JP2831985B2 - On-off valve and pulse tube refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open / close valve for opening / closing an opening through which a fluid flows in or out with an elastic material in close contact with or separated from a peripheral edge thereof, and a pulse tube refrigerator employing the open / close valve. , Small size and low power consumption.

[0002]

2. Description of the Related Art Conventionally, in order to open and close a flow path through which a fluid flows, an opening / closing valve is interposed in the middle of the flow path, which is a so-called poppet valve type or spool valve type. Valves are known. As a poppet valve type opening / closing valve, for example, there is a relief valve which opens and closes a flow path by elastic force. The relief valve is closed (closed) by forming a large diameter in the middle of the flow path and causing a valve body (poppet valve) to stop against the valve seat provided on the upstream side in the flow direction of the fluid by the elastic force of the coil spring. While the flow of the fluid is restricted, when the differential pressure between the upstream side and the downstream side becomes a certain pressure or more, the valve body moves to the downstream side against the elastic force of the coil spring to open. The valve allows the fluid to flow around the valve and opens and closes the fluid flow path. The poppet valve can be moved mechanically or electrically at an arbitrary timing by a cam or the like to open and close the fluid flow path.

In a spool valve type open / close valve (spool valve), a spool valve having a small-diameter portion formed between a large-diameter portion in the middle of a flow path is slidably disposed in a direction orthogonal to the flow of fluid. By moving the spool valve at an arbitrary timing, the valve closes when the large-diameter portion is located in the middle of the flow path to restrict the flow of fluid, and opens when the small-diameter portion is located in the middle of the flow passage. Valve to allow fluid flow,
The fluid passage is opened and closed. A rotary valve may be used to open and close the flow path by sliding the valve member.

Such an on-off valve may be applied to a so-called double inlet type pulse tube refrigerator shown in FIG. In the pulse tube refrigerator 1, the compressor 2 reciprocates the piston 2 a to repeatedly feed and suck gas (fluid) into the pulse tube 3, and a heat exchange unit on one end side (compressor side) of the pulse tube 3. When the gas is displaced in the direction of 3a, the heat is absorbed from the heat exchange section 3a by the expansion step, and when the gas is displaced in the direction of the adjacent regenerator 4, the heat is released by the compression step. The relief valve 5 is connected in series to the rear end of the pulse tube 3 together with a buffer tank 6 capable of storing gas so that the compression and expansion are performed at appropriate positions. An opening / closing valve 7 is interposed in the middle of a bypass flow path 8 for bypassing between the compressor 2 and the regenerator 4 and between the pulse tube 3 and the buffer tank 6 so as to assist the compression / expansion. That.

The relief valve 5 is connected to the pulse tube 3
By opening the valve when the gas inside the chamber becomes equal to or higher than a certain width and allowing the fluid to flow between the pulse tube 3 and the buffer tank 6, the compression process and the expansion process can be performed. Promote gas displacement between the two. Further, the opening / closing valve 7 opens at a timing opposite to that of the relief valve 5 to allow the gas to be pumped / suctioned, thereby allowing the gas to flow.
The compression and expansion of the gas in the pulse tube 3 is assisted. The pulse tube refrigerator 1 improves the heat exchange efficiency by appropriately operating the relief valve 5 and the opening / closing valve 7.

The poppet valve type opening / closing valve is
When operating by the elastic force of the coil spring, power supply is unnecessary, but since the flow path is opened and closed by the differential pressure between the upstream side and the downstream side, the flow path is branched when fluid flows in both directions. Therefore, it is necessary to dispose two sets in opposite directions. On the other hand, a spool valve type opening / closing valve opens and closes a flow path by moving the spool valve. Therefore, one set may be used even when fluid flows in both directions, but it is necessary to supply a large amount of power to move the spool valve. There is.

[0007]

However, in a poppet valve type opening / closing valve, the edge of a valve body is brought into contact with a valve seat in a flow passage regardless of mechanical or electrical. The valve body abuts against the valve seat with a large force depending on the direction in which the fluid flows, so that the seal between the valve body and the valve seat is immediately deformed. As a result, a high level of durability required for long-term use cannot be satisfied. In addition, when the poppet valve is stopped or moved electrically against the flow of the fluid, the size of the mechanism is increased and a large amount of electric power is required.

On the other hand, in the case of a spool valve type opening / closing valve, the spool valve slides and moves, so that wear cannot be avoided, and it is difficult to reduce the size mechanically and power consumption is large. Therefore, neither the poppet valve type valve nor the spool valve type open / close valve sufficiently satisfies the requirements of high durability, small size, and low power consumption.

The pulse tube refrigerator 1 shown in FIG.
Since it is not necessary to drive the piston 2a in a low-temperature portion and it is easy to reduce the size, the piston 2a may be used in a device that uses a superconducting material or the like by cooling and maintaining it at a cryogenic temperature for a long period of time. Components are required to have high durability, small size, and low power consumption. For this reason, as the relief valve 5,
Since opening and closing may be performed by a differential pressure, two sets of poppet valve type opening and closing valves for moving the valve body by a coil spring are mounted in opposite directions, but the durability is not sufficient as described above. It should be noted that the spool valve type cannot satisfy the requirements of high durability, small size, and low power consumption as the relief valve 5, and is more inappropriate than the poppet valve type using a coil spring.

[0010] Based on this, the present inventor has disclosed in Japanese Patent Application No. Hei.
In JP-A-333184, an opening portion through which gas flows (peripheral portion of the opening) is made of a conductive material, and a valve body made of a conductive elastic material and a spacer made of an insulating material are installed in the opening portion. A pressure control valve has been proposed. This pressure control valve closes (closes) the opening with an elastic force and an electrostatic force by applying a voltage between the valve body and the opening, while the valve body opens when the pressure exceeds a certain level. The pressure control valve is opened by elastically deforming while attenuating (inversely proportional to the square of the distance) the electrostatic force at a distance from the pulse tube 3 and the buffer tank 6 as a relief valve 5. By disposing the two sets in parallel in the opposite direction, it is possible to reliably close the opening and smoothly flow the gas immediately after the valve is opened, and sufficiently satisfy the requirements of high durability, small size, and low power consumption. .

On the other hand, the opening / closing valve 7 needs to be closed at a timing during the movement of the piston 2a in which the gas flows at a high flow rate in the bypass flow passage 8, so that it has high durability, small size, and low power consumption. Although it did not satisfy the requirements, a spool valve type was installed. The pressure control valve developed by the present inventor cannot be used as the on-off valve 7 because it opens when a certain pressure or more is applied.

In view of the above, the present invention provides an elastically deformable valve element which can be closed at any time in a flow path through which fluid flows in both directions by closely adhering to a peripheral portion of a flow port through which fluid flows out. The purpose of this invention is to provide an on-off valve that satisfies the requirements of high durability, small size, and low power consumption. By applying the on-off valve, the demand for high durability, small size, and low power consumption of double inlet type pulse tube refrigerators The purpose is to realize.

[0013]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a base in which a space through which a fluid flows in and out is defined, and a plurality of fluid flow openings are formed on a wall surface of the space. The member is disposed near each of the first flow ports that are independently opened at least at two or more locations on the wall surface of the base member, and adheres to the peripheral edge of the first flow port by elastic force to flow out the fluid. The restricting valve body is elastically deformed by the pressure of the inflowing fluid, and is disposed between the permitting valve body that permits the inflow of the fluid and the pair of second flow openings that open at positions substantially facing each other on the wall surface of the base member. And a restricting valve body that moves under pressure of the fluid flowing from one of the second flow ports and is in close contact with the other peripheral portion to limit the flow of the fluid, and at least the second flow port of the base member has Both the peripheral portion and the restriction valve body have conductivity, and A thin insulating material to one or both of the adhesion portion of the edge or limit valve body provided, is characterized in that it has applied configured to be capable of voltage between the restriction valve body and the peripheral edge.

According to the first aspect of the present invention, one of the first and second communication ports is connected so that a fluid flowing in the forward direction can flow therein, and the other of the first and second communication ports is connected in the reverse direction. In the first flow port, the flow of the fluid is permitted and the flow is restricted by the permissible valve body, while the restriction valve element is connected to the second flow port by the peripheral valve. When a DC voltage is applied in a state in which the opening is closed in close contact with the portion, the restricting valve body and the peripheral portion are attracted to each other by an electrostatic force (sucking force) caused by facing each other via an insulating material, and the close contact (blocking) occurs. ) Is maintained,
The flow of the fluid is restricted on the side where the restriction valve element is in close contact, and the flow of fluid is permitted on the side where the restriction valve element is not in close contact. Here, the forward direction and the reverse direction are relative directions in which the fluid flows, and do not mean the flowing direction of the fluid in the attached device. The same applies to the following.

Here, the electrostatic force for bringing the restricting valve body into close contact with the peripheral portion of the second flow opening is a force that attracts the facing electrode by applying a DC voltage to the electrode, and has the same magnitude. It is expressed by the following formula by the parallel electrode of the area. The electrostatic force F [N] = | (V / d) ² · (εS / 2) |... V: applied voltage d: distance between electrodes ε: dielectric constant between charges S: electrode area The angle at which the restricting valve element and the peripheral edge of the second flow port face each other is also a parameter, and is proportional to the square of the applied voltage V, while the distance between the restricting valve element and the peripheral edge of the second flow port is Is inversely proportional to the square of In addition, since only a DC voltage is applied between the restricting valve element and the peripheral portion of the second flow opening without flowing a current, required power (power consumption) is small.

Thereafter, when the application of the DC voltage is stopped at an arbitrary timing, the restricting valve body is actuated by the differential pressure between the upstream side of the second flow port and the space between the base member and the fluid flowing from the second flow port. It is quickly moved and closely adheres (closes) to the peripheral portion of the other second flow opening, so that outflow of fluid is restricted. Therefore, the flow of the fluid flowing in from one first flow port and flowing out from the other second flow port is controlled by the other first flow port.
The flow of the fluid flowing from the flow port and flowing out of the second flow port is restricted by applying / stopping a DC voltage at an arbitrary timing to move the restriction valve body and switch the second flow port to be opened. be able to.

When the differential pressure between the upstream side of one of the second flow ports and the space of the base member exceeds the electrostatic force between the restricting valve body and the peripheral portion of the second flow port, the restriction valve is also closed. The body is one second
Since the electrostatic force can be reduced by the square of the distance while moving away from the peripheral edge of the flow port, the fluid can be quickly moved by the inflowing fluid and brought into close contact with (closed to) the peripheral edge of the other second flow port. It is also possible to set the valve to close at an arbitrary fluid pressure by adjusting the applied voltage.

According to a second aspect of the present invention, the on-off valve according to the first aspect is interposed in a flow path bypassing a pulse tube of a double inlet type pulse tube refrigerator. According to the second aspect of the present invention, the restriction valve and the second flow port are opened and closed so as to open and close the bypass flow path at the opposite timing of opening and closing the flow path between the buffer tank and the buffer tank according to the pressure in the pulse tube. Apply DC voltage between peripheral edges
By stopping, the flow path between the buffer tank and the buffer tank can be opened and closed, and the pulse tube is allowed to flow and restrict the gas in the bypass flow passage in synchronization with the compression, expansion, and movement of the gas in the pulse tube. Can be.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIGS. 1 to 5 are views showing an embodiment of an on-off valve according to the present invention. This embodiment shows an example in which the present invention is applied to a so-called double inlet type pulse tube refrigerator. In the present embodiment, a case will be described in which the present invention is applied to the double-inlet type pulse tube refrigerator shown in FIG. 6 described in the related art described above. explain.

First, the configuration of the pulse tube refrigerator 1 will be described. In FIG. 6, the pulse tube refrigerator 1 includes, as shown in FIG. 5, a compressor 2 which reciprocates a piston 2a in a forward direction and a reverse direction to repeatedly pressurize and suction gas to thereby form a pulse tube 3 and a bypass flow. The gas in the passage 8 is made to flow in the forward direction and the reverse direction, and the gas in the pulse tube 3 is compressed, expanded, and displaced (moved).
After dissipating the heat absorbed during the expansion step from the heat exchange section 3a, the heat is dissipated to the regenerator 4 during the compression step after the displacement, and the heat of the heat exchange section 3a is carried out by the regenerator 4 to the outside. In addition, the forward direction and the reverse direction in which the gas flows only match the driving direction of the piston 2a.

At this time, when the pressure difference between the inside of the pulse tube 3 and the inside of the buffer tank 6 becomes equal to or more than a certain value after the start of the compression step, one of the relief valves 5 (forward valve) is opened. While allowing the gas to flow into the buffer tank 6, when the differential pressure becomes equal to or more than a certain value after the expansion process is started, the other (the reverse valve) is opened to open the buffer tank 6. By allowing the outflow of gas from the inside, the displacement (movement) of the gas in the pulse tube 3 is promoted,
Control is performed so that heat exchange and heat exchange are performed at optimal positions. It is preferable to use the pressure control valve described in Japanese Patent Application No. 8-333184 described above as the relief valve 5 because it can be operated with high durability, small size, and low power consumption.

The opening and closing valve 7 opens and closes at the opposite timing in synchronization with the opening and closing of the relief valve 5. When the relief valve 5 is closed to perform the compression step and the expansion step, Compression of gas in pulse tube 3
While opening to assist in expansion, relief valve 5
When the valve is opened and the gas in the pulse tube 3 is displaced, the valve is closed while the gas is flowing through the bypass passage 8 at high speed so that the gas in the pulse tube 3 is not displaced. I do.

Next, the configuration of the opening / closing valve 7 will be described. In FIG. 1, the opening / closing valve 7 is composed of a base member 11, elastic valves (allowable valve bodies) 12, 13, moving valves (restriction valve bodies) 14, and spacers 15, 16; It is interposed in the bypass passage 8 of the machine 1 and is opened and closed so as to allow and restrict the flow of gas in the bypass passage 8.

In the base member 11, a space 21 through which gas (fluid) flowing through the bypass passage 8 flows in and out is defined by block pieces 11a to 11e. The block piece 11a has an inflow port (first flow port) 22a on a wall surface defining the space 21.
And two flow passages 22 and 23 with an outlet (second flow opening) 23a opened, and two flow passages 24 having an inlet 24a and an outlet 25a in the block piece 11b as well.
25 are formed. The block piece 11c is formed with a flow path 26 that is connected to the compressor 2 side of the bypass flow path 8 and branches so as to communicate with the flow paths 22 and 23 of the block piece 11a. Similarly, the flow path 24 of the block piece 11c, which is connected to the relief valve 5 side of the bypass flow path 8,
A flow path 27 that branches off so as to communicate with 25 is formed.
Therefore, the base member 11 allows the gas to flow in the bypass flow channel 8 by communicating with the flow channels 22 to 27 so that the gas can flow into and out of the space 21.
Since the flow paths 22, 23, 26 and the flow paths 24, 25, 27 are formed symmetrically, they can be connected to the bypass flow path 8 without limitation in the mounting direction.

In the base member 11, at least the block pieces 11a and 11b are made of a conductive material, and a DC voltage described later is applied from the block piece 11a to the other block pieces 11b.
To 11e, and from the block piece 11b to the other block piece 11
a, an insulating material is interposed between them so as not to be applied to 11c to 11e. The elastic valves 12 and 13 are made of an elastic material so that they can be elastically deformed into the space 21 from a state in which they are in close contact with the peripheral portions of the inflow ports 22a and 24a of the flow paths 22 and 24. Is fixed to the part. When the gas pressure in the flow passages 22 and 24 is higher than that in the space 21, the elastic valves 12 and 13 elastically deform the front end side in the space 21 direction, and the gas flows from the inflow ports 22a and 24a into the space 21. While permitting the inflow, when the gas pressure in the channels 22 and 24 is not higher than the space 21 so as to be elastically deformed, the gas pressure in the channels 22 and 24 from the inflow ports 22a and 24a comes into close contact with the peripheral portions of the inflow ports 22a and 24a. Restrict gas outflow to the 24 side. Therefore, the elastic valve 12 allows only the gas flowing in the bypass passage 8 in the forward direction to flow into the space 21 through the flow passage 22 when the piston 2a of the compressor 2 is driven in the forward direction. On the other hand, the elastic valve 13
When a is driven in the reverse direction, only gas flowing in the bypass channel 8 is allowed to flow into the space 21 via the channel 24.

The moving valve 14 is made of an elastic material having conductivity so that the distal end side can be elastically deformed in the space 21 between the outflow / inflow ports 23a and 25a of the flow paths 23 and 25, and the base end thereof is a block piece. It is clamped and fixed between 11a and 11b. Like the elastic valves 12 and 13, the moving valve 14 receives gas pressure from the inside of the flow paths 23 and 25, and changes from a state of being in close contact with one of the peripheral portions of the outlets 23a and 25a to a state of being in close contact with the other. It is possible to move in the space 21. That is, the moving valve 14
When the gas pressure in the flow passages 23, 25 is higher than that in the space 21, the gas flowing from one of the outlets 23a, 25a is separated from one of the peripheral edges of the outlets 23a, 25a to which the front ends are in close contact. As a result, the gas is moved in the space 21 and comes into close contact with the other of the peripheral portions of the outflow ports 23a and 25a, thereby restricting the outflow of gas from the outflow ports 23a and 25a. Accordingly, the moving valve 14 restricts the gas flowing in the bypass passage 8 in the forward direction from flowing out of the outlet 25a through the space 21 while the gas flowing in the reverse direction in the bypass passage 8 is restricted. The flow out of the outlet 23a through the space 21 is restricted. In addition, moving valve
14 moves between the peripheral portions of the outflow inlets 23a and 25a due to elastic deformation of the distal end side. However, in order to restrict the outflow of the gas against the pressure of the gas in the space 21, the strength (thickness) of a certain level or more. Sa)
When moving, it elastically deforms around the base end side,
It comes into surface contact with the peripheral portions of the outflow ports 23a and 25a. Elastic valve 12,
13 is the same.

The spacers 15 and 16 are made of an insulating material. The spacers 15 and 16 sandwich the moving valve 14 between the block pieces 11a and 11b of the base member 11, and have the outlets 23a and 25a to which the moving valve 14 is in close contact. It is provided on the surface of the peripheral portion to ensure electrical insulation. And this open / close valve 7
The terminals (not shown) are pulled out from the moving valve 14 to ground, and the terminals (not shown) are also pulled out from the block pieces 11a and 11b of the base member 11, and the changeover switches 32a and 32b, respectively.
The DC power supplies 31a, 31b can be connected to the DC power supplies 31a, 31b via the 32b.
The voltage of b is applied to the moving valve 14 and the block 11a of the base member 11,
11b, or its block piece 11a,
11b can be shorted to ground. In addition,
The reason why the block pieces 11a and 11b are short-circuited to the ground by the changeover switches 32a and 32b is that the accumulated charges cannot be released only by opening the connection with the DC power supplies 31a and 31b. When applying DC voltage to one of the switches, the other is grounded
By switching between 32a and 32b, the moving valve 14 and the block pieces 11a and 11
This is for use so that a potential difference occurs only with one of b. Note that the block pieces 11a, 11b of the base member 11 are
The circuit for applying a voltage between the moving valve 14 and the moving valve 14 is not limited to the circuit shown in FIG. 1, and it goes without saying that the moving valve 14 may be configured to have a high pressure.

For this reason, as shown in FIG. 2, for example, as shown in FIG. 2, a DC voltage is applied from the DC power supply 31a to the opening / closing valve 7 between the movable valve 14 and the block piece 11a in a state in which the movable valve 14 is in close contact with the peripheral edge of the outlet 23a. When the movement valve 14 and the outlet 23
Since one of the peripheral portions a faces each other with the spacer interposed therebetween, it can be attracted to each other by the electrostatic force (attraction force) expressed by the above-described formula and can maintain the close contact state.

Therefore, during the compression step, the bypass passage 8
As shown in FIG. 3, when the gas flows in the forward direction, as long as the differential pressure between the gas pressure in the flow path 23 and the gas pressure in the space 21 does not exceed the electrostatic force, as shown in FIG. Can be maintained until the application of the DC voltage is stopped, and at this time, the elastic valve 12 elastically deforms and flows into the space 21 from the inflow port 22a. Outflow of the permitted gas from the outflow port 25a can be permitted.
Then, after the compression step is completed, the application of the DC voltage is switched to the block piece 11b side and the application to the block piece 11a side is stopped so as to synchronize with the opening of one of the relief valves 5 to displace the gas. When the moving valve 14 is turned on, the differential pressure between the gas pressure in the flow path 23 and the gas pressure in the space 21 causes the outflow port 23 a
The gas moves away in the space 21 by the gas flowing out of the outflow / inflow port 23a away from the peripheral edge of the airflow port, and is held in close contact with the perimeter of the outflow / inflow port 25a by the pressure and electrostatic force of the gas. Spills can be restricted. Thereafter, similarly, during the expansion step, the gas flowing at high speed in the reverse direction in the bypass flow path 8 can be allowed to flow into the space 21 from the inflow port 24a and out of the outflow port 23a. When the gas is displaced, the outflow of the gas from the outflow port 23a can be restricted.

At this time, the gas pressure in the flow passages 23 and 25 does not become much higher than in the space 21 by communicating with the flow passages 22 and 24, so that the moving valve 14 and the block pieces 11a and 11
It is not necessary to apply a large DC voltage between the DC power supplies 31b and 31b, and no current flows between them, so that the power consumption of the DC power supplies 31a and 31b is small. Further, since the moving valve 14 can be moved by flowing gas only by stopping the application of the DC voltage, a mechanism for driving is not required. Also,
Since the elastic valves 12, 13 and the moving valve 14 are in surface contact with the peripheral portions of the inflow ports 22a, 24a and the outflow ports 23a, 25a, the outflow ports 23a, 25a can be repeatedly closed without wear.

As described above, in the present embodiment, the inflow port
In the case of 22a and 24a, the elastic valves 12 and 13 are in close contact with the peripheral portion to allow the inflow of gas, but can restrict the outflow of gas. In addition, at the outlets 23a, 24a, the block pieces 11a,
When the moving valve 14 is brought into close contact with one of its peripheral parts due to an electrostatic force caused by the application of a DC voltage between itself and one of the outlets 11b, gas outflow from the other of the outlets 23a and 24a is allowed, but the DC When the application of the voltage is stopped and the electrostatic force stops working, it is possible to restrict the outflow of the gas by closely adhering to the other of the peripheral portions of the outflow ports 23a and 24a.
Therefore, even if the gas flows in both directions, such as the bypass flow path 8 of the pulse tube refrigerator 1, the moving valve 14 and the block piece 11
By applying / stopping the DC voltage between a and 11b, the flow can be permitted / restricted at an arbitrary timing.
After restricting the gas flowing in the forward direction in close contact with the other of the peripheral portions of the outlets 23a and 24a, the moving valve 14 is configured to use one of the peripheral portions of the outlets 23a and 24a with the gas flowing in the reverse direction. Therefore, it is possible to repeat the allowance and restriction of the gas flowing in the forward direction again.

Therefore, the inflow port 22 is provided in the base member 11.
a, 24a, outlets 23a, 25a, elastic valves 12, 13, moving valves
14. With a configuration that can be simply and easily reduced in size by simply disposing the spacers 15 and 16, a small enough to switch (stop) the application of the DC voltage between the moving valve 14 and the block piece 11a or 11b. With the power consumption, the flow path can be opened and closed at an arbitrary timing, and the gas in the bypass flow path 8 of the pulse tube refrigerator 1 circulating in both directions can be circulated in synchronization with the opening and closing of the relief valve 5. .

In this embodiment, the block members 11a and 11b of the base member 11 are insulated from one another,
Although a DC voltage is applied, the outlet 23a,
The DC voltage may be applied only when it is necessary to make the peripheral edge of 25a closely contact with one or the other by electrostatic force. Further, when the moving valve 14 is separated from one of the peripheral portions of the outlets 23a, 25a, the electrostatic force is reduced by the square of the distance, so that a DC voltage is applied simultaneously without insulating the block pieces 11a to 11e. So that
By only temporarily stopping the application, the outflow inlets 23a, 25
It may be made to adhere closely to the other of the peripheral part of a. However, the moving valve 14 can be held by the electrostatic force against the gas flowing in the space 21 at the periphery of the outflow / inflow ports 23a and 25a. Since it is not affected by electrostatic force, it is preferable to configure as in the present embodiment.

[0034]

According to the present invention, the first flow port permits the inflow of the fluid and limits the outflow. The second flow port restricts the inflow and outflow of the fluid when the restricting valve element is in close contact with the peripheral portion by the electrostatic force, while allowing the inflow and outflow of the fluid when the restricting valve element is not in close contact with the restricting valve element. When the generated DC voltage is stopped, the peripheral portion of the second flow port to which the restriction valve element is in close contact can be switched to restrict the outflow of the fluid from the second flow port that has been permitted up to that time. For this reason, it is possible to open and close the flow path in which the fluid flows in both directions simply by repeatedly applying and stopping the DC voltage in accordance with the flow direction of the fluid. Therefore, with a configuration that can be simply and easily reduced in size, the flow path through which the fluid flows in both directions can be opened and closed at an arbitrary timing simply by repeatedly applying and stopping the DC voltage, and is consumed at this time. Electric power is also small. As a result, requirements for high durability, small size, and low power consumption can be satisfied, and the present invention can be suitably applied to a double inlet type pulse tube refrigerator.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of an on-off valve according to the present invention, and is a cross-sectional view showing a schematic overall configuration thereof.

FIG. 2 is a sectional view showing an open / closed state of the valve body.

FIG. 3 is a cross-sectional view showing the valve element in an open / closed state different from that in FIG. 2;

FIG. 4 is a cross-sectional view showing an open / closed state of the valve body different from FIGS. 2 and 3;

FIG. 5 is a timing chart illustrating opening and closing of an on-off valve of the pulse tube refrigerator according to the present invention.

FIG. 6 is a schematic overall configuration diagram of a pulse tube refrigerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pulse tube refrigerator 2 Compressor 3 Pulse tube 4 Regenerator 5 Relief valve 6 Buffer tank 7 Opening / closing valve 8 Bypass flow path 11 Base member 11a-11e Block piece 12, 13 Elastic valve (allowable valve body) 14 Moving valve (limit) Valve body) 15, 16 Spacer (insulating material) 21 Space 22-27 Flow paths 22a, 24a Inflow port (first flow port) 23a, 25a Outflow port (second flow port) 31a, 31b DC power supply 32a, 32b Switch

Claims (2)

(57) [Claims] 1. A base member defining a space through which a fluid flows in and out, and a plurality of fluid flow ports are opened on a wall surface of the space, and a base member independently opening at least two or more locations on the wall surface of the base member. The first flow port is disposed in the vicinity of each of the first flow ports, and adheres to the periphery of the first flow port by elastic force to restrict the outflow of the fluid, while elastically deforming by the pressure of the inflowing fluid to prevent the inflow of the fluid. The valve element is disposed between a permissible valve body and a pair of second flow ports that open at positions substantially facing each other on the wall surface of the base member, and moves by pressure of a fluid flowing from one of the second flow ports. A restricting valve body that is in close contact with the other peripheral portion and restricts outflow of the fluid, wherein at least both the peripheral portion and the restricting valve body of the second flow port of the base member have conductivity, and the peripheral portion or One or both of the contacting parts of the restriction Sex material provided, the opening and closing valve, characterized in that applied configured to be capable of voltage between the restriction valve body and the peripheral edge. 2. A double-inlet pulse tube refrigerator, wherein the on-off valve according to claim 1 is interposed in a flow path bypassing the pulse tube.