JP3637538B2 - Refrigerant gas replacement device in refrigerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerant gas replacement device in a refrigerator, and more particularly to a refrigerant gas replacement device in a refrigerator having a gas compressor or a cold head, such as a Stirling refrigerator or a pulse tube refrigerator.
[0002]
[Prior art]
A refrigerant gas replacement device in a conventional refrigerator will be outlined with a Stirling refrigerator as an example.
FIG. 2 is a cross-sectional view of a conventional Stirling refrigerator 1, particularly, a cold head portion. The Stirling refrigerator 1 includes a gas compressor 2 and a cold head 3.
[0003]
The gas compressor 2 is for generating a refrigeration in the cold head 3 by performing a compression supply action and an expansion absorption action of a refrigerant gas such as helium gas to the cold head 3, and the cold head 3 through the gas supply pipe 4. A change in pressure of the refrigerant gas is supplied to the side at a predetermined timing to cause the cold head 3 to generate refrigeration.
[0004]
The cold head 3 includes a head housing 7 including a head case 5 and a head cover 6, a cylinder 8, a displacer 10 (piston) containing a regenerator material 9 such as a wire net, a drive rod 11, and a leaf spring 12 (spring material). ) And a cold head 13.
[0005]
A spring space 14 is formed inside the head case 5 and the head cover 6, and an operation space 15 is formed from the head case 5 and the cylinder 8 to the cold head 13.
[0006]
The displacer 10 is provided so as to be able to reciprocate in the operation space 15, forms a gas flow path 16 for communicating the charged portion of the regenerator material 9 as the operation space 15, and is integrated with the drive rod 11. Install.
The refrigeration unit 17 is configured by the displacer 10 and the regenerator material 9 accommodated in the displacer 10.
[0007]
The drive rod 11 has its end and center portion fixed to the center of the disc-shaped plate spring 12 in the spring space 14, and the outer periphery of the plate spring 12 fixes this to the end of the head case 5. The drive unit 18 is configured.
However, the drive rod 11 is supported by a leaf spring 12 and a seal member 19 so as to be reciprocally movable, and this portion is used as a clearance seal 20 to seal the spring space 14 and the operating space 15. The displacer 10 can be driven via
Therefore, the cold head 3 supplies the refrigerant gas (compression expansion) with the respective phases shifted from the gas compressor 2, and the displacer 10 in the cylinder 8 by the drive unit 18 (the leaf spring 12 and the drive rod 11). A reverse Stirling cycle is executed along with the reciprocation, and the cold stage 13 is frozen.
[0008]
In the Stirling refrigerator 1 having such a configuration, the life of the Stirling refrigerator 1 can be extended by adopting a structure in which the displacer 10 is supported by the leaf spring 12 via the drive rod 11.
Thus, the spring space 14 to which the leaf spring 12 is attached and the operation space 15 that exhibits the refrigeration function are isolated by a clearance seal 20 between the drive rod 11 and the seal member 19.
This clearance seal 20 has a sealing property that guarantees the reciprocating motion of the drive rod 11 and prevents the pressure fluctuation of the refrigerant gas sent from the gas compressor 2 to the operation space 15 from leaking into the spring space 14. Well, it does not realize perfect airtightness.
[0009]
However, helium gas is often used as the working gas (refrigerant gas), and when gas replacement is performed to fill the helium gas in the cold head 3 (spring space 14 and working space 15), a gas supply pipe is used. A helium gas supply device 21 (virtual line) is attached to 4 and gas replacement is performed so that helium gas is filled from the gas supply pipe 4 into the spring space 14 through the operation space 15 and the clearance seal 20 alone.
Therefore, in particular, there is a problem that it takes time to exhaust the gas in the spring space 14 or to replace it with helium gas, and it is difficult to sufficiently exhaust the gas.
[0010]
Since the gas replacement is insufficient, the gas (impurity gas) remaining in the spring space 14 is gradually leached to the operating space 15 side through the clearance seal 20 during normal operation, and the displacer 10 in the low-temperature portion in the cylinder 8 is discharged. There is a problem in that it condenses on the sliding surface or the gas flow path 16 to obstruct the operation of the displacer 10 and the flow of the refrigerant gas, causing the refrigeration capacity of the Stirling refrigerator 1 to become unstable and the performance to deteriorate over time.
In particular, as a result of using a leaf spring 12 instead of a conventional coil spring (not shown) as a spring material, the life of the Stirling refrigerator 1 is relatively extended, but the space of the spring space 14 is increased, and the spring space 14 is increased. There is a problem that the ratio of the impurity gas remaining in the inside increases.
[0011]
[Problems to be solved by the invention]
The present invention has been considered in view of the above problems, and it is an object of the present invention to provide a refrigerant gas replacement device in a refrigerator that can easily remove impurity gases that cause a reduction in life when refrigerant gas such as helium gas is charged. Let it be an issue.
[0012]
Another object of the present invention is to provide a refrigerant gas replacement device in a refrigerator capable of improving the purity of the refrigerant gas filled in the interior of a Stirling refrigerator or the like by quickly replacing the gas in the cold head or the like. And
[0013]
The present invention also provides a refrigerant gas replacement device in a refrigerator that can avoid instability of the refrigeration capacity caused by impurity gas remaining in the Stirling refrigerator and deterioration in performance over time. Let it be an issue.
[0014]
It is another object of the present invention to provide a refrigerant gas replacement device in a refrigerator that can stabilize the refrigeration capacity of a refrigerator such as a Stirling refrigerator or a pulse tube refrigerator and extend its life.
[0015]
[Means for Solving the Problems]
That is, the present invention focuses on forming a space communication path that connects the spring space and the operating space, and providing a bypass valve in the space communication path that opens only at the time of gas replacement. The space between the spring space for housing and the operating space for storing the refrigeration unit having the displacer is sealed by the seal portion so that the displacer can operate, and the operating space is filled with the refrigerant gas. A refrigerant gas replacement device in a refrigerator that performs gas replacement so as to fill the refrigerant gas also with respect to the spring space, forming a space communication path between the spring space and the operating space, A refrigerant gas replacement apparatus in a refrigerator having a bypass valve that can open and close the space communication path.
[0016]
The space communication passage has a spring space side passage and an operation space side passage communicating with a valve mounting space to which the bypass valve is mounted, and the refrigerant gas can be filled from the valve mounting space.
[0017]
The space between the spring space and the operation space can be sealed with a clearance seal different from the space communication path.
[0018]
The drive unit includes a plate spring as the spring material and a drive rod attached to the plate spring, and the refrigeration unit is housed in the displacer attached to the drive rod and the displacer. A cold storage material, and the drive rod can drive the displacer through the seal portion.
[0019]
The refrigerator includes a gas compressor that compresses and expands the refrigerant gas, a cold head that receives the compressed and expanded refrigerant gas and includes the driving unit for driving the displacer at a predetermined cycle; Can have.
[0020]
In the refrigerant gas replacement apparatus in the refrigerator according to the present invention, a space communication path that connects the spring space and the operating space is formed, and a bypass valve that is opened only at the time of gas replacement is provided, so the refrigerant gas such as helium gas is filled. When the gas is replaced, the bypass valve is opened so that the gas can quickly enter and exit the spring space and the operation space.
When the gas replacement is completed and the refrigerator is operated, the bypass valve is closed and only a seal by a seal portion such as a clearance seal is provided between the spring space and the operation space.
Thus, the impurity gas remaining in the spring space can be extremely reduced, and instability of the refrigerating capacity and deterioration of performance due to leaching of the impurity gas through the seal portion such as a clearance seal into the operation space can be prevented. In addition, the life of the refrigerator can be extended.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Next, a Stirling refrigerator 30 employing a refrigerant gas replacement device in a refrigerator according to an embodiment of the present invention will be described with reference to FIG. However, the same parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.
FIG. 1 is a cross-sectional view of a Stirling refrigerator 30, in particular, a cold head 31 and a refrigerant gas replacement device 32 provided in the cold head 31. The configuration is substantially the same as the cold head 3 of FIG.
[0022]
The refrigerant gas replacement device 32 includes a bypass valve 34 and a double bolt 35 provided in a valve mounting space 33 formed in the head housing 7 (head case 5), and respective O-rings 36 and 37.
[0023]
A spring space side passage 38 communicating with the spring space 14 and an operation space side passage 39 communicating with the operation space 15 are formed so as to face the bypass valve 34, and when the bypass valve 34 is opened, the valve is attached. The spring space side passage 38 and the operation space side passage 39 communicate with each other through the space 33 so that the space communication passage 40 can be formed.
[0024]
Further, the helium gas supply device 21 can be set so as to communicate with the valve mounting space 33 when the double bolt 35 is removed, and the gas replacement of the spring space 14 and the operating space 15 is performed via the valve mounting space 33. To do.
[0025]
In the Stirling refrigerator 30, the cold head 31, and the refrigerant gas replacement device 32 having such a configuration, when performing gas replacement, the double bolt 35 is removed, and the bypass valve 34 is loosened to open the space communication path 40, thereby The space side passage 38 and the operation space side passage 39 can communicate with each other, and the helium gas supply device 21 is driven so that helium gas is supplied to the spring space 14 and the operation space 15 and further to the gas compressor 2 via the gas supply pipe 4. Allow filling.
By this gas replacement operation, the refrigerant gas can fill the spring space 14 and the operation space 15 not via the clearance seal 20 but via the spring space side passage 38 and the operation space side passage 39. It is very unlikely that impurity gas will remain in the substrate.
[0026]
After the gas replacement is completed, the bypass space 34 shuts off the space between the spring space side passage 38 and the operation space side passage 39, and the double bolt 35 is tightened to double lock.
[0027]
Thus, the refrigerant gas can be filled with high purity while the possibility that the impurity gas remains in the spring space 14 and the operation space 15 is low, so that in the normal operation of the Stirling refrigerator 30 (cold head 31), the spring space 14 Even if gas leaches out to the operating space 15 side through the clearance seal 20, there is virtually no problem, and the refrigeration capacity becomes unstable due to malfunction of the displacer 10 due to freezing of impurity gas or clogging of the gas flow path 16. And degradation of performance can be avoided.
[0028]
【The invention's effect】
As described above, according to the present invention, since the bypass valve capable of opening and closing between the spring space and the operation space is provided, the gas replacement operation is easily and efficiently performed, and the impurity gas is generated in the spring space and the operation space. The possibility of remaining can be reduced, and it can contribute to the maintenance of the refrigeration capacity of the refrigerator and the extension of the service life.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a Stirling refrigerator 30 that employs a refrigerant gas replacement device 32 in a refrigerator according to an embodiment of the present invention, particularly a cold head 31 and the refrigerant gas replacement device 32 provided in the same portion.
FIG. 2 is a cross-sectional view of a conventional Stirling refrigerator 1, particularly a cold head 3 portion.
[Explanation of symbols]
1 Stirling refrigerator (Fig. 2)
2 Gas compressor 3 Cold head 4 Gas supply pipe 5 Head case 6 Head cover 7 Head housing 8 Cylinder 9 Cold storage material 10 Displacer (piston)
DESCRIPTION OF SYMBOLS 11 Drive rod 12 Leaf spring 13 Cold head 14 Spring space 15 Operation space 16 Gas flow path 17 Freezing part 18 Drive part 19 Sealing member 20 Clearance seal 21 Helium gas supply device 30 Stirling refrigerator (FIG. 1)
31 Cold head (Fig. 1)
32 Refrigerant gas replacement device in Stirling refrigerator 30 (embodiment, FIG. 1)
33 Valve mounting space 34 Bypass valve 35 Double bolt 36 O-ring 37 of bypass valve 34 O-ring 38 of double bolt 35 Spring space side passage 39 Operating space side passage 40 Space communication passage

Claims (5)

The displacer is operable to seal between the spring space that houses the drive unit having the spring material and the operation space that houses the refrigeration unit having the displacer,
A refrigerant gas replacement apparatus in a refrigerator, in which refrigerant gas is charged from the operating space and gas replacement is performed so that the operating space and the spring space are also filled with the refrigerant gas,
While forming a space communication path between the spring space and the operating space,
A refrigerant gas replacement device in a refrigerator, comprising a bypass valve capable of opening and closing the space communication path. The space communication passage has a spring space side passage and an operation space side passage communicating with a valve mounting space to which the bypass valve is attached,
The refrigerant gas replacement device in a refrigerator according to claim 1, wherein the refrigerant gas can be filled from the valve mounting space. The refrigerant gas replacement device for a refrigerator according to claim 1, wherein a clearance seal different from the space communication path is sealed between the spring space and the operation space. The drive unit has a leaf spring as the spring material and a drive rod attached to the leaf spring,
The refrigeration unit includes the displacer attached to the drive rod, and a cold storage material accommodated in the displacer.
The refrigerant gas replacement device for a refrigerator according to claim 1, wherein the drive rod can drive the displacer through the seal portion. The refrigerator is
A gas compressor for compressing and expanding the refrigerant gas;
The refrigerant gas replacement in the refrigerator according to claim 1, further comprising: a cold head that receives the compressed and expanded refrigerant gas and is provided with the driving unit for driving the displacer at a predetermined cycle. apparatus.

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