JP2003004322A - Pulse pipe refrigerating machine without buffer tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a multi-functional unit for providing a vibrationproof container with a function of a buffer tank by providing the vibrationproof container of a pulse pipe refrigerating machine with multiple functions. SOLUTION: A linear compressor 20 is disposed opposite to the vibrationproof container 30 and is composed of a mechanical metallic spring (special alloy), a vibration absorbing material (special synthetic rubber) and the like. The compressor 20 and the container 30 are completely shielded for not permitting a working gas to flow in and out, and the vibrationproof container doubles as a vibration isolator and a buffer tank. A cold head in a vacuum chamber 24 stores cold and can accommodate a (very) low temperature amplifier or the like using a superconductive material as a facility of a high frequency signal transmitting/receiving station, its repeater station or the like. A heat exchanger 22 is interposed between the compressor 20 and the chamber 24 to form a passage for a working fluid, and the terminal of a capillary tube 26 communicates with the vibrationproof container.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse tube refrigerator, and more particularly to a pulse tube refrigerator of a type without a buffer tank (hereinafter referred to as "buffer tankless").

[0002]

2. Description of the Related Art In the pulse tube refrigerator, the working gas flowing in the pulse tube is compressed and expanded to generate heat and cool, and a heat generating portion and a cool storage portion are formed in the pulse tube. Then, by radiating this heat generation to the outside of the pulse tube, it is a refrigerator capable of reaching a predetermined low temperature in the cold storage part. At this time, the working gas needs to be compressed at one predetermined position and expanded at another predetermined position. In order to satisfy these conditions, a high performance linear compressor is used. Is regularly compressed and expanded, and phase adjustment is indispensable so that the wave of the working gas has a predetermined phase. A buffer tank is conventionally known as one of the phase adjusting means provided in the pulse tube refrigerator. In order to improve the performance of the regenerator, the pulse tube refrigerator has the refrigerating capacity adjusted by the phase adjusting means so that the optimum PV phase angle at the low temperature end becomes 90 degrees (as close as possible to 90 degrees). Although it can be improved, an example thereof is Japanese Patent Laid-Open No. 2000-7451.
No. 6 publication is mentioned. In this document, a regenerator and a pulse tube are serially connected in this order to a connecting pipe of a compressor, and the room temperature end of the pulse tube (actually, not at room temperature but at a temperature of several tens degrees C There is also an example of calling the buffer tank via an orifice valve, and connecting the buffer tank and the compressor with a valve and a one-way valve (check valve) that allows the flow from the buffer tank to the compressor. Connection is made by an intervening return flow path, and the room temperature end side of the pulse tube and the room temperature end side of the regenerator are connected via a double inlet valve.

By the way, it can be said that erasing (eliminating) the buffer tank (phase adjusting means), which is a functionally indispensable element, from the pulse tube refrigerator itself is an epoch-making idea. However, there is a technical idea of omitting the buffer tank also in the related art, and an attempt to substitute another element member having a phase adjusting function other than the buffer tank has been proposed.

The pioneer of this idea is JP-A-6-18581.
As disclosed in Japanese Patent Publication No. 7, the pulse tube refrigerator has two communication tubes, and the first communication tube communicates the compression chamber with the pulse tube via the heat storage device and the low temperature heat exchanger. Further, since the second pair of communication pipes communicates the buffer chamber with the pulse tube via the room temperature heat exchanger, the working gas passes between the buffer chamber and the compression chamber via the pulse tube. It will flow. Therefore, the structure is such that there is no problem even without the conventional buffer tank, and the phase adjusting function is provided. However, this technique requires (imposes) a buffer function at the same time to the compression chamber that is responsible for the compression function of the working gas, and may cause a pressure fluctuation of the working gas. Further, the pressure fluctuation of the working gas has an indirect effect, which may make the performance of the refrigerator unstable. For this reason, practicality is questioned. In the buffer tank and the capillary where the working gas accumulates, the working gas itself may reach a temperature of about 90 ° C, and at high temperatures, the phase adjustment of the working gas tends to be more difficult than at low temperatures, so this performance is unstable. There is a question as to whether the pulse tube refrigerator will be practically usable.

In the examples disclosed in Japanese Patent Laid-Open Nos. 2000-74516 and 2000-74517, the orifice tube is a single tube and the connecting pipe of the compressor is connected by a double inlet valve. The buffer tank and the connecting pipe are connected by an orifice tube, but this type reduces the cooling capacity of the pulse tube cooler. The reason is that the working gas that has reached a high temperature on the compressor side in the connecting pipe enters the orifice tube and heats the orifice tube itself. This is because heat cannot be sufficiently dissipated, resulting in a reduction in the thermal efficiency of the entire device.

That is, the above-mentioned problems exist when trying to miniaturize the pulse tube refrigerator.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to make a vibration isolator container multi-functional so that the vibration isolator container has a buffer tank function.

[0008] In the pulse tube refrigerator, a compressor having a linear motor structure is usually used in order to bring the working gas into a regular sparse and dense state (expansion / compression state), but a stable reciprocal motion of this linear motor is secured. As a means of achieving this, a compressor with a well-balanced double cylinder type has been adopted.
However, it is necessary to downsize the pulse tube refrigerator, the compressor and other devices in terms of volume, and at the same time, a single-cylinder compressor is being developed from the viewpoint of efficiency and energy saving. In the development process, in order to operate the single-cylinder type compressor smoothly, a vibration isolator with a function to suppress the vibration of the compressor is connected to the single-cylinder type compressor and is used as a vibration isolator container in the buffer tank. The tank (container) device was modified to have functions. Then, unlike the one found in the prior art in which the buffer tank communicates with the compression chamber, it was found that the vibration isolator container of the present invention can maintain a stable state without any pressure fluctuation, and the present invention was completed. It has arrived.

[0009]

In order to solve the above problems, according to the invention of claim 1, a vibration isolator container capable of suppressing the vibration of the linear compressor is connected to the tip of the pulse tube refrigerator. It communicates with a capillary tube that has a phase adjustment function. As a result, it is possible to design a small pulse tube refrigerator that can omit the buffer tank. In the invention of claim 1, it is essential that the buffer tank can be omitted by connecting the vibration isolator container and the capillary tube to each other, and the invention can be applied to both the double cylinder linear compressor and the single cylinder linear compressor without distinction. it can. In short, it is a necessary condition that the compression section (compressor or compression chamber of the related art) and the phase adjusting means are isolated / blocked so as not to communicate with the working gas.

According to the second aspect of the invention, a single cylinder linear compressor and a vibration isolator container capable of suppressing the vibration thereof are cleverly connected as a further development of miniaturization and thermal efficiency. That is, a single-cylinder type linear compressor capable of expanding and compressing working gas, a vibration isolator container capable of suppressing the vibration of the single-cylinder type linear compressor, a low temperature vacuum chamber, and a low temperature vacuum chamber A pulse tube refrigerator including a pulse tube and a capillary tube connected to a high temperature portion of the pulse tube tip, in which the capillary tube is communicated with the vibration isolator container, and the single cylinder type The linear compressor and the vibration isolator container are characterized by being shielded so that the working gas cannot flow in and out.

The invention of claim 3 is the invention of claim 1 or claim 2.
Is a pulse tube refrigerator in which a vibration isolator container is responsible for vibration absorption and phase adjustment associated with generation of a compression wave of a working gas. That is, a vibration isolator container that has both a vibration damping function for mechanical vibration in a compressor that forms expansion / compression (dense and dense) waves in the working gas and a phase adjustment function for the working gas including the capillary tube of the pulse tube refrigerator. There is a feature that has.

In the present invention, as described above, the vibration isolator container needs to be blocked by a partition wall or the like so that the linear compressor and the working gas do not flow in and out. Also, this cutoff
Working gas flowing through a capillary tube (typically 65-70
(° C) reaches a high temperature due to compression in the compressor (90 ° C)
It is necessary from the viewpoint of thermal efficiency so that it does not mix with other materials, and has the advantage that the refrigerating capacity of the refrigerator is not different from that with a buffer tank.

[0013]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows one of the embodiments of the present invention, and is an example in which a single cylinder type linear compressor corresponding to claim 2 is used.

The linear compressor 20 is arranged so as to oppose the vibration isolator container 30, and is composed of a mechanical metal strip (special alloy), a vibration absorbing material (special synthetic rubber), an air spring and the like. . The linear compressor 20 and the vibration isolator container 30 are completely shielded so that the fluid containing the working gas does not come in and out.

A cold head is placed in the vacuum chamber 24 to store cold, and the pulse tube portion of the pulse tube refrigerator is also placed. This vacuum chamber 24 is the main part of the refrigerator, and can store a low-temperature amplifier using a superconducting material as a facility for a high-frequency signal transmission / reception station and its relay station. A heat exchanger 22 is provided between the linear compressor 20 and the vacuum chamber 24 to form a working gas flow path.

A phase adjustment is performed between the vacuum chamber 24 and the vibration isolator container 30 by a capillary tube 26.

It is possible to arrange the vibration isolator container 30 in the multi-cylinder type linear compressor as in the case of FIG. 1, and even in this case, the vibration isolator container 30 can be protected from the tip of the pulse tube refrigerator via the capillary tube 26. The working gas can be communicated with the shaker container 30. Of course, the phase adjustment function does not change.

[0019]

INDUSTRIAL APPLICABILITY The present invention makes the vibration isolator container multi-functional to reduce the size of the pulse tube refrigerator as a whole, and the thermal efficiency,
It has improved cooling capacity.

Since the pulse tube refrigerator of the present invention can be applied not only to a double cylinder type linear compressor but also to a single cylinder type linear compressor and has a vibration damping function and a phase adjusting function as a vibration isolator,
The refrigerating capacity can be maintained at a high level without providing a buffer tank.

[0021]

The pulse tube refrigerator according to the present invention has the capability of reaching a low temperature of about 70K and is miniaturized. The cold head in the vacuum chamber 24 in FIG. 1 is cooled to about 70K, and a high-precision filter using a superconducting material and a low-temperature amplifier with extremely little noise are stored in the vacuum chamber, so that a high-frequency signal transmitting / receiving station. And functions as a facility such as a relay station.

[Brief description of drawings]

FIG. 1 is a schematic view showing one of the embodiments of the present invention and corresponding to claim 2. FIG.

[Explanation of symbols] 20 Linear compressor 22 heat exchanger 24 vacuum chamber 26 capillary tubes 30 vibration isolator container

Claims (3)

[Claims] 1. A pulse tube refrigerator without a buffer tank in which a vibration isolator container capable of suppressing the vibration of a linear compressor and a capillary tube connected to the tip of the pulse tube refrigerator communicate with each other. 2. A single-cylinder type linear compressor capable of expanding / compressing a working gas, a vibration isolator container capable of suppressing the vibration of the single-cylinder type linear compressor, a low temperature vacuum chamber, and the inside of the low temperature vacuum chamber. In a pulse tube refrigerator without a buffer tank including a pulse tube stored in a pulse tube and a capillary tube connected to a high temperature portion of the pulse tube tip, communicating the capillary tube with the vibration isolator container, and A buffer tubeless pulse tube refrigerator, wherein the single cylinder type linear compressor and the vibration isolator container are shielded so that the working gas cannot flow in and out. 3. A protective device having both a vibration damping function for mechanical vibration in a compressor that forms expansion / compression (dense / dense) waves in a working gas and a phase adjusting function for a working gas including a capillary tube of a pulse tube refrigerator. Pulse tube refrigerator with shaker container.