JPH09178282A - Stirling refrigerator and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform assembly of members through a simple assembly work with high precision when a plurality of members are integrally assembled to a cylinder body, in the expansion device of a Stirling refrigerator. SOLUTION: The inside diameters of a cold head 36, integrally assembled to a tubular cylinder body 35, a Dewar-mounting flange 37, a radiation member 38, and a piping coupling member 39 are caused to approximately coincide with he outside diameter of the cylinder body 35. The cold head 36 is fitted externally of the tip part of the cylinder body 35 and the Dewar-mounting flange 37, the radiation member 38, and the piping coupling member 39 are fitted externally of the base end part of the cylinder body 35. Each fit-in part is joined through vacuum brazing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Stirling refrigerating machine and a method of manufacturing the same, and more particularly, to a structure of an expander for generating cold by causing a free displacer to reciprocate in a cylinder to expand a refrigerant to generate cold. It relates to an assembling method.

[0002]

2. Description of the Related Art Conventionally, as a kind of a small refrigerator which generates cryogenic temperature, for example, Japanese Patent Application Laid-Open No. 2-500
A free displacer type Stirling refrigerator disclosed in Japanese Patent Publication No. 52 is known. This refrigerator is configured by connecting a compressor that compresses a refrigerant gas and an expander that expands the refrigerant gas discharged from the compressor through a connecting pipe.

[0003] The above-mentioned expander is a free-standing cylinder which is reciprocally fitted into a bottomed cylindrical cylinder having a tip portion formed in a cold head and reciprocally moves inside the cylinder. And a displacer.
Then, the free displacer receives a pressure wave of a predetermined cycle generated by the compressor, reciprocates in the cylinder, and expands the refrigerant in the expansion chamber, thereby causing a cryogenic level of cold in the cold head.

[0004]

By the way, the cylinders that constitute this type of expander differ in the required thermal conductivity depending on their respective parts. In other words, on the distal end side (cold head portion) of the cylinder, it is necessary to remove heat from the outside air, and on the proximal end side, it is necessary to release the heat taken from the distal end side to the outside. Requires high thermal conductivity. On the other hand, in the middle part of the cylinder,
A low heat conductivity is required to prevent the performance of the refrigerator from being reduced due to the heat conduction of the cylinder tube wall from the base end side to the front end side. That is, it is preferable that the distal end portion, the intermediate portion, and the proximal end portion of the cylinder are each formed of a separate component made of a material having a thermal conductivity according to a request, and these are integrally assembled.

In order to satisfy this demand, the cylinder is provided with a cold head made of a material having a high thermal conductivity, which constitutes the tip of the cylinder, with respect to a cylinder body having a low thermal conductivity and a thin straight pipe member. A plurality of members, such as a heat dissipating member made of a material having a high thermal conductivity, constituting the base end portion of the cylinder are integrally assembled. In addition, regarding these assembling, in order to improve the practicality, it is required to assemble these members integrally with a high precision by a simple assembling work. No consideration has been proposed.

In general, in order to avoid the occurrence of dew condensation in a cold head which becomes extremely low in temperature, this type of expander covers the outer periphery of the cylinder with a vacuum dewar and evacuates the periphery of the cold head. ing. For this reason, it is necessary to provide a mounting flange on the cylinder for mounting the vacuum dewar by screwing or the like.
At this time, it is conceivable that the mounting flange is formed integrally with the cylinder.However, in order to suppress the heat conduction of the cylinder pipe wall from the base end side to the distal end side, the wall thickness dimension of the cylinder is as small as possible. While it is necessary to set the thickness (to be extremely thin), the mounting flange needs to have a plate thickness dimension that can keep the tightening torque at the time of screwing the vacuum dewar. In other words, when the mounting flange is formed integrally with the cylinder, an extremely thin portion and a relatively thick portion are integrally formed, which makes the processing difficult and increases the processing cost. For this reason, it is preferable that this mounting flange is formed as a separate member from the cylinder, and this is integrally assembled with the cylinder.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to simplify a case where a plurality of members are integrally assembled to a cylinder body with respect to an expander of a Stirling refrigerator. An object of the present invention is to make it possible to assemble these members with high accuracy by a simple assembling operation.

[0008]

In order to achieve the above-mentioned object, the means adopted by the present invention is to integrally integrate a cold head and a heat radiating member into a cylindrical cylinder body. It was assembled.

More specifically, according to the first aspect of the present invention, an expander (2) having a free displacer (31) reciprocally inserted in a cylinder (30) is connected to a compressor (1). Compressor
The refrigerant compressed in (1) is supplied to the expander (2), and the expander (2)
It is assumed that a Stirling refrigerator that expands the refrigerant by reciprocating motion of the free displacer (31) and generates cold at the tip of the cylinder (30). Then, at the distal end of the cylindrical cylinder body (35), a bottomed cylindrical cold head (36) having an inner diameter substantially matching the outer diameter of the cylinder body (35) is provided. Part of the cylinder body
A heat radiating member (38) having a center hole (38c) having a diameter substantially equal to the outer diameter of (35) is externally fitted to each other to form a cylinder (30).

With such a configuration, when the Stirling refrigerator is driven, the refrigerant compressed by the compressor (1) is supplied to the expander.
(2), and the refrigerant expands in the expander (2), so that cold occurs at the tip of the cylinder (30). Further, a cylinder (30) is formed by externally fitting a cold head (36) at the distal end of the cylindrical cylinder body (35) and a heat radiating member (38) at the proximal end thereof. Therefore, the assembling work of the cylinder (30) is simplified, and good assembling accuracy is obtained. Also, by making the inner diameter of the cold head (36) and the diameter of the center hole (38c) of the heat dissipating member (38) substantially coincide with the outer diameter of the cylinder body (35), respectively, Therefore, the design of each member is simple.

According to a second aspect of the present invention, in the Stirling refrigerator according to the first aspect, the outer periphery of the cold head (36) is covered with a vacuum dewar (34), and the cylinder body is provided.
(35) has a center hole (37a) having a diameter substantially matching the outer diameter of the cylinder body (35), and the vacuum dewar (34)
And a dewar mounting flange (37) for supporting the outside.

With this configuration, the vacuum dewar (3) for preventing dew condensation on the cold head (36) when the refrigerator is driven.
Similarly to the cold head (36) and the heat dissipating member (38) according to the first aspect of the present invention, the dewar mounting flange (37) for supporting the cylinder body (4) can be accurately assembled by a simple assembling operation. 35).

According to a third aspect of the present invention, there is provided the Stirling refrigerator according to the second aspect, wherein the cold head (36),
The heat dissipating member (38) and the dewar mounting flange (37) are integrally joined to the cylinder body (35) by vacuum brazing.

With this configuration, the cold head (36), the heat radiating member (38) and the dewar mounting flange (37) are firmly joined to the cylinder body (35).

According to a fourth aspect of the present invention, there is provided a method of manufacturing a cylinder by externally fitting a cold head, a heat radiating member, and the like to a cylindrical cylinder body. That is, the expander (2) and the compressor (1) in which the free displacer (31) is reciprocally inserted into the cylinder (30) whose tip is covered by the vacuum dewar (34) are connected to the connecting pipe (9). ), The refrigerant compressed by the compressor (1) is supplied to the expander (2) by the connecting pipe (9), and the refrigerant is expanded by the reciprocating motion of the free displacer (31) in the expander (2). The method is based on a method of manufacturing a Stirling refrigerator that generates cold at the tip of the cylinder (30). Then, at the distal end of the cylindrical cylinder body (35), a bottomed cylindrical cold head (36) having an inner diameter substantially matching the outer diameter of the cylinder body (35) is provided. The heat dissipating member (38), which has a central hole (38c, 37a, 39a) having a diameter substantially matching the outer diameter of the cylinder body (35), and a dewar mounting flange for supporting the vacuum dewar (34) (37) and a connecting pipe support member (39) for supporting one end of the connecting pipe (9) are respectively externally fitted, and then a brazing material is arranged at each fitting portion. Then, the brazing material is melted in a vacuum furnace to integrally join the fitting parts. Further, thereafter, the free displacer (31) is inserted into the inside of the cylinder body (35) from the base end side thereof.

According to this method, the cold head (36), the heat dissipating member (38), the dewar mounting flange (37) and the connecting pipe supporting member (39) are integrally fitted to the cylinder body (35) in an externally fitted state. Since the fitting portions are joined by vacuum brazing, the appearance of these joining portions is good.

[0017]

Next, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a compressor (1) and an expander (2) for a Stirling refrigerator according to the present embodiment, respectively. First, the compressor (1) will be described. The compressor (1) is a piston-facing linear motor compressor, has a closed cylindrical casing (3), and a cylinder member (4) is disposed inside the casing (3). ing. Further, the casing (3) includes a cylindrical body (3a) having both ends opened, and disc-shaped closing plates (3b, 3b) for closing open portions at both ends of the cylindrical body (3a). . The cylinder member (4) is made of pure iron, and is provided at an outer cylinder (4a) fixed to the inner wall of the casing (3) and at a position inside the outer cylinder (4a) at a predetermined interval. Donut-shaped connecting part with the inner cylinder (4b)
The outer cylinder (4a) and the inner cylinder (4b) are connected to each other, and a cylindrical recess (4d) concentric with the cylinder member (4) is formed between the outer cylinder (4a) and the inner cylinder (4b). Further, the inner cylinder (4b) is a part which becomes an original cylinder, and the center thereof is formed in the piston insertion hole (5).

A piston (6, 6) is inserted into the piston insertion hole (5) of the cylinder inner cylinder (4b) from each of the left and right sides in FIG. 1, and a cylinder is inserted between the pistons (6, 6). A portion surrounded by the inner cylinder (4b) is formed in the compression chamber (7). The outer diameter of the piston (6) is
(4b) is formed to have a slightly smaller diameter than the inner diameter thereof, and a small gap of, for example, about 10 μm is formed between the two, and this small gap is sealed by a clearance seal or a fluid seal to form the compression chamber (7). ) Airtightness. Further, in the present embodiment, a sealing material (6a) is provided on the outer peripheral surface of the piston (6).

Further, a gas passage (8) extending in a radial direction from the piston insertion hole (5) is formed in the cylinder member (4), and an inner end of the gas passage (8) is connected to the compression chamber (7). Opening,
The gas passage (8) communicates with an internal passage (9a) of a connecting pipe (9) connected to the outer peripheral surface of the casing (3), and communicates with the compressor (1) through the connecting pipe (9). Machine (2) is connected.

The pistons (6, 6) are drivingly connected to linear motors (10, 10) for reciprocatingly driving the pistons (6, 6). That is, each linear motor (10,10)
Has a permanent magnet (11) and a coil (12).
The permanent magnet (11) is an inner cylinder (4b) of the cylinder member (4).
Is formed of a cylindrical magnet externally fitted on the outer peripheral surface. As a result, a magnetic circuit is formed by the permanent magnet (11) using the cylinder member (4) made of pure iron as a yoke portion, and a magnetic field of a predetermined strength is formed around the periphery. The pistons (6) are integrally supported by a substantially inverted cup-shaped bobbin (13). Specifically, the bobbin (13) includes a cylindrical bobbin main body (20) and a disc-shaped piston mounting portion provided on one side edge (left and right outer edges in FIG. 1) of the bobbin main body (20). (21). And the bobbin main body (20)
In a part of the outer peripheral surface of the above, at a position facing the permanent magnet (11), a coil winding part (13a) having an outer diameter smaller than that of the other part is formed. Department
A coil (12) is wound around (13a), and the coil (12) is located in the magnetic field of the magnetic circuit.

A current introducing terminal (26, 26) is provided on the closing plate (3b) of the casing (3), and one end of a lead wire for supplying current to the coil (12) is connected to the current introducing terminal. Terminal
(26,26).

In each of the pistons (6, 6),
A spring mounting member (16) having a spring mounting seat (16a) is inserted, and at the tip of the piston (6),
A through hole is formed in the axial direction of the piston (6), and a female screw is formed in the spring mounting member (16) correspondingly. A screw (N) is screwed into the piston (6) from the distal end side. The spring mounting member (16) is
(6) is integrated. Also the casing
A spring mounting seat (3d) having the same shape as above is projected from a central portion of the closing plate (3b) of the (3) facing the piston (6), and each of the spring mounting seats (16a, 3d) is protruded. A spring (14) elastically supports the piston (6) so as to reciprocate in the cylinder member (4).

The compression mechanism is constructed in this manner, and has a predetermined frequency (for example, 5) corresponding to the natural frequency determined by the mass of each piston (6, 6) and the spring constant of the spring (14).
0Hz) AC current to the coils of both linear motors (10,10)
By energizing in synchronization with (12,12), both pistons
(6, 6) is reciprocated in the opposite direction at the above-mentioned natural frequency to generate a gas pressure of a predetermined cycle in the compression chamber (7).

Next, the expander (2) to which the refrigerant is supplied by the connecting pipe (9) will be described. This expander (2)
As shown in FIG. 2, a cylinder (30) and a free displacer fitted reciprocally within the cylinder (30).
(31), and the outer periphery of the cylinder (30) is covered with a vacuum dewar (34).

Hereinafter, each member will be described. Cylinder
As shown in FIGS. 3 and 4, a cold head (36) is attached to the tip of the cylinder main body (35), as shown in FIGS.
However, the Dewar mounting flange (37) on the base end
(38) and the pipe connecting member (39) are externally fitted and integrally assembled.

The cylinder body (35) is made of, for example, stainless steel, and is formed of a thin straight pipe having a slightly larger diameter than the free displacer (31) and open at both ends.
The outer diameter and the inner diameter are formed uniformly over the longitudinal direction.

The cold head (36) constitutes a part that generates cold as the refrigerator is driven, and has a cylindrical shape with a bottom and made of a material having high thermal conductivity (eg, copper). It consists of members. The inner diameter dimension substantially matches the outer diameter dimension of the cylinder body (35), and is externally fitted to the tip of the cylinder body (35). That is, the distal end of the cylinder body (35) is closed by the cold head (36), and as shown in FIG. 2, the expansion chamber is interposed between the cold head (36) and the free displacer (32) at this distal end.
(30a) is formed.

The dewar mounting flange (37) is made of a thin plate-like member having a relatively large diameter, and has a central opening (37a) having a central portion substantially corresponding to the outer diameter of the cylinder body (35).
Are formed. Also, this Deur mounting flange
Screw holes (37b, 37b,...) For screwing the vacuum dewar (34) are formed in a plurality of places (for example, four places in the circumferential direction) of the outer peripheral edge of (37).

The heat radiating member (38) is for releasing heat taken from the outside air at the cold head (36) at the base end portion of the cylinder (30), and is similar to the cold head (36). A plurality of radiation fins (38b, 38b, ...) extending toward the outer peripheral side are formed integrally on the outer peripheral surface of the cylindrical main body (38a). Made up of In addition, a central opening (3) that substantially matches the outer diameter of the cylinder body (35) is also provided at the center of the body (38a).
8c) is formed. Both ends of the heat dissipation member (38) in the extension direction of the central opening (38c) are formed to have a slightly larger diameter.

The pipe connecting member (39) is a cylindrical member for connecting one end (the connecting end on the expander side) of the connecting pipe (9) to the cylinder (30), and is provided in the axial direction. Through holes (3
9a, 39b) are formed. These through holes (39a, 39b)
A first through hole (39a) located closer to the heat radiating member (38) than an intermediate portion in the height direction (axial direction) of the pipe connecting member (39);
(9) The second through hole (39b) located on the side. And
The diameter of the first through hole (39a) is substantially equal to the outer diameter of the cylinder body (35), while the diameter of the second through hole (39b) is the third diameter of a spring holding member (44) described later. It corresponds to the outer diameter of the portion (44d) (see FIG. 5).

As described above, the inner diameter of the cold head (36), the central opening (37a) of the dewar mounting flange (37),
The diameter of the central opening (38c) of the heat radiating member (38) and the diameter of the first through hole (39a) of the pipe connecting member (39) substantially match the outer diameter of the cylinder body (35).

As an operation for assembling these members integrally, as shown in FIG. 3, first, the cold head (36) is externally fitted to the tip of the cylinder body (35). On the other hand, the dewar mounting flange (37), the heat radiating member (38), and the pipe connecting member (39) are sequentially fitted from the base end side of the cylinder body (35) and overlapped with each other. Then, a brazing material is arranged at each fitting portion, and the casing in which a plurality of members are combined in this way is heated in a vacuum furnace, and the brazing material is melted. The brazing material flows, and these fitting portions are joined by brazing. Thus, the cylinder (30) of the expander (2)
Is produced (see FIG. 4).

On the other hand, the free displacer (31) is inserted into the cylinder (30) so as to partition the space inside the cylinder (30) into an expansion chamber (30a) and a working chamber (30b). More specifically, a cylindrical cold storage material (41a) is filled in a cylindrical displacer case (41), and both ends of the displacer case (41) are closed by closing members (42, 43). Then, the refrigerant gas is supplied to the expansion chamber (3
0a) is provided with a first communication hole (42a) for flowing the refrigerant gas between the working chamber (30b) and the second closing hole (43) on the base end side. A communication hole (43a) is provided. Further, a spiral groove for mounting one end of a displacer spring (32) described later is formed on the outer peripheral surface of the end of the base end side closing member (43).

The expander (2) in the connecting pipe (9)
A spring holding member (44) is attached to the end connected to the spring. The spring holding member (44) has a through hole (44) having the same diameter as the diameter of the internal passage (9a) of the connecting pipe (9).
a) is formed. The outer diameter of the spring holding member (44) is different at four locations in the axial direction. Explaining the outer diameter of each part, the first portion (44b) on the distal end side is formed to be slightly smaller in diameter than the cylinder body (35), and the proximal end side closing member (43)
Similarly, a spiral groove for mounting the other end of the displacer spring (32) is formed. This first part (4
The outer second portion (44c) of 4b) is formed to have substantially the same diameter as the inner diameter of the cylinder body (35). Further, the third portion (44d) outside the second through-hole (3d) of the pipe connecting member (39) is provided.
9b) is formed with substantially the same diameter. In addition, the fourth outside
The portion (44e) is a portion to which the connecting pipe (9) is mounted, and has the same diameter as the second portion (44c).

Each end of the displacer spring (32) is mounted in each of the spiral grooves of the first portion (44b) of the spring holding member (44) and the proximal end closing member (43). The free displacer (31) is elastically supported by the spring holding member (44) and the connecting pipe (9) via the element (32).

The free displacer (31) thus constructed is inserted into the cylinder (30) from the proximal end side as shown in FIG. 5, and the spring holding member (44) is connected to the pipe connecting member (39). The expander (2) is formed by welding these two pieces while being fitted to the inner surface.

Next, the vacuum dewar (34) will be described. As shown in FIG. 2, the vacuum dewar (34) is supported by the dewar mounting flange (37) and covers the cylinder (30) and the cold head (36). More specifically, the vacuum dewar (34) has a bottomed cylindrical dewar body (46) made of, for example, glass, and an open end of the dewar body (46). And a metal (for example, stainless steel) flange portion (47) attached thereto. In the flange portion (47), similar screw holes (47a, 47a,...) Are formed corresponding to the screw holes (37b, 37b,...) Of the dewar mounting flange (37).

The vacuum dewar (34) formed as described above has the dewar body (46) covering the outer periphery of the cold head (36) and the cylinder body (35), and the flange part (47).
Is superimposed on the Dewar mounting flange (37) via packing, and the screw (N) is attached over each screw hole (37b, 47a), so that it is integrally assembled with the expander (2). I have. As a result, the cylinder (30) and the cold head (3
By maintaining a vacuum around 6), the occurrence of dew condensation on the cold head (36) during cold weather is suppressed. Also, the dewar body of this vacuum dewar (34)
An infrared sensor (50) to be cooled by the refrigerator is attached to the end face of (46), and is cooled by cold generated in the cold head (36).

Next, the operation of the above-structured Stirling refrigerator will be described. During this operation,
The coil (1) of both linear motors (10, 10) in the compressor (1)
An alternating current of a predetermined frequency (50 Hz) is synchronously applied to (2,12), and the coils (12,12) and (12,12) The pistons (6, 6) reciprocate in opposite directions while deforming the springs (14).
Move in synchronization with each other in the cylinder member (4), the volume of the compression chamber (7) increases or decreases, and a pressure wave of a predetermined cycle is generated in the compression chamber (7). And this compression chamber (7) is connected pipe
(9) communicates with the expander (2).
In (2), the free displacer (31) reciprocates in the same cycle as the pressure wave in the compression chamber (7), and the expansion of the gas in the expansion chamber (30a) causes chilling.
By repeating the reciprocating motion of (31), the cold head at the tip of the cylinder (30) is cooled to a cryogenic level.

As described above, in this embodiment, the cylinder (30) of the expander (2) is connected to the straight tubular cylinder body (35).
Since the members (36, 37, 38, 39) were externally fitted to each other and made by brazing in a vacuum furnace,
The assembling operation of (30) is simple, and good assembling accuracy can be obtained. Also, by making the inner diameter of each member (36, 37, 38, 39) substantially coincide with the outer diameter of the cylinder body (35), these can be assembled well to the cylinder body (35). Therefore, the design of each member is simple. Further, not only the joint strength of each fitting portion is sufficiently obtained, but also the appearance of each portion can be obtained well.

In each of the above embodiments, the cylinder member
The type of compressor in which the sealing material (6a) is interposed between (4) and the piston (6) has been described, but it is set so that there is a small gap between the cylinder member (4) and the piston (6). It may be applied to a non-contact type compressor described above.

Although the case has been described where the infrared sensor (50) to be cooled is disposed on the end face of the vacuum dewar (34), the present invention provides an infrared sensor (50) on the tip face of the cold head (36). The present invention can also be applied to a device to which is directly attached.

[0043]

As described above, according to the present invention, the following effects can be obtained. According to the invention as set forth in claim 1, a cold head whose inner diameter dimension substantially matches the outer diameter dimension of the cylinder main body is provided at the distal end of the cylindrical cylinder main body with respect to the expander of the Stirling refrigerator. Since the heat dissipating members each having a center hole having a diameter substantially corresponding to the outer diameter of the cylinder body are externally fitted to each other to form the cylinder, the assembling work of the cylinder is simplified and the assembling accuracy is improved. Can be obtained. In other words, according to the thermal conductivity required by each part of the cylinder, the workability of assembling in the case of integrally assembling the cylinder with a plurality of parts made of different materials is good, and the cylinder with high accuracy Can be obtained. Also, by making the inner diameter of the cold head and the diameter of the center hole of the heat radiating member substantially correspond to the outer diameter of the cylinder body, respectively, these can be satisfactorily assembled to the cylinder body. The design is simple.

According to the second aspect of the present invention, the dewar mounting flange for supporting the vacuum dewar covering the outer periphery of the cold head is externally fitted to the cylinder body, so that the dewar mounting flange is also described above. Similarly to the cold head and the heat radiating member according to the first aspect of the present invention, it is possible to accurately assemble the cylinder body with a simple assembling operation. Accordingly, it is possible to provide the cylinder body with a mounting flange having a plate thickness dimension that can be reduced to the tightening torque when screwing the vacuum dewar while allowing the wall thickness of the cylinder body to be set as small as possible. For this reason, a vacuum state around the cold head can be obtained satisfactorily while avoiding a decrease in the capacity of the refrigerator due to heat conduction in the cylinder body, and the occurrence of dew condensation on the cold head can be reliably prevented.

According to the third aspect of the present invention, since the cold head, the heat radiating member, and the dewar mounting flange are integrally joined to the cylinder body by vacuum brazing, these members are firmly attached to the cylinder body. And expandability of the expander can be improved.

According to the fourth aspect of the present invention, the cold head, the heat radiating member, the dewar mounting flange, and the connecting pipe supporting member are integrally joined to the cylinder body in an externally fitted state, and each of the fitted portions is joined. Are joined by vacuum brazing, so that the appearance of these joined portions can be ensured well.
Thereby, the practicality of the Stirling refrigerator can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an internal structure of a linear motor compressor.

FIG. 2 is a sectional view showing an internal structure of the expander.

FIG. 3 is a cross-sectional view for explaining an assembling operation of a cylinder of the expander.

FIG. 4 is a sectional view showing a cylinder of the expander.

FIG. 5 is a cross-sectional view for explaining an operation of inserting a free displacer into a cylinder.

[Explanation of symbols]

 (1) Compressor (2) Expander (30) Cylinder (31) Free displacer (34) Vacuum dewar (35) Cylinder body (36) Cold head (37) Dewar mounting flange (38) Heat dissipation member (37a, 38c) Central opening

Claims (4)

[Claims] 1. A free displacer in a cylinder (30).
Expander (2) and compressor (1) with (31) inserted reciprocally
And the refrigerant compressed by the compressor (1) is expanded by the expander (2).
To the free displacer in the expander (2).
In a Stirling refrigerator in which the refrigerant expands by the reciprocating motion of (31) to generate cold at the tip of the cylinder (30), the cylinder (30) is configured such that the tip of the cylinder (30) moves relative to the cylindrical cylinder body (35). In addition, a cylindrical cold head (36) with a bottom whose inner diameter dimension substantially matches the outer diameter dimension of the cylinder body (35),
Further, a heat radiating member (38) having a center hole (38c) having a diameter substantially matching the outer diameter of the cylinder main body (35) is fitted to the base end portion, and each of the heat radiating members (38) is configured to be fitted to the outside. Stirling refrigerator. 2. The outer periphery of the cold head (36) is covered by a vacuum dewar (34), and the cylinder body (35) has a diameter substantially equal to the outer diameter of the cylinder body (35). 2. A Stirling refrigerator according to claim 1, wherein a dewar mounting flange (37) having a center hole (37a) and supporting said vacuum dewar (34) is externally fitted. 3. The cold head (36), the heat dissipating member (38) and the Dewar mounting flange (37) are integrally joined to the cylinder body (35) by vacuum brazing. Item 2. A Stirling refrigerator according to Item 2. 4. An expander (2) and a compressor (1) having a free displacer (31) inserted in a reciprocatingly movable manner into a cylinder (30) whose tip is covered by a vacuum dewar (34). tube
(9), the refrigerant compressed by the compressor (1) is supplied to the expander (2) by the connecting pipe (9), and the refrigerant is reciprocated by the free displacer (31) in the expander (2). In a method for manufacturing a Stirling refrigerator in which cold is generated at the tip of a cylinder (30) by expansion, an inner diameter of an outer diameter of a cylinder body (35) is added to a tip of a cylindrical cylinder body (35). A cylindrical cold head (36) with a bottom substantially matching the dimensions, and a center hole (38) having a diameter substantially matching the outer diameter of the cylinder body (35) at the base end.
c, 37a, 39a), a vacuum dewar,
After fitting a dewar mounting flange (37) for supporting the (34) and a connecting pipe support member (39) for supporting one end of the connecting pipe (9), respectively, the brazing material is attached to each fitting part. After that, the brazing material is melted in a vacuum furnace to join the respective fitting portions together, and then, inside the cylinder body (35), the free displacer (31) is inserted from its base end side. And a method for producing a Stirling refrigerator.