JP2005113732A - Multistage compressor, liquid circulating device using the same, and refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize miniaturization and weight-saving by reducing the number of compressors when a multistage compressor is required. <P>SOLUTION: In a multistage compressor compressing liquid by pistons reciprocating in vessels, a plurality of pistons 44, 45, 64, 65 are provided on shafts 43, 63 reciprocating in the vessels 41, 61, a fluid compressed by one of the pistons 44, 64 is compressed again by the remaining pistons 45, 64. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multistage compressor for compressing a fluid by a piston that reciprocates in a container, a liquid circulation device using the same, and a refrigeration device. A multi-stage compressor that can be reduced in size and weight by reducing the number of compressors, suitable for use in a combined 4K class refrigeration system or a 1K class refrigeration system compressor system for JT coolers. The present invention relates to a used liquid circulation device and a refrigeration device.

  In a linearly driven vacuum pump or compressor of a reciprocating piston, multistage compression may be required as described in Patent Documents 1 and 2.

  For example, in the compressor system for a JT cooler shown in FIG. 1, the piston 12 reciprocates up and down in the pressure vessel 11 of the first-stage compressor 10 and reciprocates up and down in the pressure vessel 21 of the second-stage compressor 20. Two compressors 10 and 20 each having a pair of upper and lower drive mechanisms including a piston 22 for driving, drive coils 13 and 23, and permanent magnets 14 and 24 are connected in series by a connection pipe 30. Yes.

  In the first stage compressor 10, when the piston 12 moves outward as indicated by an arrow A, refrigerant gas (hereinafter simply referred to as gas) is sucked into the compression chamber 16 from an intake valve 15 which is a kind of check valve. When the piston 12 moves inward as indicated by an arrow B to compress the sucked gas and becomes a certain pressure or higher, it is exhausted from an exhaust valve 17 which is a kind of check valve. The two-stage compressor 20 operates similarly. Thus, for example, the gas is compressed from 0.1 Mpa to 1.6 Mpa.

  In the figure, 25 is an intake valve of the two-stage compressor 20, 26 is also a compression chamber, 27 is also an exhaust valve, 18 and 28 are coil springs that support the pistons 12 and 22 at neutral points, and 19 and 29 are hermetic connectors. It is.

Japanese National Patent Publication No. 5-506919 JP-A 64-14560

  However, the conventional technique requires as many compressors as the number of compression stages, which is an obstacle to reduction in size and weight due to space, weight, and the like.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to reduce the number of compressors necessary for multistage compression, thereby reducing the size and weight.

  The present invention provides a multistage compressor for compressing a fluid by a piston that reciprocates in a container. A plurality of pistons are provided on a shaft that reciprocates in a container, and the fluid compressed by one of the pistons The above problem is solved by compressing the piston again.

  In addition, the plurality of shafts are arranged so as to face each other so as to move on the same axis, and are reduced in size and weight while achieving balance.

  Also, the stability of the gas flow rate and the piston balance are improved so that the container also serves as a buffer tank for the fluid.

  The present invention also provides a fluid circulation device using the multistage compressor.

  The present invention also provides a refrigeration apparatus using the fluid circulation device.

  According to the present invention, since a plurality of pistons are provided on one shaft, it is possible to reduce the number of compressors by half and realize a reduction in size and weight.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the present embodiment, the present invention is applied to a compressor system having a four-stage compression structure in which two compressors are connected in series and four kinds of pistons. As shown in FIG. Both of the second compressors 60 have pistons 44, 45, 64, 65 at both ends of shafts 43, 63 supported by diaphragm springs 42, 62 and reciprocating left and right within the pressure vessels 41, 61. In order to reduce vibration, they are arranged symmetrically.

  Drive coils 46 and 66 are attached to the shafts 43 and 63, and are driven to reciprocate by passing an alternating current through a magnetic circuit having permanent magnets 47 and 67. This driving method is a general method adopted in a small Stirling cooler or the like.

  Pistons 44, 45, 64, 65 at both ends of the shafts 43, 63 are linked via the shafts 43, 63, and when the pistons 44, 64 at one end of the shaft are sucking gas (expansion work). The pistons 45 and 65 at the other end perform gas exhaustion (compression work).

  In the figure, reference numerals 55 and 75 denote coil springs that urge the shafts 43 and 63.

  Hereinafter, the operation will be described in detail.

  In the first compressor 40, when the outer piston 44 moves inward as shown by an arrow B, gas is sucked into the first compression chamber 49 from an outer intake valve 48 which is a kind of check valve, and the outer piston 44 moves to the arrow. As shown in A, the gas moves outward and compresses the sucked gas. When the pressure becomes a certain pressure or higher, the gas is exhausted from an outer exhaust valve 50 which is a kind of check valve.

  The exhausted gas passes through the U-shaped tube 51 and is guided again into the pressure vessel 41.

  When the inner piston 45 moves outward as indicated by the arrow A, the gas in the pressure vessel 41 is sucked into the second compression chamber 53 from the inner intake valve 52 which is a kind of check valve, and the inner piston 45 As shown by the arrow B, the gas moves inward and compresses the gas. When the gas reaches a certain pressure or higher, the gas is exhausted from an inner exhaust valve 54 which is a kind of check valve.

  The exhausted gas passes through the connection pipe 80 and is guided into the pressure vessel 61 of the second compressor 60.

  In the second compressor 60, when the inner piston 64 moves outward, gas is sucked into the first compression chamber 69 from an inner intake valve 68 which is a kind of check valve, and the inner piston 64 moves inward and sucks. If the gas is compressed to a certain pressure or higher, it is exhausted from the inner exhaust valve 70 which is a kind of check valve.

  The exhausted compressed gas is branched to the right and left by the external pipe 71, and when the outer piston 65 moves inward, the gas is sucked from the outer intake valve 73, which is a kind of check valve, to the second compression chamber 72 side. Led.

  The gas guided into the second compression chamber 72 is compressed by the outer piston 65, and is exhausted from the outer exhaust valve 74.

  In this way, four-stage compression, which conventionally required four compressors, can be realized with two compressors each having two types of pistons.

  In this embodiment, since the inside of the compressor container is used as a gas buffer tank, the stability of the gas flow rate and the piston balance can be improved.

  In the above-described embodiment, the gas introduced from the outside of the first compressor 40 is exhausted from the inside, and the gas introduced from the inside of the second compressor 60 is exhausted from the outside. The order of compression can be set arbitrarily. For example, the action of the inner and outer pistons can be reversed.

  Further, in order to increase the compression ratio, the number of compressors can be further increased. Alternatively, the two-stage compression as shown in FIG. 1 can be realized with a single compressor.

  As shown in FIG. 2, when two compressors 40 and 60 according to the present invention are arranged in series and compressed in four stages, helium 3 of 1 NL / min can be increased from a suction pressure of 8 kPa to a discharge pressure of 0.7 Mpa. did it.

  In addition, when only the second compressor 60 of FIG. 2 was used to compress two stages with one unit, helium 4 of 2 NL / min could be increased from a suction pressure of 0.0 Mpa to 1.6 Mpa.

  The present invention is useful as a compressor system for a JT cooler of a small 4K class refrigeration apparatus or a 1K class refrigeration apparatus in which a precooler and a JT circuit cooler are combined. For example, JTC1, JTC2, etc. as shown in FIG. It can be used for a JT circuit type compressor system. In the figure, 100 is a two-stage Stirling cooler, 102 is a compressor, 104 is a cold head, 106 is a first stage, 108 is a second stage, 110 is a 1K stage, 120 is a cryostat, 122 is a first shield, and 124 is The second shield 130 is a vacuum pump.

  Further, the present invention can be similarly applied to general fields that require a small gas circulation system other than the refrigeration apparatus.

Sectional drawing which shows the structural example of the compressor system for the conventional JT circuit cooler Sectional drawing which shows the structure of embodiment of this invention The flowchart which shows the flow of an example of the application object of this invention

Explanation of symbols

40, 60 ... compressor 41, 61 ... pressure vessel 43, 63 ... shaft 44, 65 ... outer piston 45, 64 ... inner piston 46, 66 ... drive coil 47, 67 ... permanent magnet 48, 52, 68, 73 ... intake Valve 49, 53, 69, 72 ... Compression chamber 50, 54, 70, 74 ... Exhaust valve

Claims (5)

In a multistage compressor for compressing fluid by a piston that reciprocates in a container,
A plurality of pistons are provided on a shaft that reciprocates in the container,
A multi-stage compressor characterized in that the fluid compressed by one of the pistons is compressed again by the remaining pistons.   The multistage compressor according to claim 1, wherein the plurality of shafts are arranged to face each other so as to move on the same axis.   The multistage compressor according to claim 1 or 2, wherein the container also serves as a fluid buffer tank.   A fluid circulation device using the multistage compressor according to any one of claims 1 to 3.   A refrigeration apparatus using the fluid circulation device according to claim 4.

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