JPH06129724A - Pulse tube refrigerating machine - Google Patents

Abstract

PURPOSE:To obtain a pulse tube refrigerating machine, having small size and weight and requiring no buffer tank, low in achieving temperature, high in cooling efficiency and very much reduced in the vibration thereof. CONSTITUTION:Two sets of rotary three-way valves 12, 13 are arranged in parallel to the high-pressure refrigerant gas passage 15 of a compressor 7. The high temperature terminal of a cold heat accumulator 2 is connected to one of the rotary three-way valve 12 through a main gas passage 19 while the high-temperature terminal of a pulse tube 1 is connected to the other rotary three-way valve 13 through a sub gas passage 20. The low pressure ports of respective rotary three-way valves 12, 13 are communicated with the low- pressure refrigerant gas returning passage 18 of the compressor 7 respectively. A flow rate regulating device 21 is interposed in the sub gas passage 20. Both of the rotary three-way valves 12, 13 are constituted so as to be turned synchronizedly. The opening and closing timing of one of the rotary three-way valves 12, 13 is constituted so as to be changeable with respect to the valve opening and closing timing of the other rotary three-way valves 13, 12.

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 in which a regenerator and a pulse tube are connected to each other and a gas from a compressor is taken in and out to generate cold heat in an endothermic portion.

[0002]

2. Description of the Related Art Conventionally, a double inlet type pulse tube refrigerator shown in FIG. 4 has been proposed as a pulse tube refrigerator capable of obtaining a low ultimate temperature (Academic Journal "Cryogenics", September 1990 issue). This double inlet type pulse tube refrigerator has a low temperature end (51) of the pulse tube (50) and a regenerator (52).
The cold end (53) and the endothermic connecting pipe (5
4), the gas supplied from the compressor (55) to the high temperature end (57) of the regenerator (52) through the refrigerant gas passage (56) is connected to the regenerator (52) and a heat absorbing connecting pipe. The pulse tube (50) is introduced from the low temperature end (51) of the pulse tube (50) toward the high temperature end (58) through the (54).
A phase shifter composed of a needle valve (59) and a buffer tank (60) is arranged at the high temperature end (58) of the pulse tube (50), and a refrigerant is provided in a passage portion between the high temperature end of the pulse tube (50) and the buffer tank (60). Connect the branch gas passage (61) branched from the gas passage (56),
A needle valve (62) is arranged in this branch gas passage (61), and a water cooler (6) is provided at the high temperature end of the regenerator (52) and the pulse tube (50).
3) (64) is arranged to cool the high temperature end of the regenerator and pulse tube with water.

[0003]

However, in the double-inlet type pulse tube refrigerator, the buffer tank (60) is arranged so as to communicate with the high temperature end (58) of the pulse tube (50). In addition to the problem that the entire refrigerator becomes larger, the high temperature end of the pulse tube (50) and the buffer tank (60)
Place the needle valve (59) between the
Since the needle valve (62) is arranged in the branch gas passage (61) which connects the passage portion between the high temperature end of (50) and the buffer tank (60) and the refrigerant gas passage (56), Needle valve (5
9) There was also the problem of disturbing the gas flow due to (62). It is an object of the present invention to provide a pulse tube refrigerator that does not require a buffer tank, is small and lightweight, has a low ultimate temperature, has a high cooling efficiency, and has an extremely small vibration.

[0004]

In order to achieve the above object, the present invention has two rotary type three-way valves arranged in parallel in a high pressure refrigerant gas passage of a compressor, and one rotary type three-way valve stores cold energy. The high temperature end of the reactor is communicated with the main gas passage, the high temperature end of the pulse tube is communicated with the other rotary three-way valve through the sub gas passage, and the low pressure port of each rotary three way valve is returned to the low pressure refrigerant gas of the compressor. It is connected to the passage, a flow rate adjuster is installed in the sub gas passage, and both rotary type three-way valves are configured to rotate synchronously, and the valve opening / closing timing of one rotary type three-way valve to the other rotary type three-way valve It is characterized in that it can be adjusted and changed.

[0005]

According to the present invention, two rotary three-way valves are arranged in parallel in the high-pressure refrigerant gas passage of the compressor, and the high temperature end of the regenerator is connected to one rotary three-way valve through the main gas passage, while the other is The high temperature end of the pulse tube is connected to the rotary three-way valve of the sub gas passage, the low pressure port of each rotary three way valve is connected to the low pressure refrigerant gas return passage of the compressor, and a flow rate adjuster is installed in the sub gas passage. Since both rotary type three-way valves are configured to rotate synchronously and the valve opening / closing timing of one rotary type three-way valve to the other rotary type three-way valve can be adjusted and changed, a buffer tank is arranged. It is possible to provide a small-sized pulse tube refrigerator with high refrigeration generation efficiency without lowering the reached temperature.

[0005]

1 and 2 show an embodiment of the present invention.
Is a schematic configuration diagram of a pulse tube refrigerator, and FIG. 2 is a schematic configuration diagram of a cold heat generating unit. This pulse tube refrigerator has a pulse tube (1)
And a regenerator (2), one end of which is made to communicate with each other through a heat absorption connecting path (3)
A compressor unit (5), and a rotary valve unit (6) for switching and controlling the supply and discharge of high-pressure gas generated in the compressor unit (5) to the cold heat generating section (4).

The compressor unit (5) includes a compressor (7) and a cooler.
(8), an oil separator (9), an oil adsorber (10) and a pressure-holding valve (11), and the rotary valve unit (6) includes two rotary three-way valves (12) and (13). Each of them is composed of a valve driving motor (14). Then, the high pressure refrigerant gas passage (15) led out from the adsorber (10) is connected to the first port of each rotary type three-way valve (12) (13) by the flexible hose (16), and the rotary type three-way valve ( A flexible hose (17) led out from the second ports (12) and (13) is communicatively connected to the compressor (7) through a low pressure refrigerant gas return path (18).

The third port of the first rotary type three-way valve (12) is connected to the high temperature end of the regenerator (2) by a main gas passage (19) made of a flexible connecting pipe so as to communicate with the second rotary type three-way valve. Valve (13)
The third port is a sub gas passage (20) made of a flexible connecting pipe, which is connected to the high temperature end of the pulse pipe (1) through a needle valve serving as a flow rate adjusting device (21). In addition, each rotary three-way valve (1
2) The valve drive motor (14) of (13) is composed of a stepping motor, and each valve drive motor (14) is configured to be individually driven by the motor power supply (22) (22). Each motor power source (22) (22) is connected to the pulse generator (2
The drive circuit (24) is configured by connecting to 3). As a result, the two rotary three-way valves (12) and (13) operate in synchronization.

Then, pulse generation in the drive circuit (24) of the valve drive motor (14) for operating the second rotary three-way valve (13) connecting the third port to the high temperature end of the pulse tube (1) A phase shifter (25) is arranged between the regenerator (23) and the motor power source (22) and is connected to the regenerator (2) with a first rotary three-way valve (12) and a pulse tube (1). ) Is connected to the second rotary three-way valve (13) so that the phase angle (valve opening / closing timing) of valve opening / closing can be adjusted and changed.

The cold heat generating section (4) is composed of two stainless pipes.
(26) (27) are arranged in parallel, the lower end is fitted to the copper end cap (28), and the upper end is a mounting flange (2
It is formed by fitting it to the stainless steel pipe (2
The stainless steel or copper mesh body (30) is laminated inside the 6), and the straightening vanes (31) are arranged at the upper and lower ends to form the regenerator (2) and the other stainless pipe (27). ) Of the pulse tube.
It is configured in (1). And copper end caps (28)
A gas distribution plate and a spacer are attached to form a heat absorbing communication passage (3) to connect the regenerator (2) and the pulse tube (1).

When the second rotary type three-way valve (13) communicating with the pulse tube (1) is switched, the sub gas passage (20) is compressed.
When communicating with the high pressure gas passage (15) of (7), the flow rate of the high pressure refrigerant gas is controlled by the flow rate adjuster (21) to be supplied to the pulse tube (1) from the high temperature end, and the pressure in the pulse tube is Start climbing. Then, with a slight time lag from the point of communication of the sub gas passage (20), the first rotary type three-way valve (12) communicating with the regenerator (2) is switched so that the main gas passage (19) becomes the high pressure gas passage (15). Communicate with. Therefore, the high-pressure refrigerant gas is supplied to the high temperature end of the regenerator (2), and the supplied high-pressure refrigerant gas reaches the low temperature end of the pulse tube (1) via the regenerator (2) and the inside of the pulse tube (1). Is increased in pressure to high pressure by the high pressure refrigerant gas supplied from the sub gas passage (20) and the high pressure refrigerant gas supplied from the main gas passage (19).

The second rotary three-way valve (13) is switched before the pressure in the pulse tube (1) reaches the maximum pressure, and the sub gas passage (20) communicates with the low pressure gas return passage (18). Since the flow rate adjuster (21) is provided in the sub gas passage (20), the amount of the refrigerant gas flowing out from the pulse tube (1) is limited, and the high pressure gas in the pulse tube (1) reaches the maximum pressure. As it rises, gas will move from the low temperature end to the high temperature end.

Next, the main gas passage (1) is switched by the switching operation of the first rotary type three-way valve (12) communicating with the regenerator (2).
9) communicates with the low pressure refrigerant gas return path (18), the high pressure gas in the pulse tube (1) expands to low pressure gas, generating low temperature,
It is returned to the low pressure system of the compressor (7). The above operation is repeated. This operation is comparable to the Stirling refrigeration cycle.

In the pulse tube refrigerator thus constructed,
The cold heat generating part (4) has no moving parts, and the regenerator (2)
Since the main gas passage (19) that connects the rotary valve unit (6) for controlling the supply and discharge of the refrigerant gas to the cold heat generating portion (4) is formed by the flexible connecting pipe, the refrigerator does not vibrate. Can be provided.

Then, a phase shifter is provided in the drive circuit (24) of the second rotary type three-way valve (13) communicating with the high temperature end of the pulse tube (1).
(25) is arranged so that the phase difference between the second rotary three-way valve (13) communicating with the pulse tube (1) and the first rotary three-way valve (12) communicating with the high temperature end of the regenerator (2) is increased. Since it is configured so as to operate with the above, and the phase difference is adjustable, it is possible to easily obtain the ideal phase difference depending on the target temperature range.

Further, by changing the rotational speed of the drive motor (14) which drives the two rotary type three-way valves (12) and (13), the rotary type three-way valves (12) and (13) are switched. The operating speed may be changed to change and adjust the gas supply / discharge cycle. Further, in the above-mentioned embodiment, the case where the phase shifter (25) is arranged in the drive circuit of the second rotary type three-way valve (13) has been described, but in the drive circuit of the first rotary type three-way valve (12). The phase shifter (25) may be arranged.

FIG. 3 shows another embodiment of the present invention in which two rotary type three-way valves (12) and (13) are driven by the same drive motor (14). Regenerator
The valve plate (33) of the first rotary valve (12) communicating with the high temperature end of (2) is fixed, and the second rotary three-way valve ((2) communicating with the high temperature end of the pulse tube (1) ( The valve plate (34) of 13) is arranged so as to be rotatable around the rotary shaft core of the rotary valve element (35), and the opening / closing valve actuation timing of the second rotary type three-way valve (13) is set to the first rotary type three-way valve. The phase can be adjusted with respect to the opening / closing valve operation timing of (12). An orifice is provided in the sub gas passage (20) as a flow rate adjuster (21).

In the other embodiment, the valve plate (33) of the first rotary type three-way valve (12) is fixed and the valve plate (34) of the second rotary type three-way valve (13) can be rotationally adjusted. However, the valve plate (33) of the first rotary type three-way valve (12) is configured to be adjustable in rotation, and the second rotary type three-way valve is configured.
The valve plate (34) of (13) may be fixed.

[0018]

According to the present invention, the high temperature end of the pulse tube can be switched and communicated with the high pressure refrigerant gas passage and the low pressure refrigerant gas passage of the compressor via the second rotary three-way valve. Since the flow rate adjuster is arranged in the sub gas passage between the three-way valve, the rotary operation of the rotary valve will switch and connect the inside of the pulse tube to the low pressure refrigerant gas passage and the high pressure refrigerant gas passage. Since the pressure change due to this switching plays a role equivalent to that of a double-inlet type pulse tube refrigerator, a buffer tank is omitted and a pulse tube refrigerator with a small size and light weight, high refrigeration generation efficiency, and extremely low vibration is used. Obtainable.

Further, the regenerator and the pulse tube are configured so as to be switchably connected to the high pressure refrigerant gas passage and the low pressure refrigerant gas return passage of the compressor via two rotary type three-way valves which operate in synchronism with each other. Since the rotary three-way valve that controls the regenerator and the rotary three-way valve that controls the regenerator side can be changed in opening and closing operation timing, the ideal phase difference depending on the target temperature range as a refrigerator can be easily Can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a pulse tube refrigerator.

FIG. 2 is a vertical cross-sectional view of a cold heat generating portion.

FIG. 3 is a schematic configuration diagram showing another embodiment of a rotary type three-way valve drive mechanism.

FIG. 4 is a schematic configuration diagram of a conventional double-inlet type pulse tube refrigerator.

[Explanation of symbols]

1 ... Pulse tube, 2 ... Regenerator, 3
… Heat absorption connection, 7… Compressor, 12 ・
13 ... Rotary three-way valve, 14 ... Rotary valve drive motor, 15 ... High pressure refrigerant gas passage, 18
… Low-pressure refrigerant gas return path, 19… Main gas path,
20 ... Sub gas passage, 21 ... Flow rate adjusting tool,
23 ... Pulse generator, 24 ... Rotary valve drive circuit, 33/34 ... Valve plate, 35 ... Rotary valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etsuji Kawaguchi 1095 Katsube Town, Moriyama City, Shiga Prefecture Iwatanipran Tech Co., Ltd. Shiga Plant

Claims (4)

[Claims] 1. A compressor (7) comprising a low temperature end of a pulse tube (1) and a low temperature end of a regenerator (2) which are communicated with each other through a heat absorption connecting path (3).
Refrigerant gas supplied to the high temperature end of the regenerator (2) from the regenerator
(2) In a pulse tube refrigerator configured to be introduced from the low temperature end of the pulse tube (1) to the high temperature end side via the heat absorption connecting path (3), high pressure refrigerant gas of the compressor (7) The two rotary three-way valves (12) (13) are arranged in parallel in the passage (15), and the high temperature end of the regenerator (2) is connected to the main gas passage (19) in one rotary three-way valve (12). In addition to communicating with each other, the high temperature end of the pulse tube (1) is communicated with the other rotary three-way valve (13) through the sub gas passage (20), and the low pressure ports of each rotary three-way valve (12) (13) are respectively compressed. The low pressure refrigerant gas return path (18) of (7) is communicated, the flow rate adjusting tool (21) is provided in the sub gas path (20), and both rotary type three-way valves (12) and (13) are operated in synchronization. And a rotary type three-way valve (12) (13) for one rotary type three-way valve (13) (12) is adjustable to change the opening and closing timing of the rotary type three-way valve (13) (12) Refrigerator. 2. Each rotary type three-way valve (12) (13) is configured to be individually driven by a drive motor (14), and each drive motor (14) is generated by a pulse generator (23). The stepping motor which is operated by a pulse, and the operation timing of both rotary type three-way valves (12) (13) can be adjusted and changed by adjusting the transmission pulse to each stepping motor (14). Pulse tube refrigerator. 3. The pulse tube refrigerator according to claim 1, wherein the rotational speed of each drive motor (14) of the rotary type three-way valve (12) (13) is variable. 4. A rotary type three-way valve (12) (13) is configured to be operated synchronously by one drive motor (14), and a valve plate (33) of one rotary type three-way valve (12) (13). ) (34) is fixed, and the valve plates (34) and (33) of the other rotary three-way valve (13) (12) are rotationally displaced about the rotary shaft core of the rotary valve element (35). The pulse tube refrigerator according to claim 1, wherein the operation timings of the two rotary type three-way valves (12) (13) are adjustable.