JPH086842B2 - High insulation valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly adiabatic valve for controlling the flow of a cryogenic fluid such as liquid helium.

[0002]

2. Description of the Related Art In a highly adiabatic valve for controlling a cryogenic fluid such as liquid helium, the valve itself for controlling the flow of the fluid is housed in a vacuum container and the space between the valve and the vacuum container is insulated. There is. In this case, heat transfer by convection is almost completely prevented by putting the valve in a vacuum container. Therefore, the heat transfer between the valve and the vacuum container is
Radiative heat transfer between the two, and heat from the frames that fix the vacuum container and valve to each other in the valve operating part, and the shaft that transfers the operating force to open and close the valve from outside the vacuum container to the valve opening and closing shaft. There are two types of conduction.

Of these two types of heat conduction, radiant heat conduction can be suppressed to some extent by surface treatment of the material to which the heat conduction is performed. However, the heat transmitted through the mechanical connection parts such as the frames and shafts is
As long as their mechanical connection exists, they are inevitable.

Therefore, as a means for minimizing the heat conduction of the mechanical connection portion, a means for reducing the heat transfer area and increasing the heat transfer length with a material having a small heat transfer coefficient is generally used. The inventor has also proposed one of the means for that purpose in Japanese Patent Application No. 3-32109.
However, even if such a means is adopted, it is a fact that there is a slight amount of heat transfer at all times, and further improvement is desired.

[0005]

DISCLOSURE OF THE INVENTION The technical problem of the present invention is that, in the above-described highly adiabatic valve that performs vacuum insulation, there is substantially no heat conduction through the mechanical connecting portion in the valve operating portion. To further improve the heat insulating property.

[0006]

A highly adiabatic valve according to the present invention for solving the above-mentioned problems includes a valve for controlling the flow of a cryogenic fluid in a vacuum container, and heat insulation between the valve and the vacuum container. The valve is provided with a flow path control means for controlling the flow of fluid, and the flow path control means is connected between the valve and the vacuum container only when the valve is operated. Then, the valve operating means for transmitting the valve operating force for controlling the flow of the fluid from the outside of the vacuum container is provided.

The valve operating means includes a support means for supporting the flow path control means in the vacuum container for opening and closing the valve only when the valve drive shaft is operated from outside the vacuum container, and a valve opening and closing only when the valve drive shaft is opened and closed. And an operating force transmitting means for transmitting the opening / closing operating force by being joined to the valve shaft for.

Further, as the supporting means for supporting the flow path control means on the vacuum container, a mechanism for supporting the valve by a pressing member in conjunction with the opening / closing operation of the valve drive shaft driven by an actuator is used. As the operating force transmitting means for transmitting the opening / closing operating force, it is possible to use a mechanism in which after the valve is supported by the pressing member, the driving force by the actuator is transmitted to the valve shaft and the joint with the valve shaft is released after the driving. it can.

[0009]

When the valve drive shaft is driven by the actuator, a part of the valve is clamped by the pressing member of the supporting means in synchronism with the operation of the valve drive shaft. The transmission means is joined to the valve shaft of the valve, and the valve member opens the valve seat. Further, after the valve member is driven to the predetermined position, the clamp between the clamp member and the operating force transmitting means and the joint between the valve are released, and the mechanical connection between the valve and the vacuum container is broken. Be done. Therefore, the fluid flow in the valve can be stably controlled from the outside of the vacuum container, and the mechanical connection between the valve and the vacuum container is usually completely cut off, so that the heat between the two can be prevented. There is no transmission of.

[0010]

1 and 2 show the construction of an embodiment of a highly adiabatic valve according to the present invention. In particular, a valve 1 for controlling the flow of fluid is housed in a vacuum container 2 (FIG. 2) and the valve is 1 is vacuum-insulated by decompressing the space between the vacuum container 1 and the vacuum container 2 with a vacuum device (not shown), and the valve operating force from outside the vacuum container 2 advances straight to the flow path control means (valve opening / closing mechanism) in the valve 1. The case where it is configured to transmit the valve opening / closing force as motion is illustrated.

In the above-mentioned valve 1, the flow passage control means for controlling the flow of a cryogenic fluid (liquid helium, liquid nitrogen, etc.) in the flow passage in the valve body 3 has a fluid inlet 4 and an outlet in the valve body 3. 5 is provided with a valve seat 6, and a valve member 7 attached to a valve shaft 8 is disposed so as to be able to come into contact with and separate from the valve seat 6. The valve shaft 8 passes through a bonnet 9 provided on the valve body 3 via a sealing material (such as a metal C ring that can be used at low temperature) 10 and
The valve body 3 is led out and the both ends of the bellows 11 are fixed to the valve member 7 and the bonnet 9 by welding.
The airtightness of the flow path is maintained.

On the other hand, between the valve 1 and the vacuum container 2, the valve control means is joined to the flow path control means only when the valve 1 is operated, and the valve operating force from the outside of the vacuum container 2 is transmitted to the valve shaft 8. The valve operating means is provided. This valve operating means allows a part of the valve 1 to be opened when the valve drive shaft 15 penetrating the vacuum container 2 through the seal 14 is opened and closed.
And a support means 16 for supporting the valve drive shaft 15 and an operation force transmission means 18 which is joined to the valve shaft 8 to transmit an opening / closing operation force for opening / closing the valve when the valve drive shaft 15 is opened / closed.

The operation force transmission means 18 for transmitting the opening / closing operation force to the valve shaft 8 has the following specific structure. That is, a feed screw 20 is engraved on the end portion side of the valve shaft 8 protruding from the bonnet 9, and a pinion 21 having a central hole engraved with a female screw 22 is screwed into the feed screw 20. A pair of thrust bearings 24 supported by the pinion 21 on a bonnet 9 fixedly connected to the valve body 3 and a support plate 23 integrally connected to the bonnet 9.
25, the pinion 21 is supported from both sides.

Although not shown, the valve shaft 8 is provided with a means for preventing its rotation, for example, a groove in the axial direction is provided on the surface of the valve shaft 8, and the bonnet 9 and the support plate 23 are provided.
A protrusion provided on a fixed portion such as the valve shaft 8 is fitted into the groove.
It is necessary to provide a means for allowing the axial movement of the above but preventing it from rotating.

Therefore, when the rotational driving force acts on the pinion 21 from the outside to open and close the valve 1, the pinion 2
The valve shaft 8 screwed into the female screw 22 of the center hole 1 is given a linear motion in its axial direction, and the axial thrust force associated with the opening / closing of the valve member 7 is transmitted through the thrust bearing 24 or 25 to the bonnet 9 or the support plate. 23, the pinion 21 is given a smooth rotation by a thrust bearing.

In order to give rotation to the pinion 21, a linear drive actuator (not shown) is provided at the outer end of the valve drive shaft 15 penetrating the vacuum container 2.
A rack 28 that meshes with the pinion 21 is provided at the inner end of the valve drive shaft 15. The rack 28 does not mesh with the pinion 21 at the pushing position (illustrated position) where the valve drive shaft 15 is deeply pushed into the vacuum container 2 and the pulling position where the valve driving shaft 15 is sufficiently pulled out from the vacuum container 2, In contact with pinion 2 between both positions
The teeth are provided so as to mesh with 1. The rack 28 is guided by a guide groove 30 in a rack holder 29 which is integral with the vacuum container 2, whereby a stable linear reciprocating motion of the rack 28 is obtained.

On the other hand, the supporting means 1 for supporting a part of the valve 1 on the vacuum container 2 when the valve drive shaft 15 is opened and closed.
As 6, a mechanism is used in which the valve 1 is supported by the pressing members 35 and 36 guided by the vacuum container 2 in conjunction with the opening / closing operation of the valve drive shaft 15 driven by the actuator.

That is, as shown by a chain line in FIG. 2, a guide (not shown) provided in the vacuum container 2 is provided with the pressing members 35 and 36 on both sides of the support plate 23 of the valve drive shaft 15. Although it is not movable in the driving direction, it is supported so as to be movable in the direction orthogonal to it and in the direction of contacting and separating from each other, and straight grooves 37, 38 parallel to each other are provided in these pressing members 35, 36, respectively, and At both ends of the straight grooves 37 and 38, the slope grooves 3 curved toward the joint end sides of the pressing members 35 and 36, respectively.
9, 40 are provided. In addition, the pressing members 35, 3
6 includes clamp grooves 41 and 42 for clamping the valve 1 to the vacuum container 2 by sandwiching the support plate 23 from both sides.
Is provided.

On the other hand, the valve drive shaft 15 is provided with a pair of sliders 43 and 44, and the straight grooves 37 and 38 of the pressing members 35 and 36, or the slope grooves 39 and 40 at both ends thereof are provided. When the sliders 43 and 44 are in the straight grooves 37 and 38 by the drive of the valve drive shaft 15, the pressing members 35 and 36 are supported by the pressing of the sliders 43 and 44. When the plate 23 is clamped and the sliders 43 and 44 are in the slope grooves 39 and 40, the pressing member 3
5 and 36 are set to release the clamp of the support plate 23.

The highly adiabatic valve having the above structure is driven by an actuator (not shown), for example, when the valve drive shaft 15 is driven in the direction of pulling out from the vacuum container 2 from the state shown in FIG. Pendulum 43,4
4 is a slope groove 3 in the pair of pressing members 35, 36
The grooves 9 and 40 move to the straight grooves 37 and 38, and as a result, the pressing members 35 and 35 are pressed by the sliders 43 and 44.
36 moves in the direction of joining to each other, and clamp grooves 41,
At 42, the support plate 23 is clamped.

After the valve 1 is fixed to the vacuum container 2 by the clamp of the support plate 23 by the pressing members 35 and 36, the rack 28 in the non-meshing position meshes with the pinion 21 by the driving of the valve drive shaft 15. Since the pinion 21 is rotated by the subsequent movement of the rack 28, the valve shaft 8 having the feed screw 20 engraved is driven by the valve member 7 in the direction of opening the valve seat 6. Further, after the valve seat 6 is fully opened by driving the valve member 7, the rack 28 is disengaged from the pinion 21, and then the sliders 43, 44 are pushed by the pressing members 35,
Straight groove 37, 38 from 36 to slope groove 3
9 and 40, the pressing members 35 and 36 are pushed open, so that the clamp of the support plate 23 by the pressing members 35 and 36 is released. When closing the valve seat 6 of the valve 1, the operation reverse to the above may be performed.

In this way, the flow passage control means for opening and closing the valve 1 is supported by the support means 16 on the vacuum container 2 only when the valve drive shaft 15 is operated from outside the vacuum container.
Further, since the operating force transmitting means 18 is joined to the valve shaft 8 for opening and closing the valve to transmit the opening / closing operating force, the fluid flow in the valve 1 can be stably controlled from the outside of the vacuum container 2, Moreover, after the operation of the valve drive shaft 15 is completed, the mechanical connection between the valve 1 and the vacuum container 2 is completely cut off, so that heat conduction between them can be completely eliminated.

If the surfaces of the valve 1 and the vacuum container 2 which face each other are made to be reflective surfaces which are less likely to radiate heat and less likely to receive radiant heat by reflection, the transmission of heat is effectively suppressed and more effectively. It can be insulated.

[0024]

According to the present invention described in detail above, in a highly adiabatic valve for vacuum heat insulation, a mechanism for transmitting an operating force for opening and closing the valve is provided only when the valve is opened and closed from the outside. Since it does not contact the valve and normally does not contact the valve, it is possible to substantially eliminate heat conduction through the mechanical connecting portion in the valve operating portion, and to remarkably improve the heat insulating property. Also, when operating the valve from the outside,
Since the valve is supported by the pressing member in conjunction with the opening / closing operation of the valve drive shaft driven by the actuator, and the driving force for valve operation by the actuator is transmitted to the valve shaft, the valve opening / closing operation is performed. Can be performed extremely stably.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of a highly adiabatic valve according to the present invention.

FIG. 2 is a cross-sectional view of essential parts mainly showing a valve operating means and a supporting means in the highly adiabatic valve.

[Explanation of symbols]

1 valve, 2 vacuum vessels,
8 valve shafts, 15 valve drive shafts, 16 supporting means, 18 operating force transmitting means, 35, 36 pressing members.

Claims (3)

[Claims] 1. A highly adiabatic valve in which a valve for controlling the flow of cryogenic fluid is housed in a vacuum container, and the valve and the vacuum container are thermally insulated. The valve controls the flow of the fluid. And a valve operating force for controlling the flow of fluid from the outside of the vacuum container by joining the flow path controlling device between the valve and the vacuum container only when the valve is operated. A highly adiabatic valve characterized in that a valve operating means for transmitting is provided. 2. The valve operating means according to claim 1, wherein the valve operating means is a supporting means for supporting the flow path control means for opening and closing the valve only when the valve drive shaft is operated from outside the vacuum container, in the vacuum container. A highly adiabatic valve, which is configured by an operating force transmitting means which is connected to a valve shaft for opening and closing the valve and transmits an opening and closing operating force only when the valve drive shaft is opened and closed. 3. The support according to claim 2, wherein the flow path control means is supported by the vacuum container.
Using a mechanism that supports the valve with a pressing member in conjunction with the opening / closing operation of the valve drive shaft driven by an actuator, as a control force transmission means for transmitting the opening / closing operation force to the valve shaft, after the valve is supported by the pressing member, A highly adiabatic valve characterized by using a mechanism for transmitting a driving force from the actuator to a valve shaft and releasing the connection with the valve shaft after the driving.