JP3368770B2 - Cryogenic refrigerator and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryogenic refrigerator used for a superconducting magnet applied to, for example, a magnetic resonance imaging apparatus (commonly called MRI).

[0002]

2. Description of the Related Art The refrigerating capacity of a standard cryogenic refrigerator currently put into practical use is said to be about 20K in use.
On the other hand, the superconducting magnet that is the object to be cooled is cooled to a cryogenic temperature by liquid helium and is in a superconducting state.
Since the liquefaction temperature of liquid helium is 4.2K, liquid helium is evaporated and the amount of liquid helium consumed is increased when the refrigerating capacity of the refrigerator is about 20K. For this reason,
In the above refrigerator, it is necessary to constantly inspect and replenish the consumption of liquid helium, but since liquid helium is expensive, there is little evaporation of liquid helium and it is necessary to have a cryogenic refrigerator with a refrigerating capacity of about 4K in use. Nature is increasing.

FIG. 13, FIG. 14, and FIG.
FIG. 13 shows a conventional Gifford-McMahon cycle cryogenic refrigerator shown in Japanese Patent Publication No. 6-30433.
Is a configuration diagram, FIG. 14 is an enlarged view of a connecting device portion, and FIG. 15 is an enlarged view of a connecting device portion. In these figures, 1 is a working fluid (for example, helium gas) that serves as a refrigerant of this refrigerator, 2 is an intake valve through which a first-stage cylinder 10 described later sucks the working fluid 1 from a high-pressure buffer tank 41, and 3 is an intake valve. The first-stage cylinder 10 is an exhaust valve that exhausts the working fluid 1 to the low-pressure buffer tank 42. Reference numeral 10 denotes a first-stage cylinder for containing the working fluid 1 sucked by the intake valve 2,
Reference numeral 11 is an upper gas space chamber arranged in the upper part of the first stage cylinder 10, and 12 is a first stage expansion chamber arranged in the lower part of the first stage cylinder 10.

Numeral 13 is in the first-stage cylinder 10 and reciprocates in the first-stage cylinder 10 to cause an upper gas space chamber 11 and a first-stage expansion chamber 12.
The cylindrical first-stage displacer for moving the working fluid 1 between them is provided at one end thereof with a cylindrical inner peripheral wall portion 13b forming a circular through hole 13a penetrating in a direction orthogonal to an arrow AR described later. Has been. In addition, a strip-shaped protruding portion 13c that surrounds the outer peripheral surface and protrudes about 100 micrometers from the outer peripheral surface is provided on a part of the outer peripheral surface, and a slight gap is provided between the inner peripheral wall of the first-stage cylinder 10 and the sliding portion 13c. Have been made mobile. 14 is the first stage displacer 1
3 is a first-stage regenerator for storing the cold of the working fluid 1 and stores therein a first-stage regenerator material 15 in which, for example, phosphor bronze disc-shaped wire nets are laminated.

Reference numeral 16 is arranged between the first-stage cylinder 10 and the first-stage displacer 13 so as to separate the upper gas space chamber 11 and the first-stage expansion chamber 12, and the working fluid 1 is separated from the upper gas space chamber 11 and the first gas space chamber 11. When moving between the first-stage expansion chambers 12, the first
A first stage seal to prevent movement through the first stage regenerator 14 disposed within the stage displacer 13 and through the outer periphery of the first stage displacer 13;
Reference numeral 17 is a first stage freezing stage for transmitting the coldness of the first stage expansion chamber 12 to the outside.

Reference numeral 20 denotes a second-stage cylinder connected to the first-stage cylinder 10, and reference numeral 21 denotes a second-stage expansion chamber arranged in the lower portion of the second-stage cylinder 20. 22 is the second stage cylinder 2
A cylindrical second-stage displacer that is in 0 and reciprocates in it to move the working fluid 1 between the first-stage expansion chamber 12 and the second-stage expansion chamber 21.
A cylindrical inner peripheral wall portion 22b forming a circular through hole 22a penetrating in a direction orthogonal to R is provided. In addition, the outer peripheral surface is surrounded by a part of the outer peripheral surface and is 100
A strip-shaped protruding portion 22c protruding by about a micrometer is provided, and a slight gap is provided between the protruding portion 22c and the inner peripheral wall of the second-stage cylinder 20 so that the second-stage cylinder 20 can slide. A second-stage regenerator 23 is arranged in the second-stage displacer 22 and stores the cold of the working fluid 1. In this container, for example, lead globules are contained as the second-stage regenerator material 24. .

Reference numeral 25 denotes a first stage expansion chamber 12 and a second stage expansion chamber 2 between the second stage cylinder 20 and the second stage displacer 22.
The second-stage regenerator 2 which is arranged so as to divide the first-stage expansion chamber 22 from the first-stage expansion chamber 12 when the working fluid 1 moves between the first-stage expansion chamber 12 and the second-stage expansion chamber 21.
A second stage seal to prevent movement through the outer periphery of the second stage displacer 22 and 26
Is a second freezing stage for transmitting the cold of the second expansion chamber 21 to the outside.

Numeral 30 is a first-stage and second-stage displacer 1.
A driving motor for reciprocating linear movements of 3 and 22 in the direction of the arrow AR, 32 is a Scotch yoke mechanism which is connected to the driving motor 30 and converts its rotational movement into reciprocating linear movement,
Reference numeral 33 is a drive shaft that connects the first-stage displacer 13 and the Scotch yoke mechanism 32 and transmits the driving force of the drive motor 30 to the first-stage displacer 13. ing. Reference numeral 40 is a compressor for compressing the working fluid 1, 41 is a high pressure buffer tank for reducing pressure fluctuations on the high pressure side, 42 is a low pressure buffer tank for reducing pressure fluctuations on the low pressure side, and 43 is a constant differential pressure between the high pressure and the low pressure. It is a differential pressure holding device for holding, and is linked with the operation of the Scotch yoke mechanism 32. Reference numeral 44 is a working fluid compression piping circuit in which the compressor 40, the high pressure buffer tank 41, the low pressure buffer tank 42, the intake valve 2 and the exhaust valve 3 are connected, and the inlet and outlet of the circuit are the first stage cylinder 10
Is connected to the upper gas space chamber 11.

Reference numeral 100 designates a first stage displacer 13 and a second stage displacer 13.
A regular square columnar connecting piece for connecting the step displacer 22 and a cylindrical inner peripheral wall portion 100c forming an upper circular through hole 100a penetrating in a direction orthogonal to the arrow AR.
Also, a cylindrical inner peripheral wall portion 100d forming a lower circular through hole 100b penetrating in a direction orthogonal to the arrow AR is provided. The inner peripheral wall portion 100c and the inner peripheral wall portion 10 described above.
0d are orthogonal to each other with a predetermined axial distance. 1
Reference numeral 01 is a round bar-shaped first connecting pin for connecting the connecting piece 100 and the first-stage displacer 13, and includes the contact portion 101a that contacts the upper inner peripheral wall portion 100c of the connecting piece 100 and the first-stage displacer 13. A contact portion 101b that contacts the peripheral wall portion 13b is provided. 102 is a connecting piece 10
0 and the second stage displacer 22 are round bar-shaped second connecting pins, and the inner peripheral wall portion 1 below the connecting piece 100.
00d and a contact portion 102b that contacts the inner peripheral wall portion 22b of the second stage displacer 22 are provided.

The first connecting pin 101 and the second connecting pin 102 are the inner peripheral wall portion 10 provided on the connecting piece 100.
It is slidably mounted on 0c and 100d. Further, the first connection pin 101 is mounted on the inner peripheral wall portion 13b provided on the first stage displacer 13. The second connecting pin 102 is mounted on the inner peripheral wall portion 22b provided on the second stage displacer 22. The connection piece 100, the first connection pin 101, the second connection pin 102, and the first connection pin 1 provided at one end of the first stage displacer 13
01 inner wall 13b for mounting, second stage displacer 2
The connecting device 104 is configured by the inner peripheral wall portion 22b for mounting the second connecting pin 102 provided at one end of the second connecting pin 102.

The first-stage displacer 13 and the second-stage displacer 22 are connected by a connecting device 104 so as to freely move in three directions orthogonal to each other in the above-mentioned state. The above-mentioned structure is used to reduce the heat penetration area and prevent the reduction of the refrigerating capacity, and it is necessary to reduce the length and cross-sectional area of the connecting device 104 of the two displacers. It is not a good idea to use a universal joint method that increases the length and cross-sectional area of the.

Reference numeral 300 denotes a disk-shaped nut stopper plate attached to the upper end portion of the first-stage displacer 13, and has a through hole 30 of a sufficient size so as not to come into contact with the drive shaft 33 at the center thereof.
A cylindrical inner peripheral wall portion 300b forming 0a is provided. 301 is the drive shaft 33 and the first stage displacer 13
And a mounting nut for connecting and via the nut stopper plate 300, and 302 is a mounting nut formed in the central portion of the upper end of the first stage displacer 13 having two cylindrical stepped holes with different diameters. In the nut accommodating portion that accommodates the nut 301, an inner peripheral wall portion 302b that forms a larger hole portion 302a on the upper end portion side and a bottom portion 302e that contacts the mounting nut 301 are provided, and the smaller hole portion 3
An inner peripheral wall portion 302d forming 02c is provided.
The inner peripheral wall portion 302b has a diameter large enough not to contact the mounting nut 301 and a depth larger than the height of the mounting nut 301, and the inner peripheral wall portion 302d is smaller than the size of the mounting nut 301 and does not contact the drive shaft 33. It has various diameters and depths.

The mounting nut 301 is a nut housing portion 30.
2 is screwed to the threaded portion of the drive shaft 33 that has passed through the through hole 300a of the nut stopper plate 300. Further drive shaft 3
3 is connected to the first-stage displacer 13 with a degree of freedom, the height of the mounting nut 301 is smaller than the depth of the inner peripheral wall portion 302b of the nut accommodating portion 302. It is accommodated in the nut accommodating portion 302 with a slight gap in the direction of arrow AR. Therefore, when the drive shaft 33 reciprocates, the mounting nut 301 alternately contacts the nut stopper plate 300 and the bottom portion 302e of the nut accommodating portion 302 of the first stage displacer 13. The nut stopper plate 300, the mounting nut 301, and the nut accommodating portion 302 are used to connect the connecting device 320.
Is configured. The first stage displacer 13 is connected to the drive shaft 33 by the connecting device 320 so as to be freely movable in the radial direction of the drive shaft 33 in the above-described state.

Next, the operation will be described. When the drive motor 30 is rotated, the rotational motion is converted into a reciprocating linear motion by the Scotch yoke mechanism 32 connected to the motor shaft, and the drive shaft 33 reciprocates in the direction of arrow AR. The first stage displacer 1 attached to the drive shaft 33.
Reference numeral 3 is inside the first-stage cylinder 10 while sliding with the first-stage cylinder 10 at its protrusion 13c, and second-stage displacer 22 is at the second stage while sliding with the second-stage cylinder 20 at its protrusion 22c. Each of the cylinders 20 reciprocates. When the positions of the first-stage and second-stage displacers 13 and 22 reach the lowest points and the volumes of the first-stage and second-stage expansion chambers 12 and 21 become substantially minimum, the intake valve 2 is opened and the compressor is opened. The high-pressure working fluid 1 from 40 through the intake valve 2 passes through the upper gas space 11 and exchanges heat with the first-stage regenerator material 15 inside the first-stage regenerator 14 while being cooled and the first-stage expansion chamber 12 Will be introduced to. Further, a part of the working fluid 1 is introduced into the second-stage expansion chamber 21 while being heat-exchanged with the second-stage regenerator material 24 inside the second-stage regenerator 23 to be cooled.

First and second stage displacers 13,
22 reaches the highest point and the first and second expansion chambers 1
When the intake valves 2 are closed and the exhaust valves 3 are opened when the volumes of 2, 2 are almost maximum, the first stage and the second stage
In the stage expansion chambers 12 and 21, the working fluid 1 expands from a high-pressure state to a low-pressure state, and at the same time, it receives heat.
Inside the 23, heat is exchanged with the first-stage and second-stage regenerator materials 15 and 24 to cool the first-stage and second-stage regenerator materials 15 and 24 to form the first-stage and second-stage regenerator materials 15 and 24. The cold heat is accumulated and returned to the compressor 40 through the upper gas space 11. By repeating this operation, the first-stage and second-stage expansion chambers 12 and 21 are cooled to a cryogenic temperature of 20K.

Therefore, the first-stage and second-stage expansion chambers 12, 21
1st stage freezing stage 17 and 2
When an object to be cooled (not shown) is attached to each of the freezing stages 26, the object to be cooled is deprived of heat energy and cooled.

[0017]

Since the cryogenic refrigerator produces the cryogenic temperature as described above, distortion due to thermal stress occurs in the cylinder and the like. In the cryogenic refrigerator configured as described above, for example, the second stage of the second stage cylinder 20 that has been thermally strained with respect to the axial center of the first stage displacer 13 of the first stage cylinder 10 in the reciprocating direction. When the axis of the reciprocating motion of the displacer 22 is displaced or tilted, the second-stage displacer 22 receives the external force from the inner peripheral wall of the second-stage cylinder 20 and is thermally strained along the axis of the second-stage cylinder 20. Trying to reciprocate. For that purpose, the second stage displacer 22 needs to be able to freely move in the radial direction of the first stage displacer 13.

Therefore, the first-stage and second-stage displacers 13 and 22 are connected to each other by a connecting device 104 so that they can freely move in the radial direction. Even if the axis of the two-stage displacer 22 is not coaxial with the reciprocating direction, the first
Each of the stage and second stage displacers 13, 22 must be able to move smoothly in the axial direction.

First and second stage displacers 13, 2
In order for the two to be able to move freely in the radial direction relative to each other, the connecting piece 100 of this coupling device 104 must have the first and the second connecting pin 10
Sliding part with the inner peripheral wall part 100 of the connecting piece 100
c between the contact portion 101a of the first connection pin 101 and between the inner peripheral wall portion 100d of the connection piece 100 and the contact portion 102a of the second connection pin 102), and the contact pin always slides smoothly along with the circumferential direction of the connection pin. You need to be in a good condition.

However, the inventor has expected that the connecting piece 100 of the connecting device 104, which is expected to have the above-described effects, will slide in the central axis direction of the connecting pin at the sliding portion with the first and second connecting pins 101 and 102. I have found that there are times when there is not.
The sliding portion of the coupling device 104 (the inner peripheral wall portion 100c of the connecting piece 100 and the contact portion 101a of the first connecting pin 101)
If the inner peripheral wall portion 100d of the connecting piece 100 and the contact portion 102a of the second connecting pin 102 do not slide, the first-stage and second-stage displacers 13, 22 cannot freely move in three directions orthogonal to each other. , For example, the first stage displacer 1
If the axial center of the reciprocating motion of 3 and the axial center of the reciprocating motion of the second stage displacer 22 are deviated or inclined, the sliding portion of the coupling device 104 needs to slide. Since the first-stage and second-stage displacers 13 and 22 cannot freely move in three directions orthogonal to each other, the displacer cannot reciprocate along the axial center of the cylinder that has been thermally strained, and friction due to friction with the cylinder The heat increases and the refrigerating capacity decreases. The details will be described below with the connecting piece 100.
And the first connection pin 101 sliding portion (the inner peripheral wall portion 100c of the connection piece 100 and the contact portion 101 of the first connection pin 101
14 will be described as a representative example.

In FIG. 14, X is the first connection pin 10
1 represents the central axis direction, and Y represents the central axis direction of the second connection pin 102. DA is the length of one side of the connecting piece 100 in the shape of a regular square pole, Dp1 is the diameter of the first connecting pin 101, Dp2 is the diameter of the second connecting pin 102, and L is the upper and lower circular shape provided on the connecting piece 100. The axial distance between the first connecting pin 101 and the second connecting pin 102 mounted in the through holes 100a, 100b (between the cylindrical inner peripheral wall portions 100c, 100d forming the upper and lower through holes 100a, 100b). Is also the distance between the axes). F1 is an external force in the X direction that the connecting piece 100 receives via the second connecting pin 102, and F2 is an external force F1 in the X direction that causes the connecting piece 100 to move toward the X of the first connecting pin 101.
Frictional force in the state immediately before sliding in the direction, A is the connecting piece 10
It is the end of the inner peripheral wall portion 100c that intersects one side of 0.

For example, when the connecting piece 100 is pushed by the external force F1 in the X direction via the second connecting pin 102, the connecting piece 1
00 tries to slide in the X direction at the sliding portion with the first connection pin 101. The connection piece 10 is in the state immediately before starting to slide.
Consider the moment at the end A of 0. External force F1 in X direction
When the moment due to is larger than the moment due to the frictional resistance F2, the connecting piece 100 starts to rotate about the end portion A as a center axis and starts to twist at the end portion A, so that the sliding portion with the first connecting pin 101 slides. It becomes impossible and the connecting piece 100
Was found not to slip in the X direction.

That is, when the relationship expressed by the following equation is satisfied, sliding is impossible. F2 × DA / 2 <F1 × (L-Dp1 / 2) Here, if the friction coefficient of the sliding portion between the connecting piece 100 and the first connecting pin 101 is K, then F1 = K × F2, so Substituting DA <2 × K × (L−Dp1 / 2), the larger the friction coefficient K of the sliding portion, the longer the inter-axis distance L, and the length of one side of the connecting piece 100. The smaller the DA, the less slippery.

In the conventional product coupling device 104, for example, the connection piece 100 is made of aluminum alloy and the first and second connection pins 10 are used.
Since a metallic material of stainless steel is used for 1 and 102, the friction coefficient K is large, and as shown in FIG.
The axial distance L between the through holes provided in No. 00 was also long. Due to the above, the inner peripheral wall portion 100c on the upper side of the connection piece 100
It has been found that the end portion A of the first contact pin 101 may be twisted into the contact portion 101a of the first connection pin 101 and may not be brought into a sliding state.

Further, in the cryogenic refrigerator constructed as described above, also in the connecting device 320 between the drive shaft 33 and the first stage displacer 13, the first stage displacer 13 and the second stage displacer 13 are connected.
Similar to the connecting device 104 with the stage displacer 22, the first stage displacer 13 needs to be freely movable in three directions orthogonal to the drive shaft 33. That is, in order to allow the first-stage displacer 13 to freely move in three directions orthogonal to the drive shaft 33, between the mounting nut 301 and the nut stopper plate 300 of the connection device 320 and between the mounting nut 301 and the bottom of the nut accommodating portion 302. It is necessary that the contact portion between 302e is always in a slippery state.

However, the contact portions between the mounting nut 301 and the nut stopper plate 300 of the connection device 320 and between the mounting nut 301 and the bottom portion 302e of the nut accommodating portion 302, which are expected to have the above-described effects, are orthogonal to the arrow AR. It may not slip in the X and Y directions (radial direction). If the contact portions of the connecting device 320 (between the mounting nut 301 and the nut stopper plate 300 and between the mounting nut 301 and the bottom portion 302e of the nut accommodating portion 302) do not slip, the first-stage displacer 13 will move with respect to the drive shaft 33. Since it cannot move freely in three orthogonal directions, if the axis of the drive shaft 33 in the reciprocating direction and the axis of the first stage displacer 13 in the reciprocating direction are deviated or inclined, similar to the coupling device 104. In addition, the first-stage displacer 13 cannot reciprocate along the axial center of the first-stage cylinder 10 that has been subjected to thermal strain, and frictional heat due to friction with the cylinder increases, leading to a reduction in refrigerating capacity. The details will be described below with reference to FIG. There is a slight gap between the mounting nut 301 and the nut stopper plate 300. For example, when the drive shaft 33 moves upward in the arrow AR, the nut stopper plate 300 collides with the nut stopper plate 300 and then slides. If the frictional resistance of is large, the mounting nut 301 and the nut stopper plate 300 cannot slide, and X,
It does not slip in the Y direction. This tendency is particularly strong when the mounting nut 301 is one-sided against the nut stopper plate 300. When the drive shaft 33 moves in the downward direction of the arrow AR, the mounting nut 301 is attached to the bottom portion 302e of the nut accommodating portion 302.
The same applies to the contact portion between the two.

In the conventional connecting device 320, for example, stainless steel is used for the mounting nut 301 and aluminum is used for the nut stopper plate 300, and the friction coefficient K is used for this contact portion.
It has been found that the mounting nut 301 may not slide on the nut stopper plate 300 in the above-described state because of the large value.

When using the cryogenic refrigerator constructed as described above, the cylinder may be installed horizontally due to mounting. When installed vertically, the upper part is the high temperature part of the working fluid and the lower part is the low temperature part of the working fluid, so it is difficult for convection to occur in the working fluid, and there is less reduction in the refrigeration capacity compared to horizontal installation, but it is installed horizontally. In this case, the high temperature part and the low temperature part of the working fluid in the cylinder become horizontal and convection occurs in the working fluid, heat is transferred from the high temperature part to the low temperature part, and the refrigerating capacity decreases. At this time, if the gap between the displacer and the cylinder is large, the working fluid is likely to generate convection, so the gap needs to be small. For this reason, the cryogenic refrigerator in which the cylinder is installed horizontally is designed to have a smaller gap between the displacer and the cylinder than the cryogenic refrigerator in which the cylinder is installed vertically.
High-precision machining is required to prevent the displacer from rubbing against the cylinder at locations other than those required.

A phenol resin reinforced with cotton cloth is generally used for the displacer, and it is difficult to machine with high precision compared to machining metal due to the influence of heat generation. Further, since the phenol resin easily absorbs moisture, the absorbed moisture is released during the operation of the cryogenic refrigerator, causing deformation. When this water condenses and freezes in the low temperature part, the refrigerating capacity is deteriorated due to an increase in frictional force in the sliding part of the gap between the displacer and the cylinder and a leak in the seal part. For this reason, conventional displacers are dehydrated in a vacuum drying furnace, then machined, and require careful attention during storage and assembly.
Manufacturing costs such as machining costs and management costs increase.

Further, polyimide resin and fluorine resin are superior in the friction characteristics and abrasion characteristics to the phenol resin containing cotton cloth, but since the heat shrinkage rate is large and the precision of the shape cannot be maintained when the displacer is manufactured, the conventional method is used. A method has been used in which a displacer made of a material having a small heat shrinkage, such as stainless steel, is coated with a polyimide resin or a fluorine resin.

However, coating is expensive and time consuming. Further, since there is a step of raising the temperature of the base material, the base material is limited to a metal material having high heat resistance. Furthermore, in order to repair the wear of the coating layer due to long-term operation, it is difficult to reuse the displacer because the coating layer must be removed from the surface of the displacer and coated again. Using a new coated displacer is expensive. In addition, there is a problem that the ultra-high molecular weight polyethylene, which has excellent friction and wear characteristics at low temperatures, is easily peeled off even if it is coated.

The present invention has been made in order to solve the above problems, and the reciprocating movement of the displacer is possible even if the connecting device moves smoothly and the axial center of the reciprocating movement direction of each displacer is deviated or inclined. It is an object of the present invention to obtain a cryogenic refrigerator in which frictional heat is not generated during exercise, a decrease in refrigerating capacity can be prevented, and cooling performance is stable. Furthermore,
It is an object of the present invention to obtain a cryogenic refrigerator in which the length of the connecting device is shortened, heat can be prevented from entering, and frictional heat is less generated in the sliding portion. Further, it is an object to obtain an inexpensive cryogenic refrigerator which can be used by applying a coating layer or a sleeve to a conventional material.

Further, even if the connecting device moves smoothly and the axial center of the reciprocating motion between the displacer and the drive shaft is deviated or tilted, frictional heat is less generated in the reciprocating motion of the displacer, and the lowering of the refrigerating capacity is prevented. It is an object of the present invention to obtain a cryogenic refrigerator that is capable of achieving stable refrigeration performance.

Further, the material of the strip-shaped body which is the sliding portion is not limited to the material of the displacer, and the displacer can be easily reused by exchanging the strip-shaped body. The purpose is to obtain a refrigerator. Another object is to obtain a cryogenic refrigerator in which frictional heat is less generated during reciprocating motion of the displacer, since a strip of a polymeric material having lower friction / wear properties than phenolic resin at low temperature can be used. . Furthermore, compared to a phenol resin displacer, there is no moisture released from the displacer, and it is possible to eliminate the increase in frictional force due to icing. Aim to get the opportunity. Further, since the band-shaped body can be processed with high precision and the gap between the displacer and the cylinder can be reduced, it is possible to prevent the convection of the working fluid from occurring, prevent the refrigerating capacity from decreasing, and improve the cooling performance. An object is to obtain a stable cryogenic refrigerator and a manufacturing method thereof.

[0035]

A cryogenic refrigerator according to claim 1 of the present invention is a cryogenic refrigerator having a plurality of cooling devices, a connecting device and a connecting device, wherein the cooling device is a cylinder. And a displacer disposed in the cylinder, and the connecting device has a first joint member, a first shaft member, a second joint member, a second shaft member, and an intermediate member. The first joint member and the intermediate member are provided on the first joint member and the first shaft member by the first shaft member or on the first shaft member and the intermediate member. The axial sliding portion and the first joint member and the first shaft member, or the first circumferential sliding portion provided on the first shaft member and the intermediate member, and The joint member and the intermediate member of FIG. The second joint member by member and the second
The second axial member and the second joint member and the second shaft member provided on the second shaft member and the second shaft member and the second shaft member and the intermediate member. And a second axial sliding portion provided on the first axial sliding portion, the intermediate member moving in the axial direction of the first axial member with respect to the first joint member. As described above, the couple force generated in the first axial sliding portion by the axial force of the first shaft member received by the intermediate member from the second axial member is the friction generated in the first axial sliding portion. The force is less than or equal to the force, and the first circumferential sliding portion is configured to allow the intermediate member to rotate relative to the first joint member in a direction orthogonal to the axis of the first shaft member, The axial sliding portion of the intermediate member receives from the first shaft member such that the intermediate member can move in the axial direction of the second shaft member with respect to the second joint member. The couple force generated in the second axial sliding portion by the axial force of the shaft member is less than or equal to the frictional force generated in the second axial sliding portion. The device is fixed such that each cylinder has its axis substantially co-axial, and each displacer has a first and a second coupling member of the coupling device for reciprocating axial movement of the first and second shaft members. The displacers are connected by being fixed to each displacer so as to intersect the direction, and one of the displacers is connected to the drive shaft through a connecting device so that each displacer reciprocates in each cylinder to transfer the working fluid. It is something to move.

The cryogenic refrigerator according to claim 2 of the present invention is connected to the intermediate member at a minute predetermined interval so that the first shaft member and the second shaft member do not come into contact with each other. Is.

In the cryogenic refrigerator according to the third aspect of the present invention, the first and second axial sliding portions include the first shaft member and the intermediate member, and the second shaft member and the intermediate member. There is one provided in each.

According to a fourth aspect of the present invention, in the cryogenic refrigerator, the first and second shaft members are formed of cylindrical round bar shaft members having the same size and the same material. The round bar member and the through-hole portion are penetrated by the cylindrical through-hole portions respectively provided in the first axial-direction sliding portion and the first circumferential-direction sliding portion and the second axial-direction sliding portion. Part and second circumferential sliding part, and the following conditional expression D1> 2 × K1 × (L− (Dp1) / 2) where D1: length of through hole of intermediate member K1: coefficient of friction between the first shaft member and the through hole of the intermediate member L: distance between the shafts of the first shaft member and the second shaft member Dp1: the diameter of the first shaft member.

In the cryogenic refrigerator according to the fifth aspect of the present invention, the first and second shaft members are made of metal, and the intermediate member is made of a polymer material.

According to a sixth aspect of the present invention, in the cryogenic refrigerator, at least one of the sliding parts of both members sliding in the first and second axial sliding parts has a friction coefficient with respect to metal of phenol. It is made of a polymer material lower than resin.

In the cryogenic refrigerator according to claim 7 of the present invention, the polymer material is a polyimide resin.

In the cryogenic refrigerator according to the eighth aspect of the present invention, the sliding parts of both members are formed of a coating layer of a polymer material.

In the cryogenic refrigerator according to the ninth aspect of the present invention, the sliding parts of both members are formed of a sleeve made of a polymer material.

According to a tenth aspect of the present invention, in the cryogenic refrigerator, the connecting device includes a housing portion provided at an end of the displacer and having an opening, and a metal hooking member provided near the opening. , The first and second abutting sliding parts are respectively made of a polymer material whose friction coefficient with respect to metal is lower than that of phenol resin, and can move in the accommodating part in the reciprocating direction of the displacer and the direction perpendicular thereto. And an enlarged portion in which the first contact sliding portion is hooked so as not to slip out of the housing portion by the hooking member,
The expansion part is fixed to the drive shaft, and the first and second contact sliding parts of the expansion part alternately come into contact with the accommodating part and the hooking part by the reciprocating motion of the drive shaft to reciprocate the displacer. is there.

In the cryogenic refrigerator according to the eleventh aspect of the present invention, the first and second contact sliding portions are made of a polymer material.

A cryogenic refrigerator according to a twelfth aspect of the present invention is a cryogenic refrigerator provided with a cooling device having a cylinder and a displacer, wherein the displacer has a predetermined axial interval on its outer peripheral portion. The displacer is a cylinder having a plurality of recesses that are provided at a predetermined interval to form an annular groove in the circumferential direction, and a band-shaped body that is fitted in the recesses so as to project from the recesses. It is disposed inside and is connected to a drive shaft and reciprocates in the cylinder so that the belt-like body slides on the cylinder to move the working fluid.

In the cryogenic refrigerator according to the thirteenth aspect of the present invention, the band-shaped body is made of a polymer material.

In the cryogenic refrigerator according to the fourteenth aspect of the present invention, the polymer material is ultra-high molecular weight polyethylene.

In the cryogenic refrigerator according to claim 15 of the present invention, the displacer is glass epoxy.

According to a sixteenth aspect of the present invention, in the method for manufacturing a cryogenic refrigerator, a pre-processed strip having a machining allowance on its outer diameter portion is fitted into the recess of the displacer by an interference fit and then processed. It is a manufacturing method for processing a front strip to obtain a strip having a predetermined outer diameter.

[0051]

BEST MODE FOR CARRYING OUT THE INVENTION B. Connection device between displacers, B. Connection devices between drive shaft and displacer, C.I. The displacer is shown in three parts. The relationship between these and the embodiments of the invention is as follows, and will be shown in this order. A. Connection device between displacers: Embodiments 1 to 9 of the invention B. Connection device between drive shaft and displacer: Embodiment 10 of the Invention C. Regarding displacer: Embodiment 1 of the invention
1 to 12

FIG. 1 is a sectional view for explaining the principle of operation of the embodiment of the present invention relating to the connecting device between displacers, and is an explanatory sectional view showing the main part of the connecting device for connecting two displacers. In the figure, 13,
Reference numeral 22 denotes, for example, cylindrical first-stage and second-stage displacers made of phenolic resin similar to the conventional one. As shown in FIG. 1A, the first-stage displacer 13 has a left and right circular through hole 1 that penetrates one end thereof in a direction orthogonal to the arrow AR.
It has left and right cylindrical inner peripheral wall portions 13b forming 3a. As shown in FIG. 1B, the second-stage displacer 22 has left and right cylindrical inner peripheral wall portions 22b that form left and right circular through holes 22a that penetrate in a direction orthogonal to the arrow AR.

Reference numeral 900 denotes a regular square columnar connecting piece made of, for example, an aluminum alloy similar to the conventional one. The connecting piece 900 is shown in FIG.
As shown in (a), while having an upper cylindrical inner peripheral wall portion 900c forming an upper circular through hole 900a penetrating in a direction orthogonal to the arrow AR, as shown in FIG. A lower cylindrical inner peripheral wall portion 9 forming a lower circular through hole 900b penetrating in a direction orthogonal to the arrow AR.
Has 00d. The upper and lower inner peripheral wall portions 900c, 900
d is orthogonal to each other with a predetermined axial distance. 90
Reference numerals 1 and 902 denote, for example, stainless steel rod-shaped first and second connection pins similar to the conventional ones. First connection pin 90
As shown in FIG. 1A, reference numeral 1 denotes a contact portion 901a that contacts the upper inner peripheral wall portion 900c of the connection piece 900 and a left and right contact portion 901b that contacts the left and right inner peripheral wall portions 13b of the first stage displacer 13. Have. As shown in FIG. 1B, the second connection pin 902 contacts the contact portion 902a that contacts the lower inner peripheral wall portion 900d of the connection piece 900 and the left and right inner peripheral wall portions 22b of the second stage displacer 22. It has left and right contact portions 902b.

As shown in FIG. 1A, the first connecting pin 901 has contact portions 901b on the left and right of the first connecting pin 901.
And the left and right inner peripheral wall portions 13b provided on the first-stage displacer 13 are attached to the left and right inner peripheral wall portions 13b of the first-stage displacer 13 by an interference fit, and are connected to the contact portion 901a of the first connecting pin 901. The upper inner peripheral wall portion 900c provided on the piece 900 is slidably attached to the inner peripheral wall portion 900c of the connecting piece 900 by a clearance fit. The second connecting pin 902 is, as shown in FIG.
The left and right contact portions 902b of the second connection pin 902 and the left and right inner peripheral wall portions 22b provided on the second stage displacer 22.
Is attached to the inner peripheral wall portion 22b of the second stage displacer 22 by an interference fit, and the contact portion 902a of the second connecting pin 902 and the lower inner peripheral wall portion 9 provided on the connecting piece 900.
00d is slidably attached to the inner peripheral wall portion 900d of the connecting piece 900.

The above-mentioned connecting piece 900 and the first connecting pin 90
1, second connection pin 902, first stage displacer 13
The connecting device 904 is configured by the inner peripheral wall portion 13b for mounting the first connecting pin 901 provided at one end of the Has been done. The first-stage displacer 13 and the second-stage displacer 22 are connected by a connecting device 904 so as to freely move in the three directions orthogonal to each other in the above-described state. In the figure, the other parts are the same as those in FIG. 13 and FIG. 14, so the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

Therefore, in the embodiment of the present invention, the sliding portion described below is always slidable.

With respect to the structure in which the sliding portion is always slidable, the sliding portion between the connecting piece 900 and the first connecting pin 901 (the inner peripheral wall portion 900c of the connecting piece 900 and the first connecting pin 9)
01 between the contact portions 901a) will be described as a representative example with reference to FIG. In order for the connecting device 904 to move smoothly,
Contact part 900 between connecting piece 900 and first connecting pin 901
c and 901a are configured to be slidable at all times, and for example, the connecting piece 900 is connected to the external force F1 in the X direction via the second connecting pin 902.
It is necessary that the connecting piece 900 always slides when pushed by.
In order to satisfy this condition, if the moment at the end A is considered and the moment due to F2 is made larger than the moment due to F1, the connecting piece 900 and the first connecting pin 9
01 has a relationship that can always slide in the X direction.

The above relationship is expressed by the following equation. F2 × DA / 2> F1 × (L-Dp1 / 2) Here, if the friction coefficient of the sliding portion between the connecting piece 900 and the first connecting pin 901 is K, then F1 = K × F2. When substituting, DA> 2 × K × (L-Dp1 / 2) (1), and if the relationship satisfies the conditional expression (1), the structure is such that it can always slide regardless of the magnitude of the external force F1.

The principle of operation has been described with reference to FIG. 1 using the connection piece 900 and the first connection pin 901 as a typical example.
Between the connecting piece 900 and the second connecting pin 902, the length DA of one side of the connecting piece 900 in the shape of a regular square pole is the same, and X
When the position where the external force F1 acts in the direction is replaced with the second connecting pin 902 from the first connecting pin 901 and the position where the frictional force F2 acts is replaced with the first connecting pin 901 from the second connecting pin 902, the above is considered. Since it is the same as the representative example, the above relationship is expressed by the following equation. DA> 2 × K × (L-Dp2 / 2) (2) If the relationship between the connecting piece 900 and the second connecting pin 902 also satisfies the conditional expression (2), the structure will always be slidable.

The same applies to the case where the first stage displacer 13 and the first connecting pin 901 can be slid, and the first connecting pin 901 is connected to the contact portion 901a of the first connecting pin 901. The inner peripheral wall portion 900c on the upper side of the piece 900 is attached to the inner peripheral wall portion 900c of the connecting piece 900 by an interference fit so that the left and right contact portions 901b of the first connecting pin 901 and the first-stage displacer 13 are attached. The left and right inner peripheral wall portions 13b are first fitted by a clearance fit.
When the connecting piece 900 is pushed by the external force F1 in the X direction via the second connecting pin 902, for example, the first connecting pin is slidably mounted on the inner peripheral wall portion 13b of the step displacer 13. 901 is made to slide. In this case, the length DA of one side of the connecting piece 900 in the shape of a regular square pole of the above-mentioned representative example is used as the diameter DB of the first-stage displacer 13 (see FIG. 1A).
Further, if the moment at the end A is replaced with the moment at the end B, it can be regarded as a configuration similar to the above-mentioned representative example, so the above relationship is expressed by the following equation. DB> 2 × K × (L-Dp1 / 2) (3) The first-stage displacer 13 and the first connecting pin 901 also have a configuration in which they can always slide as long as they satisfy the conditional expression (3). .

The relationship between the second-stage displacer 22 and the second connecting pin 902 is similar to the relationship between the first-stage displacer 13 and the first connecting pin 901. If the diameter DC of the two-stage displacer 22 (see FIG. 1A) is considered, it can be regarded as a configuration similar to the above representative example. Therefore, the above relationship is expressed by the following equation. DC> 2 × K × (L-Dp2 / 2) (4) The second-stage displacer 22 and the second connecting pin 902 also have a configuration that can always slide if the relation satisfying the conditional expression (4) is satisfied. .

From the above, the coupling device 904 has the following four conditional expressions (1) to (4):
It is only necessary to satisfy one of the expressions (3) and one of the expressions (2) and (4). DA, Dp1, and Dp2 are connection devices 90
Since K and L cannot be increased due to the size restriction of 4, the left and right contact between the inner peripheral wall portion 13b of the first-stage displacer 13 and the first connecting pin 901 is set so that DB becomes DB instead of DA. In part 901b, DC instead of DA
The inner peripheral wall portion 22 of the second stage displacer 22
It is practical that both b and the left and right contact portions 902b of the second connection pin 902 are slidable so that the expressions (3) and (4) are both satisfied. As a result, the structure is such that it can always slide, and the movement of the connecting device 904 can be made smooth.

The relationship between the conditional expressions and the three settings (K, L, DA) relating to the above invention and the embodiments and figures of the present invention is shown below. (A) Conditional expressions (1) and (2) are satisfied a-1. Setting K small: Embodiment 1 of the invention (FIG. 2) a-2. Setting both K and L small: Embodiments 2 to 7 of the invention (FIGS. 3 to 8) (b) Those satisfying conditional expressions (3) and (4) K and L are both small, DB instead of DA, Setting to be DC: Embodiments 8 and 9 of the invention (FIGS. 9 and 10)

Although the above description has been made for the Gifford-McMahon refrigerator, other refrigeration cycles,
For example, it can be used also in a Stirling refrigerator, a Bilmeier refrigerator, a Claude refrigerator, and a Solvay refrigerator. Moreover, although what was used for the two-stage type refrigerator was described, it can be used for a three-stage type or more refrigerator.

The cryogenic refrigerator according to the present invention will be described below.
A more specific description will be given with reference to the drawings.

Embodiment 1 of the Invention FIG. 2 is a sectional view showing a main part of a coupling device according to an embodiment of the present invention. In this embodiment, the above conditional expression (1) is used.
And (2) are satisfied. In the figure, reference numeral 105 denotes a regular square prism-shaped connecting piece made of a polyimide resin containing a polymer material, for example, the connecting piece 100 shown in FIG. 14 of Vespel SP21 (trade name),
As shown in the figure, it has upper and lower cylindrical inner peripheral wall portions 105c and 105d forming upper and lower circular through holes 105a and 105b penetrating in a direction orthogonal to the arrow AR. The upper and lower inner peripheral wall portions 105c and 105d are orthogonal to each other with a predetermined axial distance.

First stainless steel rod-shaped rod similar to the conventional one
The connection pin 101 of the first connection pin 101 is fastened to the left and right contact parts 101b of the first connection pin 101 and the left and right cylindrical inner peripheral wall parts 13b provided on the cylindrical first-stage displacer 13 made of phenol resin similar to the conventional one. The connection piece 105 is attached to the inner peripheral wall portion 13b of the first stage displacer 13 by a fit, and the contact portion 101a of the first connecting pin 101 and the upper inner peripheral wall portion 105c provided on the connection piece 105 are connected by a clearance fit. Is slidably mounted on the inner peripheral wall portion 105c of the. The round rod-shaped second connecting pin 102 made of stainless steel has a cylindrical shape that forms a circular through hole 22a provided in the contact portion 102b of the second connecting pin 102 and the cylindrical second-stage displacer 22 made of phenol resin. Inner peripheral wall portion 22b of
(In FIG. 2, it is illustrated as overlapping behind the connection piece 105 in the axial direction (Y) of the through hole 105b on the lower side of the connection piece 105. See the second-stage displacer 22 in FIG. 1B).
Is attached to the inner peripheral wall portion 22b of the second stage displacer 22 by an interference fit, and the contact portion 102a of the second connecting pin 102 and the lower inner peripheral wall portion 105d provided on the connecting piece 105 are clearance fit. Is slidably mounted on the inner peripheral wall portion 105d of the connection piece 105.

The connection piece 105 as the intermediate member, the first connection pin 101 as the first shaft member, the second connection pin 102 as the second shaft member, and the first connection pin member as the first joint member. An inner peripheral wall portion 13b for mounting the first connecting pin 101 provided on one end of the step displacer 13 and a second connecting pin 102 for mounting the second connecting pin 102 provided on one end of the second step displacer 22 as a second joint member. Inner peripheral wall portion 22b
The connection device 108 is configured by the above. The first-stage displacer 13 and the second-stage displacer 22 are connected by the connecting device 108 so as to freely move in the three directions orthogonal to each other in the above state. In the figure, the other parts are the same as those in FIG. 1, FIG. 13, and FIG. 14, so the corresponding parts are designated by the same reference numerals and the description thereof is omitted.

With the above structure, the connection as the first axial sliding portion, the first circumferential sliding portion, the second axial sliding portion and the second circumferential sliding portion is made. Piece 105
And the sliding portion between the first and second connection pins 101 and 102 (the inner peripheral wall portion 105c of the connection piece 105 and the first connection pin 1).
01 between the contact portions 101a and the inner peripheral wall portion 10 of the connecting piece 105.
5d and the contact portion 102a of the second connecting pin 102) have a friction coefficient K of 0.1 between the polyimide resin and stainless steel.
5, which is 1 / 5.5 compared to the value of 0.82 between the conventional aluminum alloy and stainless steel,
As a result, in the sliding portion (between 105c and 101a) between the connection piece 105 and the first connection pin 101, the relation of DA> 2 × K × (L-Dp1 / 2) of the conditional expression (1) is satisfied. Therefore, the structure is such that it can always slide regardless of the magnitude of the external force F1 in the X direction. Also in the sliding portion (between 105d and 102a) between the connecting piece 105 and the second connecting pin 102, DA> 2 × K × (LD
p2 / 2) is satisfied, and the movement of the connecting device 108 can be made smooth.

In this embodiment, the connecting piece 105 is made of a filled polyimide resin having a low friction coefficient and a required strength at an extremely low temperature. However, the connecting piece 105 is not limited to the polyimide resin. It may be made of trifluoride resin or tetrafluoride resin having a low friction coefficient. Also, the first stage and the second
Inner peripheral wall portions 13b, 22b of the step displacers 13, 22
Although the cylindrical shape and the first and second connection pins 101 and 102 used the round bar shape, they may be configured as follows. Inner peripheral wall portions 13b and 22b of the first and second stage displacers 13 and 22 have a square hole shape, and contact portions 101b and 10b of the first and second connection pins 101 and 102.
2b (rotational and sliding portions of the first and second stage displacers 13, 22 with respect to the inner peripheral wall portions 13b, 22b) is a regular square column. A stepped first step in which the contact portions 101a and 102a of the first and second connection pins 101 and 102 (rotational and sliding portions with the cylindrical inner peripheral wall portions 105c and 105d of the connection piece 105) are round bars. And the second connection pins 101, 1
It may be 02.

For example, the first-stage displacer 13 shown in FIG.
The first connection pin 101 will be described as a typical example. First
For example, the inner peripheral wall portion 13b on the right side of the step displacer 13 has a square hole shape. The contact portion 101b on the right side of the first connection pin 101 (rotation and sliding portion with the inner peripheral wall portion 13b on the right side of the first stage displacer 13) is formed into a square hole on the right side of the first stage displacer 13. The shape is a regular square pole that can be mounted on the inner peripheral wall portion 13b. The contact portion 101a of the first connection pin 101 (rotation and sliding portion with respect to the inner peripheral wall portion 105c of the connection piece 105) is formed into the contact portion 1 of the right square column described above.
The shape is a round bar having a diameter slightly smaller than the circle inscribed in 01b. The inner peripheral wall portion 105c of the connection piece 105 is also the contact portion 1 described above.
01a and a cylindrical shape having a clearance fit. Furthermore,
The contact portion 101b on the left side of the first connection pin 101 (rotation and sliding portion with the left inner peripheral wall portion 13b of the first stage displacer 13) is formed into a cylindrical inner peripheral wall portion 105c having the above diameter.
The shape of the square column is slightly smaller than the square inscribed in
The inner peripheral wall portion 13b on the left side of the step displacer 13 is connected to the contact portion 10 in the shape of a regular square pole on the left side of the first connection pin 101.
It has a square hole shape so that 1b can be mounted. This makes the first
In this case, the connecting pin 101 can be penetrated from the right side to the left side, and the first stage displacer 13 and the connecting piece 105 can be connected. Similarly, the second connecting pin 102 can also connect the second stage displacer 22 and the connecting piece 105.

With the above configuration, the inner peripheral wall portion 13 of the first-stage and second-stage displacers 13, 22 is formed.
Since it is not necessary to make an interference fit between b and 22b and the contact portions 101b and 102b of the first and second connection pins 101 and 102, the workability of assembly can be improved.

Embodiment 2 of the Invention FIG. 3 is a cross-sectional view showing the main parts of a coupling device according to another embodiment of the present invention. In this embodiment, the conditional expressions (1) and (2) are satisfied. In the figure, 111 is a polyimide resin containing a polymer material, for example, Vespel SP21 (trade name) in FIG.
4 is a regular square pillar-shaped connecting piece shorter than the length of the connecting piece 100 shown in FIG. 4, and has upper and lower circular through holes 111a and 111b penetrating in a direction orthogonal to the arrow AR as shown in the figure.
Upper and lower cylindrical inner peripheral wall portions 111c and 111d that form the
The axial distance L between the upper and lower through holes 111a and 111b is shortened so that the outer peripheral surface portion of the upper through hole 111a and the outer peripheral surface portion of the lower through hole 111b substantially coincide with each other.
The upper and lower inner peripheral wall portions 111c and 111d are orthogonal to each other with a predetermined axial distance.

Reference numeral 112 denotes a second cylindrical cylindrical second resin displacer 22 similar to that shown in FIG.
A cylindrical inner peripheral wall portion 112b which is a step displacer and which forms a circular through hole 112a shown in the drawing overlapping the back of the connecting piece 111 in the Y direction of the lower through hole 111b of the connecting piece 111. Having, the first connection pin 10
1 has left and right cylindrical inner peripheral wall portions 113a forming left and right circular through holes 113 through which the first connection pin 101 penetrates, with a sufficient size so as not to contact 1.

Round rod-shaped first connection pin 1 made of stainless steel
Reference numeral 01 denotes the left and right contact portions 101b of the first connecting pin 101 and the left and right contact portions provided on the cylindrical first-stage displacer 13 made of phenol resin in a state of penetrating the through-hole 113 provided on the second-stage displacer 112. Due to the interference fit with the cylindrical inner peripheral wall portion 13b, the first stage displacer 1
3 is attached to the inner peripheral wall portion 13b of the first connection pin 101
The contact portion 101a and the upper inner peripheral wall portion 111c provided on the connection piece 111 are slidably attached to the inner peripheral wall portion 111c of the connection piece 111 by a clearance fit. The round rod-shaped second connecting pin 102 made of stainless steel is provided with the contact portion 102b of the second connecting pin 102 and the second stage displacer 11.
2 is attached to the inner peripheral wall portion 112b of the second stage displacer 112 by an interference fit with the inner peripheral wall portion 112b provided on the second connecting pin 102 and the lower portion of the connecting piece 111 provided on the contact portion 102a of the second connecting pin 102. The inner peripheral wall portion 111d is slidably attached to the inner peripheral wall portion 111d of the connection piece 111 by a clearance fit.

The above-mentioned connecting piece 111 and the first connecting pin 10
1, second connection pin 102, first stage displacer 13
Inner peripheral wall portion 13b for mounting the first connecting pin 101 provided at one end of the second connecting pin 102 and inner peripheral wall portion 112b for mounting the second connecting pin 102 provided at one end of the second stage displacer 112
The connection device 114 is configured by the above. The first-stage displacer 13 and the second-stage displacer 112 are connected by a connecting device 114 so as to freely move in the three directions orthogonal to each other in the above state. In the figure, the other parts are the same as those in FIG. 1, FIG. 2, FIG. 13 and FIG.

With the above configuration, the sliding portion between the connection piece 111 and the first and second connection pins 101 and 102 (contact between the inner peripheral wall portion 111c of the connection piece 111 and the first connection pin 101). (Between the portions 101a, between the inner peripheral wall portion 111d of the connection piece 111 and the contact portion 102a of the second connection pin 102)
2 can be made smaller than that between the conventional aluminum alloy and stainless steel as in the embodiment of FIG. 2, and the upper and lower through holes 111a, 11a of the connecting piece 111 can be formed.
Since the inter-axis distance L of 1b can be made shorter than the inter-axis distance of the upper and lower through holes 100a and 100b of the conventional connecting piece 100 shown in FIG. 14, this allows the connecting piece 111 and the first and second connecting pins. In the sliding part with 101 and 102, DA> 2 × K × (L-Dp of conditional expression (1) is further enhanced.
1/2) and DA of the conditional expression (2)> 2 × K × (L-Dp
2/2) is satisfied and the structure is such that it can always slide regardless of the magnitude of the external force F1 in the X direction.
The movement of 4 can be made smooth.

In this embodiment, the connecting piece 111 is made of a filled polyimide resin having a low friction coefficient and a required strength at an extremely low temperature. However, the connecting piece 111 is not limited to the polyimide resin. It may be made of trifluoride resin or tetrafluoride resin having a low friction coefficient. Also, the first stage and the second
Inner peripheral wall portions 13b, 11 of the step displacers 13, 112
2b is cylindrical and the first and second connection pins 101, 10
Although 2 has a round bar shape, it can be configured as follows. Similar to the embodiment of FIG. 2, the first stage and the second stage
Inner peripheral wall portions 13b, 11 of the step displacers 13, 112
2b has a square hole shape, and the first and second connection pins 1
01, 102 contact portions 101b, 102b (first and second stage displacers 13, 112 inner peripheral wall portion 13b,
The rotation and sliding part with 112b) is a regular square pole.
Contact part 101 of first and second connection pins 101, 102
a, 102a (cylindrical inner peripheral wall portion 111 of the connection piece 111)
(Rotating and sliding parts with c and 111d) may be stepped first and second connection pins 101 and 102 in the shape of a round bar.

Third Embodiment of the Invention FIG. 4 shows a main part of a connecting device according to another embodiment of the present invention. FIG. 4 (a) is a sectional view showing the main part of the connecting device. FIG.4 (b) is sectional drawing which shows a side surface. In this embodiment, the conditional expressions (1) and (2) are satisfied. In the figure, reference numeral 115 denotes a regular square columnar connection piece similar to the connection piece 111 shown in FIG. 3, which is made of an aluminum alloy similar to the conventional one, for example, and has upper and lower circular shapes penetrating in a direction orthogonal to the arrow AR as shown in the figure. Through-hole 115a,
Upper and lower cylindrical inner peripheral wall portions 115c forming 115b,
It has 115d. In addition, the upper and lower inner peripheral wall portions 115c, 11
5d are orthogonal to each other with a predetermined axial distance.

Reference numerals 116 and 117 are made of a polyimide resin containing a polymer material, such as Vespel SP21 (trade name), and are formed on upper and lower inner peripheral wall portions 115c of the connecting piece 115.
It is a coating layer coated on 115d and has inner peripheral surfaces 116a and 117a as shown in the figure. Reference numeral 118 is a cylindrical second-stage displacer made of phenolic resin, which is similar to the conventional second-stage displacer 22 shown in FIG. It has a U-shaped peripheral wall portion 119a forming left and right cutout portions 119 through which the pin 101 does not come into contact.

Round rod-shaped first connecting pin 1 made of stainless steel
Reference numeral 01 denotes the left and right contact portions 101b of the first connecting pin 101 and the left and right contact portions 101b of the cylindrical first-stage displacer 13 made of phenol while passing through the notches 119 provided in the second-stage displacer 118. Cylindrical inner peripheral wall 1
3b is an interference fit for the first stage displacer 13
The inner peripheral surface 116a of the coating layer 116 mounted on the inner peripheral wall portion 13b of the first connecting pin 101 and the inner peripheral surface 116a of the coating layer 116 covered by the upper inner peripheral wall portion 115c provided on the connecting piece 115 are clearance fit. Is slidably mounted on the inner peripheral surface 116a of the coating layer 116 of the connection piece 115. Round rod-shaped second connecting pin 10 made of stainless steel
Reference numeral 2 denotes the left and right contact portions 102b of the second connection pin 102 and the inner peripheral wall portion 118 provided on the second stage displacer 118.
b is the second stage displacer 118 due to the interference fit.
Mounted on the inner peripheral wall portion 118b of the second connection pin 102
Of the contact portion 102a and the inner peripheral surface 117a of the coating layer 117 covered by the lower inner peripheral wall portion 115d provided on the connecting piece 115 to the inner peripheral surface 117a of the coating layer 117 of the connecting piece 115 by a clearance fit. It is slidably mounted.

The above-mentioned connecting piece 115 and the first connecting pin 10
1, second connection pin 102, first stage displacer 13
Inner peripheral wall portion 13b for mounting the first connecting pin 101 provided at one end of the second connecting pin 102 and inner peripheral wall portion 118b for mounting the second connecting pin 102 provided at one end of the second stage displacer 118
The coupling device 120 is configured by the above. The first-stage displacer 13 and the second-stage displacer 118 are connected by a connecting device 120 so as to freely move in three directions orthogonal to each other in the above-mentioned state. In addition, in FIG.
3 and FIG. 14 are the same as those shown in FIG.

With the above configuration, the connecting piece 111 shown in FIG. 3 is expensive because the entire connecting piece is made of polyimide resin, but the connecting piece 1 shown in FIG.
15 is formed of a polyimide resin only in the coating layers 116 and 117, and the base material can be made of, for example, an aluminum alloy similar to the conventional one, so that the cost can be lower than that of the connection piece 111.

In this embodiment, the upper and lower inner peripheral wall portions 115c and 115d of the connecting piece 115 are coated with the coating layers 116 and 117, which are made of a filled polyimide resin having a low friction coefficient. The material is not limited to the polyimide resin, and has, for example, a low friction coefficient 3
Fluororesin or tetrafluoride resin may be used. Also, the inner peripheral wall portions 13b of the first and second stage displacers 13, 118,
118b is cylindrical and the first and second connection pins 101,
Although 102 is a round bar, it may be configured as follows. Similar to the embodiment of FIG. 2, the inner peripheral wall portions 13b of the first and second stage displacers 13, 118,
118b has a square hole shape, and the contact portions 101b and 102b of the first and second connecting pins 101 and 102 (the inner peripheral wall portion 13 of the first and second stage displacers 13 and 118).
b and 118b). Contact part 1 of the first and second connection pins 101, 102
01a, 102a (cylindrical inner peripheral wall portion 1 of the connecting piece 115)
It is also possible to use stepped first and second connection pins 101 and 102 in the form of round bars in the rotation and sliding portions with 15c and 115d.

Fourth Embodiment of the Invention FIG. 5 is a sectional view showing a part of a main part of a coupling device according to a fourth embodiment of the present invention. In this embodiment, the conditional expressions (1) and (2) are satisfied. In the figure, reference numeral 125 is a regular square columnar connection piece similar to the connection piece 115 shown in FIG. 4 made of aluminum alloy similar to the conventional one, and as shown in the figure, upper and lower circular shapes penetrating in the direction orthogonal to the arrow AR. And upper and lower cylindrical inner peripheral wall portions 125c and 125d forming the through holes 125a and 125b. The upper and lower inner peripheral wall portions 125c and 125d are orthogonal to each other with a predetermined axial distance. Reference numerals 126 and 127 are sleeves made of a polyimide resin containing a polymer material, for example, Vespel SP (trade name).
The inner peripheral wall portions 125c and 125d of the upper and lower portions 25 are press-fitted so as not to come out and have inner peripheral surfaces 126a and 127a.

Round rod-shaped first connecting pin 1 made of stainless steel
01 is the contact portion 101a of the first connecting pin 101 and the inner peripheral surface 126a of the sleeve 126, which is press-fitted into the upper inner peripheral wall portion 125c provided on the connecting piece 125, by the clearance fit of the sleeve 126 of the connecting piece 125. The round rod-shaped second connecting pin 102 made of stainless steel is slidably mounted on the inner peripheral surface 126a, and the second connecting pin 102 has a contact portion 102a.
And the inner peripheral surface 127a of the sleeve 127 that is press-fitted into the lower inner peripheral wall portion 125d provided on the connecting piece 125, and the inner peripheral surface 1 of the sleeve 127 of the connecting piece 125 by clearance fit.
It is slidably attached to 27a. The configurations of the first-stage displacer 13 and the first connecting pin 101 and the second-stage displacer 118 and the second connecting pin 102 are the same as those in the embodiment shown in FIG.

The above-mentioned connecting piece 125 and the first connecting pin 10
1, second connection pin 102, first stage displacer 13
Inner peripheral wall portion 13b for mounting the first connecting pin 101 provided at one end of the second connecting pin 102 and inner peripheral wall portion 118b for mounting the second connecting pin 102 provided at one end of the second stage displacer 118
The connection device 128 is configured by the above. The first-stage displacer 13 and the second-stage displacer 118 are connected by a connecting device 128 so as to freely move in three directions orthogonal to each other in the above-mentioned state. 1 to 4 and
3 and FIG. 14 are the same as those shown in FIG.

With the above configuration, the connecting piece 111 shown in FIG. 3 is expensive because the entire connecting piece is made of polyimide resin, but the connecting piece 1 shown in FIG.
25, only the sleeves 126 and 127 are made of polyimide resin, and the base material can be made of, for example, the same aluminum alloy as the conventional one, so that the cost can be lower than that of the connection piece 111. Further, the connecting piece 115 shown in FIG. 4 has an inner peripheral wall portion 115c,
115d is coated with the coating layers 116 and 117, but the connecting piece 125 shown in FIG.
Since the sleeves 126 and 127 are press-fitted into the c and 125d, the construction is easier and the workability can be improved as compared with the case where the coating layer is constructed. In this embodiment, the upper and lower inner peripheral wall portions 125 provided on the connection piece 125.
Although the sleeve 126, 127 press-fitted into c, 125d is made of a polyimide resin containing a filler having a low friction coefficient, it is not limited to the polyimide resin, and is made of, for example, a trifluoride resin having a low friction coefficient. It may be made of tetrafluororesin or the like.

Fifth Embodiment of the Invention FIG. 6 is a sectional view showing a main part of a coupling device according to another embodiment of the present invention. In this embodiment, the conditional expressions (1) and (2) are satisfied. In the figure, reference numeral 141 denotes, for example, a connecting piece 111 made of an aluminum alloy similar to the conventional one and having a regular square pole shape similar to the connecting piece 111 shown in FIG. And upper and lower cylindrical inner peripheral wall portions 141c and 141d forming the through holes 141a and 141b.
The upper and lower inner peripheral wall portions 141c and 141d are orthogonal to each other with a predetermined axial distance.

Reference numerals 142 and 143 are made of a polyimide resin containing a polymer material, for example, first and second connection pins 101 of Vespel SP21 (trade name) shown in FIG.
The first and second connection pins 142 are round bar-shaped first and second connection pins similar to the first connection pin 102.
1, a contact portion 142a with the upper cylindrical inner peripheral wall portion 141c and a left and right contact portion 14 with the left and right cylindrical inner peripheral wall portions 13b provided in the first stage displacer 13.
With 2b. The second connection pin 143 has a cylindrical shape that forms a contact portion 143 a with the lower cylindrical inner peripheral wall portion 141 d provided on the connection piece 141 and a circular through hole 112 a provided on the second stage displacer 112. Inner wall part 11
2b (in FIG. 6, it is illustrated as overlapping behind the connecting piece 141 in the Y direction of the through hole 141b below the connecting piece 141) and has a contact portion 143b.

The first connecting pin 142 is left and right of the first connecting pin 142 in a state of penetrating the left and right circular through holes 113 provided in the cylindrical second-stage displacer 112 made of phenol resin similar to the conventional one. Of the contact portion 142b and the left and right inner peripheral wall portions 13b of the cylindrical first-stage displacer 13 made of phenolic resin are attached to the inner peripheral wall portion 13b of the first-stage displacer 13 by an interference fit,
The contact portion 142a of the first connection pin 142 and the connection piece 141
The inner peripheral wall portion 141c on the upper side is slidably attached to the inner peripheral wall portion 141c of the connecting piece 141 by a clearance fit. The second connection pin 143 is connected to the contact portion 143b of the second connection pin 143 and the second stage displacer 112.
The inner peripheral wall portion 112b of the second stage displacer 112 is fitted to the inner peripheral wall portion 112b of the second stage displacer 112 by an interference fit, and the contact portion 143a of the second connecting pin 143 and the lower inner portion of the connecting piece 141 are provided. The inner peripheral wall portion 141d of the connection piece 141 is slidably attached to the peripheral wall portion 141d by a clearance fit.

The above-mentioned connecting piece 141 and the first connecting pin 14
2, second connection pin 143, first stage displacer 13
Inner peripheral wall portion 13b for mounting the first connecting pin 142 provided at one end of the second displacer 112, and inner peripheral wall portion 112b for mounting the second connecting pin 143 provided at one end of the second stage displacer 112.
The coupling device 140 is configured by the above. The first-stage displacer 13 and the second-stage displacer 112 are connected by the connecting device 140 so as to freely move in the three directions orthogonal to each other in the above-described state. It should be noted that, in the drawings, other components are shown in FIGS.
3 and FIG. 14 are the same as those shown in FIG.

With the above configuration, the sliding portion between the first and second connection pins 142 and 143 and the connection piece 141 (contact between the inner peripheral wall portion 141c of the connection piece 141 and the first connection pin 142). Between the portions 142a, between the inner peripheral wall portion 141d of the connection piece 141 and the contact portion 143a of the second connection pin 143)
The friction coefficient K can be made smaller than that between the conventional stainless steel and the aluminum alloy as in the embodiment of FIG. 2, and the axial distance L can be made shorter than the conventional one as in FIG. Therefore, in the sliding portion between the connection piece 141 and the first connection pin 142, DA of conditional expression (1)> 2 × K × (L-Dp1 / 2) and DA of conditional expression (2) are further satisfied. > 2 × K × (L-Dp2 / 2) is satisfied, and the structure is such that it can always slide regardless of the magnitude of the external force F1 in the X direction, and the movement of the coupling device 140 can be made smooth.

In this embodiment, the first and second connection pins 142 and 143 are made of a high molecular weight filler-containing polyimide resin having a low friction coefficient, but are limited to the polyimide resin. Instead, it may be made of, for example, a trifluoride resin or a tetrafluoride resin having a low friction coefficient.
Further, the inner peripheral wall portions 13b and 112b of the first and second stage displacers 13 and 112 are cylindrical and the first and second connecting pins 142 and 143 are round bar-shaped. You can also do it. Similar to the embodiment of FIG. 2, the inner peripheral wall portions 13b and 112b of the first and second stage displacers 13 and 112 have a square hole shape, and the contact portions of the first and second connection pins 142 and 143. 142b, 1
43b (first and second stage displacers 13, 112)
The inner peripheral wall portions 13b and 112b are pivoted and slid with respect to the inner peripheral wall portions 13b and 112b. First and second connection pins 142, 1
The stepped first and second connection pins 1 in which the contact portions 142a and 143a of 43 (rotation and sliding portions with the cylindrical inner peripheral wall portions 141c and 141d of the connection piece 141) are round rods.
42 and 143 may be used.

Sixth Embodiment of the Invention FIG. 7 is a sectional view showing a main part of a coupling device according to a sixth embodiment of the present invention. In this embodiment, the conditional expressions (1) and (2) are satisfied. In the figure, 144 and 145 are the first and second parts shown in FIG.
The first and second connection pins are round rods similar to the connection pins 101 and 102 of FIG. 144a and 145a are, for example, the same stainless steel first and second connection pins 14 as the conventional one.
4,145 base material. 144b and 145b are coating layers made of a polyimide resin containing a polymer material, for example, Vespel SP21 (trade name) and covering the outer peripheral surfaces of the base materials 144a and 145a of the first and second connection pins. . As shown in the figure, the first connection pin 14
Reference numeral 4 denotes a contact portion 144c with the upper cylindrical inner peripheral wall portion 141c provided on the connection piece 141 and a left and right contact portion 144d with the left and right inner peripheral wall portions 13b of the first stage displacer 13.
Have. The second connecting pin 145 contacts the lower cylindrical inner peripheral wall portion 141 d provided on the connecting piece 141 with the contact portion 14.
5c and a cylindrical inner peripheral wall portion 118b forming a circular through hole 118a provided in the second stage displacer 118.
(In FIG. 7, the through-hole 141b on the lower side of the connection piece 141 is shown to overlap behind the connection piece 141 in the Y direction) and has a contact portion 145d.

The first connecting pin 144 and the left and right contact portions 144d of the first connecting pin 144 and the first contact pin 144 are in a state of passing through the notch 119 provided in the second stage displacer 118.
Left and right inner peripheral wall portions 13 provided on the step displacer 13
b is attached to the inner peripheral wall portion 13b of the first-stage displacer 13 by an interference fit, and the contact portion 144c of the first connecting pin 144 and the upper inner peripheral wall portion 141c provided on the connecting piece 141 are clearance fit. Is slidably attached to the inner peripheral wall portion 141c of the connection piece 141. The second connecting pin 145 is attached to the inner peripheral wall portion 118b of the second stage displacer 118 by an interference fit between the contact portion 145d of the second connecting pin 145 and the left and right inner peripheral wall portions 118b provided on the second stage displacer 118. The contact portion 145c of the second connecting pin 145 and the lower inner peripheral wall portion 141d provided on the connecting piece 141 are slidably attached to the inner peripheral wall portion 141d of the connecting piece 141 by a clearance fit. There is.

The above-mentioned connection piece 141 and the first connection pin 14
4, second connection pin 145, first stage displacer 13
The inner peripheral wall portion 13b for mounting the first connecting pin 144 provided at one end of the second connecting pin 145 and the inner peripheral wall portion 118b for mounting the second connecting pin 145 provided at one end of the second stage displacer 118.
The connection device 148 is configured by the above. The first-stage displacer 13 and the second-stage displacer 118 are connected by a connecting device 148 so as to freely move in the three directions orthogonal to each other in the above-mentioned state. It should be noted that, in the drawings, other components are shown in FIGS.
3 and FIG. 14 are the same as those shown in FIG.

With the above-described structure, the first and second connection pins 142 and 143 shown in FIG. 6 are expensive because the entire connection pins are made of polyimide resin. Shown first and second connection pins 144, 1
45 is formed of polyimide resin only in the coating layers 144b and 145b, and the base material can be made of, for example, the same stainless steel as the conventional one, so that the first and second connection pins 142 and 14 can be used.
In addition to being less expensive than 3, the strength can be increased. In this embodiment, the base materials 144a and 145a of the first and second connection pins 144 and 145 are used.
Coating layers 144b, 14 coated on the outer peripheral surface of the
Although a polyimide resin containing a filler having a low coefficient of friction, which is a polymer material, is used for 5b, it is not limited to the polyimide resin and, for example, trifluoride resin or tetrafluoride resin having a low coefficient of friction may be used. .

The first and second stage displacers 1
The inner peripheral wall portions 13b and 118b of 3, 118 have a cylindrical shape and the first and second connection pins 144 and 145 have a round bar shape, but they may be configured as follows. As with the embodiment of FIG. 2, first and second stage displacers 1
The inner peripheral wall portions 13b and 118b of the third and 118 are square holes, and the contact portions 144d and 145d of the first and second connecting pins 144 and 145 (the inner peripheral walls of the first and second stage displacers 13 and 118). (Rotating and sliding parts 13b and 118b) is a regular square column. A stepped first step in which the contact portions 144c and 145c of the first and second connection pins 144 and 145 (rotational and sliding portions with the cylindrical inner peripheral wall portions 141c and 141d of the connection piece 141) are round rods. And the second
The connection pins 144 and 145 of FIG. Further, the coating layers 144b and 145b cover the entire outer peripheral surface portions of the base materials 144a and 145a of the first and second connection pins 144 and 145, but the cylindrical inner peripheral wall portions 141c and 141d of the connection piece 141 are It suffices if the contact portions 144c and 145c, which are the rotating and sliding portions, have a coating layer.

Seventh Embodiment of the Invention FIG. 8 is a sectional view showing a part of a main portion of a coupling device according to a further embodiment of the present invention. In this embodiment, the conditional expressions (1) and (2) are satisfied. In the figure, reference numerals 154 and 155 denote round rod-shaped first and second connection pins similar to the first and second connection pins 144 and 145 shown in FIG. 154a and 155a are, for example, stainless steel first and second connection pins 1 similar to the conventional ones.
54 and 155 are base materials. 154b and 155b are sleeves made of a polyimide resin containing a polymer material, such as Vespel SP21 (trade name).
Are press-fitted into the outer peripheral surface portions of the base materials 154a and 155a of the connecting pin.

The first connecting pin 154 is in contact with the upper cylindrical inner peripheral wall portion 141c of the connecting piece 141 and is in contact with the first connecting pin 154.
54c and contact portions 154d with the left and right cylindrical inner peripheral wall portions 13b of the first-stage displacer 13 shown in FIG. The second connection pin 155 has a cylindrical shape that forms a contact portion 155c with the lower inner peripheral wall portion 141d provided on the connection piece 141 and a circular through hole 118a provided on the second stage displacer 118 shown in FIG. 8 has a contact portion 155d with the inner peripheral wall portion 118b (in FIG. 8, the through hole 141b on the lower side of the connection piece 141 is shown to overlap behind the connection piece 141 in the Y direction).

The first connecting pin 154 is the first connecting pin 1
The contact portion 154c of 54 and the upper inner peripheral wall portion 141c provided on the connecting piece 141 are connected to each other by a clearance fit.
It is slidably attached to the inner peripheral wall portion 141c of No. 1. The second connecting pin 155 is the contact portion 1 of the second connecting pin 155.
55c and the lower inner peripheral wall portion 14 provided on the connection piece 141
1d is the inner peripheral wall portion 1 of the connecting piece 141 by a clearance fit.
It is slidably attached to 41d. The configurations of the first-stage displacer 13 and the first connecting pin 154 and the second-stage displacer 118 and the second connecting pin 155 are the same as those in the embodiment shown in FIG.

The above-mentioned connecting piece 141 and the first connecting pin 15
4, second connection pin 155, first stage displacer 13
Inner peripheral wall portion 13b for mounting the first connecting pin 154 provided on one end of the second connecting pin 155 and inner peripheral wall portion 118b for mounting the second connecting pin 155 provided on one end of the second stage displacer 118.
The connection device 158 is configured by the above. The first-stage displacer 13 and the second-stage displacer 118 are connected by the connecting device 158 so as to freely move in the three directions orthogonal to each other in the above state. 1 to 7 and
3 and FIG. 14 are the same as those shown in FIG.

With the above structure, the first and second connection pins 142 and 143 shown in FIG. 6 are expensive because the entire connection pins are made of polyimide resin. Shown first and second connection pins 154, 1
55 is made of polyimide resin only for the sleeves 154b and 155b, and the base material can be made of stainless steel similar to the conventional one, for example, so that it can be made cheaper than the first and second connection pins 142 and 143, Can also be higher. Further, the first and second connection pins 144 and 145 shown in FIG. 7 have coating layers 144b and 145b on the outer peripheral surface of the base material, but the first and second connection pins 154 shown in FIG. 155 is a base material 154a,
Since the sleeves 154b and 155b are press-fitted onto the outer peripheral surface of 155a, compared with the case where the coating layer is applied,
Construction is easy and workability can be improved.

In this embodiment, the filler having a low friction coefficient, which is a polymer material, is filled in the sleeves 154b and 155b press-fitted into the outer peripheral surfaces of the base materials 154a and 155a of the first and second connection pins 154 and 155. Although the polyimide resin is used, the material is not limited to the polyimide resin, and may be, for example, a trifluoride resin or a tetrafluoride resin having a low friction coefficient.

The first and second stage displacers 1
The inner peripheral wall portions 13b and 118b of 3, 118 have a cylindrical shape and the first and second connection pins 154 and 155 have a round bar shape, but may be configured as follows. As with the embodiment of FIG. 2, first and second stage displacers 1
The inner peripheral wall portions 13b and 118b of the third and 118th holes are square holes, and the contact portions 154d and 155d of the first and second connecting pins 154 and 155 (the inner peripheral wall of the first and second stage displacers 13 and 118). (Rotating and sliding parts 13b and 118b) is a regular square column. A stepped first step in which the contact portions 154c and 155c of the first and second connection pins 154 and 155 (rotational and sliding portions with the cylindrical inner peripheral wall portions 141c and 141d of the connection piece 141) are round bars. And the second
The connection pins 154 and 155 of FIG. Further, the sleeves 154b and 155b are provided with the first and second connection pins 15
The cylindrical inner peripheral wall portion 1 of the connecting piece 141 is press-fitted into the entire outer peripheral surface portions of the base materials 154a and 155a of the nozzles 4 and 155.
Contact part 1 which is a rotating and sliding part with 41c and 141d.
A sleeve may be used for 54c and 155c.

Eighth Embodiment of the Invention FIG. 9 is a sectional view showing a main part of a coupling device according to another embodiment of the present invention. In this embodiment, the conditional expressions (3) and (4) are satisfied. Here, instead of conditional expressions (1) and (2), conditional expression (3)
In order to satisfy (4), the length DA of one side of the connecting piece 141 in the shape of a regular square pole is set to the first and second stage displacers 17.
It is replaced with the diameter DB and DC of 1,172.
171 and 172 are made of phenolic resin similar to the conventional one.
It is a cylindrical second-stage displacer similar to the first-stage displacer 13 and the second-stage displacer 22 shown in FIG. As shown in the figure, the first-stage displacer 171 is a circular through hole 1 having left and right circular holes penetrating in a direction orthogonal to the arrow AR.
71a has left and right cylindrical inner peripheral wall portions 171b.

As shown in the figure, the second stage displacer 172 has a cylindrical inner peripheral wall portion 172b (a lower side of the connecting piece 141 in FIG. 9) forming a circular through hole 172a penetrating perpendicularly to the direction of the arrow AR. Of the through hole 141b in the Y direction, which overlaps behind the connecting piece 141 and is shown by a dotted line).
And left and right notches 11 through which the first connection pin 101 passes
It has a U-shaped peripheral wall portion 119a that forms the number 9. 17
3, 174 are sleeves made of polyimide resin containing a polymer material, for example, Vespel SP21 (trade name), which do not come out to the inner peripheral wall portions 171b and 172b of the first-stage displacer 171 and the second-stage displacer 172. And has inner peripheral surfaces 173a and 174a.

The first connecting pin 101 passes through the notch 119 provided in the second-stage displacer 172, and the contact portion 101a of the first connecting pin 101 and the connecting piece 14 are connected.
1 is attached to the inner peripheral wall portion 141c of the connecting piece 141 by an interference fit with the upper cylindrical inner peripheral wall portion 141c forming the upper circular through hole 141a, and the first connecting pin 101 contacts The portion 101b and the inner peripheral surfaces 173a of the left and right sleeves 173 mounted on the left and right inner peripheral wall portions 171b provided on the first-stage displacer 171 are fitted by a clearance fit to the sleeve 1 of the first-stage displacer 171.
It is slidably attached to the inner peripheral surface 173 a of the 73. The second connecting pin 102 is the contact portion 1 of the second connecting pin 102.
02a and the cylindrical inner peripheral wall portion 141d forming the lower circular through hole 141b provided in the connecting piece 141 are attached to the inner peripheral wall portion 141d of the connecting piece 141 by an interference fit, and the second connecting pin The contact portion 102b of the second stage displacer 172 and the inner peripheral surface 174a of the sleeve 174 mounted on the inner peripheral wall portion 172b of the second stage displacer 172 are fitted by a clearance fit to the sleeve 1 of the second stage displacer 172.
It is slidably attached to the inner peripheral surface 174 a of the 74.

The connecting piece 141 and the first connecting pin 10 described above.
1, second connection pin 102, first stage displacer 17
A sleeve 173 for mounting the first connecting pin 101 provided at one end of the first connecting pin 102, and a sleeve 174 for mounting the second connecting pin 102 provided at one end of the second stage displacer 172.
The connecting device 178 is configured by the above. The first-stage displacer 171 and the second-stage displacer 172 are connected by a connecting device 178 so as to freely move in three directions orthogonal to each other in the above-mentioned state. It should be noted that, in the drawings, other components are shown in FIGS.
3 and FIG. 14 are the same as those shown in FIG.

With the above structure, the length DA of one side of the regular square columnar connection piece 141 can be replaced with the diameter DB of the first stage displacer 171.
Since it is> DA, it has a practically more slippery structure that satisfies the conditional expression (3), so that the structure can always slide regardless of the magnitude of the external force F1 in the X direction. Also, in the sliding portion between the second-stage displacer 172 and the second connecting pin 102 (between the inner peripheral surface 174a of the sleeve 174 and the contact portion 102b of the second connecting pin 102), the coupling device 1 is also used as described above.
The movement of 78 can be made smooth. Furthermore, the first
Stage displacer 171 and second stage displacer 17
The inner peripheral wall portions 171b and 172b of the second sleeve 173,1
Since 74 is press-fitted, the construction is easy and the workability can be improved.

In this embodiment, the sleeve 17 is press-fitted into the inner peripheral wall portions 171b and 172b provided on the first-stage displacer 171 and the second-stage displacer 172, respectively.
Although a polyimide resin made of a polymer material having a low coefficient of friction and containing a filler is used for 3,174, it is not limited to the polyimide resin, and for example, a trifluoride resin or a 4-fluorine resin having a low friction coefficient is used. It may be made of chemical resin.

Also, the first and second stage displacers 17
The inner peripheral wall portions 171b and 172b of the first and second 172 are cylindrical, the inner peripheral wall portions 141c and 141d of the connecting piece 141 are also cylindrical, and the first and second connecting pins 101 and 102 are round bar-shaped. It can also be configured as follows. Similar to the embodiment shown in FIG. 2, the inner peripheral wall portion 141 of the connection piece 141.
c and 141d are square holes, and the contact portions 101a and 102a of the first and second connection pins 101 and 102 (rotational and sliding portions with the inner peripheral wall portions 141c and 141d of the connection piece 141) are square. Columnar. First and second connection pin 1
01, 102 contact portions 101b, 102b (the sleeve 17 of the first and second stage displacers 171, 172)
The rotation and sliding portions of the inner peripheral surfaces 173a and 174a of the outer peripheral surfaces 173a and 174a may be round rod-shaped stepped first and second connection pins 101 and 102. By configuring as described above, the inner peripheral wall portions 141c, 141 of the connecting piece 141 are formed.
d and the contact portion 1 of the first and second connection pins 101 and 102
Since it is not necessary to form an interference fit between 01a and 102a, the workability of assembly can be improved.
Further, although the first-stage displacer 171 and the second-stage displacer 172 are made of the same phenol resin as the conventional one, they may be made of stainless steel, for example.

Ninth Embodiment of the Invention FIG. 10 is a cross-sectional view showing a main part of a coupling device according to another embodiment of the present invention. In this embodiment, the conditional expressions (3) and (4) are satisfied.
Here, instead of conditional expressions (1) and (2), conditional expression (3)
In order to satisfy (4), the length DA of one side of the connecting piece 141 in the shape of a regular square pole is set to the first and second stage displacers 17.
It is replaced with the diameter DB and DC of 1,172.

Reference numerals 191 and 192 denote cylindrical second-stage displacers made of stainless steel similar to the first-stage displacer 13 and the second-stage displacer 22 shown in FIG.
As shown in the figure, the first stage displacer 191 has an arrow A
Left and right circular through holes 191 penetrating in a direction orthogonal to R
It has left and right cylindrical inner peripheral wall portions 191b forming a. As shown in the figure, the second-stage displacer 192 has a circular through hole 192a penetrating in a direction orthogonal to the arrow AR.
Forming a cylindrical inner peripheral wall portion 192b (in FIG. 10, is shown by a dotted line overlapping the back of the connecting piece 141 with respect to the Y direction of the lower through hole 141b of the connecting piece 141) and the first connecting pin. It has a U-shaped peripheral wall portion 119a forming left and right cutout portions 119 through which 101 passes. 193, 19
Reference numeral 4 denotes a coating layer made of a polymer-filled polyimide resin, for example, Vespel SP21 (trade name), which covers the inner peripheral wall portions 191b and 192b of the first-stage displacer 191 and the second-stage displacer 192, It has inner peripheral surfaces 193a and 194a.

The first connecting pin 101 passes through the notch 119 provided in the second stage displacer 192, and the contact portion 101a of the first connecting pin 101 and the connecting piece 14 are connected.
1 is attached to the inner peripheral wall portion 141c of the connecting piece 141 by an interference fit with the upper cylindrical inner peripheral wall portion 141c forming the upper circular through hole 141a, and the first connecting pin 101 contacts The portion 101b and the inner peripheral surfaces 193a of the left and right coating layers 193 covered by the left and right inner peripheral wall portions 191b provided on the first-stage displacer 191 and the inner periphery of the coating layer 193 of the first-stage displacer 191 by a clearance fit. It is slidably mounted on the surface 193a. The second connection pin 102 is the second connection pin 10
The second contact portion 102a and the lower cylindrical inner peripheral wall portion 141d forming the lower circular through hole 141b provided in the connecting piece 141 are attached to the inner peripheral wall portion 141d of the connecting piece 141 by an interference fit. The contact portion 102b of the second connection pin 102 and the inner peripheral wall portion 1 of the second stage displacer 192 are removed.
Inner peripheral surface 19 of coating layer 194 coated on 92b
4a is a second stage displacer 19 by a clearance fit.
It is slidably attached to the inner peripheral surface 194a of the second coating layer 194.

The connecting piece 141 and the first connecting pin 10 described above.
1, second connection pin 102, first stage displacer 19
Coating layer 193 covering the inner peripheral wall portion 191b for mounting the first connecting pin 101 provided at one end of the first connecting pin 102, and the inner peripheral wall for mounting the second connecting pin 102 provided at one end of the second stage displacer 192 The coupling device 198 is configured by the coating layer 194 coated on the portion 192b. The first-stage displacer 191 and the second-stage displacer 192 are connected by a connecting device 198 so as to freely move in three directions orthogonal to each other in the above-mentioned state. In the figure, the other parts are the same as those in FIGS. 1 to 9 and FIGS. 13 and 14, so the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

With the above-mentioned structure, the length DA of one side of the connecting piece 141 in the shape of a regular square pole can be replaced with the diameter DB of the first-stage displacer 191.
Since it is> DA, it has a practically more slippery structure that satisfies the conditional expression (3), so that the structure can always slide regardless of the magnitude of the external force F1 in the X direction. Further, the sliding portion between the second-stage displacer 192 and the second connecting pin 102 (the inner peripheral surface 194a of the coating layer 194 and the second connecting pin 1)
Even between the contact portions 102b of No. 02), the movement of the connecting device 198 can be made smooth similarly to the above.

In this embodiment, the coating layers 193 and 194, which cover the inner peripheral wall portions 191b and 192b of the first-stage displacer 191 and the second-stage displacer 192, have a low friction coefficient, which is a polymer material. Although the polyimide resin containing the filler is used, it is not limited to the polyimide resin, and may be, for example, a trifluoride resin or a tetrafluoride resin having a low friction coefficient.

Also, the first and second stage displacers 19
The inner peripheral wall portions 191b and 192b of the first and the second connection members 192b are cylindrical, the inner peripheral wall portions 141c and 141d of the connecting piece 141 are also cylindrical, and the first and second connecting pins 101 and 102 are round rod-shaped. It can also be configured as follows. Similar to the embodiment shown in FIG. 2, the inner peripheral wall portion 141 of the connection piece 141.
c and 141d are square holes, and the contact portions 101a and 102a of the first and second connection pins 101 and 102 (rotational and sliding portions with the inner peripheral wall portions 141c and 141d of the connection piece 141) are square. Columnar. First and second connection pin 1
01, 102 contact portions 101b, 102b (rotating and sliding portions with the inner peripheral surfaces 193a, 194a of the coating layers 193, 194 of the first and second stage displacers 191, 192) are round bar-shaped The first and second connection pins 101 and 102 may be used. By configuring as described above, the inner peripheral wall portion 141c of the connection piece 141,
Since it is not necessary to form an interference fit between 141d and the contact portions 101a and 102a of the first and second connection pins 101 and 102, the workability of assembly can be improved.

Tenth Embodiment of the Invention FIG. 11 is a sectional view showing a main part of a connection device according to a further embodiment of the present invention. In the figure, the disk-shaped nut stopper plate 300 has a circular through hole 3 at the center thereof.
00a is provided. The through hole 300a is the drive shaft 33.
It is large enough not to come in contact with. The nut stopper plate 300 is attached to the upper end portion of the first stage displacer 13, one end of the drive shaft 33 penetrates the through hole 300a, and the mounting nut 301 is screwed into the nut housing portion 302. Numeral 303 indicates a polyetheretherketone (Polyetheret) containing a filler which is a polymer material.
Herktone) (hereinafter referred to as peak resin) is a disc-shaped sliding plate made of resin, and has a through hole 303a in the center thereof.
Has a cylindrical inner peripheral wall portion 303b that forms the. The sliding plate 303 has a predetermined thickness, and has a sufficiently small diameter so as not to come into contact with the inner peripheral wall portion 302b of the larger hole portion 302a of the nut housing portion 302. The through hole 303a is circular and has a size large enough not to contact the drive shaft 33.

The upper and lower sliding plates 303 are larger between the mounting nut 301 and the nut stopper plate 300 and between the mounting nut 301 and the nut accommodating portion 302 with the drive shaft 33 penetrating the through holes 303a of the upper and lower sliding plates 303. It is inserted between the bottom portions 302e of the hole portions 302a so as to be freely movable in the radial direction. The axial height, which is the sum of the thickness of the mounting nut 301 and the thickness of the upper and lower sliding plates 303, is the same as that of the conventional one.
It is slightly smaller than the depth of 2a. The upper slide plate 303 is slidable with respect to the nut stopper plate 300.
The mounting nut 301 is also slidable. When the drive shaft 33 moves above the arrow AR, the upper sliding plate 303 collides with the nut stopper plate 300 because of a slight gap. However, since the friction coefficient of the contact surface is reduced by the sliding plate 303, the upper sliding plate 303 can slide on the nut stopper plate 300. The mounting nut 301 is also slidable. or,
This is also the case when the drive shaft 33 moves downward, and due to the existence of a slight gap, the mounting nut 301 causes the lower sliding plate 303 to move.
Even when it collides with the sliding plate 303, the friction coefficient of the contact surface is reduced, so that the lower sliding plate 303 slidably contacts the mounting nut 301 and the nut receiving portion 302.
Is also slidable with the bottom portion 302e of the larger hole portion 302a.

The nut accommodating portion 302 has two cylindrical stepped holes with different diameters provided at the center of the upper end of the first-stage displacer 13 and forms the larger hole 302a on the upper end side. The inner peripheral wall 302b and the inner peripheral wall 302d forming the smaller hole 302c are provided to form a housing for housing the mounting nut 301. The mounting nut 301, the upper sliding plate 303 shown in FIG. 11 as the first contact sliding part, and the lower sliding plate 303 shown in FIG. The enlarged part is configured. Further, the enlarged portion, the nut stopper plate 300 as a latch member, the nut accommodating portion 302
The connection device 330 is configured by. The first stage displacer 13 is connected to the drive shaft 33 by the connecting device 330 so as to freely move in three directions orthogonal to the drive shaft 33 in the above-described state. In the figure, the other parts are the same as those in FIG. 13, FIG. 14, and FIG. 15, so the corresponding parts are designated by the same reference numerals and the description thereof is omitted.

With the above construction, the value of the friction coefficient K of the contact portion between the mounting nut 301 and the nut stopper plate 300 is 0.1 to 0.
2. Between the peak resin and stainless steel is 0.1 to 0.2, which is about 1/8 to 1/4 and 1/8 to 1/4, respectively, compared to the value 0.82 between stainless steel and aluminum of conventional products. The value of the friction coefficient K of the contact portion between the mounting nut 301 and the bottom portion 302e of the nut housing portion 302 is 0.1 to 0.2 between the peak resin and the phenol resin, and 0 between the peak resin and the stainless steel. 0.1 to 0.2, which is 1 / each compared to the value of 0.5 between stainless steel and phenol resin of conventional products.
Since it can be set to 5 to 1 / 2.5 or 1/5 to 1 / 2.5, the movement of the mounting nut portion is always smooth, and the movement of the connecting device can be smooth. In this embodiment, the sliding plate 303 is made of a peak resin containing a filler having a low coefficient of friction and good creep characteristics. Resin or tetrafluoride resin may be used. Further, the mounting plate is not limited to the sliding plate 303, and the mounting nut 301 may be covered on both sides with a sliding layer made of a polymer material having a low coefficient of friction. Further, the entire mounting nut 301 may be made of a polymer material having a low friction coefficient.

Although the above description has been made for the Gifford-McMahon refrigerator, other refrigerating cycles such as a Stirling refrigerator and a Bilmeier refrigerator,
It can also be used for Claude refrigerators and Solvay refrigerators. Also, although the one used for the two-stage refrigerator has been described, it can be used for a single-stage refrigerator or a three-stage refrigerator or more.

Eleventh Embodiment of the Invention FIG. 12 is a sectional view showing a main part of a displaceable-part separation-type displacer according to a further embodiment of the present invention. In the figure, reference numeral 400 is a cylindrical displacer made of a polymer material such as glass epoxy. As shown in the figure, the displacer 400 has a recess 400b that forms upper and lower annular grooves 400a surrounding the outer peripheral surface portion in the circumferential direction. 41
Reference numeral 0 denotes a ring-shaped strip made of ultra-high molecular weight polyethylene which is a polymer material and has a rectangular cross section. As shown in the figure, the band-shaped body 410 has an outer peripheral surface 410a which is a contact portion of a sliding portion with the inner peripheral wall portion of the cylinder, and the displacer 40
It has an inner peripheral surface 410b which is a contact portion with a concave portion 400b forming a zero annular groove 400a.

As shown in FIG. 12, the band-shaped body 410 is heated and fitted with almost no axial gap between the inner peripheral surface 410b of the band-shaped body 410 and the recess 400b forming the annular groove 400a of the displacer 400. The displacer 400 is firmly mounted in the recesses 400b forming the upper and lower annular grooves 400a by an interference fit due to residual stress during cooling after cooling. The displacer 400 and the strip-shaped body 410 form a displacer-type displacer 420. The protruding-separation-type displacer 420 is mounted in the cylinder so that the inner peripheral wall of the cylinder and the outer peripheral surface 410a of the band-like body 410 can reciprocate in the cylinder. In the figure, the other parts are the same as those in FIGS. 1 to 11, 13, 14, and 15, and therefore, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

With the above-described structure, the strip-shaped body 410 has the inner peripheral surface 410b of the strip-shaped body 410 and the recessed portion 400b forming the annular groove 400a of the displacer 400 by interference fit due to residual stress and thus the displacer 40.
Since it is firmly mounted in the recesses 400b forming the upper and lower annular grooves 400a of 0, it can be fixed without the need for any special bonding means, and it does not shift in the axial direction. In the subsequent maintenance, the displacer 40 can be replaced by replacing the strip 410.
It is possible to reuse 0, make it cheap, and save resources. Further, since the band-shaped body 410 is firmly fixed, the band-shaped body 410 can be machined with high accuracy, and thus the thin-wall processing of the band-shaped body 410 can be easily performed, and the cylinder-shaped body and the band-shaped body 4 which is the protruding portion can be processed.
The gap between 10 can be made small. For example, thickness 2
With a 00 micrometer strip 410, 7
The amount of shrinkage when cooled to 0K is about 8 micrometers, and the gap (5
The influence on the working fluid is small and it is possible to prevent convection of the working fluid. Further, the wear characteristics of the contact portion between the cylinder and the outer peripheral surface 410a of the strip 410 made of ultra-high molecular weight polyethylene, which is the protrusion of the protrusion-separated displacer 420, are the same as those of the cylinder and the conventional cotton cloth-filled phenol resin. Compared with the wear characteristics of the contact portion between the displacer protrusions, it can be 1/150, and the friction coefficient K can also be about 1/5 to 1 / 2.5, so that the protrusion The movement of the part separation type displacer 420 becomes smooth, and for example, the displacers 13, 22 made of phenolic resin containing cotton cloth similar to the conventional ones are used.
It is possible to improve the friction and wear characteristics of the contact portion of the sliding portion as compared with.

Since the displacer 400 of the protruding-separation-type displacer 420 is made of glass epoxy and does not absorb moisture, there is no moisture released from the displacer 400 and the increase in frictional force at the sliding portion due to freezing is eliminated. You can Since the glass epoxy constituting the displacer 400 is a polymer material, the displacer 400 other than the uncoated strip 410 is formed.
Even if the outer peripheral surface of the slab directly contacts the cylinder, it is possible to reduce the generation of friction heat due to rubbing. Therefore, the displacer-type displacer 420 can move smoothly, and the friction and wear characteristics of the contact portion of the sliding portion can be improved as compared with the conventional displacers 13 and 22 made of phenol resin containing cotton cloth. Further, it is possible to eliminate the leak at the seal portion.

In this embodiment, the belt 410 is made of ultra-high molecular weight polyethylene which is excellent in friction and wear characteristics at low temperature. However, it is not limited to ultra-high molecular weight polyethylene. It may be a filler-containing trifluoride resin, tetrafluoride resin, or the like. Further, the shape of the bottom surface of the recess 400b forming the annular groove 400a provided on the outer peripheral surface of the displacer 400 is not limited to the concentric circular cylindrical surface with the outer peripheral surface, and for example, an uneven shape or A knurled shape or a shape in which a flat surface portion is provided on a cylindrical surface may be used.

Although the above description has been made for the Gifford-McMahon refrigerator, other refrigerating cycles such as a Stirling refrigerator and a Bilmeier refrigerator,
It can also be used for Claude refrigerators and Solvay refrigerators. Also, although the one used for the two-stage refrigerator has been described, it can be used for a single-stage refrigerator or a three-stage refrigerator or more.

Twelfth Embodiment of the Invention An example of a method of manufacturing a protrusion-separated displacer 420 according to another embodiment of the present invention will be described with reference to FIG. First, the recess 400a that forms the upper and lower annular grooves provided on the outer peripheral surface of the displacer 400 is machined. Since the polymeric material used for the band-shaped body 410 is soft and has low processing accuracy when it is thin, a thick-walled band-shaped body 410 with a machining margin left is made. The inner diameter is made smaller than the outer diameter of the recess 400a forming the annular groove of the displacer 400. This is expanded with hot water or the like, and after the inner diameter becomes larger than the diameter of the displacer 400, it is inserted into the recess 400a forming the annular groove provided on the outer peripheral surface of the displacer 400. When the entire band-shaped body 410 becomes almost uniformly at room temperature, the band-shaped body 410 is firmly attached to the recess 400a forming the annular groove of the displacer 400 by an interference fit due to a predetermined residual stress. Next, the thick band-shaped body 410, which is firmly mounted in the recess 400a forming the annular groove of the displacer 400, is attached to a machining apparatus, and the outer diameter DD of the band-shaped body 410 is machined to a predetermined size.

By the manufacturing method described above, the strip 410 has an inner peripheral surface 410b of the strip 410 and the recess 400b forming the annular groove 400a of the displacer 400 by interference fit due to residual stress. Since it is firmly attached to the concave portion 400b that forms the groove, it can be fixed without the need for any special bonding means and is not displaced in the axial direction. Four
By replacing 10, the displacer 400 can be reused and can be made inexpensive, which is also useful for resource saving.
Further, since the band-shaped body 410 is firmly fixed, it can be machined with high accuracy, so that the band-shaped body 410 can be easily thin-walled, and the gap between the cylinder and the band-shaped body 410 serving as the protruding portion can be reduced. it can. For example, if the band 410 having a thickness of 200 μm is used, the amount of shrinkage when cooled to 70 K is about 8 μm and the influence on the gap (50 μm) between the cylinder and the band 410 as the protrusion. It is possible to prevent the occurrence of working fluid convection. In addition, the wear characteristics of the contact portion between the cylinder and the outer peripheral surface 410a of the strip 410 made of ultra-high molecular weight polyethylene, which is the protrusion of the protrusion-separated displacer 420, are the same as those of the cylinder and the conventional cotton cloth-filled phenol resin. Compared with the wear characteristics of the contact portion between the displacer protrusions, it can be 1/150, and the friction coefficient K can also be about 1/5 to 1 / 2.5. The movement of the part-separated displacer 420 becomes smooth, and the friction and wear characteristics of the contact part of the sliding part can be improved as compared with, for example, the displacers 13 and 22 made of phenolic resin containing cotton cloth as in the conventional case.

Further, since the displacer 400 of the protruding-separation-type displacer 420 is made of glass epoxy and does not absorb moisture, there is no moisture released from the displacer 400 and an increase in frictional force at the sliding portion due to freezing is eliminated. You can Since the glass epoxy constituting the displacer 400 is a polymer material, the displacer 400 other than the uncoated strip 410 is formed.
Even if the outer peripheral surface of the slab directly contacts the cylinder, it is possible to reduce the generation of friction heat due to rubbing. Therefore, the displacer-type displacer 420 can move smoothly, and the friction and wear characteristics of the contact portion of the sliding portion can be improved as compared with the conventional displacers 13 and 22 made of phenol resin containing cotton cloth. Further, it is possible to eliminate the leak at the seal portion.

In this embodiment, the belt 410 is made of ultra-high molecular weight polyethylene excellent in friction and wear characteristics at low temperature. However, it is not limited to ultra-high molecular weight polyethylene, and for example, a low friction coefficient is used. It may be a filler-containing trifluoride resin, tetrafluoride resin, or the like. Further, the shape of the bottom surface of the recess 400b forming the annular groove 400a provided on the outer peripheral surface of the displacer 400 is not limited to the concentric circular cylindrical surface with the outer peripheral surface, and for example, an uneven shape or A knurled shape or a shape in which a flat surface portion is provided on a cylindrical surface may be used. Further, although the band-shaped body 410 is machined by cutting, it may be polished.

[0136]

As described above, according to the cryogenic refrigerator described in claim 1 of the present invention, it is a cryogenic refrigerator having a plurality of cooling devices, a connecting device, and a connecting device. Includes a cylinder and a displacer disposed in the cylinder, and the connecting device includes a first joint member, a first shaft member, a second joint member, a second shaft member, and an intermediate member. And the first joint member and the intermediate member are provided on the first joint member and the first shaft member by the first shaft member or on the first shaft member and the intermediate member. A first axial sliding portion and a first joint member and a first shaft member, or a first circumferential sliding portion provided on the first shaft member and the intermediate member. , The second joint member and the intermediate member are arranged to intersect with the first shaft member at a predetermined interval. A second axial slide provided on the second joint member and the second shaft member by the second shaft member or on the second shaft member and the intermediate member, and the second joint member and the second joint member. The first axial sliding portion is connected to the shaft member or the second shaft member and the intermediate member via a second circumferential sliding portion, and the intermediate member is the first joint member. On the other hand, the second intermediate member is provided so as to move in the axial direction of the first axial member.
The couple force generated in the first axial sliding portion by the axial force of the first shaft member received from the shaft member is less than or equal to the frictional force generated in the first axial sliding portion, The first circumferential sliding portion is configured such that the intermediate member can rotate relative to the first joint member in a direction orthogonal to the axis of the first shaft member, and
The axial sliding portion of the second shaft member is received by the intermediate member from the first shaft member so that the intermediate member can move in the axial direction of the second shaft member with respect to the second joint member. Is set so that the couple force generated in the second axial sliding portion by the force of is less than or equal to the frictional force generated in the second axial sliding portion. The axes are fixed such that they are substantially co-axial, and each displacer is such that the first and second joint members of the coupling device have the axial directions of the first and second shaft members intersecting the direction of reciprocating movement. Since each of the displacers is connected to the drive shaft through the connecting device so that each displacer reciprocates in each cylinder to move the working fluid. , The connecting device moves smoothly Because also it is or inclined displacement reciprocating direction of the axis of the placer generation of frictional heat in the reciprocating motion of the displacer decreases, prevents a reduction in refrigeration capacity, and cooling performance is stabilized.

According to the cryogenic refrigerator described in claim 2 of the present invention, the cryogenic refrigerator is connected to the intermediate member with a minute predetermined interval so that the first shaft member and the second shaft member do not come into contact with each other. Since the coupling force generated in the first axial direction sliding portion and the second axial direction sliding portion is reduced, the intermediate member receives the first axial member and the second axial member from the first axial member. In addition to the smooth movement of the coupling device regardless of the magnitude of the axial force of the shaft member and the second shaft member, the length of the coupling device can be shortened to reduce the intrusion of heat. Can be prevented, and the cooling performance is stable.

According to the cryogenic refrigerator of the third aspect of the present invention, the first and second axial sliding portions are provided on the first shaft member and the intermediate member and between the second shaft member and the intermediate member. Since it is provided on each of the members, even if the coupling device moves smoothly and the axis of the reciprocating motion of each displacer is deviated or tilted, frictional heat is less generated in the reciprocating motion of the displacer. It is possible to prevent the deterioration of the refrigeration capacity,
In addition, the cooling performance is stable.

According to the cryogenic refrigerator of claim 4 of the present invention, the first and second shaft members are formed of cylindrical round bar shaft members of the same material and having the same size. The round bar member and the through-hole are penetrated by the cylindrical through-holes respectively provided in the intermediate member, and the round bar member and the through-hole are respectively the first axial sliding portion and the first circumferential sliding portion and the second axial direction. It is a sliding portion and a second circumferential sliding portion, and the following conditional expression D1> 2 × K1 × (L− (Dp1) / 2) is used, where D1: is the through-hole portion of the intermediate member. Length K1: Friction coefficient between the first shaft member and the through hole of the intermediate member L: Distance between the shafts of the first shaft member and the second shaft member Dp1: The diameter of the first shaft member is satisfied. As a result, the displacer reciprocates even if the connecting device moves smoothly and the axis of the displacer reciprocating direction is misaligned or tilted. Since generation of definitive frictional heat is reduced, it is possible to prevent a drop in refrigeration capacity, and cooling performance is stabilized.

According to the cryogenic refrigerator of claim 5 of the present invention, the first and second shaft members are made of metal, and the intermediate member is made of a polymeric material. Even if the device moves smoothly and the axis of the reciprocating motion of each displacer is deviated or tilted, frictional heat is less generated during the reciprocating motion of the displacer, so it is possible to prevent the refrigeration capacity from decreasing and to stabilize the cooling performance. To do.

According to the cryogenic refrigerator of claim 6 of the present invention, at least one of the sliding parts of both members sliding in the first and second axial sliding parts has a coefficient of friction with respect to metal. Since it is made of a polymer material lower than that of the phenol resin, frictional heat is less likely to be generated in the sliding portion, so that the refrigerating capacity can be prevented from lowering and the cooling performance can be stabilized.

In the cryogenic refrigerator according to claim 7 of the present invention, since the polymer material is the polyimide resin, frictional heat is less generated in the sliding portion, so that the refrigerating capacity is lowered. Can be prevented and the cooling performance is stable.

According to the cryogenic refrigerator described in claim 8 of the present invention, the sliding portions of both members are formed of the coating layer of the polymeric material. It can be applied and used at a low cost.

According to the cryogenic refrigerator described in claim 9 of the present invention, since the sliding portions of both members are formed by the sleeve of the polymeric material, the conventional material is sleeved. Since it can be used, it can be made inexpensive.

According to the cryogenic refrigerator of the tenth aspect of the present invention, the connecting device is provided with a connecting device which is provided at an end of the displacer and has an opening and a metal hook provided near the opening. The member and the first and second abutting and sliding portions respectively formed of a polymer material having a friction coefficient with respect to metal lower than that of phenol resin are provided in the accommodating portion in the reciprocating direction of the displacer and the direction perpendicular thereto. An enlarged portion that is movably accommodated and has a first contact sliding portion that is retained by a retaining member so as not to slip out of the accommodation portion, and the enlarged portion is fixed to the drive shaft. By the reciprocating motion of the drive shaft, the first and second contact sliding parts of the enlarged part alternately contact the accommodating part and the latching part to reciprocate the displacer, so that the connecting device moves smoothly. To and from the drive shaft Since the generation of frictional heat in the reciprocating motion of the displacer also be or inclined shift movement direction of the axis is reduced, it is possible to prevent a drop in refrigeration capacity, and cooling performance is stabilized.

According to the eleventh aspect of the cryogenic refrigerator of the present invention, since the first and second contact sliding portions are made of the polymer material, the connecting device moves smoothly. Even if the axis of the reciprocating motion between the displacer and the drive shaft is deviated or tilted, frictional heat is less generated in the reciprocating motion of the displacer, so that the refrigerating capacity can be prevented from lowering and the cooling performance can be stabilized.

According to the twelfth aspect of the present invention, there is provided a cryogenic refrigerator provided with a cooling device having a cylinder and a displacer, wherein the displacer has a predetermined axial direction on its outer peripheral portion. The displacer includes a plurality of recesses that are provided at intervals to form an annular groove in the circumferential direction, and a strip-shaped body that projects from the recesses and is fitted into each of the recesses in an interference fit state. Is arranged in the cylinder, connected to the drive shaft, and reciprocates in the cylinder so that the belt-like body slides on the cylinder to move the working fluid. The material can be freely selected without being limited to the material of the above, and it is possible to reduce the cost. In addition, the belt can be removed and the belt can be replaced when the sliding part is worn. The difference may be less expensive because you can easily re-use.

According to the thirteenth aspect of the cryogenic refrigerator of the present invention, since the band-shaped body is made of the polymer material, the polymer having friction and wear characteristics at a low temperature lower than that of the phenol resin. The use of the strip of material reduces the generation of frictional heat during the reciprocating motion of the displacer, so that the refrigerating capacity can be prevented from lowering and the cooling performance can be stabilized.

In the cryogenic refrigerator according to the fourteenth aspect of the present invention, since the polymer material is ultra-high molecular weight polyethylene, the generation of frictional heat during the reciprocating motion of the displacer is reduced, so that the refrigerator is frozen. It is possible to prevent the decrease in capacity and stabilize the cooling performance.

In the cryogenic refrigerator according to the fifteenth aspect of the present invention, since the displacer is made of glass epoxy, the displacer does not release water as compared with the displacer of phenol resin, and the frictional force due to freezing increases. In addition, it is possible to eliminate the occurrence of friction heat even when the outer peripheral surface of the displacer directly contacts the cylinder.

According to the method of manufacturing a cryogenic refrigerator according to claim 16 of the present invention, after the unprocessed belt-shaped body having the machining allowance provided on the outer diameter portion is fitted into the recess of the displacer by an interference fit. Since the manufacturing method of processing the band-shaped body before processing into a band-shaped body having a predetermined outer diameter dimension, it is possible to process the band-shaped body with high accuracy and reduce the gap between the displacer and the cylinder. Since it is possible to prevent convection of the working fluid, it is possible to prevent deterioration of the refrigerating capacity and stabilize the cooling performance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view for explaining the principle of operation in an embodiment of the present invention, showing an essential part of a connecting device that connects two displacers.

FIG. 2 is a cross-sectional view showing a main part of a connecting device that is an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a main part of a coupling device according to another embodiment of the present invention.

4A and 4B show a main part of a connecting device according to another embodiment of the present invention, wherein FIG. 4A is a sectional view showing a main part of the connecting device, and FIG. is there.

FIG. 5 is a sectional view showing a main part of a connecting device according to another embodiment of the present invention.

FIG. 6 is a sectional view showing a main part of a coupling device according to another embodiment of the present invention.

FIG. 7 is a sectional view showing a main part of a coupling device according to another embodiment of the present invention.

FIG. 8 is a sectional view showing a main part of a connecting device according to another embodiment of the present invention.

FIG. 9 is a sectional view showing a main part of a connecting device according to another embodiment of the present invention.

FIG. 10 is a sectional view showing a main part of a coupling device according to another embodiment of the present invention.

FIG. 11 is a sectional view showing a main part of a connection device according to another embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a main part of a protrusion-separated displacer according to another embodiment of the present invention.

FIG. 13 is a configuration diagram showing a conventional Gifford-McMahon cycle cryogenic refrigerator.

FIG. 14 is an enlarged view of a connecting device portion of a conventional Gifford-McMahon cycle cryogenic refrigerator.

FIG. 15 is an enlarged view of a connection device section of a conventional Gifford-McMahon cycle cryogenic refrigerator.

[Explanation of symbols]

1: Working fluid, 10: First stage cylinder, 11: Upper gas space chamber, 12: First stage expansion chamber, 13: First stage displacer, 13b: Inner peripheral wall portion, 14: First stage regenerator, 20:
2nd stage cylinder, 21: 2nd stage expansion chamber, 22: 2nd stage displacer, 22b: inner peripheral wall part, 23: 2nd stage regenerator, 30: drive motor, 33: drive shaft, 100: connecting piece, 100c: inner peripheral wall portion, 100d: inner peripheral wall portion, 10
1: connection pin, 101a: contact part, 101b: contact part,
102: connection pin, 102a: contact part, 102b: contact part, 104: connecting device, 105: connecting piece, 105c: inner peripheral wall part, 105d: inner peripheral wall part, 108: connecting device, 11
1: connection piece, 111c: inner peripheral wall portion, 111d: inner peripheral wall portion, 112: second stage displacer, 112b: inner peripheral wall portion, 114: connecting device, 115: connecting piece, 115c: inner peripheral wall portion, 115d: inner peripheral wall Part, 116: coating layer, 117: coating layer, 118: second stage displacer, 118b: inner peripheral wall part, 119: notch part, 1
20: coupling device, 125: connection piece, 125c: inner peripheral wall portion, 125d: inner peripheral wall portion, 126: sleeve, 127:
Sleeve, 128: coupling device, 140: coupling device, 14
1: connection piece, 141c: inner peripheral wall portion, 141d: inner peripheral wall portion, 142: connection pin, 142a: contact portion, 142b:
Contact part, 143: connection pin, 143a: contact part, 143
b: contact part, 144: connection pin, 144b: coating layer, 144c: contact part, 144d: contact part, 145:
Connection pin, 145b: coating layer, 145c: contact part, 145d: contact part, 148: coupling device, 154: connection pin, 154b: sleeve, 154c: contact part, 15
4d: contact part, 155: connection pin, 155b: sleeve, 155c: contact part, 155d: contact part, 158: coupling device, 171: first stage displacer, 171b: inner peripheral wall part, 172: second stage displacer, 172b. : Inner peripheral wall portion, 173: sleeve, 174: sleeve, 17
8: Connection device, 191: First stage displacer, 191
b: inner peripheral wall portion, 192: second stage displacer, 192
b: inner peripheral wall portion, 193: coating layer, 194: coating layer, 198: coupling device, 300: nut stop plate, 301: mounting nut, 302: nut accommodating portion,
302e: bottom part, 303: slide plate, 320: connection device,
330: Connection device, 400: Displacer, 400
a: annular groove, 400b: concave portion, 410: band-shaped body, 410
a: outer peripheral surface, 410b: inner peripheral surface, 420: protruding portion separation type displacer, 900: connecting piece, 900c: inner peripheral wall portion, 900d: inner peripheral wall portion, 901: connecting pin, 901
a: contact part, 901b: contact part, 902: connection pin, 9
02a: contact part, 902b: contact part, 904: coupling device, X: central axis direction, Y: central axis direction, DA: length of one side, DB: diameter, DC: diameter, DD: outer diameter, Dp1: diameter. , Dp2: diameter, L: distance between axes.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masashi Nagao 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (56) Reference JP-A-6-159828 (JP, A) JP-A-2 -140560 (JP, A) JP-A-64-49858 (JP, A) JP-A-6-101923 (JP, A) JP-A-6-323667 (JP, A) JP-A-1-291069 (JP, A) ) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 9/14 530 F25B 9/14 510

Claims (16)

(57) [Claims] 1. A cryogenic refrigerator having a plurality of cooling devices, a connecting device, and a connecting device, wherein the cooling device has a cylinder and a displacer disposed in the cylinder. The coupling device includes a first joint member, a first shaft member, a second joint member, a second shaft member, and an intermediate member, and the first joint member and the intermediate member are A first axial sliding portion provided on the first joint member and the first shaft member by the first shaft member, or on the first shaft member and the intermediate member, and the first shaft member. The joint member and the first shaft member, or the first shaft member and the intermediate member via a first circumferential sliding portion, and the second joint member and the second joint member. The intermediate member is disposed so as to intersect the first shaft member at a predetermined interval. And a second axial sliding portion provided on the second joint member and the second shaft member or on the second shaft member and the intermediate member by the second shaft member and the second shaft member. Two joint members and the second shaft member, or the second shaft member and the intermediate member through a second circumferential sliding portion, and the first axial sliding member. The moving portion of the first shaft member receives the intermediate member from the second shaft member so that the intermediate member can move in the axial direction of the first shaft member with respect to the first joint member. The couple force generated in the first axial sliding portion by the axial force is set to be equal to or less than the frictional force generated in the first axial sliding portion, and the first circumferential sliding portion is Is arranged so that the intermediate member can rotate with respect to the first joint member in a direction orthogonal to the axis of the first shaft member. In the second axial sliding portion, the intermediate member is the first axial member so that the intermediate member can move in the axial direction of the second axial member with respect to the second joint member. The couple force generated by the axial force of the second shaft member received from the second axial sliding portion is set to be equal to or less than the frictional force generated by the second axial sliding portion. A plurality of the cooling devices are fixed such that the cylinders of the cylinders are substantially co-axial, and the displacers are the first and second joint members of the coupling device. The second shaft member is connected by being fixed to each of the displacers such that the axial direction of the second shaft member intersects the direction of the reciprocating motion, and one of the displacers is connected to the drive shaft via the connecting device. The above displacers are Cryogenic refrigerator that reciprocates in the binder to move the working fluid. 2. The pole according to claim 1, wherein the first shaft member and the second shaft member are connected to the intermediate member at a minute predetermined distance so as not to come into contact with each other. Low temperature refrigerator. 3. The first and second axial sliding portions are provided on the first shaft member and the intermediate member, and on the second shaft member and the intermediate member, respectively. Item 2. The cryogenic refrigerator according to item 2. 4. The first and second shaft members are formed by cylindrical rod members made of the same material and having the same dimensions, and penetrate the cylindrical through holes provided in the intermediate member. Thus, the round bar member and the through-hole portion serve as a first axial sliding portion / first circumferential sliding portion and a second axial sliding portion / second circumferential sliding portion, respectively. And the following conditional expression D1> 2 × K1 × (L− (Dp1) / 2), where D1: the length K1 of the through hole portion of the intermediate member: the first shaft member and the intermediate member. 4. The cryogenic temperature according to claim 3, wherein the friction coefficient L with the through hole is an inter-axial distance Dp1 between the first shaft member and the second shaft member, which satisfies the diameter of the first shaft member. refrigerator. 5. The cryogenic refrigerator according to claim 4, wherein the first and second shaft members are made of metal, and the intermediate member is made of a polymer material. 6. A member in which at least one of the sliding parts of both members sliding in the first and second axial sliding parts is made of a polymer material having a friction coefficient with respect to metal lower than that of a phenol resin. The cryogenic refrigerator according to claim 1, wherein 7. The cryogenic refrigerator according to claim 6, wherein the polymer material is a polyimide resin. 8. The cryogenic refrigerator according to claim 6, wherein the sliding portion of both members is formed of a coating layer of a polymer material. 9. The cryogenic refrigerator according to claim 6, wherein the sliding portions of both members are formed of a sleeve made of a polymer material. 10. The connecting device comprises a housing portion provided at an end portion of the displacer and having an opening, and a metal hooking member provided near the opening, and a high friction coefficient against metal lower than that of phenol resin. It has first and second abutting and sliding parts respectively formed of a molecular material, and is accommodated in the accommodating part so as to be movable in the reciprocating direction of the displacer and in a direction perpendicular thereto, and by the latching member. An enlarged portion to which the first contact sliding portion is locked so as not to slip out of the housing portion, the enlarged portion is fixed to the drive shaft, and the enlarged portion is reciprocated by the drive shaft. The cryogenic refrigerator according to claim 1, wherein the first and second abutting sliding portions of the aforesaid alternately abut the housing portion and the hooking portion to reciprocate the displacer. . 11. The cryogenic refrigerator according to claim 10, wherein the first and second contact sliding portions are made of a polymer material. 12. A cryogenic refrigerator provided with a cooling device having a cylinder and a displacer, wherein the displacer is provided with an annular groove in the outer peripheral portion at a predetermined interval in the axial direction. And a strip-shaped body that is fitted into the plurality of recesses in an interference fit state so as to project from the recesses, and the displacer is disposed in the cylinder and is attached to the drive shaft. A cryogenic refrigerator that is connected and reciprocates in the cylinder so that the strip slides on the cylinder to move the working fluid. 13. The cryogenic refrigerator according to claim 12, wherein the band-shaped body is formed of a polymer material. 14. The cryogenic refrigerator according to claim 13, wherein the polymer material is ultra-high molecular weight polyethylene. 15. The cryogenic refrigerator according to claim 12, wherein the displacer is glass epoxy. 16. A belt-shaped body having a predetermined outer diameter dimension obtained by fitting an unmachined belt-shaped body having a machining allowance on its outer diameter portion into a recess of a displacer by interference fitting, and then machining the unmachined belt-shaped body. The method for manufacturing a cryogenic refrigerator according to claim 12, wherein the method is a body.