JPH01310271A - Refrigerating machine - Google Patents

Abstract

PURPOSE:To prevent the change of timing of the movement of a moving body even when the sealing capacity of a seal for a piston member is changed due to abrasion or the like and reduce the deterioration of the refrigerating capacity of a refrigerating machine by communicating a buffer space with a gas spring space through a first connecting circuit. CONSTITUTION:A first connecting circuit 18 communicates a gas spring space 16 with a buffer space 7 and, consequently, the pressure level of the gas spring space 16 can be kept equal to the pressure level of the buffer space 7 even when the sealing capacity of a seal for a piston member is changed due to abrasion or the like. As a result, the relation of a driving force is not changed, the timing of the movement of a moving body 10 is constant at all times and accordingly the change of a cooling capacity is little. Accordingly, a refrigerating machine, having a long life and excellent in reliability, may be obtained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a refrigerator in which a moving body is driven to reciprocate by a pressure difference between its ends, such as a free piston type Stirling refrigerator used for cooling an infrared element.

[Conventional technology]

(I) to (IV) in FIG. 4(a) are, for example,
This figure shows the structure and operation of a conventional refrigerator disclosed in Japanese Patent No. 73873, and this refrigerator includes a reciprocating compressor 1 and a cold finger section 2. The compressor 1 is composed of a piston 3 and a cylinder 4 housing the piston 3, and a working gas such as helium is pressurized and sealed inside the cylinder 4. A piston seal 5 is provided between the piston 3 and the cylinder 4, which separates a second compression space 6 and a buffer space 7, which form part of the working space, and allows the cylinder 3 to be reciprocated within the cylinder 4. By doing so, one surface thereof causes sinusoidal pressure fluctuations within the second compression space 6. And this second compression space 6
The sinusoidal pressure fluctuations in the cold finger section 2 are caused to change the volumes of the first compression space 11 and the expansion space 12 in the cold finger section 2 through the supply pipe 8. In addition, the moving body 10 houses a regenerative heat exchanger 13 and is equipped with a moving body seal 14, so that helium gas is supplied to the first compression space 11.
and the expansion space 12 between the grooves 10a, 10b and the heat exchanger 13.
It is structured so that it flows through. Furthermore, the moving body 10 has an integral screw!・Gas spring space 1 including a piston member 15 and into which a piston member 15 is inserted
6 is a screw-in member seal 17 provided around this.
It is separated from the first compression space 11 by. The refrigerator described above is understood to include three separate gas spaces. That is, the gas working space is composed of the second compression space 6 , the space inside the supply pipe 8 , the first compression space 11 , the expansion space 12 , and the space inside the heat exchanger 13 . A buffer space 7 and a gas spring space 16 form another gas space, and these spaces are separated by a piston seal 5 and a piston member seal 17, respectively. Next, the operation of the above-mentioned refrigerator will be explained using FIG. 4. At the time of the cycle of FIG. 4(a)(I), the lower end of the moving body 10 is connected to the cold finger portion 2
The pressure in the working space increases from the lowest pressure to the highest pressure when the compressor 1 operates in conjunction with the compression. The pressure in the spring space 16 is at a level between the lowest and highest pressure levels in the working volume;
Thus, at some point, the increasing pressure in the working space will create a pressure difference against the piston member 15 sufficient to overcome the frictional resistance of the moving object seal 14 and the piston member seal 17. Then, the piston member 15 and the movable body 10 rapidly rise to the positions shown in FIGS. 4(a) and 4(n). Due to the movement of the moving body 10, the high-pressure gas at approximately ambient temperature in the first compression space 11 passes through the heat exchanger 13, is precooled, and is then introduced into the expansion space 12. Thus, the sinusoidal movement of the piston 3 by the drive mechanism (not shown) begins to expand the volume of the working space as shown in FIG. It is further cooled down. The cooling effect of this refrigerator is mainly generated during this process. Then, at some point in this expansion movement of the piston 3, the pressure in the working space increases to the gas spring space 1.
6, and the pressure difference causes the moving body seal 1
4 and the piston member seal 17, the moving body 10 and the piston member 15 are driven downward toward the position shown in FIG. 4(a) (IV). The position of FIG. 4(a) (IVI) is also the position before reaching FIG. When passing through, it releases cold heat to the heat exchanger 13 and returns to the first compression space 11 as a gas at approximately ambient temperature.As shown in FIG. 4(b), as shown in FIG. When the working gas sealed in the working space moves in response to pressure changes in the working space while maintaining a certain appropriate phase difference during each process, the working gas enclosed in the working space undergoes a thermodynamic cycle known as the "reverse Stirling cycle". The details of the above-mentioned "reverse Stirling cycle" and its principle of generating cold heat can be found in the document "Cryocoolersll." (G. Walker, Plenurn Press. New York, 1983). ) Please refer to

[Problems to be Solved by the Invention] Conventional refrigerators are constructed as described above, so if the sealing ability of the seal for screw parts becomes directional due to wear caused by operation, the gas spring space As shown in Fig. 4(b), a pressure difference occurs between the average pressure in the interior and the average pressure in the working space due to this directionality, and this pressure difference is caused by the reciprocating motion of the moving body. This means changing the quiming value from the initially set optimal value. Therefore, in conventional refrigerators configured in this way, changes in the sealing ability of the piston member seal due to wear etc. will result in a significant decrease in the refrigerating function, so it is difficult to create a refrigerator with sufficient durability and reliability. There was a problem that I couldn't get it. This invention was made to solve the above-mentioned problems, and it has improved durability and reliability so that a constant cooling capacity can always be obtained without being affected by changes in the sealing capacity of the seal for the piston member. The purpose is to obtain an excellent refrigerator.

[Means to solve the problem]

In the refrigerator according to the present invention, the buffer space and the gas spring space are connected by a first connection circuit.

[For production]

In the refrigerator according to the present invention, the gas spring space is connected to the buffer space by a first connection circuit, and even if the sealing ability of the piston member seal changes, the pressure in the gas spring space is always constant (=buffer space). pressure). As a result, the timing of the reciprocating movement of the movable body does not change during operation, and stable motion is achieved, resulting in a long-life and highly reliable refrigerator.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 18 is a first connection circuit, and by communicating the buffer space 7 and the gas spring space 16,
The pressure in both spaces is made equal. In the figure, the same parts as in FIG. 4(a) of the conventional example are given the same reference numerals, and the explanation thereof will be omitted. Next, the operation of this embodiment will be explained using FIG. 2. As explained with reference to (I) to (IV) in FIG. 4(a) of the conventional example, the sinusoidal vertical movement of the piston 3 is caused by the second compression space 6 and the space inside the supply pipe 8. ,
- Compression space 1 and expansion space 12, and heat exchanger 13
Figure 2 (a)
This produces a sinusoidal pressure change as shown in . At this time, the pressure in the gas spring space 16 is kept equal to a certain pressure level between the lowest pressure and the highest pressure in the working space, so the movable body 10 has a pressure level between the working space and the gas spring space 16. A sinusoidal driving force shown in FIG. 2(b) is applied which is equal to the pressure difference multiplied by the cross-sectional area of the piston member 15. On the other hand, since the movable body 10 is equipped with a movable body seal 14 and a screw I/N member seal 17, the movable body 10 ends up at a timing delayed from this driving force by the frictional force of both seals. will start moving. In other words, as shown in FIG. 2(C), a reciprocating motion is performed with a certain phase delay from this driving force. In this way, when the movable body 10 performs reciprocating motion while maintaining a certain phase difference with respect to the pressure change in the working space, the working gas in the working space undergoes the "1 reverse Stirling cycle" as described in the conventional example. generates cold heat in the expansion space 12. In the above cycle, the refrigerator according to this embodiment differs from the conventional example in the following points. That is, in this embodiment, the first connection circuit 18 The gas spring space 16 and the buffer space 7 are communicated with each other, so that even if the sealing ability of the piston member seal changes due to wear etc., the pressure level in the gas spring space 16 remains the same as the buffer space 7.
is always kept equal to the pressure level. As a result, the relationship between the driving forces shown in FIG. 2(b) does not change, and the timing of the movement of the moving body 10 is always constant, so there is little change in the cooling capacity. Thus, according to this embodiment, a refrigerator with long life and excellent reliability can be obtained. In the above embodiment, the case of a split-type refrigerator in which the cold finger section 2 and the compressor 1 are separated from each other via the supply pipe 8 has been described, but in another embodiment of the present invention shown in FIG. In this case, the cold finger section 2 and the compressor 1 may be integrated into an integrated refrigerator in which the cold finger section 2 and the compressor 1 are mechanically strongly coupled, and the same effects as in the above embodiment can be obtained.

【Effect of the invention】

As described above, according to the present invention, since the buffer space and the gas spring space are communicated through the first connection circuit, even if the sealing ability of the piston member seal changes due to wear etc., the timing of the movement of the moving body changes. This has the effect of providing a long-life and highly reliable refrigerator, since there is no reduction in cooling capacity.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view showing a refrigerator according to an embodiment of the invention, FIG. 2 is an explanatory diagram showing the operation of the refrigerator according to an embodiment of the invention, and FIG. 3 is another embodiment of the invention. 4(a) (I) to (IV).
) is a cross-sectional side view showing the operating state of a conventional refrigerator, and FIG. 4(b) is a characteristic diagram showing the relationship between the average pressure in the conventional gas spring space and the average pressure in the working space. 1. Compressor, 2. Cold finker, 3.-
Piston, 4, cylinder, 5...piston seal,
6 - Second compression space, 7 - Buffer space, 8 - Supply pipe, 9 - Housing, 10 Moving body, 11 - First compression space, Work 2 - Expansion space, 13... Heat exchanger, 14 Seal for moving body , 15. Piston member, 16. Gas spring space, 17. Seal for piston member, 18 First connection circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] The compressor consists of a compressor that causes periodic pressure fluctuations in the working gas in the working space, and a cold finger section that communicates with the working space of the compressor through a supply pipe. A piston is housed in a reciprocating manner, the piston changes the volume of a buffer space by one surface, and the cold finger part has a movable body reciprocating therein and a part of the movable body. The movable body has a piston member forming a piston member, a piston member seal surrounding the piston member, and a gas spring space separated from the working space by the piston member seal, and the movable body has a gas spring space separated from the working space by the piston member seal. In the refrigerator, which is driven by a differential pressure between the working space and the moving body, the buffer space and the gas spring space are first connected to each other. A refrigerator characterized by being connected by a circuit.