JP2015075255A - Stirling type refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a plate spring mounted on a Stirling type refrigerator in a mounting position more surely.SOLUTION: A Stirling type refrigerator includes: a container; a movable member for reciprocating in the container; and a support part 40 for supporting the movable member in the container so that the movable member can reciprocate. The support member 40 includes at least one plate spring 48. The plate spring 48 includes an inner peripheral part 50 mounted on the movable member and an outer peripheral part 52 mounted on the container, and has a through-hole 62 in the outer peripheral part 52 or the inner peripheral part 50. The support part 40 includes a pin member 60 press-fitted in the through-hole 62.

Description

  The present invention relates to a Stirling refrigerator.

  Regarding a Stirling refrigerator, a linear motor compressor is known in which a movable body inside a linear motor compressor is supported by a flexure bearing. The flexure bearing has a hole through which a mounting screw is inserted. With screws, the inner peripheral fixed part of the flexure bearing is fixed to the movable body, and the outer peripheral fixed part is fixed to the housing of the compressor. The flexure bearing has an arm portion that connects the inner periphery fixing portion and the outer periphery fixing portion, and the movable body is allowed to move in the axial direction by bending of the arm portion.

Japanese Patent Laid-Open No. 11-173695 JP 2008-215440 A

  In general, there is a slight gap between the hole through which the screw is inserted and the screw. When the movable body moves in the axial direction, the inner peripheral fixing portion and the outer peripheral fixing portion of the leaf spring such as the flexure bearing described above are bent in the in-plane direction (for example, the circumferential direction) perpendicular to the axial direction. The force acts on. For this reason, the leaf spring can be laterally shifted in the in-plane direction from the designed arrangement within the above-described gap. Such lateral displacement may change some of the characteristics of the leaf spring (eg, spring constant) and may affect the motion of the movable body. Further, the movable body can also be displaced laterally with the lateral displacement of the leaf spring. Then, deterioration of these members may be promoted by friction between the movable body and the surrounding fixed parts, for example.

  One exemplary object of an aspect of the present invention is to securely hold a leaf spring attached to a Stirling type refrigerator by its attachment position.

  According to an aspect of the present invention, the apparatus includes a container, a movable member that reciprocates in the container, and a support portion that supports the movable member on the container so that the movable member can reciprocate. A Stirling refrigerator is provided. The support part includes at least one leaf spring. The leaf spring includes an inner peripheral portion attached to the movable member and an outer peripheral portion attached to the container, and has a through hole in the outer peripheral portion or the inner peripheral portion. The support part includes a pin member press-fitted into the through hole.

  Note that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention replaced with each other among methods, apparatuses, systems, and the like are also effective as an aspect of the present invention.

  According to the present invention, the leaf spring attached to the Stirling type refrigerator can be reliably held by the attachment position.

1 is a diagram schematically showing a Stirling refrigerator according to an embodiment of the present invention. It is a figure which shows roughly the expander of the Stirling refrigerator which concerns on one embodiment of this invention. The cross section seen from the dashed-dotted line A shown in FIG. It is a figure which shows the leaf | plate spring attachment structure which concerns on embodiment with this invention. It is a figure which shows the leaf | plate spring attachment structure which concerns on embodiment with this invention. It is a figure which shows the leaf | plate spring attachment structure which concerns on embodiment with this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Moreover, the structure described below is an illustration and does not limit the scope of the present invention at all.

  FIG. 1 is a diagram schematically showing a Stirling refrigerator 10 according to an embodiment of the present invention. The Stirling refrigerator 10 includes a compressor 11, a connecting pipe 12, and an expander 13.

  The compressor 11 includes a compressor case 14. The compressor case 14 is a pressure vessel configured to hold a high-pressure working gas in an airtight manner. The working gas is, for example, helium gas. The compressor 11 includes a compressor unit that is accommodated in the compressor case 14. The compressor unit includes a compressor piston and a compressor cylinder, one of which is a movable member 15 configured to reciprocate in the compressor case 14 and the other is fixed to the compressor case 14. It is a stationary member. The compressor unit includes a drive source for moving the movable member 15 relative to the compressor case 14 in a direction along the central axis of the movable member 15. The compressor 11 includes a support portion 16 that supports the movable member 15 on the compressor case 14 so that the movable member 15 can reciprocate. The movable member 15 vibrates with respect to the compressor case 14 and the stationary member with a certain amplitude and frequency.

  A working gas chamber is formed between the compressor piston and the compressor cylinder. This working gas chamber is connected to one end of the connection pipe 12 through a communication passage formed in the stationary member and the compressor case 14 described above. The other end of the connection pipe 12 is connected to the working gas chamber of the expander 13. In this way, the working gas chamber of the compressor 11 is connected to the working gas chamber of the expander 13 by the connection pipe 12.

  As will be described later with reference to FIG. 2, the expander 13 includes an expander container 20, a displacer 22, and a support unit 40.

  FIG. 2 is a diagram schematically showing an expander 13 according to an embodiment of the present invention. FIG. 2 shows an outline of the internal structure of the expander 13. FIG. 3 shows a cross section viewed from the alternate long and short dash line A shown in FIG.

  The expander 13 includes an expander container 20 and a displacer 22. The expander container 20 is a pressure container configured to hold a high-pressure working gas in an airtight manner. The displacer 22 is a movable member configured to reciprocate in the expander container 20. The expander 13 includes at least one support portion 40 that supports the displacer 22 on the expander container 20 so that the displacer 22 can reciprocate.

  The expander container 20 includes a first compartment 24 and a second compartment 26. The first compartment 24 includes a working gas expansion space 28 formed between the expander vessel 20 and the displacer 22. A portion of the expander container 20 adjacent to the expansion space 28 is provided with a cooling stage (not shown) for cooling the object. The second section 26 is configured to support the displacer 22 on the expander container 20 via the elastic member 30.

  The second section 26 is adjacent to the first section 24 in the reciprocating direction of the displacer 22 (indicated by an arrow C in the figure). A seal portion 25 is provided between the second compartment 26 and the first compartment 24, whereby the second compartment 26 is partitioned from the first compartment 24. Therefore, the pressure fluctuation of the working gas in the first section 24 is not transmitted to the second section 26 or does not significantly affect the pressure of the working gas in the second section 26.

  The displacer 22 includes a displacer main body 32 accommodated in the first section 24 and a displacer rod 34. The displacer rod 34 is a shaft portion that is thinner than the displacer main body 32. The displacer 22 has a central axis that is parallel to the reciprocating direction thereof, and the displacer main body 32 and the displacer rod 34 are provided coaxially with the central axis of the displacer 22.

  The displacer rod 34 extends from the displacer body 32 through the seal portion 25 to the second compartment 26. The displacer rod 34 is supported by the expander vessel 20 in the second compartment 26 to allow the displacer 22 to reciprocate. The above-described seal portion 25 may be, for example, a rod seal formed between the displacer rod 34 and the expander container 20.

  The first section 24 forms a cylinder portion that surrounds the displacer body 32. An expansion space 28 is formed between the bottom surface of the cylinder portion and the end surface of the displacer main body 32. The expansion space 28 is formed on the opposite side of the joint between the displacer body 32 and the displacer rod 34 in the reciprocating direction of the displacer 22. A gas space 36 connected to the connection pipe 12 (see FIG. 1) is formed between the joint portion and the seal portion 25.

  A regenerator 38 may be provided between the side surface of the cylinder part and the displacer main body 32. The regenerator 38 may be attached to the expander container 20. For example, the regenerator 38 has a laminated structure of wire mesh. Alternatively, a regenerator may be incorporated in the displacer main body 32. The working gas can be circulated between the expansion space 28 and the gas space 36 through a regenerator 38.

  The expander 13 supports the displacer 22 on the expander container 20 so that the displacer 22 can reciprocate at a plurality of different positions in the reciprocating direction of the displacer 22. For this purpose, the expander 13 includes two support portions 40. These two support portions 40 are provided in the second section 26. In this way, tilting of the displacer 22 with respect to the central axis can be suppressed.

  The support unit 40 includes the elastic member 30 described above. The elastic member 30 is disposed between the displacer rod 34 and the expander container 20 so that an elastic restoring force acts on the displacer 22 when the displacer 22 is displaced from the neutral position.

  The elastic member 30 includes, for example, a spring mechanism including at least one leaf spring 48. The elastic member 30 may include a laminated leaf spring portion 49 (see FIG. 5) in which a plurality of leaf springs 48 are arranged in the moving direction of the displacer 22. As shown in FIG. 3, the leaf spring 48 connects the inner peripheral portion 50 for fixing to the displacer rod 34, the outer peripheral portion 52 surrounding the inner peripheral portion 50, and the inner peripheral portion 50 and the outer peripheral portion 52. And a plurality of arms 54. The inner peripheral portion 50 is fixed to the elastic member attaching portion 51 of the displacer rod 34. The outer peripheral part 52 is fixed to the expander container 20. Due to the elastic deformation of the arm 54, axial relative displacement between the inner peripheral portion 50 and the outer peripheral portion 52 is allowed. The attachment structure of the leaf spring 48 will be described later with reference to FIGS. 4 and 5, and is not shown in FIG. 3.

  Such a leaf spring 48 is also called a flexure spring and is flexible in the reciprocating direction of the displacer 22 and rigid in a direction perpendicular to the reciprocating direction. Such a leaf spring is disclosed in, for example, Japanese Patent Application Laid-Open No. 2008-215440. This document is incorporated herein by reference in its entirety. Therefore, the displacer 22 is allowed to move in the direction along the central axis by the elastic member 30, but the movement in the direction orthogonal to the displacer 22 is restricted.

  In this way, a vibration system including the displacer 22 and the elastic member 30 is configured. This vibration system is configured such that the displacer 22 vibrates at the same frequency as the vibration of the movable member 15 of the compressor 11 and has a phase difference with the vibration. The displacer 22 is driven by the pulsation of the working gas pressure generated by the vibration of the movable member 15 of the compressor 11. A reciprocating motion of the displacer 22 and the movable member 15 of the compressor 11 forms a reverse Stirling cycle between the expansion space 28 and the working gas chamber of the compressor 11. Thus, the cooling stage adjacent to the expansion space 28 is cooled, and the Stirling refrigerator 10 can cool the object.

  4, 5 and 6 are views showing a leaf spring mounting structure according to an embodiment of the present invention. FIG. 4 shows the leaf spring 48 when viewed from the axial direction. FIG. 5 shows the vicinity of the fastening member 56 in the laminated leaf spring portion 49. FIG. 6 shows the vicinity of the pin member 60 in the laminated leaf spring portion 49. The laminated leaf spring portion 49 includes, for example, three leaf springs 48. An auxiliary spring or a spacer (not shown) may be interposed between adjacent leaf springs. The fastening member 56 is, for example, a bolt or a screw. The pin member 60 is a positioning pin such as a knock pin.

  The support portion 40 includes a fastening member 56 for attaching the outer peripheral portion 52 of the leaf spring 48 to the expander container 20, and a fastening member 56 for attaching the inner peripheral portion 50 of the leaf spring 48 to the displacer 22.

  The leaf spring 48 has several holes in the inner peripheral portion 50 and the outer peripheral portion 52 that are non-movable portions. A part thereof is a fastening hole 58 for allowing the fastening member 56 to pass therethrough, and another part is a through hole 62 for fitting the pin member 60. The fastening holes 58 are provided in the inner peripheral portion 50 and the outer peripheral portion 52, and the through holes 62 are provided in the outer peripheral portion 52. In the illustrated example, three fastening holes 58 in the inner peripheral portion 50, three fastening holes 58 in the outer peripheral portion 52, and three through holes 62 are provided at equal intervals. The fastening hole 58 and the through hole 62 are circular, and similarly, the fastening member 56 and the pin member 60 have a circular cross section. A shaft hole 55 that receives the displacer rod 34 is formed at the center of the inner peripheral portion 50.

  As shown in FIG. 5, the fastening member 56 is inserted into the fastening hole 58 of the leaf spring 48 and the fastening hole of the expander container 20 (or the displacer 22) continuous thereto, and a nut 57 is provided at the end of the fastening member 56. It is concluded. Thus, the laminated leaf spring portion 49 is attached to the expander container 20 (or the displacer 22).

  There is a slight gap 59 between the fastening member 56 and the fastening hole 58. When the displacer 22 moves in the axial direction, a force acts on the inner peripheral portion 50 and the outer peripheral portion 52 of the leaf spring 48 from the arm 54 in the in-plane direction perpendicular to the axial direction as a reaction of the elastic restoring force of the arm 54. . For example, a reaction force that rotates the outer peripheral portion 52 in the circumferential direction acts on the outer peripheral portion 52 from the arm 54. Therefore, the leaf spring 48 can be laterally shifted in the in-plane direction from the designed mounting position. The size of the lateral shift corresponds to the size of the gap 59 at the maximum.

  Therefore, apart from the fastening member 56, the support portion 40 includes a pin member 60 fitted in the through hole 62. As shown in FIG. 6, when the inner peripheral surface of the through hole 62 and the side surface of the pin member 60 are in close contact with each other, rigidity is generated against relative displacement in the in-plane direction between the adjacent leaf springs 48. Therefore, it is possible to prevent lateral displacement between the leaf springs 48 forming the laminated leaf spring portion 49 and / or lateral displacement between the laminated leaf spring portion 49 and the expander container 20.

  In this way, it is possible to eliminate the influence on the characteristics (for example, spring constant) of the laminated leaf spring portion 49 due to the lateral displacement. Since the displacement of the displacer 22 is similarly prevented, an increase in friction between the displacer 22 and surrounding fixed parts (for example, the seal portion 25) is also prevented.

  Further, the fastening member 56 is provided separately from the pin member 60. As a result, the plurality of leaf springs 48 are integrated by the pin member 60 to form the laminated leaf spring portion 49, and then the laminated leaf spring portion 49 is attached to the expander 13, so that the attachment work is relatively easy. It can be carried out.

  In the above, this invention was demonstrated based on the Example. It will be understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, various modifications are possible, and such modifications are within the scope of the present invention. By the way.

  In the above-described embodiment, the pin member 60 is not attached to the expander container 20. However, in an embodiment, the pin member 60 may be fixed to the expander container 20. For example, the pin member 60 may be erected from the expander container 20. In this way, the laminated leaf spring portion 49 can be more reliably fixed to the expander container 20.

  Further, the through hole 62 may be provided in the inner peripheral portion 50. Even in this case, the lateral displacement of the leaf spring 48 can be prevented by fitting the pin member 60 into the through hole 62. However, from the viewpoint of resisting the reaction force from the arm 54, it is considered that it is more effective to provide the through hole 62 in the outer peripheral portion 52.

  In the above-described embodiment, the pin member 60 has a shape that fits the through hole 62, and the pin member 60 is fitted in the through hole 62. However, the shape of the pin member 60 and the through hole 62 may not completely match. For example, the pin member 60 having an elongated cross section or a cross section having a width corresponding to the diameter of the through hole 62 may be press-fitted into the circular through hole 62. Even in this case, the outer periphery of the cross-section of the pin member 60 is pressed against the inner peripheral surface of the through hole 62, and the rigidity with respect to the relative displacement between the adjacent leaf springs 48 can be generated. it can.

  Moreover, the pin member 60 may have an elongated cross section in the circumferential direction. In this way, the pin member 60 has high rigidity in the circumferential direction. Therefore, the lateral displacement of the leaf spring 48 can be prevented with a smaller number of pin members 60 (for example, one pin member 60).

  In some embodiments, the fastening member 56 may not be provided. In this case, the laminated leaf spring 49 may be attached to the expander container 20 and the displacer 22 by the pin member 60.

  In an embodiment, the expander 13 may include a dynamic vibration absorber for suppressing vibration of the expander container 20 due to the reciprocating movement of the displacer 22. The leaf spring mounting structure described above may be applied to a dynamic vibration absorber. A dynamic vibration absorber is arrange | positioned outside the expander container 20, for example, and is accommodated in the dynamic vibration absorber cover which is a container for dynamic vibration absorbers. The dynamic vibration absorber includes a mass element that reciprocates within the dynamic vibration absorber cover, and an elastic element that connects the mass element to the expander container 20. This elastic element may include the laminated leaf spring portion 49 or the leaf spring 48.

  In an embodiment, the above-described leaf spring mounting structure may be applied to the compressor 11. As described above, the Stirling refrigerator 10 includes a compressor case 14, a movable member 15 that reciprocates in the compressor case 14, and a movable member 15 that is capable of reciprocating the movable member 15. And a support portion 16 that is supported by the case 14. The support unit 16 may include at least one leaf spring 48 or a laminated leaf spring portion 49. The leaf spring 48 includes an inner peripheral portion 50 attached to the movable member 15 and an outer peripheral portion 52 attached to the compressor case 14, and may have a through hole 62 in the outer peripheral portion 52 or the inner peripheral portion 50. . The support portion 16 may include a pin member 60 that is press-fitted into the through hole 62. The support unit 16 may further include a fastening member 56 for attaching the plate spring 48 to the compressor case 14 and / or a fastening member 56 for attaching the plate spring 48 to the movable member 15.

  The above-described embodiment has been described using the Stirling refrigerator 10. However, the above-described leaf spring mounting structure may be applied to other Stirling type refrigerators, for example, Stirling type pulse tube refrigerators.

  DESCRIPTION OF SYMBOLS 10 Stirling refrigerator, 11 compressor, 13 expansion machine, 14 compressor case, 15 movable member, 16 support part, 20 expander container, 22 displacer, 30 elastic member, 32 displacer main body, 34 displacer rod, 40 support part, 48 leaf springs, 49 laminated leaf spring parts, 50 inner circumference parts, 52 outer circumference parts, 54 arms, 56 fastening members, 60 pin members, 62 through holes.

Claims (4)

A container,
A movable member that reciprocates in the container;
A support part for supporting the movable member on the container so as to enable reciprocal movement of the movable member,
The support portion includes at least one leaf spring, and the leaf spring includes an inner peripheral portion attached to the movable member and an outer peripheral portion attached to the container, and the outer peripheral portion or the inner peripheral portion is provided with the outer peripheral portion. Has a through hole,
The Stirling-type refrigerator, wherein the support portion includes a pin member press-fitted into the through hole.   The Stirling type refrigerator according to claim 1, wherein the support part further includes a fastening member for attaching the leaf spring to the container or the movable member.   The Stirling type refrigerator according to claim 1 or 2, wherein the leaf spring has the through hole in the outer peripheral portion.   The Stirling type refrigerator according to any one of claims 1 to 3, wherein the pin member is fixed to the container.

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