JP2010175117A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sophisticated refrigerator by achieving appropriate operation of a displacer. <P>SOLUTION: The refrigerator includes: a pulse tube 3; a cooling storage device 2 connected to the low temperature side 32 of the pulse tube 3; pressure vibration sources 11, 12 connected to the high temperature side 22 of the cooling storage device 2 and applying pressure vibration to working gas; cylinders 41, 42 having a first cylinder 41 having one end 411 communicated with the high temperature side 31 of the pulse tube 3 and a second cylinder 42 having a cross section smaller than that of the first cylinder 41 and one end 422 communicated with the high temperature side 21 of the cooling storage device 2; and pistons 43, 44 having a first piston 43 reciprocated within the first cylinder 41 and a second piston 44 cooperatively operated with opposite displacement amount with respect to the first piston 43 and reciprocated within the second cylinder 42. Since the cross sections of the first and second cylinders 41, 42 are different from each other, even if pressure differs, force applied to the pistons 43, 44 can be controlled to be operated properly. As a result, the refrigerator can be operated efficiently. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a refrigerator using a pulse tube having a so-called displacer.

  As a configuration of a displacer in a conventional GM type pulse tube refrigerator, one having a cylinder that connects the high temperature side of the regenerator and the high temperature side of the pulse tube and a piston that reciprocates within the cylinder is disclosed ( Patent Document 1). In the cylinder of this apparatus, the diameter in the regenerator side and the pulse tube side is the same.

JP 2002-81776 A (FIG. 1 etc.)

  When the displacer is applied to a high-frequency pulse tube refrigerator, the pressure loss in the regenerator increases, and the magnitude of pressure fluctuation at both ends of the displacer greatly differs. For this reason, the pistons arranged in the displacer receive pressures of different sizes from both sides, and the displacer itself works or exchanges work through the piston of the displacer. In order for the displacer to work, it is necessary to input energy from the outside, so that the energy efficiency of the refrigerator is reduced, and as a result of the exchange of work, the performance of the refrigerator cannot be fully exhibited.

  This invention is made | formed in view of the said situation, and makes it the problem which should be solved to provide a high-performance refrigerator by implement | achieving the suitable operation | movement of a displacer.

The features of the refrigerator according to claim 1 for solving the above-described problems are a pulse tube,
A regenerator connected to the low temperature side of the pulse tube;
A pressure vibration source connected to the high temperature side of the regenerator to apply pressure vibration to the working gas;
A first cylinder having one end communicating with the high temperature side of the pulse tube and a cylinder having a second cylinder having a different cross-sectional area from the first cylinder and one end communicating with the high temperature side of the regenerator;
A piston having a first piston that reciprocates in the first cylinder and a second piston that reciprocates in the second cylinder in conjunction with an amount of displacement opposite to the first piston;
It is in having. The cross-sectional areas of the first and second cylinders are cross-sectional areas in a direction orthogonal to the direction in which the working gas flows. Here, “the fluctuation amounts of the first piston and the second piston are opposite” means that when the first piston is displaced in the direction of expanding the inside of the first cylinder, the second piston contracts within the second cylinder. When the second piston is displaced in the direction of expanding the inside of the second cylinder, the first piston is displaced by the same amount in the direction of reducing the inside of the first cylinder. means.

A feature of the refrigerator according to claim 2 that solves the above-described problem is that in claim 1, the first cylinder and the second cylinder are connected in a back-facing state on the other end side to form the same space. Partition and
The piston has a connecting member that integrally connects the first piston and the second piston so as not to move relative to each other in the axial direction.

  The feature of the refrigerator according to claim 3 that solves the above-mentioned problem is that, in claim 1 or 2, the first piston has a larger cross-sectional area than the second piston.

  A feature of the refrigerator according to claim 4 that solves the above-described problem is that in any one of claims 1 to 3, the first piston and the second piston are connected to the first cylinder and the second cylinder. There is a biasing member for biasing to the neutral position.

  A feature of the refrigerator according to claim 5 that solves the above-described problem is that in any one of claims 1 to 4, the pressure vibration source includes a piston position detecting unit that detects a relative position between the cylinder and the piston. In other words, pressure vibration is applied to the working gas based on the relative position.

  In the invention which concerns on Claim 1, even if there exists a difference in the pressure in a 1st and 2nd cylinder by making the cross-sectional area of a 1st cylinder and a 2nd cylinder different, the force applied to a piston is appropriate. It is possible to control to operate at the same time.

  In the invention which concerns on Claim 2, while connecting a 1st and 2nd cylinder and integrating, it can prevent that working gas leaks out of a system. The first and second pistons can be easily connected with a simple configuration.

  In the invention which concerns on Claim 3, it is connected to the high temperature side of a pulse tube, and the cross-sectional area of the 1st piston which is lower pressure than a 2nd piston by the pressure fall by a cool storage is made into the cross-sectional area of a 2nd piston. Also, by increasing the force, it is possible to reduce the work consumed by the piston by balancing the force applied to the entire piston.

  According to the invention which concerns on Claim 4, it becomes possible to operate a piston appropriately by providing a biasing member.

  In the invention which concerns on Claim 5, it becomes possible to optimize the pressure fluctuation and pressure distribution of the working gas in a pulse tube by controlling a pressure vibration source according to the position of a piston.

It is a conceptual schematic diagram of the refrigerator of an Example. It is a conceptual schematic diagram of the refrigerator of the modification. It is a conceptual schematic diagram of the refrigerator of the modification.

  The refrigerator of the present invention will be described in detail based on the following embodiments. The refrigerator of the present embodiment has a pulse tube, a regenerator, a pressure vibration source, and a cylinder and a piston corresponding to a displacer. The pulse tube and the regenerator are connected to each low temperature side. The regenerator is filled with a regenerator material. A heat exchanger can be interposed between the pulse tube and the regenerator. Since the inner diameter of the pulse tube and the regenerator is usually different (the regenerator has a larger diameter than the pulse tube), a connecting member having an inner space with an inner surface tapered between them is interposed. be able to. When the inner diameters of the two are different, a heat exchanger can be provided at each end of the regenerator and the pulse tube. In that case, the connecting member is interposed between the heat exchangers. The connecting member can have a guide member for controlling the flow of the working gas inside. The guide member can be shaped so that the working gas flow is uniform. For example, the cross section at both ends is a size that can be disposed in the internal space of the connecting member as a guide member, and whose shape is reduced at a ratio equivalent to the ratio of the cross sectional area of the internal space of the connecting member and both ends. A funnel-shaped member having

  The cylinder has a first cylinder and a second cylinder. One end of the first cylinder is connected to the high temperature side of the pulse tube, and the second cylinder is connected to the high temperature side of the regenerator. The first cylinder and the second cylinder have different cross-sectional areas. Considering the pressure loss in the regenerator, the pressure in the first cylinder connected to the pulse tube side is lower than the pressure in the second cylinder. Therefore, in order to equalize the force applied to the piston, It is desirable to make the cross-sectional area of one cylinder larger than the cross-sectional area of the second cylinder. The size of the cross-sectional area of each of the first and second cylinders is one cycle of pressure vibration in consideration of the magnitude of pressure loss in the regenerator and the phase difference of pressure fluctuations in the first and second cylinders. When viewed as a whole, it is desirable that the force applied to the first piston and the second piston, which will be described later, be balanced. The first cylinder and the second cylinder can also be integrated into separate members. In the case of integration, it is desirable that the axial directions of the respective cylinders be parallel, and it is more desirable that the axes of the respective cylinders coincide. For example, both are connected on the other end side in a back-facing state.

  The piston has a first piston and a second piston. The first piston reciprocates within the first cylinder, and the second piston reciprocates within the second cylinder. The first piston and the second piston are interlocked with the same displacement. The method for interlocking the first piston and the second piston is not particularly limited. For example, it is possible to employ a connecting member that connects the first cylinder and the second cylinder in a back-facing state and connects the two. The connecting member is a member that integrates the first piston and the second piston so that they cannot move relative to each other in the axial direction of each cylinder. Furthermore, the first piston and the second piston can be completely integrated. In addition, the first piston and the second piston are urged in a direction in which the spaces defined in the first and second cylinders are reduced, respectively, and then, the two pistons are pulled toward each other on the back side. Thus, it is possible to adopt a configuration in which connection is made with a wire or the like. Further, it is desirable that the first piston and the second piston are urged toward the neutral position in the cylinder. The piston can be biased by a biasing member. The urging member can be realized by an elastic body such as a spring. The positions where the springs are arranged can be arranged in a space defined by the first cylinder and the first piston and in a space defined by the second cylinder and the second piston. Moreover, the structure which employ | adopts the connection member which connects a 1st piston and a 2nd piston, and connects between a cylinder etc. and its connection member with a flexure bearing is mentioned. Furthermore, the piston can be configured to adjust the amount of displacement by being driven by a drive source such as a motor. By adopting a configuration that positively controls the displacement, the performance of the refrigerator can be improved. Here, although the energy is consumed by providing the drive source, as described above, since the cross-sectional areas of the cylinders are optimized to be different, less energy is input. It is also possible to dispose a seal member that can provide sealing between the cylinders 41 and 42 on the peripheral portions of the first piston 43 and the second piston 44.

  The pressure vibration source is connected to the high temperature side of the regenerator. The pressure vibration source vibrates the pressure of the working gas. The pressure vibration method is not particularly limited, but a method in which a cylinder and a piston are combined and the piston is driven by a drive source, and a method of generating pressure vibration by preparing a high pressure source and a low pressure source and switching them alternately. There is. As the high pressure source and the low pressure source, the suction side (low pressure source) and the discharge side (high pressure source) of the pump can be used. Application of pressure vibration to the working gas can be controlled in accordance with the relative position (phase) between the piston and the cylinder.

Example 1
(Constitution)
The refrigerator of the present invention will be described below in detail based on examples. The drawings used in this embodiment are schematic diagrams, and the scale and details of the structure may not always be accurate. As shown in FIG. 1, the pulse tube refrigerator of the present embodiment includes pressure vibration sources 11 and 12, a regenerator 2, a pulse tube 3, cylinders 41 and 42, pistons 43 and 44, heat exchangers 51 and 52, And a connecting member 6.

  The regenerator 2 and the pulse tube 3 are connected via the heat exchangers 51 and 52 and the connecting member 6 at the low temperature sides 22 and 32 respectively. The pressure vibration sources 11 and 12 are connected to the high temperature side 21 of the regenerator 2 by a pipe 71. The cylinders 41 and 42 have one end 422 connected to the first cylinder 41 and the high temperature side 21 of the regenerator 2 connected to the high temperature side 31 of the pulse tube 3 via a pipe 72 via a pipe 73. And a second cylinder 42. The 1st cylinder 41 and the 2nd cylinder 42 are arrange | positioned in the back state, and are integrated in each other end part side, and have divided the inside and outside. The first cylinder 41 and the second cylinder 42 have different cross-sectional areas. The cross-sectional area will be described in detail later.

  The pistons 43 and 44 are disposed in a space defined by the first cylinder 41 and the second cylinder 42 as a whole. The pistons 43 and 44 include a first piston 43 slidably disposed in the first cylinder 41 and a second piston 44 slidably disposed in the second cylinder 42. Both pistons 43 and 44 are integrated by a connecting member 45. The positions of the pistons 43 and 44 are detected by the piston position detecting means 8. Both pistons 43 and 44 are provided with sealing members 431 and 441 that improve the sealing performance between the cylinders 41 and 42.

  The pressure vibration sources 11 and 12 include a cylinder 11, a piston 12, and a power source (not shown). The piston 12 is slidably arranged in the cylinder 11, and is reciprocated in the cylinder 11 by a power source, so that the working gas passes through the pipe 71, the regenerator 2, and the second cylinder. 42 to move between. The phase when driving the piston 12 can also be determined according to the positions of the pistons 43 and 44 detected by the piston position detecting means 8. That is, the phase difference between the pressure vibration phase of the working gas generated by the pressure vibration sources 11 and 12 and the phase of the working gas in the pulse tube 3 (which can be estimated by the positions of the pistons 43 and 44) is appropriate. Control.

  The regenerator 2 is filled with a regenerator material. A first heat exchanger 51 is connected to the low temperature end 22. The first heat exchanger 51 has substantially the same diameter as the regenerator 2. In the pulse tube 3, a second heat exchanger 52 is connected to the low temperature end 32. The pulse tube 3 has a smaller diameter than the regenerator 2. The first heat exchanger 51 and the second heat exchanger 52 are connected by the connection member 6. The connecting member 6 includes an outer cylinder member 61 having a first end side 611 connected to the first heat exchanger 51 and a second end side 612 connected to the second heat exchanger 52 and a guide member 62. The outer cylinder member 61 has one end 611 having substantially the same diameter as the first heat exchanger 51 and the other end 612 having the same diameter as the second heat exchanger 52. The guide member 62 is formed of a thin plate and is a funnel-shaped member that is reduced in diameter from the one end side 611 toward the other end side 612 in the same manner as the outer cylinder member 61. The guide member 62 is fixed inside the outer cylinder member 61.

(Function and effect)
Since it has the above structure, the refrigerator of a present Example has the following effects. That is, the pressure vibration generated by the pressure vibration sources 11 and 12 is input to the second cylinder 42 and the high temperature side 21 of the regenerator 2. Since the regenerator 2 is filled with the regenerator material, a certain pressure loss occurs. Therefore, the pressure in the first cylinder 41 connected to the high temperature side 31 of the pulse tube 3 is reduced by the value of the pressure loss. Here, since the cross-sectional areas of the first cylinder 41 and the second cylinder 42 have different sizes, the pistons 43 and 44 are appropriately moved (vibrated) within the cylinders 41 and 42 without being affected by the pressure difference. Can be made. Here, the pressure amplitude in the first cylinder 41 is P1, the pressure amplitude in the second cylinder 42 is P2 (smaller than P1), the sectional area of the first cylinder 41 is S1, and the sectional area of the second cylinder 42 is S2. Then, ideally, it is desirable to set P1 × S1 = P2 × S2. Here, if the phase of fluctuation of each value of P1 and P2 is the same, the ratio of the cross-sectional areas S1 and S2 can be determined in consideration of the ratio of the pressure loss in the regenerator 2, but each of P1 and P2 can be determined. Since the value of f1 varies in a state having a certain phase difference (for example, the pressure fluctuation in the first cylinder 41 may fluctuate later than the pressure fluctuation in the second cylinder 42), P1 and It is also possible to determine the ratio of S1 and S2 using the maximum value or the effective value of each value of P2 in one cycle.

  As described above, since there is a phase difference in the pressure difference between the high temperature side 21 of the regenerator 2 and the high temperature side 31 of the pulse tube 3, the value of P1 × S1 is P2 × S2 in a predetermined phase range. And the pistons 43 and 44 are pressed toward the second cylinder 42 (the left side in the drawing), and in other predetermined phase ranges, the value of P1 × S1 becomes smaller than P2 × S2 and the pistons 43 and 44 Is pressed to the first cylinder 41 side (right side of the drawing). In this case, since the sizes of the cross-sectional areas S1 and S2 are different, the amount of energy input from the outside can be reduced during one cycle of the pressure oscillation of the working gas, and the refrigerator can be operated efficiently. Can do. In particular, when the ratio of the cross-sectional areas S1 and S2 is determined by an average value during one cycle of pressure vibration, the amount of energy input can be minimized within one cycle.

(Modification)
As shown in FIG. 2, the refrigerator of this modification includes a coil spring 91 as an urging member disposed in the first cylinder 41, and a coil spring 92 as an urging member disposed in the second cylinder 42. The configuration is the same as that of the embodiment except that In addition, the same code | symbol is attached | subjected to the same member. The coil spring 91 is disposed so as to be compressed between the top surface of the piston 43 and the inner wall of the first cylinder 41, and the coil spring 92 is compressed between the top surface of the piston 44 and the inner wall of the second cylinder 42. Arranged as described above. The coil springs 91 and 92 transmit an urging force via the pistons 43 and 44, and the pistons 43 and 44 move to a position (neutral position) where the urging forces are balanced. Here, the neutral position is a position that varies depending on the working gas input from the outside. The neutral position is set to a desired position with respect to the phase of the working gas input from the pressure vibration sources 11 and 12. The neutral position (balance position) can be adjusted by adjusting the spring constants of the coil springs 91 and 92. By providing the urging members 91 and 92, it is possible to improve the followability of the piston position (phase) against the pressure vibration of the working gas.

  Here, instead of (in addition to) the coil springs 91 and 92, a flexure bearing 93 as an urging member can be employed (FIG. 3). The flexure bearing 93 connects between the connecting member 45 and the cylinders 41 and 42. The piston 43 and 44 are urged in a direction to return the displacement of the pistons 43 and 44 according to the magnitude of the displacement generated between the cylinders 41 and 42.

11 ... Pressure vibration source (cylinder) 12 ... Pressure vibration source (piston)
2 ... Regenerator 2 21 ... High temperature side 22 ... Low temperature side 3 ... Pulse tube 31 ... High temperature side 32 ... Low temperature side 41 ... Cylinder (first cylinder) 42 ... Cylinder (second cylinder) 43 ... Piston (first piston) 44 ... Piston (second piston) 431, 441 ... Sealing member 51, 52 ... Heat exchanger 6 ... Connection member 61 ... Outer cylinder member 62 ... Guide member 71, 72, 73 ... Piping 8 ... Piston position detecting means 91, 92 ... Coil spring 93 ... Flexure bearing

Claims (5)

A pulse tube,
A regenerator connected to the low temperature side of the pulse tube;
A pressure vibration source connected to the high temperature side of the regenerator to apply pressure vibration to the working gas;
A first cylinder having one end communicating with the high temperature side of the pulse tube and a cylinder having a second cylinder having a different cross-sectional area from the first cylinder and one end communicating with the high temperature side of the regenerator;
A piston having a first piston that reciprocates in the first cylinder and a second piston that reciprocates in the second cylinder in conjunction with an amount of displacement opposite to the first piston;
A refrigerator having the above. The first cylinder and the second cylinder are connected in a back-facing state on the other end side to define the same space,
2. The refrigerator according to claim 1, wherein the piston has a connecting member that integrally connects the first piston and the second piston so as not to move relative to each other in the axial direction.   The refrigerator according to claim 1 or 2, wherein the first piston has a larger cross-sectional area than the second piston.   The refrigerator according to any one of claims 1 to 3, further comprising a biasing member that biases the first piston and the second piston toward a neutral position with respect to the first cylinder and the second cylinder.   5. The pressure vibration source according to claim 1, wherein the pressure vibration source includes a piston position detection unit that detects a relative position between the cylinder and the piston, and applies pressure vibration to the working gas based on the relative position. The refrigerator as described.

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