JPS61190255A - Cryogenic refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a cryogenic refrigeration device applicable to a Talio bomb, a He liquefaction device, and the like.

[Prior Art] Conventionally, this type of refrigeration equipment has a piston-shaped tire bracer slidably fitted in a cylinder, and by reciprocating the displacer, the displacer and the cold end of the cylinder are connected to each other. The volume of the expansion chamber formed between the two is increased or decreased, and by expanding and contracting the expansion chamber, the gas is sequentially expanded to run a predetermined refrigeration cycle.

By the way, there are conventional types in which the regenerator is held inside the disbracer, and there are types in which it is disposed outside the cylinder, but both have the following problems. . In other words, if the regenerator is installed inside the displacer, the inertial force of the moving part (
The drawback is that vibrations tend to build up. Further, in the case where the regenerator is provided outside the cylinder (including the outer circumferential surface of the cylinder wall), there is a wasted volume inside the displacer, and there is a problem that the overall volume of the device increases. Furthermore, various mechanisms have been devised to control the movement of this displacer, but all of them increase the number of gas seals and add complex moving parts, making the device NIl. was.

In order to eliminate such inconveniences, a cryogenic refrigeration device is equipped with an internal regenerator supported by a fixed member, a regenerator that is slidably fitted around the outer circumference of the regenerator, and a low-temperature side end of the regenerator and the regenerator. a movable shell that forms an internal expansion chamber between the low-temperature end of the movable shell, an external regenerator installed around the outer circumference of the movable shell, and a A casing that forms an external expansion chamber between an end portion and the movable shell, and a timing valve that connects the high temperature end of each regenerator to an air supply system path or an exhaust system path at a predetermined timing. The idea is to make it something that can be done. With this type of device, the pressure of the cooling gas can be used to slide the operating shell, so a drive part is not required and the structure is simple, and the operating shell can expand adiabatically twice per reciprocation. It has the advantage of providing greater refrigeration capacity with the same size.

However, such a method also has the following disadvantages. That is, even if the movable shell is accelerated by the gas, there is no means to decelerate the movable shell, so the movable shell does not stop until it collides with the stopper at the slide end position, and the collision generates vibrations. .

[Problems to be solved by the invention] The present invention was made with attention to these circumstances, and
It is an object of the present invention to provide a cryogenic refrigeration device that has a simple structure, has a high refrigeration capacity, and does not generate vibrations due to the collision.

Means for Solving Problem E] In order to achieve such an object, the present invention provides the above-described cryogenic refrigeration device with a movable shell provided on the external high-temperature end side to move the movable shell to a sliding end position. It is characterized by the provision of a waste damper that decelerates the speed from the vicinity and stops the slide at the T position.

[Function] According to this configuration, as the movable shell reciprocates, the internal expansion chamber formed inside the movable shell and the external expansion chamber formed outside the movable shell alternately expand and contract. I will do it. Therefore, high-pressure gas introduced into the internal expansion chamber from the supply air system path through the internal regenerator expands in this expansion chamber, becomes low temperature, and is discharged to the exhaust system path again through the internal regenerator and circulated. , High-pressure gas introduced from the air supply system path through the external regenerator into the external expansion chamber expands in the expansion chamber to become low temperature, and is again discharged through the external regenerator to the exhaust system path and circulated. It turns out. Furthermore, since the gas damper decelerates the movable shell from near the slide end position of the movable shell, the movable shell stops at the slide end position without any impact.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a small-sized cryogenic refrigerator according to the present invention, and numeral 1 in the figure is a base serving as a fixing member. The base l has a disc-shaped upper end, and has a pair of inflow and outflow boats 2.3 on the bottom plate 1a. One outflow/inflow boat 2
is bored in the center of the bottom plate 1a, and a communication pipe 4 is airtightly fitted into the upper half of the inflow/outflow boat 2 via a seal member 5 and fixed by a set screw 6. This communication pipe 4 extends in the L direction, and a mounting disk 7 is attached to its upper end. Then, the first stage internal regenerator 8 is placed on this mounting disc 7, and a plurality of poles) 9a
It is fixed by This internal regenerator 8 is constructed by stacking a plurality of heat storage elements 11 and spacers (not shown) alternately.

The heat storage element '11' is a disc-shaped element made of copper or the like, and has a large number of vertically penetrating ventilation holes 11a made of spacer L±stainless steel fljA! It is made of 11 pieces of wire, etc. The high temperature end (ordinary temperature end) 8a of this internal regenerator 8 is connected to a port formed in the mounting disc 7.
7a and the communication pipe 4 to the inflow/outflow boat 2, and the port 7b communicates with the channel/<10
is connected to. Also, the low temperature end 8b of this internal regenerator 8
A port 12a and a communication path 12b are provided in the mounting member 12.
It is connected to the high temperature end 13a of the second-stage internal regenerator 13 via the boat 12C. This mounting member 12 is
] Disk-shaped mounting portions 12d and 12e at both ends of the bottom, respectively.
It has the following. The internal regenerator 13 is also composed of a plurality of heat storage elements 11 and spacers (not shown) stacked in alternating stages, and is fixed by a plurality of ports 9b.

A movable shell 14 is mounted on the outer periphery of these internal regenerators 8 and 13 as a slide valve. The movable shell 14 is a two-stage cylindrical body that fits around the outer periphery of the regenerators 8 and 13, and its first stage portion 14a surrounds the internal regenerator 8 of the first stage, and also surrounds the internal regenerator 8 of the second stage. The second stage internal regenerator 13 is surrounded by the portion 14b. A first-stage internal expansion chamber 16 is formed between the first-stage ceiling wall 14c of the movable shell 14 and the low-temperature end 8b of the first-stage internal regenerator 8, and the regenerator 8 and the attached They communicate through the port 12a of the member 12, the j1 passage 12b, and the communication hole 12f. Further, the end of the second stage portion 14b on the low temperature side is closed by the second stage ceiling wall 14d. Further, a second-stage internal expansion chamber 17 is formed between the second-stage ceiling wall 14d and the low-temperature end 13b of the internal regenerator 13.

A shaft hole 14f is bored in the center of the bottom wall 14e at the end of the first stage of the movable shell 14 on the high temperature side. A first-stage external regenerator 21 and a second-stage external regenerator 2 held in the casing 19 are fitted around the outer periphery of the movable shell 14.
2 are provided. The casing 19 is connected to the external regenerator 2
It is a two-stage cylindrical body that encloses 1 and 22, and a top wall 19a is provided at the end of the first stage on the low temperature side,
The end of the second stage on the low temperature side is closed by an inverted cup-shaped top wall 19b. Further, a flange portion 19e is provided on the high temperature end side of the casing 19, and this flange portion 19e is attached to the upper end opening of the base 1 via a sealing member 20. And the second stage external cold storage 22
A first stage external expansion chamber 23 is located between the high temperature end 22a of the casing 19 and the top wall 14c of the movable shell 14, and a second stage external expansion chamber 23 is located between the top wall 19b of the casing 19 and the top wall 14d of the movable shell 14. Eye external expansion chambers 24 are respectively formed. The external regenerators 21 and 22 are each made up of a plurality of alternately stacked heat storage elements 25 and spacers (not shown), and are fixed to the casing 19 using ports 26a and 28b, respectively. The heat storage element 25 is an annular element made of copper or the like, and has a large number of ventilation holes 2 passing through it vertically.
5a. The spacer is made of stainless steel wire or the like. The high-temperature end 21a of the first-stage external regenerator 21 communicates with the loading/unloading λ boat 3 via the chamber 28. The low temperature end 21b of the regenerator 21 is connected to the bow provided in the casing 19) 19c.
and the second stage external regenerator 22 via the external expansion chamber 23.
It communicates with the high temperature end 22a of. The low temperature end 22b of the second stage external regenerator 22 communicates with the external expansion chamber 24 via the boat 19d.

Both the inflow and outflow boats 2.3 are connected to an air supply line 32 or an exhaust line 33 via a timing valve 31. Specifically, the timing valve 31 is composed of a slide valve or the like that operates a boat block using a motor to switch boats, and switches in the manner shown by symbols in FIG. 1. It has become. That is, in the HA, one of the inflow/outflow boats 2 is connected to the air supply system path 32, and the other outflow/inflow boat 3 is connected to the exhaust system path 33. Furthermore, at position B, one of the inflow and outflow boats 2 is connected to the exhaust system path 33, and the other outflow and inflow boat 3 is connected to the air supply line path 32. Then, the buds switch to the above-mentioned position A and the pre-arrangement ff1B. The air supply line 32 is connected to the discharge port 3 of the compressor 2 34.
The exhaust line 33 is for supplying high-pressure waste discharged from the timing valve 31 through the cooler 35 to the air supply bow 31a of the timing valve 31. This is for guiding low-pressure gas to the intake port 34b of the compressor 34.

Further, a gas damper 36 is disposed on the external high temperature end side of the movable shell 14. This gas damper 36 has a movable member 37 formed in an annular shape and an annular fixed member 38 protruding from the inner periphery of the casing 19 . The movable member 37 has a collar 37a on the inner circumference side of the upper end and a collar 37a on the outer circumference side.
b has a flange 37c on the inner periphery side of the lower end and a flange 37d on the outer periphery side, and is slidably in contact with the inner periphery of the casing 19. The fixed member 38 is disposed between the flanges 37b and 37d on the outer peripheral side of the movable member 37, and forms a fluid chamber 39 between the flanges 37b and a fluid chamber 41 between the flanges 37d and 37d. Do 1. These fluid chambers 39.41 are filled with gas, and both chambers 39.41 are communicated through a narrow fluid passage 42. Furthermore, a protrusion 43 protruding from the high temperature end of the movable shell 14 is provided between the flanges 37a and 37c on the inner peripheral side. This protrusion 43 slides together with the movable shell 14, and comes into contact with the collar 37a near the final γ position of the upward slide, thereby causing the movable member 37 of the gas damper 36 to slide upward together. At the same time, the movable member 37 is made to come into contact with the collar 37c near the end position of the downward slide and slide the movable member 37 downward as a unit.

Next, the operation of this embodiment will be explained.

Internal expansion chamber 16.17 is the smallest, external expansion chamber 23.24
is at its maximum (see Figures 1 and 2a), the timing valve 31 is set to position A to connect one of the inflow and outflow boats 2 to the air supply system passage 32, and connect the other inflow and outflow boat 3 to the exhaust system. Connect to road 33. As a result, high-pressure gas flows from the compressor 34 through the air supply line 32 into the -10,000 inflow/outflow boat 2. The high-pressure gas that has flowed into the inflow/outflow boat 2 is guided to the high temperature end 8a of the first-stage internal regenerator 8 via the communication pipe 4 and the boat 7a.
The gas that has passed through is introduced into the first-stage internal expansion chamber 16 through the boat 12a, the communication path 12b, and the communication hole 12f of the mounting member 12.

Also, a part of the gas that has passed through the regenerator 8 is transferred to the mounting member 1.
It is introduced into the second-stage internal regenerator 13 through the second-stage internal regenerator 13 through the second-stage internal regenerator 13, the second-stage internal regenerator 13, and the second-stage internal expansion. It is introduced into chamber 17. Further, a part of the high pressure gas introduced through the communication pipe 4 and the boat 7a is also guided to the chamber IO through the boat 7b. In this state, the movable shell 14 is pressed upward by the high pressure gas in the internal expansion chambers 16 and 17, while the movable shell 14 is urged downward by the pressure of the high pressure gas in the chamber IO. Ru. however.

The pressure receiving area for receiving the axial pressure component for the chamber IO is larger by an amount corresponding to the cross-sectional area of the communication pipe 4 than the pressure receiving area for receiving the axial pressure component for the chamber IO (see FIG. 3a). , the movable shell 14 is urged upward and moved by the difference therebetween (see Figure 2).

At the start of this movement, the protrusion 43 is in contact with the collar 37c on the lower end side of the movable member 37 (see FIG. 4a). Once movement begins, the gas is transferred to the internal regenerator 8.13.
The regenerator 8.13 continuously enters the expansion chamber 16.17, but at this time a pressure loss occurs due to the regenerator 8.13, so the pressure pushing up the shell upper surface 14C114d is stronger than the pressure pushing up the shell bottom surface 14e. The pressure is slightly smaller than the pressure pushing down, and due to the relationship with the area difference, the forces are equal to each other. At this time, the movable shell 14 moves at a constant velocity. When the movable shell 14 reaches near the upper slide end position, the protrusion 43 comes into contact with the collar 37a at the upper end of the movable member 37 of the gas damper 36 and rises in FIG. 4b. Then,
As the movable member 37 rises, the volume of the fluid chamber 41 decreases while the volume of the fluid chamber 39 increases. Due to this change in volume, the gas in the fluid chamber 41 moves to the fluid chamber 39, but since the fluid passage 42 that communicates the two chambers 39 and 41 is narrow, when the gas passes through the fluid passage 42, there is a large Frictional resistance occurs. This frictional resistance causes the movable member 37,
It is transmitted to the movable shell 14 via the spring 43, and applies a brake to the upward movement of the movable shell 14. Then, the movable shell 14 is gradually decelerated by the brake and stopped at a predetermined slide end position. At this time, the movable member 37 has slid upward to a predetermined position (the fourth
(See Figure C). In this way, the internal expansion chambers 16 and 1
7 reaches its maximum volume and is filled with high-pressure gas, the timing valve 31 is switched to position B,
One of the inflow/outflow boats 2 is connected to the exhaust system path 33, and the other outflow/inflow boat 3 is communicated with the air supply system path 32 (see FIG. 2C). As a result, a part of the gas in the internal expansion chambers 16, 17 is blown out through the regenerator 8 and the communication pipe 4 into the exhaust system path 33 and returned to the intake port 34b of the compressor 34. At this time, the internal expansion chamber 16
．． The gas remaining in the tube 17 does the job of pushing out other gases and cools the eyes. At this stage, since the timing pulp 31 is held at position B as described above, the high pressure gas discharged from the compressor 34 flows into the other outflow/inflow boat 3 through the air supply line 32.

The high pressure gas that has flowed into the inflow/outflow boat 3 is transferred to the chamber 2
8 to the high temperature fi 21a of the first-stage external regenerator 21, and through this regenerator 21 to the first-stage external expansion chamber 2.
3 will be introduced. Further, a part of the gas introduced into the external expansion chamber 23 passes through the second-stage external regenerator 22 and is introduced into the second-stage external expansion chamber 24 . In this state, the movable shell 14 is pressed downward by the high pressure gas in the external expansion chamber 23.24, while the chamber 28
The movable shell 14 is urged upward by the pressure of the high pressure gas inside. However, the pressure receiving area of the movable shell 14 for receiving the axial pressure component with respect to the external expansion chamber 23.24 is larger than the pressure receiving area of the movable shell 14 with respect to the axial direction pressure component of the chamber 28. Since it is large by the amount corresponding to the area (see Figure 3),
Due to the difference, the movable shell is urged downward and moves (see FIG. 2C). At this time, the low-temperature gas remaining in the internal expansion chamber 13 passes through the internal regenerator 8 while being cooled and is pushed out to the exhaust system path 33. When the movable shell 14 reaches the vicinity of the downward slide end position, the flange 37c at the lower end of the movable member 37 of the gas tamper 36
(see FIG. 2C), the movable member 37 descends together with the movable shell 14. Then, as the movable member 37 descends, the volume of the fluid chamber 39 decreases, while the volume of the fluid chamber 41 decreases.
The volume of will increase. Due to this change in volume, the gas in the fluid chamber 39 moves to the fluid chamber 41, but as described above,
When the gas passes through the fluid passage 42, a large frictional resistance is generated. This frictional resistance applies a brake to the downward movement of the movable shell 14. Then, by using the brake, the movable shell 14 is gradually made to move at a speed of :g and is stopped at a predetermined slide end position. At this time, the movable member 37 returns to the position at the start of operation (see FIG. 4C).

In this way, when the external expansion chambers 23 and 24 reach their maximum volume and are filled with high-pressure gas, the timing valve 31 is switched to position tA again, and the other inflow/outflow boat 3 is evacuated. At the same time as connecting to the system 33, the inflow/outflow boat 2 of the blade is communicated with the air supply system 32 (see Fig. a), so that a part of the gas in the external expansion chamber 23, 24 is is passed through external regenerators 21 and 22 to exhaust system path 3.
3 and is returned to the intake port 34b of the compressor 34. At this time, the gas remaining in the external expansion chambers 23, 24 works to push out other gases and cools itself. At this stage, the high-pressure gas discharged from the compressor 34 is again supplied to one of the inflow and outflow boats 2,
The movable shell 1 is introduced into the interior while being pre-cooled, and then the movable shell 1 is
4 moves to -1-'fi. At this time, the low-temperature gas remaining in the external expansion chambers 23.24 passes through the external regenerators 21.22 while being cooled and is pushed out to the exhaust system path 33. Therefore, by repeating the above operations, the Gifford McMahon cycle (Gifford
-Mc+*ahon Cycle) is carried out, and one end portion of the casing 19 becomes extremely low temperature.

This is how it performs its freezing action.

In this case, expansion chambers 16.23 are provided on both sides of the top wall 14c of the first stage portion 14a of the movable shell 14, and expansion chambers 17.24 are provided on both upper and lower sides of the top wall 14d of the second stage portion 14b. Separate cold storage units 8.2
1 to the expansion chamber 16.23, and also to the regenerator 13.2.
Gas is supplied to the expansion chambers 17 and 24 through the expansion chambers 17 and 24, respectively. Therefore, independent refrigeration cycles are operated using the expansion chamber 16.17 and the regenerator 8.13, and the expansion chamber 23.24 and the regenerator 21.22. Moreover, since the expansion chambers 16, 17 and the expansion chambers 23, 24 expand and contract in alternating directions q- due to the reciprocating motion of the movable shell 14, the expansion operation is performed twice for each reciprocating motion of the movable shell 14. By doing so, the refrigeration capacity can be roughly doubled compared to conventional systems at the same frequency. Furthermore, internal expansion chambers 16, 17, external expansion chambers 23,
Since both 24 are formed in two stages, it is possible to obtain a lower temperature near the top wall 19b of the casing 19 than in the case where there is only one stage. Moreover, since the movable part is a hollow shell, the inertial mass is small and vibrations can be significantly reduced. Furthermore, since the regenerator 8 is disposed by effectively utilizing the internal space of the movable shell 14, it is possible to make the regenerator more compact than conventional products in which the regenerator is disposed outside the casing. In addition, when operating the Gift McMahon cycle as in this embodiment, the movable shell 1
The movable shell 14 is
can be moved only by the biasing force of the high-pressure scrap.Therefore, there is no need for any mechanism to operate the displacer (movable shell), and the structure can be significantly simplified.

In addition, since the slide of the movable shell 14 is decelerated from near the end position of the slide by the gas damper 36 and stopped at the end position, the slide of the movable shell 14 is stopped at the end position, so that the 1# dormitory is stopped by colliding with the stopper. There is no inconvenience such as vibration occurring every time.

Note that the present invention is not limited to refrigeration equipment that operates on the Gifford McMahon cycle, but is also applicable to small-sized cryogenic refrigeration systems that use the Solvay cycle, Starlink cycle, etc. ! ! It can be similarly applied to devices.

Further, in the above embodiment, a two-stage type was described, but the present invention can of course be applied to a one-stage type and a multi-stage type of three or more stages.

Further, the configuration of the gas tamper may be similar to that of the above-described embodiment, and the fixing members may be lids fixed to the top and bottom of the piston, respectively. Further, an elastic member may be attached to a contact surface between the protrusion and the inner periphery side collar. Furthermore, the protrusion may be flexible and may have an elastic effect. Further, a seal may be placed in a sliding portion of the movable member with the inner circumferential surface of the casing. Further, the fluid passage is not limited to the gap between the fixed member and the movable member, but may be, for example, a throttle hole provided in the fixed member.

[Effects of the Invention] Since the present invention has the above-described configuration, it is possible to provide a cryogenic refrigeration device that has high refrigerating capacity, has a simple structure, can be made compact, and does not generate vibrations. It is something.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view;
Fig. 2 a, b, c, d are explanatory diagrams of operation; Fig. 3 a, b are explanatory diagrams of action to explain the pressure distribution on the movable shell; Fig. 4 a, b, c, dl...fixed Components (base) 8, 13...Internal regenerator 14...Fist movable shell 16.17...Internal expansion chamber 19...Casing 21.22...External regenerator 23.24 Fist・External expansion chamber 31...Timing valve 32...Air supply system path 33...Exhaust system path 36...Cass damper 37・φφ movable member 38...Fixed member 39.41---Fluid chamber 421・Fluid passage 43...Protrusion

Claims (1)

[Claims] An internal regenerator supported by a fixed member, and a hollow space that is slidably fitted around the outer periphery of the regenerator and forms an internal expansion chamber between the low temperature side end of the internal regenerator and the low temperature end of the regenerator. a movable shell, an external regenerator disposed around the outer periphery of the movable shell, and an external regenerator provided to surround the external regenerator and between the end on the low temperature side and the movable shell. A casing forming an external expansion chamber that communicates with the regenerator, and a cooling gas that connects the high temperature end of each regenerator to the air supply system path or the exhaust system path at a preset timing and discharges from the air supply system path. A timing valve that presses a pressure receiving surface of the movable shell to slide the movable shell, and a gas damper provided on an external high temperature end side of the movable shell to decelerate the movable shell from near a slide end position and stop it at the slide end position. A cryogenic freezing device characterized by: