JP2692651B2 - refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator suitable for cooling an object to be cooled such as an infrared sensor and a superconductor to an extremely low temperature.

[0002]

2. Description of the Related Art Stirling refrigerators, Gifford McMahon refrigerators, pulse tube refrigerators and the like are known as conventional refrigerators of this type.
The basic structure of the cooling part (cold head part) for cooling the object to be cooled will be described with reference to FIG. 21. The entire expansion part of the refrigerator is hermetically sealed, and the refrigerant (helium, helium,
The working gas 3 such as argon, hydrogen, and nitrogen repeatedly expands and compresses, and the cold heat generated by the adiabatic expansion of the refrigerant is stored in the regenerator 5 while the temperature of the refrigerant 3 in the expansion space 4 decreases.

As means for cooling the object 2 to be cooled by the cold heat of the expansion space 4, the object 2 to be cooled is directly placed in the cooling section 1 of the refrigerator, or is made of an indium foil or the like made of a material having good heat conduction. The object 8 is sandwiched and attached to the cooling unit 1. Then, the cooling unit 1 and the object to be cooled 2 are housed in the vacuum heat insulating container 9 to insulate them from the outside,
The object to be cooled 2 can be cooled to an extremely low temperature.

[0004]

Generally, when the object 2 to be cooled is cooled using this type of refrigerator, heat is transferred in the order of the object 2 to be cooled, the inclusions 8, the cooling section 1, and the refrigerant 3. Inevitably, a large temperature difference occurs between the object to be cooled 2 and the refrigerant 3. Therefore, in order to cool the object to be cooled 2 to a predetermined temperature, it is necessary to lower the temperature of the refrigerant by a predetermined value below the cooling temperature of the object to be cooled, which deteriorates the refrigeration efficiency and the size of the refrigerator. There was a problem that it turned into.

Further, in order to improve heat transfer, the cooling unit 1
Is made of a material having good thermal conductivity, such as copper, stainless steel, titanium (or a combination thereof).
Therefore, from the room temperature part of the refrigerator (the lower end side of FIG. 21),
The heat entering the cooling unit 1 made of a material having good heat conduction increases, and the refrigeration efficiency further deteriorates. The present invention has been made in view of the above points, and an object of the present invention is to improve the refrigeration efficiency by improving the arrangement configuration of the cooling unit and the object to be cooled.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention employs a technical means of cooling a substance to be cooled by directly contacting a cooling medium and the substance to be cooled without inclusions. That is, specifically, in the invention described in claim 1, the compression space (13)
In the refrigerator in which the refrigerant (3) is repeatedly compressed and expanded between the expansion space (4) and the expansion space (4) to exert a refrigerating action on the cooling unit (1), the expansion space of the cooling unit (1) is used. The object to be cooled (2) is arranged on the inner surface facing the object (4), and the refrigerant (3) in the expansion space (4) is brought into direct contact with the object to be cooled (2). Is characterized by.

The invention according to claim 2 is characterized in that the cooling part (1) has a multi-layer structure, and a vacuum layer (6) is formed between each layer of the cooling part (1).
The invention according to claim 3 is characterized in that the cooling part (1) is provided with a hole (35) for directly exposing the object to be cooled (2) to the outside of the cooling part (1). There is.

In the invention according to claim 4, the object to be cooled (2) is provided with a wiring member (10), and the wiring member (10) passes through the hole (35) and the cooling unit (1). ) Is taken out to the outside. The invention according to claim 5 is characterized in that the cooling part (1) is made of a material having a low thermal conductivity.

In the invention according to claim 6, the object to be cooled (2) is provided with a wiring member (10), and the wiring member (10) is cooled by passing through a low temperature portion of the cooling unit (1). It is characterized in that it is taken out of the part (1). In the invention according to claim 7, the article to be cooled (2) is provided with a wiring member (10), and the wiring member (10) is located at a normal temperature portion (adjacent to the cooling portion (1)). It is characterized in that it is taken out through A).

In the invention according to claim 8, the wiring member (10) is taken out from the room temperature part (A) through the inside of the expansion space (4), the inside of the refrigerator component equipment (28, 11). It is characterized by being. By the above-mentioned technical means, in the inventions according to claims 1 to 8, by directly contacting the refrigerant and the object to be cooled without inclusions,
Since the object to be cooled is directly cooled by the refrigerant, the temperature difference between the refrigerant and the object to be cooled can be reduced, so that the lowest temperature reached by the object to be cooled can be lowered. Alternatively, when the object to be cooled is cooled to a predetermined temperature, the temperature of the refrigerant can be raised, and the refrigerating efficiency can be improved.

Further, since the object to be cooled is directly cooled by the refrigerant, the cooling part can be made of a material having a low thermal conductivity as in the invention of claim 5. As a result, the amount of heat that flows from the room temperature part of the refrigerator to the cooling part by heat conduction can be reduced, and the refrigeration efficiency can be further improved. Here, if a resin or the like is used as the material having a low thermal conductivity, the weight of the refrigerator can be reduced.

According to the second aspect of the invention, since the cooling unit has a multi-layer structure and the vacuum layer is provided between them, the cooling unit itself can also serve as a heat insulating function from the outside.
As a result, it is not necessary to separately provide a vacuum insulation container, and the number of parts of the refrigerator can be reduced and the size and weight can be reduced. Further, according to the invention of claim 3, since the object to be cooled is provided with the hole portion directly exposed to the outside of the cooling portion, it is possible to irradiate the object to be cooled with light from the outside through the hole portion. When using an infrared sensor as a cooling object,
The sensor function can be demonstrated very easily. Further, as in the invention according to claim 4, the wiring member can be easily taken out of the cooling portion through the hole.

According to the sixth aspect of the invention, since the wiring member is taken out directly from the low temperature portion of the cooling portion to the outside,
The wiring distance can be shortened, and since it is not necessary to wire the wiring member inside the refrigerator constituent device for a long distance, the wiring member can be easily taken out. Claims 7 and 8
In the invention described, since the wiring member is taken out to the outside through the room temperature portion located adjacent to the cooling unit, the taking-out portion of the wiring member to the outside is at room temperature, and sealing is easy,
Further, there is an effect that heat invasion from the wiring member due to heat conduction is reduced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows an outline of the entire structure of a Stirling refrigerator to which the present invention is applied. In this Stirling refrigerator, a connecting rod 26 is formed by a rotor 16 driven by a prime mover such as a motor. It has a displacer 22 that reciprocates through a compression piston 25 that reciprocates through a connecting rod 27. The displacer 22 functions as an expansion piston that reciprocates in the expansion cylinder 28 integrally with the regenerator 5. The compression piston 25 is reciprocally fitted in the compression cylinder 29.

The displacer 22 has a refrigerant passage 22a communicating with the expansion space 4 through the refrigerant passage in the regenerator 5.
Is provided. Compression space 13 in compression cylinder 29
Is connected to the inside of the expansion cylinder 28 via a pipe 30 and can be connected to the refrigerant passage 22 a of the displacer 22. The regenerator 5 has a structure in which a plurality of metal mesh bodies made of a metal having a high thermal conductivity such as stainless steel, copper, and a copper alloy are stacked, or a structure in which metal balls such as stainless steel and lead are packed.

A fin-shaped radiator 14 made of a metal material having a high thermal conductivity is provided on the outer surface of the compression cylinder 29 to radiate the compression heat of the refrigerant. As the _{refrigerant, He, Ar, N 2,} O 2, H 2, is liquefied difficult working gas at a low temperature such as air is used. A cooling unit (cold head) 1 is integrally formed with an expansion cylinder 28 on the end surface of the expansion space 4 so as to close the end surface, and an object to be cooled (not shown) is cooled in the cooling unit 1. It has become.

The freezing action is performed as follows. When the displacer 22 descends in the expansion cylinder 28 and the expansion space 4 expands, the refrigerant 3 expands in the expansion space 4 to generate cold heat. And the refrigerant 3
Passes through the regenerator 5, stores the generated cold heat in the regenerator 5,
After the temperature rises to normal temperature, the refrigerant flows into the refrigerant passage 22a.
And through the pipe 30 to the compression space 13.

Next, the refrigerant 3 is compressed in the compression space 13 by the compression piston 25. Since the heat of compression is released to the outside by the radiator 14, the refrigerant is compressed at room temperature. Next, the compressed refrigerant 3 flows into the regenerator 5 through the pipe 30 and the refrigerant passage 22a. Since this regenerator 5 has been cooled in the previous cycle and has a low temperature, the refrigerant moves to the expansion space 4 after being cooled by the regenerator 5, and the refrigerant in the expansion space 4 has an even lower temperature. .

As described above, an extremely low temperature is generated in the cooling portion 1 formed on the end surface of the expansion space 4 to cool the object to be cooled. Next, FIG. 2 shows an outline of the overall configuration of a Gifford-McMahon refrigerator to which the present invention is applied. This Gifford-McMahon refrigerator is basically the same configuration as the Stirling refrigerator, and is different. Is the next point. The displacer 22 and the regenerator 5 are integrally housed in the expansion cylinder 28 so as to be able to reciprocate, and the expansion space 4 is formed on one end side of the expansion cylinder 28 and the compression space 13 is formed on the other end side thereof. A seal member 23 is provided on the outer peripheral portion of the displacer 22 so that the expansion space 4 and the compression space 13 are hermetically separated from each other.

Further, a compressor 15 for sucking the refrigerant from the second valve 18 side and compressing and discharging the refrigerant to the first valve 17 side is provided, and the first valve 17 is opened at the top dead center of the displacer 22. By closing the second valve 18 and closing the first valve 17 and opening the second valve 18 at the bottom dead center of the displacer 22, the expansion space 4 and The refrigerant in the compression space 13 is compressed and expanded.

Next, FIG. 3 shows an outline of the overall configuration of a pulse tube refrigerator to which the present invention is applied. In this pulse tube refrigerator, the regenerator 5 is connected to the compression space 13 via a pipe 30. Then, the pulse tube 11 is connected to the regenerator 5 via the expansion space 4, and the pulse tube 11 is connected to the buffer tank 21 via the first orifice valve (flow rate adjusting valve) 20. Further, the pipe 30 is directly connected between the pulse tube 11 and the first orifice valve 20 via a bypass circuit 31 having a second orifice valve (a flow rate adjusting valve called a double inlet valve) 19. ing.

With such a structure, the compression piston 25 of the compression section compresses and expands the refrigerant 3 to give pressure vibration to the refrigerant in the pulse tube 11 from the regenerator 5 side, thereby expanding the refrigerant. The refrigerant 3 expands in the space 4 to generate cold heat. What is common to the refrigerators illustrated in FIGS. 1 to 3 is that cold heat is generated by the expansion of the refrigerant 3 in the expansion space 4, and the generated cold heat is used to cool the object to be cooled in the cooling unit 1. It is about to be cooled.

Since the present invention is characterized by the arrangement of the cooling unit 1 and the object to be cooled in the refrigerator having the above-described refrigerating action, this arrangement will be specifically described below. FIG. 4 is a schematic cross-sectional view of a part of a cooling unit (cold head) in a refrigerator such as the Stirling refrigerator or the Gifford-McMahon refrigerator described above. The object to be cooled 2 is arranged on the inner surface of the cooling unit 1 facing the expansion space 4 so that the refrigerant 3 in the expansion space 4 directly contacts the object to be cooled 2. Here, the object to be cooled 2 has an electric wiring 10 such as a superconductor.

FIGS. 5 (a) and 5 (b) exemplify a concrete assembly structure of the object to be cooled 2 and the cooling part 1, in which the electric wiring 10 of the cooling part (1) is penetrated. A hole is made in the site, and the hermetic connector (sealing member) 12 is previously attached to this hole. The electric wiring 10 penetrating the inside of the hermetic connector 12 is sealed and fixed in advance. Here, the hermetic connector 12 is
It is a sealing member manufactured by matching the linear expansion coefficient with the cooling part 1 and the electric wiring 10, and as the material thereof, one made of ceramics, one obtained by melting metal and glass, or the like can be used.

The object to be cooled 2 is provided with a groove (recess) 2a into which the end of the electric wiring 10 is inserted. Then, the object 2 to be cooled is placed from the inside of the cooling unit 1 in FIG.
As shown in (b), the electric wire 10 of the hermetic connector 12 is inserted and fixed. Here, when the force for fixing the object to be cooled 2 is insufficient only with the joining force by the hermetic connector 12, the object to be cooled 2 is cooled with the low temperature adhesive 24 by using the low-temperature adhesive 24 having excellent adhesive force at low temperature. It is preferable to adhere and fix it to the inside.

Here, as a specific material example of the low-temperature adhesive 24, an epoxy two-component room temperature curing adhesive can be used. In FIG. 4, a vacuum heat insulating container (not shown) is installed on the outer surface side of the cooling unit 1 and the expansion cylinder 28 so as to insulate the low temperature portion around the cooling unit 1 from the outside. There is.

According to the first embodiment, the object to be cooled 2 is arranged on the inner surface side of the cooling part 1 as described above, so that the object to be cooled 2 is directly cooled by the refrigerant 3 in the expansion space 4. be able to. As a result, the temperature difference between the refrigerant 3 and the object to be cooled 2 becomes smaller, so that the temperature of the object to be cooled 2 can be made lower if the refrigerant temperature is the same as in the conventional cooling structure. . That is, it is possible to lower the lowest temperature of the object to be cooled 2.

Further, when the temperature of the object to be cooled 2 is set to a certain constant temperature, the refrigerant temperature can be increased, so that the refrigerating efficiency is improved. Further, since it is not necessary to cool the object to be cooled 2 through the thick portion of the cooling unit 1, the cooling unit 1
As the material of the above, a material having low thermal conductivity can be used. For example, if a polymer material such as resin is used, it is possible to reduce the amount of heat flowing from the normal temperature portion A (the lower end portion side of the expansion cylinder 28) of the refrigerator to the cryogenic portion of the inner surface of the cooling portion 1. Refrigeration efficiency is improved. Further, the weight can be reduced by using a polymer material such as resin.

The hermetic connector 12 has a glass sealing structure or the like, and is generally a member having a low thermal conductivity. In addition to the above-mentioned polymer material, an inorganic material such as ceramics can be used as the material of the cooling unit 1 having a low thermal conductivity. Further, in the first embodiment, since the electric wiring 10 is taken out directly from the low temperature part of the cooling unit 1, the length of the electric wiring 10 is shortened and there is no wiring work inside the expansion cylinder 28. , Has the advantage that wiring work becomes easier. (Second Embodiment) FIGS. 6 and 7 show a second embodiment, in which the cooling section 1 and the expansion cylinder 28 have a multi-layered structure, in the illustrated example, a two-layered structure, with an outer surface layer 32 and an inner surface thereof. The vacuum layer 6 is integrally formed with the layer 33.
Thus, by integrally forming the vacuum layer 6 in the cooling unit 1 and the expansion cylinder 28, it is not necessary to separately install a vacuum heat insulating container outside, and it is possible to reduce the size and weight of the refrigerator by reducing the number of parts. be able to.

In FIG. 6, concrete examples of the structure for fixing the object to be cooled 2, the structure for taking out the wiring 10, etc. are shown in FIG.
As shown in (b), the structure is basically the same as that shown in FIG. 5, but in this example, the hermetic connector 12 is doubly provided on both the outer surface layer 32 and the inner surface layer 33. Further, also in this example, as the material forming the cooling unit 1, it is advantageous to use a material having a low thermal conductivity for improving the refrigerating efficiency and lowering the minimum attainable temperature. (Third Embodiment) FIG. 8 shows a third embodiment, in which a circular concave portion 34 is provided on the inner surface of the cooling portion 1 facing the expansion space 4, and the central portion of the concave portion 34 is provided. The cooling hole 1 is provided with a circular hole portion 35 for penetrating the cooling portion 1 to the outside of the cooling portion 1.
Is provided.

Then, the object 2 to be cooled is formed into a disk shape that can be accommodated in the concave portion 34, and the object 2 to be cooled is joined to the concave portion 34 by the low temperature adhesive 24. The electric wiring 10 joined to the object to be cooled 2 is taken out to the outside through the circular hole 35. In the third embodiment, since the object to be cooled 2 is directly exposed to the outside through the circular hole 35, when the infrared sensor is used as the object to be cooled 2, the object to be cooled is passed through the circular hole 35 from the outside. Since it is possible to irradiate the (infrared sensor) 2 with light, the infrared sensor can be cooled to an extremely low temperature and, at the same time, its sensor function can be realized with a simple structure.

In the third embodiment, since the circular hole portion 35 that directly exposes the object to be cooled 2 to the outside is formed, the cooling portion 1 cannot be provided with the vacuum layer 6 having a multilayer structure. Therefore, it is necessary to separately provide a vacuum heat insulating container. (Fourth Embodiment) FIG. 9 shows a fourth embodiment which is a modification of the third embodiment.
The circular hole portion 35 for directly exposing the cooling water to the outside is formed, and the divided piece 1a of the cooling unit 1 is provided. In this example, the object to be cooled 2 is adhered to the divided piece 1a of the cooling part 1 by the low temperature adhesive 24, the hermetic connector 12 is provided on the divided piece 1a, and the electric wiring 10 is taken out through the hermetic connector 12. There is.

Further, the divided piece 1a of the cooling unit 1 is bonded and fixed to the inner surface of the cooling unit 1 with the sealing adhesive 7. Here, as a method of connecting the divided pieces 1a of the cooling unit 1, brazing, welding, adhesion with an adhesive 7 or the like can be selected and performed depending on the material and shape thereof. In the fourth embodiment, the cooling unit 1 is divided into a plurality of pieces in this way, and the divided pieces 1a are formed.
The object to be cooled 2 is preliminarily combined with the cooling target 2, and the object to be cooled 2 is in direct contact with the refrigerant 3 and the circular hole 35
It is possible to easily take out the electric wiring 10 through it.

In the fourth embodiment as well, the vacuum layer 6 having a multi-layer structure cannot be provided in the cooling unit 1, so that it is necessary to separately provide a vacuum heat insulating container. (Fifth Embodiment) FIGS. 10 and 11 show a fifth embodiment, in which the electric wiring 10 fixed to the object to be cooled 2 is passed through the inside of the expansion cylinder 28 from the object to be cooled 2 to the expansion cylinder 2
8 is taken out to the room temperature side (the lower end side A in the drawing) of FIG. 8, and the object to be cooled 2 is the low temperature adhesive 24 shown in FIG.
Is adhered to the inner surface of the cooling unit 1.

In the case of the Stirling refrigerator shown in FIG. 1 and the Gifford McMahon refrigerator shown in FIG. 2, since the displacer 22 reciprocates inside the expansion cylinder 28,
It is necessary to pass the wiring 10 so as not to interfere with the reciprocating motion of the displacer 22. Therefore, it is necessary to provide an escape passage for the wiring 10 in the axial direction of the outer peripheral surface of the displacer 22 or to embed the wiring 10 in the inner peripheral surface of the expansion cylinder 28.

According to the fifth embodiment, since the electric wiring 10 of the object to be cooled 2 is taken out to the room temperature side of the expansion cylinder 28 (the lower end side A in the figure), the electric wiring 10 is taken out to the outside. At the position, since the temperature difference between the inside and outside of the refrigerator is small, the need for heat insulation is reduced, and therefore, the structure in which the electric wire 10 is easily sealed at the take-out portion is sufficient. In addition, the cooling unit 1 is externally supplied through the electric wiring 10.
The amount of heat penetrating into the can also be reduced. (Sixth Embodiment) FIG. 12 shows a sixth embodiment. In the fifth embodiment, the cooling section 1 and the expansion cylinder 28 have a two-layer structure, and an outer surface layer 32 and an inner surface layer 33 thereof. By integrally forming the vacuum layer 6 between
This eliminates the need to separately install a vacuum heat insulating container. (Seventh Embodiment) FIGS. 13 and 14 show a seventh embodiment, in which the cooling section 1 and the expansion cylinder 28 are divided and formed separately, and the inner surface of the cooling section 1 is cooled. The object 2 is adhered by the low temperature adhesive 24, and the hermetic connector 12 is provided in the radial direction of the cooling unit 1, and the electric wiring 10 of the object 2 to be cooled is taken out of the cooling unit 1 through the hermetic connector 12. There is.

After arranging the object to be cooled 2 and the wiring 10 on the cooling unit 1 side in this way, the end outer peripheral surface of the expansion cylinder 28 is fitted to the end inner peripheral surface of the cooling unit 1, and the space between the both is fitted. Are fixed by an adhesive 7 for sealing. (Eighth Embodiment) FIGS. 15 and 16 show an eighth embodiment, in which the portion of the cooling unit 1 in the seventh embodiment is divided into two parts.
As a layered structure, the vacuum layer 6 is integrally formed between the outer surface layer 32 and the inner surface layer 33 so that it is not necessary to separately install a vacuum heat insulating container. (Ninth Embodiment) FIG. 17 shows a ninth embodiment, which is a case where the present invention is applied to a pulse tube refrigerator, and this example shows the inner surface of the cooling unit 1 of the pulse tube refrigerator. The object 2 to be cooled is arranged in the same structure as shown in FIGS. 4 and 5, and the wiring 10 is taken out. (Tenth Embodiment) FIG. 18 shows a tenth embodiment, in which the portion of the cooling unit 1 in the ninth embodiment and the portion forming the pulse tube 11 and the regenerator 5 have a two-layer structure. As a result, the vacuum layer 6 is integrally formed between the outer surface layer 32 and the inner surface layer 33 so that it is not necessary to separately install a vacuum heat insulating container. (Eleventh Embodiment) FIG. 19 shows an eleventh embodiment. In this example, the object to be cooled 2 is arranged on the inner surface of the cooling unit 1 of the pulse tube refrigerator with the same structure as that shown in FIG. Install and wire 1
It is designed to take out 0. (Twelfth Embodiment) FIG. 20 shows a twelfth embodiment. In this example, the object 2 to be cooled is placed on the inner surface of the cooling unit 1 of the pulse tube refrigerator in the same manner as the structure shown in FIG. Adhesive 24
It is fixed by adhesion. Further, after the electric wiring 10 fixed to the object to be cooled 2 is bent in the expansion space 4 from the object to be cooled 2, it is passed through the pulse tube 11 and the normal temperature side of the pulse tube 11 (the lower end side A in the figure). It was taken out to.

Here, in the case of the pulse tube refrigerator, the pulse tube 11 and the regenerator 5 remain fixed and do not move, so that the wiring 10 can be easily taken out to the room temperature side A. In each of the above-described embodiments, the configuration in which the electric wiring 10 of the object to be cooled 2 itself is taken out has been described, but the object to be cooled 2 is not provided with the electric wiring 10, and instead of this, In the case where the temperature measuring means such as a thermocouple is integrally provided so as to come into contact with the object to be cooled 2 and the electric wiring 10 of the thermocouple is taken out to the outside, the present invention similarly applies. It is feasible.

In each of the above-described embodiments, the case where the input / output signal to / from the object to be cooled 2 and the signal for temperature measurement are transmitted / received by the electric wiring 10 has been described, but the transmission / reception of these signals is performed wirelessly. If it is possible to carry out the above, even if the object to be cooled 2 is arranged inside the cooling part 1, it is not necessary to take out the electric wiring 10, and the present invention is very easy to implement, which is particularly advantageous.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing the configuration of a Stirling refrigerator to which the present invention is applied.

FIG. 2 is a schematic cross-sectional view showing the configuration of a Gifford-McMahon refrigerator to which the present invention is applied.

FIG. 3 is a schematic sectional view showing a configuration of a pulse tube refrigerator to which the present invention is applied.

FIG. 4 is a schematic cross-sectional view showing a cooling unit of the refrigerator showing the first embodiment of the present invention.

FIG. 5 is an enlarged cross-sectional view of an essential part showing the assembly structure of the main part in the first embodiment.

FIG. 6 is a schematic cross-sectional view showing a cooling unit of a refrigerator showing a second embodiment.

FIG. 7 is an enlarged cross-sectional view of an essential part showing the assembling structure of the main part in the second embodiment.

FIG. 8 is a schematic cross-sectional view showing a cooling unit of a refrigerator showing a third embodiment.

FIG. 9 is an enlarged sectional view of an essential part showing the assembling structure of the main part of the cooling part in the fourth embodiment.

FIG. 10 is a schematic cross-sectional view showing a cooling unit of a refrigerator showing a fifth embodiment.

FIG. 11 is an enlarged sectional view of an essential part showing an assembling structure of a main part in the fifth embodiment.

FIG. 12 is an enlarged sectional view of an essential part showing the assembling structure of the main part in the sixth embodiment.

FIG. 13 is an enlarged sectional view of an essential part showing a state before assembly of a main part in a seventh embodiment.

FIG. 14 is an enlarged sectional view of an essential part showing a state after the assembly of the main part in the seventh embodiment.

FIG. 15 is an enlarged sectional view of an essential part showing a state before assembly of a main part in the eighth embodiment.

FIG. 16 is an enlarged sectional view of an essential part showing a state after assembling of the main part in the eighth embodiment.

FIG. 17 is a sectional view of a cooling unit of a pulse tube refrigerator according to a ninth embodiment.

FIG. 18 is a sectional view of a cooling unit of a pulse tube refrigerator showing a tenth embodiment.

FIG. 19 is a sectional view of a cooling unit of a pulse tube refrigerator according to the eleventh embodiment.

FIG. 20 is a cross-sectional view of a cooling unit of a pulse tube refrigerator according to the twelfth embodiment.

FIG. 21 is a cross-sectional view of a cooling unit in a conventional refrigerator.

[Explanation of symbols]

1 ... Cooling part, 2 ... Cooled object, 3 ... Refrigerant, 4 ... Expansion space,
5 ... Regenerator, 10 ... Electrical wiring, 11: Pulse tube, 13 ...
Compression space.

Claims (8)

(57) [Claims] 1. A compression space (13) for compressing a refrigerant (3).
An expansion space (4) for expanding the refrigerant (3) compressed in the compression space (13), and a cold storage for storing the cryogenic cold heat generated by the expansion of the refrigerant (3) in the expansion space (4) A container (5) and a cooling unit (1) provided in the expansion space (4) for cooling the object to be cooled (2), and between the compression space (13) and the expansion space (4). so,
In a refrigerator that exerts a refrigerating action by repeating compression and expansion of a refrigerant (3), the object to be cooled (2) is provided on an inner surface of the cooling section (1) facing the expansion space (4). A refrigerator, characterized in that the refrigerant (3) in the expansion space (4) is brought into direct contact with the object to be cooled (2). 2. The refrigerator according to claim 1, wherein the cooling unit (1) has a multi-layer structure, and a vacuum layer (6) is formed between each layer of the cooling unit (1). . 3. The cooling part (1) is provided with a hole (35) for directly exposing the object to be cooled (2) to the outside of the cooling part (1). The refrigerator according to 1 or 2. 4. The wiring member (1) is attached to the object (2) to be cooled.
0) is provided, and the wiring member (10) is taken out to the outside of the cooling section (1) through the hole (35). 5. The refrigerator according to claim 1, wherein the cooling unit (1) is made of a material having a low thermal conductivity. 6. The wiring member (1) is attached to the object (2) to be cooled.
0) is provided and the wiring member (10) is taken out of the cooling section (1) through the low temperature section of the cooling section (1). ,
The refrigerator according to any one of 5. 7. A wiring member (1) is attached to the object (2) to be cooled.
0) is provided and the wiring member (10) is taken out to the outside through the room temperature part (A) located adjacent to the cooling part (1).
The refrigerator according to any one of 3 and 5. 8. The wiring member (10) is taken out from the room temperature part (A) through the inside of the refrigerator component (28, 11) from the inside of the expansion space (4). The refrigerator according to claim 7.