JP2006284061A - Pulse pipe refrigerating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat exchanging efficiency and to reduce costs in a pulse pipe refrigerating machine provided with a heat exchanger on an end portion of a pulse pipe. <P>SOLUTION: In this pulse pipe refrigerating machine having pressure vibration generators 21, 23A, 23B generating pressure vibration to a helium gas, cold storage units 22A, 22B of first and second stages, pulse pipes 26A, 26B of first and second stages, and phase control mechanisms 28A, 28B, 27a-27d, a cooling stage member 50 functioned as the heat exchanger, is mounted on a connection part of the cold storage unit 22B of the second stage and the pulse pipe 26B of the second stage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pulse tube refrigerator, and more particularly to a pulse tube refrigerator in which a heat exchanger is disposed at an end of a pulse tube.

  In general, the pulse tube refrigerator includes a pressure vibration generator, a regenerator, a pulse tube, a phase control mechanism, and the like. This pulse tube refrigerator is superior in quietness compared to GM refrigerators and Stirling refrigerators, so it is expected to be applied as a cooling device for various inspection / analyzers such as nuclear magnetic resonance diagnostic equipment (NMR) and electron microscopes. Has been.

  FIG. 8 shows a known double inlet type pulse tube refrigerator. In the figure, the helium compressor 1, the high pressure valve 3a, and the high pressure valve 3b constitute a pressure vibration generator. The high pressure valve 3 a is disposed on the high pressure gas output side of the helium compressor 1, and the low pressure valve 3 b is disposed on the gas recovery side of the helium compressor 1. This pressure vibration generator is connected to the high temperature part 2 a of the regenerator 2. The high-pressure valve 3a and the low-pressure valve 3b are configured to be switched at a predetermined cycle. Therefore, the high-pressure helium gas generated by the helium compressor 1 is supplied to the regenerator 2 at a predetermined cycle. Has been.

  The upper ends of the regenerator 2 and the pulse tube 6 are supported by a stainless steel housing 12. Further, the lower ends of the regenerator 2 and the pulse tube 6 are connected by a connection path 4. Specifically, a heat exchanger 5 b is provided at the lower end portion of the pulse tube 6, and the heat exchanger 5 b and the low temperature portion 2 b of the regenerator 2 are connected by a connection path 4. .

  A buffer tank 8 is connected to the high temperature side (upper end side) of the pulse tube 6 through a heat exchanger 5a and an orifice 7a. Further, a bypass passage 9 is provided between a pipe connecting the pressure vibration generator and the regenerator 2 and a pipe connecting the pulse tube 6 and the buffer tank 8. 7b is provided.

  The regenerator 2 is filled with a regenerator material such as copper or stainless steel wire mesh, and the heat exchangers 5a and 5b are filled with a punching plate such as aluminum or a copper mesh 10 as a heat exchange member. Has been. 11 is a rectifier.

  In the above-described pulse tube refrigerator, when the high pressure valve 3a is opened and the low pressure valve 3b is closed to enter the operation mode, the high pressure helium gas compressed by the compressor 1 flows into the regenerator 2. The helium gas that has flowed into the regenerator 2 is cooled by the regenerator material disposed in the regenerator 2, and flows into the heat exchanger 5b from the low temperature portion 2b of the regenerator 2 through the connection path 4 while lowering the temperature. Then, it is further cooled and flows into the low temperature side of the pulse tube 6.

  Since the low-pressure gas already existing in the pulse tube 6 is compressed by the newly introduced working gas, the pressure in the pulse tube 6 becomes higher than the pressure in the buffer tank 8. For this reason, the working gas in the pulse tube 6 flows into the buffer tank 8 through the orifice 7a.

  Next, when the high pressure valve 3a is closed and the low pressure valve 3b is opened, the working gas in the pulse tube 6 flows into the low temperature portion 2b of the regenerator 2 and passes through the regenerator 2 from the high temperature portion 2a. It is recovered to the compressor 1 via the low pressure valve 3b.

  As described above, the high temperature side of the pulse tube 6 and the high temperature portion 2a side of the regenerator 2 are connected by the bypass passage 9 having the orifice 7b. For this reason, the phase of the pressure fluctuation and the phase of the volume change of the working gas change with a certain phase difference. Due to this phase difference, cold accompanying the expansion of the working gas is generated at the low temperature end of the pulse tube 6, and the above process is repeatedly performed to act as a refrigerator. In the double orifice type pulse refrigerator, the phase difference can be adjusted by adjusting the orifice 7 b provided in the bypass passage 9.

  In order to improve cooling efficiency and heat transfer characteristics, heat exchangers 5a and 5b are disposed at the upper and lower ends of the pulse tube 6, but the heat exchanger 5b disposed particularly at the lower end. As shown in an enlarged view in FIG. 9, the heat exchanger 5b has a structure in which a metal mesh 10 (mesh) made of aluminum or copper is laminated.

  On the other hand, what was disclosed by patent document 1 is known as a heat exchanger of another structure. FIG. 10 (a configuration corresponding to the configuration shown in FIG. 9 is given the same reference numeral) shows a heat exchanger 5c provided in the pulse refrigerator disclosed in Patent Document 1.

The heat exchanger 5c is a heat exchanger main body having a plurality of vertical slits 14 formed in the vertical direction in the figure and an arcuate slit 15 connected to the lower end of the vertical slit 14 and extending in the horizontal direction in the figure. A portion 13 is provided. The arcuate slit 15 is connected to the connection path 4 via a connection hole 16 formed in the heat exchanger 5c. The heat exchanger 5c is configured such that heat exchange is performed between the helium gas and the heat exchange main body 13 in the process in which helium gas passes through the vertical slit 14 formed in the heat exchange main body 13. .
JP 2002-257428 A

  By the way, in order to improve the cooling characteristics in the pulse tube refrigerator, it is important to efficiently extract the cold generated by the adiabatic expansion of the working gas in the pulse tube 6, and for this reason, it is disposed on the low temperature side of the pulse tube 6. It is important to improve the heat exchange characteristics of the heat exchanger 5b.

  However, in the conventional heat exchanger 5b shown in FIG. 9, it is necessary to fix the copper mesh 10 to the housing of the heat exchanger 5b by brazing or the like. In this case, the thermal resistance at the brazing portion increases. As a result, there is a problem that the heat exchange characteristics of the heat exchanger 5b deteriorate. Moreover, in the heat exchange by the metal mesh 10 made of aluminum or copper, the ratio between the heat exchange area and the dead volume is low and the dead volume is large, which also deteriorates the heat exchange characteristics of the heat exchanger 5b.

  In addition, since the heat exchanger 5c shown in FIG. 10 performs heat exchange through the longitudinal slit 14 provided in the heat exchange main body 13 disposed in the pulse tube 6, the heat exchange area is widened. The ratio between the heat exchange area and the dead volume can be increased. Therefore, heat exchange characteristics can be improved as compared with the heat exchanger 5b shown in FIG.

  However, in the heat exchanger 5c, a number of vertical slits 14 are formed in the heat exchanger main body 13 in the vertical direction in the figure, and an arcuate slit 15 is formed at the lower end so as to be connected to the lower end of the vertical slit 14. There is a problem that the configuration of the heat exchanger main body 13 is complicated, the manufacturing efficiency is poor, and the manufacturing cost increases. In addition, since the cold extraction site (that is, the thermal connection position with the object to be cooled) is limited to the lower end portion of the pulse tube 6, there is a problem that the cooling of the object to be cooled is restricted.

  The present invention has been made in view of the above points, and an object thereof is to provide a pulse tube refrigerator having a heat exchanger with high heat exchange efficiency and low cost.

  In order to solve the above-described problems, the present invention is characterized by the following measures.

The invention according to claim 1
A pressure vibration generator for generating a pressure vibration for the working gas;
A regenerator connected to the pressure fluctuation source;
A pulse tube connected to the regenerator;
In a pulse tube refrigerator having a phase control mechanism connected to the pulse tube,
A heat exchanger is provided at a site where the regenerator and the pulse tube are connected.

  According to the above invention, the heat exchanger is provided not at the inside of the pulse tube but at the portion where the regenerator and the pulse tube are connected, so that a large space for heat exchange can be taken, and the cooling efficiency is improved. Can be increased. Moreover, since the cooling process can be performed in a relatively wide range as compared with the lower end portion of the pulse tube, usability can be improved.

The invention according to claim 2
The pulse tube refrigerator according to claim 1, wherein
The heat exchanger is
A regenerator connection to which the regenerator is connected;
A pulse tube connection to which the pulse tube is connected;
A plurality of flow passages are formed between the regenerator connection portion and the pulse tube connection portion so that the working gas can flow therethrough, and a stage member is provided.

  According to the above invention, the regenerator connecting portion and the pulse tube connecting portion are connected by the plurality of flow passages formed in the stage member. For this reason, when working gas distribute | circulates between a cool storage connection part and a pulse tube connection part, it can take widely compared with the case where the contact area which a working gas contacts with a stage member is made into a single channel | path. Thereby, the heat exchange efficiency between working gas and a stage member can be raised, and a stage member can be cooled efficiently.

The invention according to claim 3
In the pulse tube refrigerator according to claim 2,
The flow path is a slit.

  According to the above invention, since the slit is easy to form, the flow passage can be formed easily and at low cost.

The invention according to claim 4
The pulse tube refrigerator according to claim 3,
While providing a lid that covers the stage member in an airtight manner,
The regenerator connecting portion and the pulse tube connecting portion are provided on the lid so as to face the slit.

  According to the above invention, since the regenerator connecting part and the pulse tube connecting part are provided in the lid part and the slit is provided in the stage member, the regenerator connecting part and the pulse are separately provided in the independent lid part and the stage member, respectively. A pipe connection part and a slit can be formed. For this reason, compared with the structure which forms a cool storage connection part, a pulse tube connection part, and a slit in the same member, formation of a cool storage device connection part, a pulse tube connection part, and a slit can be performed easily and at low cost.

The invention according to claim 5
In the pulse tube refrigerator according to claim 3 or 4,
The slit is formed integrally with the stage member.

  According to the above invention, the thermal resistance of the slit can be reduced as compared with the configuration in which the slit is formed by joining the plate material to the stage member by brazing or the like, so that the heat exchange efficiency of the heat exchanger is improved even if the slit is provided Can do.

  As described above, according to the present invention, it is possible to increase the heat exchange efficiency of the heat exchanger, and it is possible to increase the cooling processing area, so that the usability of the pulse tube refrigerator can be improved.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  1 and 2 show pulse tube coolers 20A and 20B in which the present invention can be implemented. A pulse tube cooler 20A shown in FIG. 1 is a two-stage double inlet type pulse tube cooler, and a pulse tube cooler 20B shown in FIG. 2 is a two-stage four-valve type pulse tube cooler. First, a two-stage double inlet type pulse tube cooler 20A will be described with reference to FIG.

  Since the pulse tube cooler 20A is a two-stage type, it has a first-stage regenerator 22A and a second-stage regenerator 22B as regenerators, and a first-stage pulse tube 26A as a pulse tube. A second stage pulse tube 26B. The high temperature portion 30a of the first stage regenerator 22A, the upper end portion of the first stage pulse tube 26A, and the upper end portion of the second stage pulse tube 26B are configured to be supported by the flange 32.

  The first-stage regenerator 22A and the second-stage regenerator 22B are configured to be directly connected. That is, the low temperature part 30b of the first stage regenerator 22A is connected to the high temperature part 31a of the second stage regenerator 22B. The low temperature part 30b of the first stage regenerator 22A and the lower end part of the first stage pulse tube 26A are connected by a connection path 24A. The low temperature part 31b of the second stage regenerator 22B and the lower end part of the second stage pulse tube 26B are connected by a second connection path 24B.

  Further, the helium compressor 21, the high pressure valve 23a, and the low pressure valve 23b constitute a pressure vibration generator. The high pressure valve 23 a is disposed on the high pressure gas output side of the helium compressor 21, and the low pressure valve 23 b is disposed on the gas recovery side of the helium compressor 21.

  This pressure vibration generator is connected to the high temperature part 30a of the first stage regenerator 22A. The high-pressure valve 23a and the low-pressure valve 23b are configured to be switched at a predetermined cycle. Therefore, the high-pressure working gas (helium gas in this embodiment) generated by the helium compressor 21 is changed at a predetermined cycle. It is supplied to the first stage regenerator 22A.

  The high temperature side (upper end side) of the first stage pulse tube 26A and the first buffer tank 28A are connected by a pipe 35b, and an orifice 27a is provided in the pipe 35b. A first bypass passage 29A is provided between the pipe 35a connecting the pressure vibration generator and the first stage regenerator 22A and the high temperature side of the first stage pulse pipe 26A. One bypass passage 29A is provided with an orifice 27b.

  On the other hand, the high temperature side (upper end side) of the second stage pulse tube 26B and the second buffer tank 28B are connected by a pipe 35c, and an orifice 27c is provided in the pipe 35c. Further, a second bypass passage 29B is provided between the pipe 35a and the high temperature side of the second stage pulse tube 26B, and an orifice 27d is provided in the second bypass passage 29B.

  In the pulse tube cooler 20A, when the high pressure valve 23a is opened and the low pressure valve 23b is closed to enter the operation mode, the high pressure helium gas compressed by the helium compressor 21 is first supplied through the pipe 35a. It flows into the stage regenerator 22A. The helium gas that has flowed into the first-stage regenerator 22A is cooled by the regenerator material disposed in the first-stage regenerator 22A to lower the temperature, and from the low temperature portion 30b of the first-stage regenerator 22A. A part thereof flows into the low temperature side (lower end side) of the first stage pulse tube 26A through the connection path 24A.

  Since the low-pressure helium gas already present in the first stage pulse tube 26A is compressed by the newly introduced helium gas, the pressure in the first stage pulse tube 26A is in the first buffer tank 28A. Higher than the pressure. For this reason, the helium gas in the first stage pulse tube 26A flows into the first buffer tank 28A through the orifice 27a.

  Next, when the high pressure valve 23a is closed and the low pressure valve 23b is opened, the helium gas in the first stage pulse tube 26A flows into the low temperature part 30b of the first stage regenerator 22A, and the first stage It passes through the regenerator 22A and is recovered from the high temperature portion 30a to the helium compressor 21 via the low pressure valve 23b.

  As described above, the high temperature side of the first stage pulse tube 26A and the pipe 35a are connected by the first bypass passage 29A having the orifice 27b. For this reason, the phase of pressure fluctuation and the phase of volume change of helium gas (working gas) change with a certain phase difference. Due to this phase difference, cold accompanying the expansion of the helium gas occurs at the low temperature end (lower end) of the first stage pulse tube 26A.

  On the other hand, in the operation mode in which the high pressure valve 23a is opened and the low pressure valve 23b is closed, the first stage pulse of the helium gas flowing from the helium compressor 21 into the first stage regenerator 22A through the pipe 35a. The helium gas that has not flowed into the pipe 26A flows from the first-stage regenerator 22A into the second-stage regenerator 22B.

  At this time, as described above, the helium gas cooled by the first stage pulse tube 26A flows into the low temperature part 30b of the first stage regenerator 22A, so the low temperature part 30b is cooled. Therefore, the helium gas flowing into the second stage regenerator 22B from the first stage regenerator 22A is cooled by the first stage pulse tube 26A and then flows into the high temperature portion 31a of the second stage regenerator 22B. To do.

  The helium gas flowing into the second-stage regenerator 22B is cooled by the regenerator material disposed in the second-stage regenerator 22B and reaches the low temperature part 31b while further lowering the temperature, and then the cooling stage member 50 And flows into the low temperature side (lower end) of the second stage pulse tube 26B. Since the low-pressure helium gas already existing in the second-stage pulse tube 26B is compressed by the newly introduced helium gas, the pressure in the second-stage pulse tube 26B is set at the second buffer tank 28B. Higher than the pressure inside. Therefore, the working gas in the second stage pulse tube 26B flows into the second buffer tank 28B through the orifice 27c.

  Next, when the high pressure valve 23a is closed and the low pressure valve 23b is opened, the helium gas in the second stage pulse tube 26B flows into the low temperature part 30b of the second stage regenerator 22B. The helium gas that has flowed into the low temperature section 30b of the second stage regenerator 22B further passes through the first stage regenerator 22A, and passes from the high temperature section 30a to the helium compressor 21 via the low pressure valve 23b. Collected.

  Further, as described above, the high temperature side of the second stage pulse tube 26B and the pipe 35a are connected by the second bypass passage 29B having the orifice 27d. Therefore, also in the second-stage pulse tube 26B, the phase of pressure fluctuation and the phase of volume change of helium gas (working gas) change with a constant phase difference. Due to this phase difference, cold accompanying the expansion of helium gas occurs at the low temperature end (lower end) of the second stage pulse tube 26B.

  In the two-stage double inlet pulse refrigerator 20A described above, the first buffer tank 28A, the second buffer tank 28B, and the orifices 27a to 27d constitute a phase control mechanism. Then, the phase difference can be adjusted by adjusting the orifices 27b and 27d provided in the first bypass passages 29A and 29B constituting the phase control mechanism, thereby achieving highly efficient cooling. it can. Further, the helium gas cooled by the first stage regenerator 22A and the first stage pulse tube 26A is further cooled by the second stage regenerator 22B and the second stage pulse tube 26B. Therefore, the temperature on the cooling side of the second stage pulse tube 26B can be made extremely low (for example, about 4K).

  Next, a two-stage four-valve type pulse tube cooler 20B will be described with reference to FIG. In FIG. 2, the same components as those of the pulse tube cooler 20A shown in FIG.

  In the two-stage four-valve type pulse tube cooler 20B, two pipes 35d and 35e are connected to the high temperature side of the first stage pulse tube 26A, and the high temperature side of the second stage pulse tube 26B. Also, two pipes 35f and 35g are connected. The pipe 35d connected to the first stage pulse tube 26A is connected to the supply side (high pressure side) of the helium compressor 21 via the orifice 27e and the high pressure valve 33a. The pipe 35g connected to the second stage pulse tube 26B is connected to the supply side (high pressure side) of the helium compressor 21 via the orifice 27f and the high pressure valve 34a.

  The other pipe 35e connected to the high temperature side of the first stage pulse tube 26A is connected to the supply side (high pressure side) of the helium compressor 21 via the orifice 27e and the high pressure valve 33a. Further, the other pipe 35f connected to the high temperature side of the second stage pulse tube 26B is connected to the gas recovery side (low pressure side) of the helium compressor 21 via the orifice 27d and the low pressure valve 34b.

  Thus, in the 4-valve type pulse tube cooler 20B, the pipes 35d and 35g connected to the high pressure side of the helium compressor 21 on the high temperature side of the regenerators 22A and 26B, respectively, and the low pressure of the helium compressor 21 Pipings 35e and 35f connected to the side are connected. In addition, orifices 27b, 27d, 27e, and 27f, high pressure valves 33a and 34a, and low pressure valves 33b and 34b are disposed in the respective pipes 35d to 35g, and the flow of helium gas in each of the pipes 35d to 35g is determined. It is set as the structure which can be controlled.

  In the four-valve type pulse tube cooler 20B, the first buffer tank 28A, the second buffer tank 28B, the orifices 27a to 27f, and the various valves 33a, 33b, 34a, and 34b constitute a phase control mechanism. By adjusting the orifices 27b, 27d, 27e, and 27f and the valves 33a, 33b, 34a, and 34b, the phase of the pressure fluctuation between the first-stage regenerator 22A and the first-stage pulse tube 26A and helium are adjusted. The phase of the volume change of the gas (working gas) and the phase of the pressure fluctuation between the second stage regenerator 22B and the second stage pulse tube 26B and the phase of the volume change of the helium gas are controlled to a constant phase difference. Therefore, highly efficient cooling can be performed in each of the pulse tubes 26A and 26B.

  Then, the cooling stage member 50 used as the principal part of this invention is demonstrated. As described above, the cooling stage member 50 connects the low temperature part 31b of the second stage regenerator 22B and the lower end part of the second stage pulse tube 26B. As shown in FIG. 3, the cooling stage member 50 includes a cooling stage main body 51 and a lid 52, and functions as a heat exchanger as will be described later.

  The cooling stage body 51 and the lid body 52 are both made of a material such as copper having a high thermal conductivity. The cooling stage main body 51 is a disk-shaped member, and the lid body 52 is mounted so as to cover the cooling stage main body 51. A plurality of slits 53 are formed in the cooling stage body 51. In this embodiment, the slit 53 is constituted by a linear groove.

  On the other hand, a cold tube connection hole 54 and a pulse tube connection hole 55 are formed in the lid 52. The second-stage regenerator 22B is connected to the cold tube connection hole 54, and the second-stage pulse tube 26B (low temperature side) is connected to the pulse tube connection hole 55. The arrangement positions of the cold tube connection hole 54 and the pulse tube connection hole 55 are configured such that the connection holes 54 and 55 face the slit 53 in a state where the lid 52 is mounted on the cooling stage main body 51. Accordingly, when the state in which the lid 52 is mounted on the cooling stage main body 51 is viewed in plan, the slit 53 formed in the cooling stage main body 51 can be viewed through the connection holes 54 and 55 as shown in FIG. .

  In addition, with the lid 52 attached to the cooling stage main body 51, the portion of the top surface of the cooling stage main body 51 where the slit 53 is not formed is in airtight contact with the inner side surface of the top plate of the lid 52. State. Note that the method for joining the cooling stage main body 51 and the lid 52 is not particularly limited as long as both the methods 51 and 52 can be joined in an airtight manner.

  As described above, helium gas flows in both directions between the second-stage regenerator 22B and the second-stage pulse tube 26B in the operation mode, but in this embodiment, the slit formed in the cooling stage main body 51. 53, helium gas flows between the second stage regenerator 22B and the second stage pulse tube 26B. That is, the slit 53 functions as a flow path for flowing helium gas between the second-stage regenerator 22B and the second-stage pulse tube 26B.

  FIG. 5 is an enlarged view showing the slit 53. The width of the slit 53 (indicated by the arrow W in FIG. 5) can be set to 0.1 mm to 1.5 mm, and the height of the slit 53 (indicated by the arrow H in FIG. 5) is set to 1.0 mm to 10.0 mm. be able to. Further, from the viewpoint of workability of the slit 53 and heat exchange characteristics described later, the width W of the slit 53 is preferably set to 0.15 mm to 0.50, and the height of the slit 53 is preferably about 4.5 mm. .

  As a method of processing the slit 53, a cutting method, an etching method, and the like can be considered, but it is preferable to use a wire cutting method. When the wire cut method is used, the slit 53 (groove) can be formed easily and at low cost.

  As shown in FIGS. 1 and 2, the cooling stage member 50 configured as described above is disposed at a site where the second stage regenerator 22B and the second stage pulse tube 26B are connected. Therefore, the low temperature part 31b of the second stage regenerator 22B and the low temperature side of the second stage pulse tube 26B are connected by the cooling stage member 50. Specifically, helium gas flows through the slit 53 in the cooling stage member 50 between the second stage regenerator 22B and the second stage pulse tube 26B.

  Since the slit 53 is an aggregate of a plurality of grooves, when helium gas flows between the second-stage regenerator 22B and the second-stage pulse tube 26B, the area where the helium gas contacts the cooling stage body 51 is as follows. In comparison with the conventional communication path 4 (see FIG. 8), it can be made wider. Thereby, the heat exchange efficiency between a working gas and a stage member can be improved, and it becomes possible to cool a stage member efficiently.

  Thus, in this embodiment, the heat exchanger 5b is not provided on the low temperature side of the pulse tube 6 as in the prior art (see FIG. 8), but the second stage regenerator 22B, the second stage pulse tube 26B, The cooling stage member 50 which functions as a heat exchanger is provided in the site | part to which is connected. Thereby, the freedom degree of design of the cooling stage member 50 increases, it becomes possible to take a space for heat exchange, and cooling efficiency can be improved. Moreover, since the cooling process can be performed in a relatively wide range as compared with the conventional configuration in which the object to be cooled is cooled at the lower end of the pulse tube 6 pulse tube, the usability of the pulse tube coolers 20A and 20B Can be increased.

  Further, in this embodiment, the cooling stage member 50 is constituted by two members, a cooling stage main body 51 and a lid body 52, the connection holes 54 and 55 are provided in the lid body 52, and the slit 53 is provided in the cooling stage main body 51. Since it was set as the structure, compared with the structure which forms the slit 53 and each connection hole 54, 55 in the same member, formation of the slit 53 and each connection hole 54, 55 can be performed easily and at low cost.

  Further, in this embodiment, the slit 53 is formed integrally with the cooling stage main body 51 by a wire cutting method. For this reason, the thermal resistance of the slit 53 can be reduced as compared with the conventional structure in which the slit is formed by joining the plate material to the stage member by brazing or the like. Efficiency can be increased.

  6 and 7 show another embodiment of the present invention. In the above-described embodiment, an example in which the linear slit 53 is used as a flow path through which helium gas flows between the second-stage regenerator 22B and the second-stage pulse tube 26B is shown. On the other hand, in the embodiment shown in FIG. 6, the second-stage regenerator 22B and the second-stage pulse tube 26B are connected by a curved slit 56.

  As described above, the slit connecting the second-stage regenerator 22B and the second-stage pulse tube 26B is not limited to a straight line, and may be a curved shape shown in FIG. Various shapes such as a shape can be used. In this configuration, the contact area between the helium gas and the cooling stage main body 51 can be further increased, so that the heat conversion efficiency can be further increased.

  The embodiment shown in FIG. 7 is characterized in that the second stage regenerator 22B and the second stage pulse tube 26B are connected by a plurality of communication holes 59 instead of the grooves. Specifically, the second-stage regenerator 22B and the second-stage pulse tube 26B are connected to each other by a communication member 57 in which a plurality of communication holes 59 are formed in a main body 58 made of copper, aluminum or the like having good thermal conductivity. Connect. Also in the present embodiment, the contact area between the helium gas and the communication member 57 can be increased, and the heat exchange efficiency between the helium gas and the communication member 57 can be increased.

  In this embodiment, helium is used as the working gas, but nitrogen, hydrogen, or the like may be used.

FIG. 1 is a configuration diagram showing a two-stage double inlet type pulse tube cooler which is an embodiment of the present invention. FIG. 2 is a block diagram showing a two-stage four-valve type pulse tube cooler that is an embodiment of the present invention. FIG. 3 is an exploded perspective view showing, in an enlarged manner, the vicinity of the heat exchanger that is a main part of the present invention. FIG. 4 is a plan view of a heat exchanger as a main part of the present invention. FIG. 5 is an enlarged view showing a slit provided in the cooling stage member. FIG. 6 is a diagram illustrating a modified example of the slit. FIG. 7 is a view for explaining a modification using a connection member having a large number of connection holes instead of slits. FIG. 8 is a configuration diagram of a conventional pulse tube cooler. FIG. 9 is an enlarged cross-sectional view of a heat exchanger provided in a conventional pulse tube cooler (part 1). FIG. 10 is an enlarged cross-sectional view of a heat exchanger provided in a conventional pulse tube cooler (part 2).

Explanation of symbols

20A, 20B Pulse tube cooler 21 Helium compressor 22A First stage regenerator 22B Second stage regenerator 23a High pressure valve 23b Low pressure valve 24A First connection path 24B Second connection path 26A First stage pulse tube 26B First stage pulse tube 27a to 27f Orifice 28A First buffer tank 28B Second buffer tank 29A First bypass passage 29B Second bypass passage 32 Flange 33a, 34a High pressure valve 33b, 34b Low pressure valve 50 Cooling stage Member 51 Cooling stage main body 52 Lid 53, 56 Slit 54 Regenerator tube connection hole 55 Pulse tube connection hole 57 Connection member 58 Main body 59 Connection hole

Claims (5)

A pressure vibration generator for generating a pressure vibration for the working gas;
A regenerator connected to the pressure fluctuation source;
A pulse tube connected to the regenerator;
In a pulse tube refrigerator having a phase control mechanism connected to the pulse tube,
A pulse tube refrigerator, wherein a heat exchanger is provided at a site where the regenerator and the pulse tube are connected. The pulse tube refrigerator according to claim 1, wherein
The heat exchanger is
A regenerator connection to which the regenerator is connected;
A pulse tube connection to which the pulse tube is connected;
A pulse tube refrigerator having a plurality of flow passages connected to allow the working gas to flow between the regenerator connection portion and the pulse tube connection portion, and having a stage member. In the pulse tube refrigerator according to claim 2,
The pulse tube refrigerator, wherein the flow passage is a slit. The pulse tube refrigerator according to claim 3,
While providing a lid that covers the stage member in an airtight manner,
A pulse tube refrigerator, wherein the regenerator connection portion and the pulse tube connection portion are provided on the lid so as to face the slit. In the pulse tube refrigerator according to claim 3 or 4,
The pulse tube refrigerator, wherein the slit is formed integrally with the stage member.

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