JP3686353B2 - Stirling engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a check valve portion which is a part of a high pressure maintaining structure for a working gas necessary for a gas bearing used in a Stirling engine.
[0002]
[Prior art]
FIG. 16 is a schematic configuration diagram of a conventional Stirling engine. As shown in FIG. 16, in the Stirling refrigerator, the displacer 2 and the piston 3 are disposed in the space in the cylinder 1 having a cylindrical space inside, and the compression space 4 formed in the space is expanded. A regenerator 6 is provided between the space 5 to form a closed circuit, and the working space of the closed circuit is filled with a working gas such as helium, and the piston 3 is connected to the shaft of the cylinder 1 by external power such as a linear motor 7. Vibrate in the direction.
[0003]
The vibration of the piston 3 causes a periodic pressure change in the working gas sealed in the compression space 4, and the working gas flows into the expansion space 5 through the regenerator 6 due to the pulsation of the back pressure that has risen with the compression. At this time, the axial displacement of the displacer 2 is caused by the change in the gas movement amount.
[0004]
As a result, the displacer 2 is fixed at the same cycle as the piston 3 by the spring 9 connected between the other end of the displacer rod 8 penetrating the piston 3 and the bottom of the cylinder 1 with one end fixed to the displacer 2. The cylinder 1 reciprocates in the axial direction while maintaining a predetermined phase difference. When the displacer 2 and the piston 3 reciprocate while maintaining an appropriate phase difference, the working gas enclosed in the working space constitutes a thermodynamic cycle known as a reverse Stirling cycle, and mainly generates cold in the expansion space 5.
[0005]
The principle will be described below. When the working gas in the compression space 4 compressed by the piston 3 moves to the expansion space 5 via the regenerator 6, the regenerator 6 receives the cold stored in the half cycle before and is precooled.
[0006]
At this time, the heat generated in the compression space 4 is released from the radiator 11 to the outside via the high temperature side heat exchanger 10. When most of the working gas flows into the expansion space 5, the expansion starts so as to push up the displacer 2 by the pressure increase in the expansion space 5.
[0007]
When the air expands to some extent, the displacer 3 is pushed up by the restoring force of the piston 3, and the working gas in the expansion space 5 whose pressure has increased passes through the regenerator 6 and moves again to the compression space 4.
[0008]
At this time, heat is taken from the outside by the heat absorber 13 through the cold temperature side heat exchanger 12 to cool the outside air. When most of the working gas returns to the compression space 4, the piston 3 is compressed again and moves to the next cycle. By repeating the above series of cycles continuously, it is possible to take out the cryogenic cold from the Stirling refrigerator.
[0009]
Now, the piston 3 and the displacer 2 that reciprocate in the cylinder 1 as described above reciprocate in a state of floating from the inner wall surface of the cylinder 1 by the gas bearing so that they can reciprocate without contacting the inner wall surface of the cylinder 1. It has become.
[0010]
The side walls of the piston 3 and the displacer 2 are provided with communication holes 14 and 15 for communicating the piston internal space 3a and the displacer internal space 2a with the compression space 4, and the communication holes 14 and 15 are compressed. There are provided check valves 16 and 17 that can flow gas from the space 4 only in the direction of the piston internal space 3a and the displacer internal space 2a.
[0011]
Further, on the cylindrical side surfaces of the piston 3 and the displacer 2, there are minute communication holes 18 and 19 for communicating the piston internal space 3 a and the displacer internal space 2 a with the space sandwiched between the piston 3, the displacer 2 and the cylinder 1. Is provided.
[0012]
Therefore, the high-pressure gas produced in the compression space 4 passes through the check valve 16 and 17 of the piston 3 and the displacer 2 and enters the piston internal space 3a and the displacer internal space 2a. A gas bearing is formed by a gas layer formed between 19 and the piston 3 and the cylinder 1 and between the displacer 2 and the cylinder 1. As a result, a gas bearing is formed, and the piston 3 and the displacer 2 are not in contact with the cylinder 1. Can reciprocate inside.
[0013]
Next, the operation of the check valves 16 and 17 will be described taking the piston 3 side as an example. In the compression space 4, compression-expansion is always repeated with respect to the internal working gas by the reciprocating motion of the piston 3 and the displacer 2. The working gas is sealed at high pressure from the beginning. During operation, the working gas is compressed to a higher pressure and flows through the check valve 16 into the piston internal space 3a, which is in a stopped state, and the piston internal space 3a instantaneously has a pressure in the compression space. It becomes a state.
[0014]
Then, the working gas is ejected from the minute communication hole 18 provided on the cylindrical side wall surface of the piston 3, and a gas layer is formed between the cylinder 1 wall surface and the outer periphery of the piston 3 to form a gas bearing.
[0015]
If the check valve 16 is not provided when the compression space 4 is in the expanded state, the working gas that has flowed into the piston internal space 3a during compression flows out in the same path as that during the flow, and the cylindrical shape of the piston 3 The working gas is not ejected from the minute communication hole 18 provided on the side surface, the gas bearing between the inner wall of the cylinder 1 and the outer periphery of the piston 3 is eliminated, and the piston 3 and the cylinder 1 come into contact with each other.
[0016]
For this reason, the piston 3 reciprocating in the cylinder 1 reciprocates while sliding on the inner surface of the cylinder 1, and the performance deteriorates or breaks due to wear at this time.
[0017]
Therefore, it is necessary to keep the pressure of the piston internal space 3a at a high level even when the compression space 4 is expanded, and a mechanism for flowing the working gas from the compression space 4 only in the direction of the piston internal space 3a is required, and the check valve 16 is provided. It has been.
[0018]
[Problems to be solved by the invention]
Conventionally, the check valves 16 and 17 are attached to the piston 3 and the inner wall surface of the displacer 2 with screws directly at one end, using a thin metal plate as a valve. However, such a structure causes the following problems.
[0019]
The workability at the time of fixing a metal thin plate, which is a valve component, to the inner wall surfaces of the piston 3 and the displacer 2 with screws is deteriorated.
[0020]
The piston 3 and the displacer 2 are composed of a plurality of parts. If it is found that the check valve 16 or 17 has a problem after the piston 3 or the displacer 2 is once assembled, It is necessary to disassemble the piston 3 or the displacer 2 in order to replace the stop valves 16 and 17, and particularly when the piston 3 or the displacer 2 is assembled using an adhesive, parts are damaged during disassembly. There is a possibility.
[0021]
Furthermore, since the metal thin plates constituting the check valves 16 and 17 are thin, handling during assembly is difficult. When the thickness of the thin plate is large, it is difficult to follow the change in pressure of the working gas. Therefore, in the conventionally used check valves 16 and 17, the metal thin plate is slightly thick on the inner wall surface side of the piston 3 and the displacer 2. The thin plate is fixed in an openable and closable state at the communicating holes 14 and 15 so as to be pressed by the metal plate.
[0022]
The present invention has been made to solve the above problems. An object of the present invention is to make it easy to attach and replace a check valve in a Stirling engine.
[0023]
[Means for Solving the Problems]
A Stirling engine according to the present invention includes a casing, a cylinder provided in the casing, a piston and a displacer that reciprocates in the cylinder and has an internal space, a compression space provided between the piston and the displacer, a compression space, and an internal A non-return valve provided in a communication path communicating with the space, and allowing a flow of the working gas from the compression space to the internal space and preventing a backflow of the working gas from the internal space to the compression space; And A check valve is installed in the displacer. The Check valve mounting part is piston And It is composed of separate parts from other parts of the displacer.
[0024]
In this way, the check valve mounting part itself can be And By configuring the displacer as a separate part from the other parts, the check valve mounting part is connected to the piston. And By detaching from the displacer, the check valve can be moved to the piston at the same time. And It can be detached from the displacer. Narrow piston And It is not necessary to install and assemble the check valve on the inner wall surface of the displacer. Even if a check valve malfunction is detected, the piston And The check valve can be taken out without disassembling the displacer.
[0025]
Check valve mounting part is piston And A check valve base that forms part of the outer wall of the displacer and is provided with a check valve; And Removably attached to the displacer The Accordingly, the check valve can be attached / removed by attaching / removing the check valve base.
[0026]
The check valve base preferably has a flange portion. In this case, it is preferable that the piston and the displacer are provided with a recess having a support portion that supports the flange portion. Then, the check valve base is attached to the recess while the flange portion is placed on the support portion. In the present specification, the concept of “concave portion” is defined to include “through hole”.
[0027]
By providing a flange on the check valve base in this way, the piston And The flange is supported by a displacer-side support (for example, a step) and the check valve base is pistoned by, for example, screwing a screw through the flange to the support. And Can be easily installed on the displacer.
[0028]
Stirling engine of the present invention But , Piston the working gas in the compression space And The first communication hole leading to the inner space of the displacer and the piston And Piston from the inner space of the displacer And A second communication hole for guiding the working gas to the outer periphery of the displacer and forming a gas bearing; Case The first communication hole is provided in the check valve base.
[0029]
In the present invention, the piston is And Piston through the inner space of the displacer And The present invention is useful for a Stirling engine of a type in which a working gas is guided to the outer periphery of a displacer to form a gas bearing.
[0030]
piston And It is preferable to provide a groove in the check valve base mounting portion of the displacer and install a seal member in the groove. Also piston And A seal member may be sandwiched between the check valve base mounting portion of the displacer and the check valve base. In this case, the piston And It is preferable to provide a chamfered portion in the mounting portion of the check valve base in the displacer, and to install a seal member between the chamfered portion and the check valve base.
[0031]
Examples of the sealing member include a sealing sheet material, a sealing rubber layer, and an O-ring.
[0032]
Piston as above And By installing a seal member between the displacer and the check valve base, the sealing performance of the check valve mounting portion can be improved, and the piston And The internal pressure of the displacer can be efficiently maintained at a high pressure, and input loss due to unnecessary leakage and movement of the working gas can be reduced. As a result, for example, the performance as a refrigerator can be improved.
[0033]
Note that the seal member is composed of a check valve base flange and a piston. And It is preferable to install between the check valve base mounting portion of the displacer.
[0034]
By providing a flange on the check valve base, the piston And The length of the boundary between the displacer and the check valve base can be increased, and the sealing performance of the check valve mounting portion can be improved. In addition to this, the sealing performance can be further improved by installing a seal member between the flange portion and the check valve base mounting portion.
[0035]
The valve body of the check valve is preferably made of resin. When the valve body is made of a metal material, the metal material is made thin and a reinforcing plate is required. However, if the valve body of the check valve is made of resin, the plate thickness can be increased to give the same function as the metal plate, making it easy to handle as a single product and omitting the reinforcing plate Became possible. Therefore, the valve itself can be substantially composed of one part, and the check valve can be easily assembled.
[0036]
The surface of the check valve base located on the compression space side is the outer surface of the piston on the compression space side. And Flush with the outer surface of the displacer or the outer surface of the piston And A position farther from the compression space than the outer surface of the displacer (the outer surface of the piston And It is preferable to arrange it at a position lower than the outer surface of the displacer.
[0037]
When performing a gas leak inspection of the check valve, a gas reverse leak inspection device in which the check valve portion and the gas ejection portion are isolated can be used. In the inspection apparatus, the gas can be easily fed into the piston or the displacer simultaneously from a plurality of gas ejection portions. At this time, as described above, the surface of the check valve base is moved to the compression space side piston. And By arranging the displacer on the side farther from the compression space than the outer surface of the displacer, the surface of the check valve base becomes the piston And Protruding upward from the outer surface of the displacer can be prevented. Check valve base surface is piston And When projecting onto the outer surface of the displacer, the sealing material is connected to the inspection device and the piston. And When it is installed between the outer surface of the displacer and sealing is attempted, the sealing material may be pushed up to the check valve base and the sealing performance may be lowered. Therefore, as described above, the height of the surface located on the compression space side of the check valve base is set to the piston on the compression space side. And By making the height less than the height of the outer surface of the displacer, it is possible to prevent the sealing performance from being lowered due to the sealing material being pushed up by the check valve base. Accordingly, the check valve portion and the gas ejection portion can be reliably separated, and a highly accurate gas reverse leak inspection can be performed.
[0038]
It is preferable to provide a notch on the outer periphery of the check valve base. Accordingly, the check valve base can be easily detached from the piston or the displacer using the cutout portion, and the check valve can be further easily removed.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0040]
(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of a Stirling refrigerator (Stirling engine) having a check valve portion as a separate part. FIG. 2 is a detailed view of a check valve portion in the piston 3.
[0041]
As shown in FIG. 1, the Stirling refrigerator of the present invention includes a casing, a cylinder 1 provided in the casing, a piston 3 and a displacer 2 that reciprocate in the cylinder 1 and have internal spaces 2a and 3a. Provided in the compression space 4 provided between the piston 3 and the displacer 2, and in the communication path that connects the compression space 4 and the internal spaces 2 a and 3 a, allows the flow of working gas from the compression space 4 to the internal spaces 2 a and 3 a And check valves 16 and 17 for preventing the backflow of the working gas from the internal spaces 2a and 3a to the compression space 4.
[0042]
In addition, the Stirling engine of the present invention operates on the outer periphery of the piston 3 and the displacer 2 from the communication holes 14 and 15 for guiding the working gas of the compression space 4 to the internal space 2a and 3a of the piston 3 and the displacer 2, and from the internal spaces 2a and 3a. And communication holes 18 and 19 for introducing gas and forming gas bearings.
[0043]
The check valve mounting portion to which the check valves 16 and 17 are mounted in the piston 3 and the displacer 2 is configured as a separate part from the other portions (outer wall portions) in the piston 3 and the displacer 2. That is, the structure of the mounting portion of the check valves 16 and 17 in the piston 3 and the displacer 2 is different from the conventional example shown in FIG. The other structure is basically the same as the conventional example shown in FIG.
[0044]
As described above, the check valve mounting portion is configured as a separate part from the piston 3 and the other parts of the displacer 2, and the check valve mounting portion is attached to and detached from the piston 3 and the displacer 2. , 17 can also be detached from the piston 3 and the displacer 2. This eliminates the need for mounting and assembly of the check valves 16 and 17 on the narrow piston 3 and the inner wall surface of the displacer 2.
[0045]
Even when a malfunction of the check valves 16 and 17 is found, only the check valve mounting portion can be removed without disassembling the piston 3 and the displacer 2. Therefore, the check valves 16 and 17 can be easily attached, assembled and removed.
[0046]
FIG. 2 shows an enlarged view of the check valve portion in the piston 3. As shown in FIG. 2, the check valve mounting portion includes a check valve assembly 21. The check valve assembly 21 constitutes a part of the outer wall of the piston 3 and is fixed to the piston 3 with a screw 26.
[0047]
Here, the structure of the check valve assembly 21 will be described in more detail with reference to FIGS.
[0048]
As shown in FIGS. 3A to 3C, the check valve assembly 21 includes a check valve base 22, a communication hole 14 provided in the check valve base 22, and a pressure difference between the communication holes 14. A valve (valve main body) 23 made of a thin metal plate that opens and closes, a reinforcing plate 24 that presses down the valve 23, and a screw 25.
[0049]
The check valve base 22 is a member serving as a base of the check valve assembly 21, and constitutes a part of the outer wall of the piston 3 when the check valve assembly 21 is attached to the piston 3. The check valve base 22 has a flange portion 28 on the outer periphery, and the flange portion 28 is provided with a screw receiving hole 20a.
[0050]
The valve 23 and the reinforcing plate 24 are fastened to the check valve base 22 with screws 25. The reinforcing plate 24 is made of a thin plate so that the metal valve 23 can follow even a very short pressure fluctuation period, so that excessive deformation does not occur even at a high pressure.
[0051]
The check valve assembly 21 having the above structure is attached to the piston 3 as shown in FIG. At this time, on the piston 3 side, a screw hole 20b having a female screw formed on the inner periphery is provided at a position corresponding to the screw receiving hole 20a, and the screw 26 is screwed to the piston 3 through the screw hole 20b and the screw receiving hole 20a. By doing so, the check valve base 22 is attached to the piston 3.
[0052]
Since the check valve 16 is attached to the check valve base 22 with screws 25 as shown in FIGS. 3B and 3C, the check valve base 22 is attached to the piston 3 at the same time. A valve 16 can also be attached to the piston 3.
[0053]
4A and 4B show structural examples on the piston 3 side. As shown in these drawings, the attachment portion of the check valve assembly 21 on the piston 3 side is provided with a recess 3b that is lowered by one step from the surface of the piston 3 by the amount that the check valve assembly 21 is fitted. The check valve assembly 21 is fitted into the recess 3b and attached to the piston 3 by the screw 26 as described above.
[0054]
As shown in FIGS. 4A and 4B, there is a step portion in the recess 3b, and the flange portion 28 of the check valve base 22 is placed on the step portion. That is, the step portion functions as a support portion that supports the flange portion 28. Then, the screw 26 is screwed to the step portion through the flange portion while the flange portion is supported by the step portion on the piston 3 side, so that the check valve base 22 and the check valve 16 can be easily attached to the piston 3. Can do.
[0055]
(Embodiment 2)
Next, Embodiment 2 of the present invention will be described with reference to FIGS. 5 (a) and 5 (b). FIGS. 5A and 5B are views showing a mounting portion of the check valve assembly 21 in the piston 3 of the second embodiment.
[0056]
As shown in FIGS. 5A and 5B, an annular groove 3 c is provided on the surface of the stepped portion in the mounting recess 3 b of the check valve assembly 21 in the piston 3. A sealing material 27a, such as room temperature curable silicone rubber, is applied to the groove 3c.
[0057]
The check valve assembly 21 is fitted into the recess 3 b having the above structure, and the check valve assembly 21 is fixed to the piston 3 with a screw 26. At this time, the sealing portion 27 is formed by the sealing material 27a filled in the groove portion 3c of the piston 3, and the working gas leakage from the gap between the piston 3 and the check valve assembly 21 can be eliminated.
[0058]
Thereby, the sealing performance of the check valve mounting portion can be improved, the internal pressure of the piston 3 can be efficiently maintained at a high pressure, and input loss due to unnecessary leakage and movement of the working gas is reduced. be able to. As a result, the performance as a refrigerator can be improved.
[0059]
(Embodiment 3)
Next, Embodiment 3 of the present invention will be described with reference to FIGS. 6 (a), 6 (b) and FIG. FIGS. 6A and 6B are views showing a mounting portion of the check valve assembly 21 in the piston 3 of the third embodiment.
[0060]
As shown in FIGS. 6A and 6B, the corner portion of the outer edge portion of the fitting hole 3d of the check valve assembly 21 in the piston 3 (the piston 3 on which the flange portion of the check valve base 22 is mounted). A chamfered portion is provided by chamfering the corner portion of the stepped portion. In the example shown in FIGS. 6A and 6B, the chamfered portion 3e is tapered, but any other shape can be adopted.
[0061]
FIG. 7 shows a state where the check valve assembly 21 is fitted into the mounting portion of the check valve assembly 21 shown in FIGS. As shown in FIG. 7, a space 3f having a triangular cross section sandwiched between the piston 3 and the check valve assembly 21 is formed over the entire outer edge portion of the fitting hole 3d.
[0062]
The chamfered portion 3e is preferably coated with a sealing material 38, for example, room temperature curable silicone rubber. After applying the sealing material 38 to the chamfered portion 3e, the check valve assembly 21 is fitted on the piston 3 side and screwed to form a seal portion in the space 3f.
[0063]
(Embodiment 4)
Next, a fourth embodiment of the present invention will be described. In the example shown in FIG. 7, a sealing material 38 such as room temperature curable silicone rubber is installed in the space 3f sandwiched between the piston 3 and the check valve assembly 21, but an O-ring (not shown) is used instead. It may be fitted into 3f. With the O-ring fitted, the check valve assembly 21 is fitted to the piston 3 side and screwed to form a seal portion in the space 3f by the O-ring.
[0064]
(Embodiment 5)
Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a view showing a state where the check valve assembly 21 is attached to the piston 3 of the fifth embodiment.
[0065]
As shown in FIG. 8, a seal sheet 29 in which a sheet-shaped sealing material, for example, a silicon rubber sheet is punched into an outer shape matching the shape of the flange portion 28 of the check valve base 22, is formed on the stepped portion in the recess 3 b of the piston 3 The sealing sheet 29 is sandwiched between the flange portion 28 and the step portion of the piston 3. In this state, operating gas leakage can be prevented by screwing the check valve base 22 to the piston 3 side mounting portion.
[0066]
In addition, by providing the check valve base 22 with the flange portion 28, the length of the boundary portion between the piston 3 and the check valve base 22 can be increased, which also improves the sealing performance of the check valve mounting portion. Can contribute. By installing the sealing member between the flange portion 28 and the mounting portion of the check valve base 22 as described above, the sealing performance can be further improved.
[0067]
(Embodiment 6)
Next, Embodiment 6 of the present invention will be described with reference to FIG. FIG. 9 is a cross-sectional view of the check valve assembly 21 according to the sixth embodiment.
[0068]
As shown in FIG. 9, a seal rubber layer 30 is formed in advance on the back surface of the flange portion 28 of the check valve base 22 placed on the stepped portion of the concave portion 3 b of the piston 3 and then solidified after the seal rubber is smoothly applied. Keep it. A through hole 30 a communicating with the screw receiving hole 20 a is formed in the seal rubber layer 30.
[0069]
The check valve base 22 is fitted into the recess 3 b of the piston 3 and attached to the piston 3 side with a screw 26. At this time, by forming the seal rubber layer 30 on the flange portion 28, the seal rubber layer 30 can seal between the check valve assembly 21 and the piston 3.
[0070]
(Embodiment 7)
Next, Embodiment 7 of the present invention will be described with reference to FIG. FIG. 10 is a cross-sectional view of the check valve assembly 21 receiving portion of the piston 3 in the seventh embodiment.
[0071]
As shown in FIG. 10, a seal rubber layer 31 is formed after applying a smooth seal rubber in advance on the stepped portion of the recess 3b on the piston 3 side where the flange portion 28 of the check valve base 22 is placed. In addition, a through hole 31 a is provided in the seal rubber layer 31.
[0072]
In this way, the check valve assembly 21 is attached to the recess 3b on the piston 3 side where the seal rubber layer 31 is formed in advance, and the seal rubber layer 31 provides a sealing effect.
[0073]
(Embodiment 8)
Next, an eighth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a cross-sectional view of the check valve assembly 21 according to the eighth embodiment.
[0074]
In the first to seventh embodiments described above, the valve 23 is made of a thin metal plate, and both the valve 23 and the valve reinforcing plate 24 are separate metal parts. This is because the elasticity of the metal itself is strong, so that it is necessary to reduce the thickness of the valve so that it can follow even a slight pressure change and a small pressure change period. This is because the reinforcing plate 24 for pressing against 22 is necessary.
[0075]
However, in the eighth embodiment, as shown in FIG. 11, the check valve is constituted only by the valve 32 made of resin, and the reinforcing plate 24 is omitted. Examples of the material of the valve 32 include polyester.
[0076]
When a SUS plate is used as the material of the valve 23, a material having a thickness of about 0.02 mm to 0.05 mm is used. However, by changing the material of the valve 32 to polyester, the thickness is changed to 0.2 mm to 0 mm. It can be about 5 mm, and handling becomes easy. In the case of metal, the valve 23 is produced by etching. However, in the case of resin, the valve 32 can be easily produced by punching from a sheet material.
[0077]
Thus, by appropriately selecting the material, thickness, and the like of the valve 32, the valve 32 having a plate thickness that is easy to handle while having necessary elasticity can be obtained, and the reinforcing plate 24 can be omitted. Therefore, the valve itself can be substantially constituted by one part, and the check valve 16 can be easily assembled.
[0078]
(Embodiment 9)
Next, a ninth embodiment of the present invention will be described with reference to FIGS. FIG. 12 is a cross-sectional view showing a state in which the check valve assembly 21 according to the ninth embodiment is attached to the piston 3.
[0079]
As shown in FIG. 12, in the ninth embodiment, when the check valve assembly 21 is attached to the piston 3, the check valve assembly 21 is prevented from jumping out from the surface of the piston 3. That is, the surface of the check valve base 22 located on the compression space 4 side is arranged flush with the outer surface of the piston 3 on the compression space 4 side or at a position lower than the outer surface.
[0080]
Thereby, it is possible to easily and accurately check whether or not the function of the check valve 16 in which the working gas flows only from the compression space 4 to the inside of the piston 3 is working. Hereinafter, the reason will be described with reference to FIG. 13 and FIG.
[0081]
FIG. 13 shows whether or not the gas is fed back from the check valve 16 to the outside through the minute communication hole 18 on the side surface of the piston 3 where the working gas is originally ejected to form the gas bearing. It is the schematic of the inspection apparatus which investigates.
[0082]
An inspection apparatus 33 shown in FIG. 13 includes an inspection apparatus main body 35 into which a piston assembly 34 is fitted, and a lid body 36 covering the upper opening of the inspection apparatus main body 35. A pressing rubber 37 is sometimes attached to prevent the working gas from leaking between the inspection apparatus main body 35 and the lid body 36 and from the vicinity of the central rod through hole 33.
[0083]
At the time of inspection, the gas is fed into the inspection apparatus through a working gas inlet 35a provided on the side surface of the inspection apparatus main body 35. The working gas that has entered the inspection apparatus is filled into the piston internal space 3a from the micro communication hole 18 on the side surface of the piston 3. Further, the lid 36 is provided with an opening 36a for detecting a working gas. By connecting a working gas flow meter (not shown) to the opening 36a, if the check valve 16 is not functioning, the check valve 16 is detected by detecting the flow rate of the working gas. Can be inspected.
[0084]
When the check valve assembly 21 protrudes from the surface of the piston 3 as shown in FIG. 14, the sealing rubber 37 for sealing prevents the gas from flowing from the periphery of the piston 3 and the vicinity of the central rod through hole 33. There is a possibility that the valve assembly 21 will be lifted by the bulge of the valve stop assembly 21 and not sealed reliably.
[0085]
However, by eliminating the protrusion of the check valve assembly 21 as shown in FIGS. 12 and 13, the presser rubber 37 can substantially contact only the piston 3 portion, and the lift can be eliminated to ensure the seal. . Accordingly, the check valve 16 portion and the gas ejection portion can be reliably isolated, and a highly accurate gas reverse leak test can be performed.
[0086]
(Embodiment 10)
Next, a tenth embodiment of the present invention will be described with reference to FIGS. 15 (a) and 15 (b). 15A and 15B are cross-sectional views showing a check valve assembly 21 according to the tenth embodiment.
[0087]
As shown in FIGS. 15A and 15B, a notch 22 a is provided at the edge (flange) of the check valve base 22 in the check valve assembly 21. In this example, a pair of substantially U-shaped cutout portions 22a is provided at the longitudinal end of the check valve base 22, but the shape and position of the cutout portions 22a can be arbitrarily selected.
[0088]
By providing the notch 22a described above, the work of removing the check valve assembly 21 from the piston 3 can be easily performed. For example, when a gas leak is detected at the time of a gas leak inspection of the check valve assembly 21 and it is necessary to remove the check valve assembly 21 for repair, the reverse is performed by inserting some jig into the notch 22a. The check valve assembly 21 can be removed from the check valve assembly 21 mounting recess of the piston 3, and the check valve assembly 21 can be easily removed from the piston 3.
[0089]
In the above-described first to tenth embodiments, the example in which the present invention is applied to the check valve 16 mounting portion of the piston 3 has been described. However, the same structure is also used for the check valve 17 mounting portion of the displacer 2. Can do.
[0090]
Although the embodiments of the present invention have been described as above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0091]
【The invention's effect】
According to the Stirling engine of the present invention, it is not necessary to mount and assemble the check valve on the inner wall surface portion of the narrow piston and the displacer, and the piston and the displacer can be disassembled even when a malfunction of the check valve is found. Therefore, only the check valve mounting portion can be removed, so that the check valve can be attached, assembled and removed much more easily than before. As a result, it is possible to remarkably improve the workability when attaching, assembling and removing the check valve, and it is possible to accurately attach the check valve and improve the reliability of the check valve. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a Stirling refrigerator of the present invention.
FIG. 2 is an enlarged cross-sectional view of a check valve mounting portion in FIG.
FIG. 3A is a plan view of a check valve assembly of the present invention.
(B) is sectional drawing of the non-return valve assembly of this invention.
(C) is a bottom view of the check valve assembly of the present invention.
FIG. 4A is a front view of a check valve mounting portion in a piston.
(B) is sectional drawing of the non-return valve attachment part in a piston.
FIG. 5A is a plan view of another example of the check valve mounting portion in the piston.
(B) is sectional drawing of the other example of the non-return valve attaching part in a piston.
FIG. 6A is a plan view of still another example of the check valve mounting portion of the piston.
(B) is sectional drawing of the further another example of the non-return valve attaching part in a piston.
7 is a cross-sectional view showing a state in which the check valve assembly of the present invention is attached to the check valve attaching portion of the piston shown in FIG. 6 (b).
FIG. 8 is a cross-sectional view showing a state in which the check valve assembly of the present invention is attached to the check valve mounting portion of the piston.
FIG. 9 is a cross-sectional view of another example of a check valve assembly according to the present invention.
FIG. 10 is a cross-sectional view of still another example of the check valve mounting portion in the piston of the present invention.
FIG. 11 is a cross-sectional view of still another example of a check valve assembly according to the present invention.
FIG. 12 is a cross-sectional view showing a state in which the check valve assembly of the present invention is attached to the check valve mounting portion of the piston.
FIG. 13 is a cross-sectional view of a check valve inspection apparatus according to the present invention.
FIG. 14 is a cross-sectional view for explaining a problem when a check valve assembly protrudes from a piston.
FIG. 15 (a) is a plan view of still another example of the check valve assembly according to the present invention.
(B) is sectional drawing of the further another example of the non-return valve assembly which concerns on this invention.
FIG. 16 is a cross-sectional view of a conventional Stirling refrigerator.
[Explanation of symbols]
1 cylinder, 2 displacer, 2a, 3a internal space, 3 piston, 3b recess, 3c groove, 3d insertion hole, 3e chamfer, 3f space, 4 compression space, 5 expansion space, 6 regenerator, 7 linear motor, 8 Displacer rod, 9 spring, 10 high-temperature side heat exchanger, 11 radiator, 12 low-temperature side heat exchanger, 13 heat absorber, 14, 15, 18, 19 communication hole, 16, 17 check valve, 20a screw receiving hole, 20b Screw hole, 21 Check valve assembly, 21a Top surface, 22 Check valve base, 22a Notch, 23, 32 Valve, 24 Reinforcement plate, 25, 26 Screw, 27 Seal part, 27a, 38 Seal material, 28 Flange , 29 Seal sheet, 30, 31 Seal rubber layer, 30a Through hole, 33 Rod through hole, 34 Piston assembly, 35 Inspection device body, 35a Working gas inlet , 36 Lid, 36a Opening, 37 Presser rubber.

Claims (5)

A casing,
A cylinder provided in the casing;
A piston and a displacer reciprocating in the cylinder and having an internal space;
A compression space provided between the piston and the displacer;
Provided in a communication path that connects the compression space and the internal space, allows a flow of working gas from the compression space to the internal space, and prevents a backflow of the working gas from the internal space to the compression space. in the Stirling engine comprising and a check valve for preventing,
A Stirling engine characterized in that a check valve base , which constitutes a part of an outer wall of the piston or the displacer and to which the check valve is attached, is detachably attached to the piston or the displacer. The check valve base has a flange portion;
Said piston or said displacer is to support the flange portion having to install them recess the check valve base, Stirling engine according to claim 1. A first communication hole for guiding the working gas in the compression space to an internal space of the piston or the displacer;
And a second communicating hole which forms the piston or the piston or gas bearing guiding the working gas in the outer periphery of the displacer from the inner space of the displacer,
The Stirling engine according to claim 1 or 2 , wherein the first communication hole is provided in the check valve base. The surface of the check valve base located on the compression space side is flush with the outer surface of the piston or the outer surface of the displacer on the compression space side, or more than the outer surface of the piston or the outer surface of the displacer. It was located away from the compression space, the Stirling engine according to any one of claims 1 to 3. Wherein a notch is provided on the check valve based circumference Stirling engine according to any one of claims 1 to 4.

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