JPH0541321Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a regenerator that uses high-pressure helium gas as a cooling medium and generates cold at extremely low temperatures, which is applied to cryopumps, thermometer calibration devices, etc. Concerning improvements to type refrigerators.

[Conventional technology]

2. Description of the Related Art A regenerator type refrigerator that uses high-pressure helium gas or the like as a cooling medium has been known as one type of refrigerator. Among them, Fig. 2 is a sectional view showing a schematic configuration example of this kind of Gifford-McMahon type regenerator type refrigerator, in which 1 is a compressor that supplies high-pressure helium gas as a cooling medium; 2
is a high pressure helium gas pipe, 3 is a low pressure helium gas pipe, 4 and 5 are connectors to the high pressure helium gas pipe 2 and low pressure helium gas pipe 3, respectively, 6 is a motor housing, 7 is a motor, 8 is a motor shaft,
9 is a control valve that controls helium gas; 10 is a support base that supports the motor housing 6; 11 is a control block that controls the flow of helium gas in combination with the control valve 9; 12 and 13 are helium gas passages; 14 is a helium gas passage. Seal, 15 is a sub-piston that controls the reciprocating motion of the displacer, 16 is a seal, 1
7 is a helium gas passage, 18 is a first-stage displacer, and 19 is a first-stage regenerator, which are usually made of stacked copper wire meshes or the like. Also, 20
is the first stage cylinder, 21 is the helium gas passage,
22 is a first-stage cold generation space, 23 is a first-stage heat station for attaching objects to be cooled, 24 is a seal, 25 is a second-stage cylinder, and 26 is a second-stage regenerator, which is usually a lead ball with a diameter of 1 mm or less. etc. are filled. Furthermore, 27 is a second stage displacer,
28 is a helium gas passage, 29 is a second stage heat station to which an object to be cooled is attached, 30 is a second stage cold generation space, and 31 is a helium gas space for driving the sub-piston 15. In the regenerator type refrigerator shown in FIG. 2, room-temperature helium gas pressurized by the compressor 1 passes through the high-pressure helium gas pipe 2 and the connector 4 to the motor housing 6.
Go inside. On the other hand, as the motor 7 rotates, a rotary control valve 9 and a control block 11 control the passage of high pressure helium gas, and a sub-piston 15 controls the movement of the displacer. Further, the high-pressure helium gas passes through the helium gas passages 13 and 17 and is cooled in the first stage regenerator, and passes through the helium gas passage 21 and is partially stored in the first stage cold generation space 22. Furthermore, the remaining high-pressure helium gas is further cooled through the second stage regenerator 26 and stored in the second stage cold generation space 30 through the helium gas passage 28.

FIG. 2 shows a case where the displacer is located at the top, and high-pressure and cryogenic helium gas is stored in the first-stage cold generation space 22 and the second-stage cold generation space 30. Here, the control valve 9 is rotated by the rotation of the motor 7, and the cold generation spaces 22 and 30 are connected to the low pressure helium gas pipe 3 of the compressor 1. As a result, the helium gas in each of the cold generation spaces 22 and 30 undergoes adiabatic expansion,
The temperature becomes even lower, causing a chill. after that,
In order to recover the cold of the low-temperature helium gas in the cold generation spaces 22 and 30 in the first stage regenerator 19 and the second stage regenerator 26, the first stage displacer 1
8. The second stage displacer 27 is the sub-piston 1
It descends due to the action of 5. Furthermore, in order to introduce high-pressure helium gas into the first-stage cold generation space 22 and the second-stage cold generation space 30, the first-stage displacer 18 and the second-stage displacer 27 are raised, as shown in FIG. Return to state. By repeating the above cycle, the refrigerator can generate low temperatures intermittently.

As an example of equipment using a regenerator type refrigerator, a thermometer calibration device is shown in FIG. In Figure 3,
It is assumed that each part indicated by 1 to 3, 23, and 29 has the same structure and the same function as each part indicated by the same reference numeral in FIG. In FIG. 3, 32 is a regenerator type refrigerator, 33 is a vacuum container for heat insulation, 34 is a vacuum part, 35 is a refrigerator flange part for connecting the vacuum container 33, and 36 is a part for maintaining vacuum. A seal, 37 is a calibration unit attached to the second stage heat station 29, 38 is a thermometer, and 39 is a thermometer 3.
8 is a lead wire, 40 is a heater for adjusting the temperature of the calibration section 37, and 41 is a shield plate cooled by the first stage heat station 23 in order to reduce the radiant heat from the normal temperature section to the calibration section 37. .

Referring to FIG. 3, when the compressor 1 starts operating, the temperatures of the first heat station 23 and the second heat station 29 decrease due to the cooling action of the refrigerator 32. The calibration section 37 is equipped with a standard thermometer that serves as a reference and a plurality of thermometers to be calibrated (only one thermometer 38 is shown in Figure 3, and the others are omitted). The structure is such that the temperature required for calibrating the thermometer to be calibrated can be set using the generated cold and the heater 40. Therefore, when the thermometer is cooled to a predetermined temperature, by comparing the outputs of the standard thermometer and the thermometer to be calibrated, the temperature of the thermometer to be calibrated can be calibrated based on the temperature indicated by the standard thermometer.

[Problem that the invention attempts to solve]

For example, in the case of a thermometer calibration device, when it is necessary to calibrate a large number of thermometers to be calibrated, once the calibration is completed, the refrigerator and the calibration section are returned to room temperature as soon as possible in order to replace the thermometers to be calibrated. It is necessary. (In the case of natural temperature rise, 1
(It takes about a day).

For this reason, conventional methods have been used to heat the first and second stage heat stations by wrapping heaters around them, but this often results in localized temperature rises.
Heating efficiency was poor. In addition, the displacer and sealing material used in refrigerators are made of synthetic resin, so they have low heat resistance, and if the temperature reaches higher than room temperature due to the heater, the displacer and seal may be damaged. It was a lot.

SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a regenerator type refrigerator that can solve the above-mentioned problems of the conventional refrigerator and can heat up in a short time without damaging refrigerator parts that have low heat resistance.

[Means for solving problems]

The regenerator type refrigerator according to the present invention is a regenerator type refrigerator that uses high-pressure helium gas as a cooling medium, and has a double structure with a cylinder in which a displacer (or piston) containing a regenerator moves back and forth. The cylinder is characterized by having a gas inlet and a gas outlet between the inner cylinder and the outer cylinder, forming a space through which an external gas other than the cooling medium can flow.

[Effect]

According to the present invention, by having the above configuration, when raising the temperature of the low-temperature section of the refrigerator, the temperature can be raised efficiently without locally increasing the temperature. Therefore, damage to refrigerator parts such as displacers and seals that have low heat resistance is reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cross-sectional view of a configuration example of a regenerator type refrigerator according to the present invention. The same parts as in FIG. I will only describe it.

In FIG. 1, 50 is a first-stage outer cylinder provided outside the first-stage cylinder 20, 51 is a second-stage outer cylinder provided outside the second-stage cylinder 25, and 56 is the first-stage cylinder 20. and a first stage space composed of the first stage outer cylinder 50, 57 a second stage space composed of the second stage cylinder 25 and the second stage outer cylinder 51, 52 and 53 heating the first stage space. This is a thin tube for supplying gas or for vacuuming. Reference numerals 54 and 55 are thin tubes for supplying heating gas to the second stage space 57 or evacuating it. Although the thin tubes 52, 53, 54, and 55 are only shown halfway in FIG. 1, for example, in the thermometer calibration device shown in FIG. , connected to vacuum pump piping for evacuation or gas piping for supplying heating gas.

The operation of one embodiment of the present invention shown in FIG. 1 will be explained.

In FIG. 1, before the compressor 1 starts operating, the first stage space 56 and the second stage space 57 are evacuated and are in a well-insulated state. Next, when the operation is started, the first and second stage heat stations 23 and 29 are cooled, and the thermometers and the like are calibrated. Since it is necessary to heat the refrigerator after calibration, for example, helium gas is supplied through the thin tubes 52 and 54, and the heated helium gas is taken out from the thin tubes 53 and 55 to the outside of the refrigerator. By the above operation, the temperature of the refrigerator can be raised efficiently and in a short time.

[Effect of idea]

According to the present invention, when raising the temperature of the low-temperature part of the refrigerator, the temperature can be raised efficiently and in a short time without causing a local temperature rise. As a result, excellent effects such as less damage to refrigerator parts such as displacers and seals having low heat resistance can be achieved.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional diagram of a regenerator type refrigerator as an embodiment of the present invention, Figure 2 is a cross-sectional diagram of a conventional regenerator type refrigerator, and Figure 3 is a cross-sectional diagram of a conventional thermometer calibration device. FIG. 50... First stage outer cylinder, 51... Second stage outer cylinder, 52, 53... Thin tube, 54, 55...
Thin tube, 56...first stage space, 57...second stage space.

Claims (1)

[Scope of utility model registration request] In storage refrigerators that use high-pressure helium gas as a cooling medium, the cylinder in which the displacer (or piston) with a built-in regenerator moves back and forth has a double structure, and the inner cylinder and outer cylinder of this cylinder are separated. A regenerator type refrigerator having a gas inlet and a gas outlet therebetween, forming a space through which an external gas other than the cooling medium can flow.