with a bottom outside.
A bottom shaft joined to the bottom of the tip shaft outside the vacuum vessel, and the tip shaft is folded back from an inlet opening at the bottom toward the tip and back to an outlet opening at the bottom again. While a flow path is formed, a cooling fluid inflow / outflow path is formed in the bottom shaft, which is joined to an entrance opening at the bottom of the tip shaft. This allows
At least a portion of the flow path for cooling the contact inside the vacuum vessel can be formed by excavation or the like without dividing the shaft, so that the flow path and the vacuum vessel are fixed by brazing or the like. Joints can be eliminated.

[0014] The vacuum valve according to the second aspect is the first aspect of the invention.
In the vacuum valve according to the above, the vicinity of the folded portion of the flow path formed on the distal end shaft is formed in a shape such that the cross-sectional area of the flow path becomes smaller as it is closer to the folded portion, for example, a stepped shape or a tapered shape. It is. Accordingly, the flow rate of the cooling fluid flowing in the flow channel increases at the folded portion near the contact point, so that the heat transfer amount increases.

According to a third aspect of the present invention, the contact provided at the distal end of the fixed shaft and the contact provided at the distal end of the movable shaft are separated or contact in the vacuum vessel in accordance with the movement of the movable shaft. In a vacuum valve that opens and closes an electric circuit, at least one of the fixed shaft and the movable shaft has a tip portion provided with a tip portion inside the vacuum vessel and a bottom portion outside the vacuum vessel, and an outside portion of the vacuum vessel. And a bottom shaft joined to the bottom of the tip shaft, and an entrance opening to the bottom by joining a partition plate to the inner wall of a vertical hole formed from the bottom to the vicinity of the tip of the tip shaft. A flow path is formed which returns to the outlet opening at the bottom while being turned back through the communication portion from the front end to the front end, while the cooling fluid flowing into the bottom shaft is joined to the entrance opening at the bottom of the tip shaft. A way out was formed Than it is. Accordingly, at least a portion of the flow path for cooling the contact inside the vacuum vessel can be formed without dividing the shaft. Parts can be eliminated.

[0016] The vacuum valve according to the fourth aspect is the third aspect of the invention.
In the vacuum valve described in (1), the vicinity of the communication portion of the partition plate fixed to the vertical hole has a shape in which the thickness increases as the distance from the communication portion increases, for example, a stepped shape or a tapered shape. Thereby, the cross-sectional area of the flow path near the communication part becomes smaller as it is closer to the communication part, and the flow velocity of the cooling fluid flowing in the flow path increases in the communication part near the contact point.

According to a fifth aspect of the present invention, the contact provided at the tip of the fixed shaft and the contact provided at the tip of the movable shaft are separated or contacted in the vacuum vessel in accordance with the movement of the movable shaft. In a vacuum valve that opens and closes an electric circuit, at least one of the fixed shaft and the movable shaft has a tip portion provided with a tip portion inside the vacuum vessel and a bottom portion outside the vacuum vessel, and an outside portion of the vacuum vessel. And a bottom shaft joined to the bottom of the tip shaft, and the tip shaft has a vertical hole formed from the bottom to the vicinity of the tip and a cooling fluid outflow passage joined to a lower portion of the vertical hole. On the other hand, the bottom shaft is formed with an inner cylinder which is coaxially inserted into the vertical hole, which is thinner and slightly shorter than a vertical hole formed in the tip shaft, and a cooling fluid inflow passage joined to the inner cylinder. Is formed Thereby, in the vertical hole, a flow path for contact cooling can be configured by a flow path inside and an external flow path of the inner cylinder that communicates with a tip end of the vertical hole, and at least a portion in the vacuum vessel, Since the flow path for cooling the contact can be formed without dividing the shaft, it is possible to eliminate a fixed joint portion between the flow path and the inside of the vacuum vessel by brazing or the like. Further, the cooling fluid passes through the inside of the inner cylinder from the inflow path to reach the vicinity of the contact, and is discharged from the outflow path through the outside of the inner cylinder.

[0018] The vacuum valve according to claim 6 is the same as the vacuum valve according to claim 5.
In the vacuum valve described in (1), the distal end of the inner cylinder formed on the bottom shaft has a shape in which the thickness increases as it approaches the distal end, for example, a stepped shape or a tapered shape. Thereby, the cross-sectional area near the communication part of the flow path formed near the tip end of the vertical hole, that is, the contact becomes smaller as it is closer to the communication part, and the flow rate of the cooling fluid flowing in the flow path is closer to the contact. It increases in the communication part.

The vacuum valve according to claim 7 is the same as the vacuum valve according to claim 5.
In the vacuum valve described in (1), annular projections are formed on the outer surface of the inner cylinder at intervals in the axial direction. As a result, the flow of the cooling fluid flowing through the flow path outside the inner cylinder is disturbed.

[0020] The vacuum valve according to claim 8 is a vacuum valve according to claim 5.
The helical projection is formed on the outer surface of the inner cylinder. Thereby, the cooling fluid flowing in the flow path outside the inner cylinder is guided by the spiral projection and spirally flows.

According to the ninth aspect of the present invention, there is provided a vacuum valve according to the fifth aspect.
The helical projection is fixed to the inner surface of the vertical hole. Thereby, the cooling fluid flowing through the flow path outside the inner cylinder is guided by the helical projection fixed to the inner surface of the vertical hole and flows helically.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described.

FIG. 14 shows a vacuum valve according to the first embodiment.
The movable shaft 3 having the configuration shown in FIG. 1 is applied as the movable shaft 3 of the vacuum valve having the configuration shown in FIG.

In FIG. 1, the movable shaft 3 has a tip shaft 3a.
And a bottom shaft 3b fixed to the bottom of the tip shaft 3a by a joining portion 12 by brazing or the like. The contact 2 is fixed to the distal end shaft 3a at the distal end inside the vacuum vessel 1, and the inflow-side water passage 8aa and the outflow-side water passage 8b
a are formed diagonally from the bottom outside the vacuum vessel 1 toward the tip before being joined to the bottom shaft 3b, and intersect at the intersection 8c near the contact 2 at the tip. on the other hand,
An inflow passage 8ab and an outflow passage 8bb communicating with the inflow-side water passage 8aa and the outflow-side water passage 8ba of the tip shaft 3a are formed in the bottom shaft 3b by excavation before joining. The inflow path 8ab and the outflow path 8bb are connected to a cooling fluid circulation system (not shown) through an inflow port 10 and an outflow port 11, which are fixed to side surfaces.

Thus, the movable shaft 3 has the inflow passage 8ab,
By forming the flow path 8 including the inflow-side flow path 8aa, the intersection 8c, the outflow-side flow path 8ba, and the outflow path 8bb, the vicinity of the contact 2 can be efficiently reduced similarly to the conventional flow path 8 shown in FIG. Can be cooled well.

Further, since the joining portion 12 of the movable shaft 3 can be disposed outside the vacuum vessel 1, no joining portion is formed on the movable shaft 3 in the vacuum vessel 1, and as a result, the joining as in the prior art is achieved. There is no risk of vacuum breakage due to leakage of the cooling fluid from the part, and a highly reliable vacuum valve can be obtained.

FIG. 14 shows a vacuum valve according to the second embodiment.
The movable shaft 3 having the structure shown in FIG. 2 or FIG. 3 is applied as the movable shaft 3 of the vacuum valve having the structure shown in FIG.

The movable shaft 3 shown in FIG. 2 or FIG. 3 is a modified example of the movable shaft 3 according to the first embodiment shown in FIG. 1. In the movable shaft 3 shown in FIG. The flow passage near the intersection 8c with the outflow-side water passage 8ba is formed in a stepped shape. Further, in the movable shaft 3 shown in FIG. 3, the flow path near the intersection 8c is formed in a tapered shape.

As a result, the cross-sectional area of the flow path 8 near the intersection 8c closest to the contact point 2 to be cooled becomes smaller as it approaches the intersection 8c, and the cooling fluid flowing through the flow path 8 becomes smaller. Increases at the intersection 8c near the contact point 2,
The cooling capacity of the contact 2 and the contact 4 on the fixed shaft 5 side that comes into contact therewith is improved.

FIG. 14 shows a vacuum valve according to the third embodiment.
4 and a movable shaft 3 having a structure shown in FIG. 5 which is a cross-sectional view taken along line VV in FIG. 4 is applied as the movable shaft 3 of the vacuum valve having the structure shown in FIG.

In FIGS. 4 and 5, the movable shaft 3 is composed of a tip shaft 3a and a bottom shaft 3b fixed to the bottom of the tip shaft 3a by a joining portion 12 by brazing or the like. A contact 2 is fixed to the distal end shaft 3a at the distal end inside the vacuum vessel 1, and formed by excavation from the bottom outside the vacuum vessel 1 to the vicinity of the distal end inside the vacuum vessel 1 before being joined to the bottom shaft 3b. The partition plate 13 is fixed to the inner wall of the vertical hole by brazing or the like, thereby forming an inflow-side water passage 8aa and an outflow-side water passage 8ba that communicate with each other at a communication portion 8d near the distal end. On the other hand, an inflow channel 8ab and an outflow channel 8bb communicating with the inflow-side water channel 8aa and the outflow-side water channel 8ba of the tip shaft 3a are formed in the bottom shaft 3b by excavation before joining. And the inflow channel 8ab and the outflow channel 8bb
Are respectively connected to a cooling fluid circulation system (not shown) through an inflow port 10 and an outflow port fixed to the side surface.

As described above, in the movable shaft 3, the inflow path 8
ab, inflow side flow path 8aa, communication portion 8d, outflow side flow path 8b
a and the flow path 8 composed of the outflow path 8bb, the contact 2 is formed in the same manner as the conventional flow path 8 shown in FIG.
The vicinity can be efficiently cooled.

Further, no joint is formed on the movable shaft 3 in the vacuum vessel 1, and as a result, there is no risk of vacuum breakage due to leakage of the cooling fluid from the joint as in the prior art, and reliability is reduced. A highly efficient vacuum valve can be obtained.

The vacuum valve according to the fourth embodiment is shown in FIG.
The movable shaft 3 having the structure shown in FIG. 6 or 7 is applied as the movable shaft 3 of the vacuum valve having the structure shown in FIG.

The movable shaft 3 shown in FIG. 6 or FIG. 7 is a modification of the movable shaft 3 according to the third embodiment shown in FIGS. 4 and 5, and the movable shaft 3 shown in FIG. The vicinity of the communicating portion 8d at the tip of the thirteen is formed in a stepped shape. In the movable shaft 3 shown in FIG. 7, the vicinity of the communicating portion 8d at the tip of the partition plate 13 is formed in a tapered shape.

As a result, the cross-sectional area of the flow passage 8 near the communication portion 8 d closest to the contact 2 to be cooled becomes smaller as it is closer to the communication portion 8 d, and the cooling fluid flowing through the flow passage 8 becomes smaller. Increases at the communication portion 8c close to the contact 2,
The cooling capacity of the contact 2 and the contact 4 on the fixed shaft 5 side that comes into contact therewith is improved.

FIG. 14 shows a vacuum valve according to the fifth embodiment.
The movable shaft 3 having the structure shown in FIG. 8 is applied as the movable shaft 3 of the vacuum valve having the structure shown in FIG.

In FIG. 8, the movable shaft 3 has a tip shaft 3a.
And a bottom shaft 3b fixed to the bottom of the tip shaft 3a by a joining portion 12 by brazing or the like. The contact 2 is fixed to the distal end shaft 3a at the distal end inside the vacuum vessel 1, and the vacuum vessel 1 is joined before being joined to the bottom shaft 3b.
A vertical hole is formed by excavation or the like from the outer bottom to the vicinity of the front end inside the vacuum vessel 1, and an outflow passage 8bb communicating with a lower portion of the vertical hole is formed. The outflow passage 8bb is fixed to a lower side surface of the tip shaft 3a. The outlet 11 communicates with the outlet.

On the other hand, the tip shaft 3a is attached to the bottom shaft 3b before joining.
The inner cylinder 14 is formed by being fixed to a position coaxially inserted into the vertical hole, which is slightly shorter than the vertical hole formed in the inner cylinder 14, and the inflow passage 8ab communicating with the inner cylinder 14 is formed by excavation. The inflow path 8ab communicates with the inflow port 10 fixed to the side surface. The inlet 10 and the outlet 11 are connected to a cooling fluid circulation system (not shown). Note that the inner cylinder 14 may be formed by excavating a columnar projection formed integrally with the bottom shaft 3b.

As described above, the inflow passage 8ab,
The inflow side flow path 8aa, the communicating portion 8d, and the inner side surface of the vertical hole formed in the distal end portion 3a and the inner cylinder 14 are formed inside the inner cylinder 14.
Outflow side channel 8ba formed between the outer surface of
By forming the flow path 8 composed of the outflow path 8bb,
Similar to the conventional flow path 8 shown in FIG. 16, the vicinity of the contact 2 can be efficiently cooled.

Further, no joint is formed on the movable shaft 3 in the vacuum vessel 1, and as a result, there is no danger of vacuum breakage due to leakage of the cooling fluid from the joint as in the prior art, and reliability is reduced. A highly efficient vacuum valve can be obtained. Further, the cooling fluid reaches the vicinity of the contact through the inside of the inner cylinder 14 and is discharged through the outside of the inner cylinder 14, so that the cooling fluid reaches the vicinity of the contact 2 without a significant rise in temperature, and the efficiency is improved. Can take heat well.

FIG. 14 shows a vacuum valve according to the sixth embodiment.
The movable shaft 3 having the structure shown in FIG. 9 or 10 is applied as the movable shaft 3 of the vacuum valve having the structure shown in FIG.

The movable shaft 3 shown in FIG. 9 or FIG.
Is a modification of the movable shaft 3 according to the fifth embodiment shown in FIG. 8, and in the movable shaft 3 shown in FIG. 9, the vicinity of the communication portion 8d at the tip of the inner cylinder 14 is formed in a stepped shape. FIG.
In the movable shaft 3 shown in FIG.
The vicinity is formed in a tapered shape.

As a result, the shape of the inner cylinder 14 becomes thicker as the distal end portion is closer to the distal end. As a result, of the flow channel 8, the flow channel near the communication portion 8d closest to the contact 2 to be cooled is cut off. The area becomes smaller as the area is closer to the communication section 8d, and the flow rate of the cooling fluid flowing in the flow path 8 increases in the communication section 8c closer to the contact 2, and the cooling capacity of the contact 2 and the contact 4 on the fixed shaft 5 side that comes into contact therewith. Is improved.

FIG. 14 shows a vacuum valve according to the seventh embodiment.
The movable shaft 3 having the structure shown in FIG. 11 is applied as the movable shaft 3 of the vacuum valve having the structure shown in FIG.

The movable shaft 3 shown in FIG. 11 is a modified example of the movable shaft 3 according to the fifth embodiment shown in FIG. 8, and the movable shaft 3 shown in FIG. The annular protrusion 15 is formed by fixing the annular member at intervals in the direction. The annular projection 15 may be formed integrally with the inner cylinder 14.

As a result, the flow of the cooling fluid flowing through the outflow side flow path 8ba outside the inner cylinder 14 is disturbed, and the boundary layer of the heat transfer surface of the inner wall of the vertical hole is separated, so that the amount of heat transfer is increased and the cooling is performed. Ability is improved.

FIG. 14 shows a vacuum valve according to the eighth embodiment.
The movable shaft 3 having the structure shown in FIG. 12 is applied as the movable shaft 3 of the vacuum valve having the structure shown in FIG.

The movable shaft 3 shown in FIG. 12 is a modified example of the movable shaft 3 according to the fifth embodiment shown in FIG. 8, and the movable shaft 3 shown in FIG. The helical projection 16 is formed by fixing the shape member. Note that the spiral projection 16 may be formed integrally with the inner cylinder 14.

As a result, the cooling fluid spirally flows through the outflow-side flow path 8ba outside the inner cylinder 14, so that the flow path in contact with the inner wall of the vertical hole becomes substantially longer, and the heat transfer amount increases. The cooling capacity is further improved.

FIG. 14 shows a vacuum valve according to the ninth embodiment.
The movable shaft 3 having the structure shown in FIG. 13 is applied as the movable shaft 3 of the vacuum valve having the structure shown in FIG.

The movable shaft 3 shown in FIG. 13 is a modification of the movable shaft 3 according to the fifth embodiment shown in FIG. 8, and the movable shaft 3 shown in FIG. The spiral projection 17 is formed by fixing the member.

As a result, the cooling fluid spirally flows through the outflow-side flow path 8ba outside the inner cylinder 14, so that not only the flow path in contact with the inner wall of the vertical hole becomes substantially long, but also the spiral projection 17 is formed. It acts as a radiating fin to increase the contact area between the inner wall of the vertical hole and the cooling fluid, thereby increasing the amount of heat transfer and further improving the cooling capacity.

As described above, according to the present embodiment, at least the vacuum vessel 1 in the flow path 8 for cooling the contact is provided.
As for the portion inside, the joining portion between the vacuum in the vacuum vessel 1 and the flow path 8 is eliminated, so that the reliability of the vacuum valve can be improved. In addition, the vacuum in the vacuum vessel 1 and the flow path 8
By devising various shapes of the flow path 8 without providing a joining portion between them, the cooling efficiency of the contact portion can be further improved while maintaining the reliability of the vacuum valve.

In the above-described embodiment, the case where the flow path 8 is formed on the movable shaft 3 side is described as an example. However, the flow path 8 may be formed on the fixed shaft 5 side.
Needless to say, it may be formed on both the movable shaft and the fixed shaft 5.

[0056]

According to the first aspect of the present invention, it is possible to eliminate the bonding portion between the flow path for cooling the contact and the vacuum in the vacuum vessel by brazing or the like. It is possible to supply a large amount of current while suppressing the leakage of the cooling fluid in the flow path, and to obtain a highly reliable vacuum valve capable of maintaining the shut-off performance for a long time without leaking into the vacuum vessel. The effect is obtained.

According to the second aspect of the present invention, the flow rate of the cooling fluid flowing in the flow path increases in the folded portion close to the contact, so that the heat transfer increases, the heat generation increases, and the temperature rise increases. Can be more efficiently cooled.

According to the third aspect of the present invention, it is possible to eliminate a bonding portion between the flow path for cooling the contact and the vacuum in the vacuum vessel by brazing or the like, thereby suppressing a rise in the temperature of the contact. A large current can be supplied, and a highly reliable vacuum valve capable of maintaining the shut-off performance for a long time without leaking the cooling fluid in the flow path into the vacuum vessel can be obtained. can get.

According to the fourth aspect of the invention, the flow rate of the cooling fluid flowing in the flow passage increases in the communication portion near the contact point, so that the heat transfer amount increases, the heat generation amount increases, and the temperature rise increases. The effect that the contact can be cooled more efficiently can be obtained.

According to the fifth aspect of the present invention, it is possible to eliminate a bonding portion by brazing between the flow path for cooling the contact and the vacuum in the vacuum vessel, thereby suppressing a rise in the temperature of the contact. A large current can be supplied, and a highly reliable vacuum valve capable of maintaining the shut-off performance for a long time without leaking the cooling fluid in the flow path into the vacuum vessel can be obtained. can get. Further, since the cooling fluid reaches the vicinity of the contact point without passing through the inside of the inner cylinder without increasing the temperature, heat near the contact point can be efficiently removed and the cooling efficiency can be improved.

According to the sixth aspect of the invention, the flow rate of the cooling fluid flowing in the flow passage increases in the communication portion near the contact point, so that the amount of heat transfer increases, the calorific value increases, and the temperature rise increases. The effect that the contact can be cooled more efficiently can be obtained.

According to the seventh aspect of the present invention, since the flow of the cooling fluid flowing through the flow path outside the inner cylinder is disturbed, separation occurs on the boundary layer of the heat transfer surface of the inner wall of the vertical hole. Separation of the boundary layer of the heat transfer surface of the movable shaft between the fluid and the cooling fluid occurs, and the effect of increasing the heat transfer amount and further improving the cooling capacity is obtained.

According to the eighth aspect of the present invention, since the cooling fluid spirally flows outside the inner cylinder, the flow path in contact with the inner wall of the vertical hole becomes substantially long, and the heat transfer amount increases. The effect of further improving the cooling capacity is obtained.

According to the ninth aspect of the present invention, since the cooling fluid spirally flows outside the inner cylinder, not only the flow path in contact with the inner wall of the vertical hole becomes substantially longer, but also the spiral projection is formed. Acts as a radiating fin to increase the contact area between the inner wall of the vertical hole and the cooling fluid, so that the heat transfer amount is increased and the cooling capacity is further improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a movable shaft applied to a vacuum valve according to a first embodiment of the present invention.

FIG. 2 is a side sectional view showing an example of a movable shaft applied to a vacuum valve according to a second embodiment of the present invention.

FIG. 3 is a side sectional view showing another example of a movable shaft applied to a vacuum valve according to a second embodiment of the present invention.

FIG. 4 is a side sectional view of a movable shaft applied to a vacuum valve according to a third embodiment of the present invention.

FIG. 5 is a sectional view taken along line VV in FIG.

FIG. 6 is a side sectional view showing an example of a movable shaft applied to a vacuum valve according to a fourth embodiment of the present invention.

FIG. 7 is a side sectional view showing another example of a movable shaft applied to a vacuum valve according to a fourth embodiment of the present invention.

FIG. 8 is a side sectional view of a movable shaft applied to a vacuum valve according to a fifth embodiment of the present invention.

FIG. 9 is a side sectional view showing an example of a movable shaft applied to a vacuum valve according to a sixth embodiment of the present invention.

FIG. 10 is a side sectional view showing another example of the movable shaft applied to the vacuum valve according to the sixth embodiment of the present invention.

FIG. 11 is a side sectional view of a movable shaft applied to a vacuum valve according to a seventh embodiment of the present invention.

FIG. 12 is a side sectional view of a movable shaft applied to a vacuum valve according to an eighth embodiment of the present invention.

FIG. 13 is a side sectional view of a movable shaft applied to a vacuum valve according to a ninth embodiment of the present invention.

FIG. 14 is a diagram illustrating a configuration example of a vacuum valve.

FIG. 15 is a side view of a conventional movable shaft in which a flow path for contact cooling is formed.

16 is a sectional view taken along the line XVI-XVI in FIG.

DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Contact 3 Movable shaft 3a Tip shaft 3b Bottom shaft 4 Contact 5 Fixed shaft 8 Flow path 8aa Inflow side flow path 8ab Inflow path 8ba Outflow side flow path 8bb Outflow path 8c Intersection 8d Communication part 10 Inflow port 11 Outflow port 12 Joining portion 13 Partition plate 14 Inner cylinder 15 Annular projection 16 Spiral projection 17 Spiral projection

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshifumi Miura 801 Mukaiyama, Naka-cho, Naka-machi, Naka-gun, Ibaraki Pref. No. 1 Naka Research Institute of Japan Atomic Energy Research Institute (72) Inventor Toshiharu Kubota 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Fuchu Plant (72) Inventor Kenji Watanabe 1-1-1, Shibaura, Minato-ku, Tokyo Shares (72) Inventor Hiroo Ikegame 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu Plant, Toshiba Corporation (72) Inventor Shuichi Kawashima 1-1-1, Shibaura, Minato-ku, Tokyo Toshiba Corporation

Claims (9)

[Claims] 1. A vacuum for opening and closing an electric circuit by separating or contacting a contact provided at a tip of a fixed shaft and a contact provided at a tip of a movable shaft in a vacuum container in accordance with the movement of the movable shaft. In the valve, at least one of the fixed shaft and the movable shaft is joined to a tip shaft provided with a tip portion inside the vacuum vessel and a bottom portion outside the vacuum vessel, and to a bottom portion of the tip shaft outside the vacuum vessel. And a flow path is formed in the distal end shaft from the inlet opening at the bottom portion to the end portion and turned back to the outlet opening at the bottom portion again, while the bottom shaft has A cooling fluid inflow / outflow passage formed at an inlet / outlet opening at the bottom of the tip shaft. 2. The vacuum according to claim 1, wherein the vicinity of the folded portion of the flow path formed on the distal end shaft is formed in a shape that becomes smaller as the cross-sectional area of the flow path is closer to the folded portion. valve. 3. A vacuum for opening and closing an electric circuit by separating or contacting a contact provided at a tip of a fixed shaft and a contact provided at a tip of a movable shaft in a vacuum vessel in accordance with the movement of the movable shaft. In the valve, at least one of the fixed shaft and the movable shaft is joined to a tip shaft provided with a tip portion inside the vacuum vessel and a bottom portion outside the vacuum vessel, and to a bottom portion of the tip shaft outside the vacuum vessel. Along with the bottom shaft, the front end shaft is connected to a partition plate on an inner wall of a vertical hole formed from the bottom portion to the vicinity of the front end portion, thereby forming a communicating portion from the inlet opening at the bottom portion to the front end portion. A flow path that returns to an outlet that opens back to the bottom is formed by folding back, while a cooling fluid inflow / outflow path that is joined to an inlet and outlet that opens to the bottom of the tip shaft is formed in the bottom shaft. Characteristic vacuum valve . 4. The vacuum valve according to claim 3, wherein a portion of the partition plate fixed to the vertical hole in the vicinity of the communication portion has a shape that increases in thickness as the portion is closer to the communication portion. 5. A vacuum for opening and closing an electric circuit by separating or contacting a contact provided at a tip of a fixed shaft and a contact provided at a tip of a movable shaft in a vacuum container in accordance with the movement of the movable shaft. In the valve, at least one of the fixed shaft and the movable shaft is joined to a tip shaft provided with a tip portion inside the vacuum vessel and a bottom portion outside the vacuum vessel, and to a bottom portion of the tip shaft outside the vacuum vessel. A bottom hole formed from the bottom to the vicinity of the tip and a cooling fluid outflow passage joined to a lower portion of the bottom hole are formed in the tip shaft. An inner cylinder that is coaxially inserted into the vertical hole is formed to be thinner and slightly shorter than a vertical hole formed in the distal end shaft, and a cooling fluid inflow passage that is joined to the inner cylinder is formed. And vacuum valve. 6. A tip of an inner cylinder formed on the bottom shaft,
The vacuum valve according to claim 5, wherein the shape is such that the thickness increases as the distance from the tip increases. 7. The vacuum valve according to claim 5, wherein annular projections are formed on the outer surface of the inner cylinder at intervals in the axial direction. 8. The vacuum valve according to claim 5, wherein a spiral projection is formed on an outer surface of the inner cylinder. 9. The vacuum valve according to claim 5, wherein a spiral projection is fixed to an inner surface of the vertical hole.