JPH09236347A - Cryogenic generator - Google Patents

Abstract

(57) Abstract: A rotary drive force for rotating a rotor valve of a high / low pressure switching rotary valve unit used in a cryogenic device is reduced. A rotary valve unit 30 is arranged in a high pressure space, and a high pressure side housing 37 having a high pressure space inside, low pressure side housings 34 and 35 having a low pressure space inside, and can be rotationally driven by a driving means. Rotary valve 38
A valve plate 39 arranged in the low pressure space so as to face the rotary valve, and a low pressure passage 52 bored in the valve plate from the low pressure space to the opposing surfaces of the rotary valve 38 and the valve plate 39, A main passage 48 that is bored in the valve plate 39 and has one end surface that opens to the opposing surface and the other end that communicates with the regenerator, and the main passage 48 that is drilled in the rotary valve 38 from the high-pressure space to the opposing surface and that communicates with the main passage 48. The high pressure passage 50 and the low pressure passage 5 formed in the rotary valve 38
A communication passage 51 that connects the main passage 48 and the main passage 48 to each other and a spring 40 that urges the rotary valve element 38 in a direction in which the rotary valve element 38 is separated from the valve plate 39 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryogenic generator, and more particularly to a valve for controlling high and low pressures of working fluid represented by Gifode-McMahon refrigerators and valve type pulse tube refrigerators. The present invention relates to a high / low pressure switching mechanism of a cryogenic generator for switching.

[0002]

2. Description of the Related Art A conventional cryogenic generator for switching high and low pressures of working fluid by a valve will be described by taking a pulse tube refrigerator as an example.

FIG. 2 shows a conventional pulse tube refrigerator. In the figure, a compressor 1 includes a high pressure discharge port 1a and a low pressure suction port 1a.
b. A high-pressure pipe 2 is connected to the high-pressure discharge port 1a side, and a low-pressure pipe 3 is connected to the low-pressure suction port 1b side. The high-pressure pipe 2 communicates with the high-pressure valve 4 and the low-pressure pipe 3 communicates with the first conduit 7 via the low-pressure valve 5, and the other end of the first conduit 7 communicates with one end of the regenerator 8. 6 is a valve opening / closing control unit. The other end of the regenerator 8 is connected to a cold head 9, which further includes a pulse tube 10
Is connected to one end of. The other end of the pulse tube 10 is in communication with the second conduit 11, and the second conduit 11 has the first orifice 1
It communicates with the buffer tank 13 via 2. 14
Connects the first conduit 7 and the second conduit 11 to the second orifice 1
It is a bypass pipe that communicates via 5, and is commonly called a double inlet passage.

In the pulse tube refrigerator having the above-mentioned structure, when the high pressure valve 4 is opened and the low pressure valve 5 is closed, the working gas in the high pressure state enters the regenerator 8 through the first conduit 7 and a part of the working gas. It enters the buffer tank 13 from the bypass pipe 14 through the second orifice 15 and the first orifice 12. The high-pressure working gas that has entered the regenerator 8 enters the buffer tank 13 via the cold head 9, the pulse tube 10, the second conduit 11, and the first orifice 12. When the high pressure valve 4 is closed and the low pressure valve 5 is opened from this state, the high pressure working gas in the buffer tank 13 passes through the pulse tube 10, the cold head 9, the regenerator 8, the first conduit 7, and the low pressure valve 5. Then, while returning to the low pressure suction port 1b of the compressor 1, a part thereof returns to the low pressure suction port 1b from the bypass pipe 14 through the low pressure valve 5. The high-pressure gas in the pulse tube 10, the cold head 9, and the regenerator 8 passes from the first conduit 7 through the low-pressure valve 5 to the low-pressure inlet 1b.
Return to.

During the above series of operations, the flow rate of the working gas entering the buffer tank 13 is controlled by the first orifice 12 and the second orifice 15, so that a phase shift occurs between the pressure change and the position change of the working gas. Further, since the flow rate of the working gas discharged from the buffer tank 13 is controlled by the first orifice 12 and the second orifice 15, a phase shift occurs between the pressure change and the position change of the working gas. In this way, by producing a phase difference between the pressure fluctuation and the fluctuation fluctuation of the working gas, the heat of the working gas is pumped from the cold head 9 to the regenerator 8 side, and the cold head 9
At a very low temperature.

In the pulse tube refrigerator having the above-described structure, the compressor 1, the high pressure pipe 2, the low pressure pipe 3, the high pressure valve 4, the low pressure valve 5, and the valve opening / closing control unit 6 are used as a pressure oscillation source 60 for the working gas.
And a first orifice 12, a second orifice 15,
The bufferer tank 13 constitutes a working gas phase adjusting mechanism 16.

The high-pressure valve 4, the low-pressure valve 5 and the valve opening / closing control section 6 are usually integrated into a rotary valve unit in many cases. The configuration of a conventional rotary valve unit is shown in FIG.

In FIG. 3, the rotary valve unit 1
7 is a rotary valve 18 and a valve drive motor 19
It consists of The rotary valve 18 includes a rotary valve element 20 that is rotationally driven by a valve drive motor 19, and a valve plate 21 that is arranged so as to face the rotary valve element 20. As shown in FIG. 4, the rotary valve member 20 is formed by cutting out a symmetrical portion of a disk into a fan surface shape having a predetermined angle, and forming a first low pressure gas passage 22 in the central portion thereof. Circular arc-shaped long grooves 23 are formed on the sliding surfaces with the valve plate 21 at the two projecting piece portions remaining in a fan shape, and the long grooves 23 and the first low-pressure passage 22 communicate with each other inside the rotary valve 20. doing. On the other hand, in the valve plate 21, a second low pressure passage 24 is formed from the center to the side surface thereof, and a main passage 25 communicating with the regenerator side is formed at a position eccentric from the center. Further, a high pressure communication hole 27 that communicates with a high pressure discharge port of the compressor is provided on a side portion of the housing 26 that houses the rotary valve 20. The second low pressure passage 24 provided in the valve plate 21 communicates with the low pressure suction port of the compressor.

In the rotary valve unit 17 having the above structure, the rotary valve element 20 is rotated by the rotation of the valve driving motor 19. At this time, the valve plate 21
When the main passage 25 is not covered with the rotary valve element 20, the main passage 25 has a high pressure communication hole 27.
Communicate with a space filled with high pressure working gas from. Therefore, high-pressure working gas is supplied from the main passage 25 to the regenerator. In addition, when the main passage 25 is covered by the rotary valve 20 and the arc-shaped long groove 23 and the main passage 25 face each other, the second low-pressure passage 24 communicating with the low-pressure suction port of the compressor connects the first low-pressure passage 22. Since it communicates with the main passage 25 via the rotary valve 18, high-pressure working gas is supplied from the regenerator side.
To the compressor from the second low pressure passage 24.

[0010]

In the conventional rotary valve unit, as shown in FIG. 3, the space inside the housing 26 accommodating the rotary valve 20 is communicated with the high pressure discharge port of the compressor. , Is always in a high pressure state. Therefore, the rotary valve element 20 is constantly pressed against the valve plate 21 with a strong pressure. Therefore, the rotary valve 20
Since a very large driving force is required to drive the motor, the driving means such as a motor is increased in size, which leads to an increase in size of the device. Further, since the rotary valve element 20 rotates while being pressed against the valve plate 21 by such an extremely large pressure, the rotary valve element 20 is greatly worn, which causes a significant deterioration in the durability of the rotary valve.

Therefore, the present invention has been made in view of the above situation, and reduces the contact pressure between the rotary valve and the valve plate to reduce the drive torque of the rotary valve.
Further, it is a technical subject to prevent the wear of the rotary valve element and improve the durability of the rotary valve.

[0012]

In order to solve the above technical problems, the technical measures taken in claim 1 of the present invention include a pressure vibration source, a regenerator, a cold head, and a phase adjusting mechanism. Are connected in series, and a phase difference between the pressure fluctuation and the fluctuation fluctuation of the working gas supplied from the pressure vibration source is adjusted by the phase adjusting mechanism to generate a temperature difference at both ends of the regenerator, and the cold head In a cryogenic device for generating cryogenic temperature in, the pressure vibration source, a compressor having a high pressure discharge port and a low pressure suction port, a high pressure side housing having a high pressure space communicating with the high pressure discharge port inside, A low-pressure side housing having a low-pressure space communicating with the low-pressure inlet therein, a rotary valve member arranged in the high-pressure space and rotatably driven by a driving means, and a low-pressure space in the low-pressure space. A valve plate facing the revalve, a low-pressure passage bored in the valve plate from the low-pressure space to the facing surface of the rotary valve and the valve plate, and a bore in the valve plate. A main passage having one end surface opened to the facing surface and the other end communicating with the regenerator; and a high pressure passage formed in the rotary valve from the high pressure space to the facing surface and communicating with the main passage. A rotary valve unit including: a communication passage formed in the rotary valve and connecting the low pressure passage and the main passage; and an elastic body that urges the rotary valve in a direction of separating from the valve plate. Is a cryogenic generator.

According to the above technical means, the urging member for urging the rotary valve element in the direction away from the valve plate is provided in the rotary valve unit. Since the rotary valve element is arranged in the high pressure space and the valve plate is arranged in the low pressure space, the rotary valve element is pressed against the valve plate due to the pressure difference. At this time, the urging force of the urging member for urging the rotary valve element in the direction of separating from the valve plate and a part of the pressing force are offset, and the pressing force is relaxed.

In order to solve the above technical problem, as in the technical means taken in claim 2 of the present invention, the pressure vibration source has an annular bearing between the rotary valve element and the valve plate. It is preferable that the cryogenic generator according to claim 1 is characterized in that: If a bearing is provided between the rotary valve and the valve plate, the pressing force applied to the bearing portion does not become a frictional resistance against the rotation of the rotary valve, so that the rotary drive force of the rotary valve can be further reduced. .

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The structure of the entire cryogenic device is the same as that of the pulse tube refrigerator or the Gihodo McMahon refrigerator described in the prior art. Therefore, the description will be omitted and only the configuration of the rotary valve unit will be described.

FIG. 1 is a sectional view of a rotary valve unit according to a first embodiment of the present invention. In the figure, the rotary valve unit 30 includes a drive unit 31 that rotationally drives the rotary valve element 38, and a rotary valve 32. The drive unit 31 includes a first housing 33, a cylindrical second housing 34 connected to the first housing 33 via a seal member, and a motor 35 arranged inside the first housing 31 and the second housing 34. . The rotary valve 32 includes a third housing 36 and a fourth housing 3 which is connected to the third housing 36 via a seal member.
7, a rotary valve element 38 arranged inside the third housing 36 and the fourth housing 37, a valve plate 39,
It consists of a spring 40 and a bearing 41.

One end of the motor 35 is fixed to a plate 42, and the plate 42 is screwed and fixed to the third housing 36 by a screw 43. A bottomed hole whose bottom is sealed by a stopper 56 is formed in the center of the rotary valve 38, and a low-pressure passage 52 described later is formed in the center of the valve plate 39. The bottomed groove and the low-pressure passage 52 are formed. A shaft 44 for transmitting the rotational drive of the motor 35 is inserted therein, and the shaft 44 and the rotary valve element 38 are axially movable and fixed coaxially and rotatably by the engagement of the key groove. Therefore, the rotary valve 39 is connected to the motor 35.
When is rotated, the rotational force is transmitted by the shaft 44,
It rotates coaxially with the shaft 44.

A high pressure introducing passage 45 is formed in the fourth housing 37 from its upper portion in the drawing to an internal space 53 in which the rotary valve element 38 is accommodated. Further, the first housing 33 is provided with a low-pressure introduction passage 46 extending from the right side of the first housing 33 to the internal space 54 in which the motor 35 is accommodated. The external opening end 45a of the high pressure introduction passage 45 communicates with a high pressure discharge port of a compressor (not shown). The external opening end 46a of the low pressure introduction path 46 communicates with a low pressure suction port of a compressor (not shown). Therefore, the internal space 53 communicates with the high-pressure discharge port of the compressor, and the high-pressure space and the internal space 54 communicate with the low-pressure suction port of the compressor, forming a low-pressure space.

The valve plate 39 housed inside the third housing 36 is fixed to the third housing 3 by the pin 47.
It is positioned and fixed in the position 6. On the left side of the valve plate 39 in the drawing, a rotary valve element 38 is arranged so as to face the valve plate 39, and a facing surface 5 is provided between the two.
5 are formed. The valve plate 39 has a facing surface 5
5 to the third housing 36, the first main passage 48
Is formed in the third housing 36.
A second main passage 49 is formed from the portion facing the main passage 48 to the upper portion in the drawing. The outer opening end 49a of the second main passage 49 communicates with a regenerator (not shown).

The valve plate 39 further includes a motor 3
The low-pressure passage 52 described above is formed from the low-pressure space 54 accommodating 5 to the opposing surface 55 side. Also,
Rotary valve 3 housed inside the fourth housing 37
8 is the facing surface 5 from the high pressure space 53 side in which it is housed.
5 side, the high pressure passage 50 is formed, and the low pressure passage 52 formed in the valve plate 39 and the facing surface 5 are formed.
A communication passage 51 communicating with each other is formed. here,
The distance from the center of rotation of the rotary valve 38 to the high pressure passage 50 is set equal to the distance from the center of rotation to the communication passage 51, and these distances are set to the valve plate 39.
The distance from the center of the first main passage 48 is also equal. Therefore, the rotary valve 38 rotates, the high pressure passage 50 and the first main passage 48 are in communication at a certain moment, and the low pressure passage 52, the communication passage 51 and the first main passage 48 at a certain moment. The communication is established.

An annular bearing 41 is arranged between the rotary valve element 38 and the valve plate 39. An annular bottomed groove is formed in a part of the rotary valve element 38 that comes into contact with the annular bearing 41, and a spring 40 is arranged in this groove.

In the rotary valve unit having the above structure, the high pressure working gas from the high pressure discharge port of the compressor enters the rotary valve unit 30 through the external opening end 45a of the high pressure introducing passage 45, and communicates with the high pressure introducing passage 45. Enters the high pressure space 53. Further, the low-pressure inlet of the compressor communicates with the low-pressure introduction passage 46 of the first housing 33 at its outer opening end 46a, and the low-pressure introduction passage further communicates with the low-pressure space 54 in which the motor 35 is housed. Therefore, the low pressure space 54 is always in a low pressure state. In this state, the motor 35 is driven, and the shaft 44 connected to the motor 35 and the rotary valve element 38 connected to the shaft 44 rotate. As the rotary valve 38 rotates,
In the state shown in FIG. 5, the high pressure passage 5 of the rotary valve 38 is
0 and the first main passage of the valve plate 39 are in communication with each other. Since the high-pressure passage 50 communicates with the high-pressure space 53, the high-pressure working gas causes the high-pressure passage 50, the first main passage 4
8, it is introduced into the regenerator via the second main passage 49. When the rotary valve 38 further rotates from this state and the low pressure passage 52 of the valve plate 39, the communication passage 51 of the rotary valve 38, and the first main passage 48 of the valve plate are in communication with each other, the low pressure passage 52 is Since the high pressure gas in the regenerator is always in communication with the low pressure space 54, the high pressure gas in the regenerator is the second main passage 49, the first main passage 48, the communication passage 51, and the low pressure passage 5.
2 into the low pressure space 54.

By repeating the above operation, the working gas introduced into the regenerator is switched between high pressure and low pressure.

In FIG. 1, the high pressure space 53 is located on the rotary valve 38 side, and the low pressure space 54 is the valve plate 39.
Located on the side. Therefore, the rotary valve element 38 is pressed against the valve plate 39 by the pressure corresponding to the differential pressure between the high pressure and the low pressure. At this time, since the rotary valve 38 is urged in the direction away from the valve plate 39 by the spring 40 arranged in the bottomed groove of the rotary valve 38, the urging force of the spring 40 and the pressure due to the differential pressure are applied. Power and power are offset to some extent. As a result, the force with which the rotary valve element 38 is pressed against the valve plate 39 is relaxed, and the rotational torque of the rotary valve element 38 can be greatly reduced.

A bearing 41 is arranged between the rotary valve element 38 and the valve plate 39. Therefore, most of the pressing force applied to the valve plate 39 from the rotary valve element 38 is transmitted through the bearing 41. The pressing force transmitted via the bearing 41 does not affect the frictional force when the rotary valve element 38 rotates. Therefore, the rotary torque of the rotary valve element 38 can be further reduced significantly.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the embodiment, as shown in FIG. 1, one end of the spring 40 is in contact with the bearing 41, but the present invention is not limited to this, and the tip end surface of the shaft 44 and the rotary valve 38 are not limited thereto. The same effect can be obtained by disposing the spring in the space H surrounded by and. Further, even if an elastic body such as rubber or resin is arranged instead of the spring 44, the same effect can be obtained, and it is applicable without departing from the gist of the present invention.

[0027]

The invention of claim 1 has the following effects.

An urging member for urging the rotary valve element in the direction away from the valve plate is arranged in the rotary valve unit. As a result, it is possible to offset to some extent the urging force of the urging member to the force that presses the two on the basis of the difference between the pressure on the rotary valve element side and the pressure on the valve plate side. For this reason, the net pressing force is reduced, and the drive torque of the drive means for driving the rotary valve can be reduced, and the drive means can be downsized, and thus the rotary valve unit or the cryogenic temperature using the rotary valve unit can be reduced. It contributes to downsizing of the generator.

The invention of claim 2 has the following effects.

Between the rotary valve and the valve plate,
An annular bearing was provided. As a result, the bearing receives most of the force that presses the two on the basis of the difference between the pressure on the rotary valve element side and the pressure on the valve plate side. The pressing force applied to the bearing does not contribute to the rotational frictional resistance when the rotary valve element rotates. Therefore, what actually contributes to the rotational friction resistance is only the pressing force applied only to the portion where the rotary valve element and the valve plate are in direct contact, and the drive torque for driving the rotary valve element can be further reduced.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a rotary valve unit according to an embodiment of the present invention.

FIG. 2 is an overall schematic view of a pulse tube refrigerator.

FIG. 3 is a cross-sectional view of a rotary valve unit in the related art.

FIG. 4 is a perspective view of a rotary valve element and a valve plate in the related art.

[Explanation of symbols]

 1 Compressor 1a High-pressure discharge port 1b Low-pressure suction port 8 Regenerator 9 Cold head 12 First orifice 13 Buffer tank 15 Second orifice 16 Phase adjusting mechanism 30 Rotary valve unit 31 Drive part 32 Rotary valve 33 First housing (low-pressure side housing) ) 34 second housing (low pressure side housing) 35 motor 36 third housing 37 fourth housing (high pressure side housing) 38 rotary valve 39 valve plate 40 spring (biasing member) 41 bearing 44 shaft 48 first main passage (main) Passage) 50 High-pressure passage 51 Communication passage 52 Low-pressure passage 53 High-pressure space 54 Low-pressure space 55 Opposing surface 56 Stopper 60 Pressure vibration source

Claims (2)

[Claims] 1. A pressure vibration source, a regenerator, a cold head, and a phase adjusting mechanism are connected in series, and the phase difference between the pressure fluctuation and the fluctuation fluctuation of the working gas supplied from the pressure vibration source is calculated as the phase difference. A cryogenic generator that produces a cryogenic temperature in the cold head by producing a temperature difference between both ends of the regenerator by adjusting with an adjusting mechanism, wherein the pressure vibration source has a high pressure discharge port and a low pressure suction port. Machine, a high-pressure side housing having a high-pressure space communicating with the high-pressure discharge port therein, a low-pressure housing having a low-pressure space communicating with the low-pressure suction port therein, and a driving means arranged in the high-pressure space A rotary valve that can be driven to rotate by means of a valve plate, a valve plate that faces the rotary valve in the low-pressure space, and the rotary valve and the valve plate from the low-pressure space. A low-pressure passage bored in the valve plate toward the opposite surface, a main passage bored in the valve plate, one end surface of which opens to the facing surface and the other end communicates with the regenerator, A high pressure passage that is bored in the rotary valve from the space to the opposite surface and communicates with the main passage; and a communication passage that is formed in the rotary valve and that communicates the low pressure passage and the main passage,
A cryogenic generator, comprising: a rotary valve unit including an elastic body that urges the rotary valve element in a direction away from the valve plate. 2. The cryogenic generator according to claim 1, wherein the pressure vibration source is provided with an annular bearing between the rotary valve element and the valve plate.