JP2002303461A - Stirling refrigerating machine, and stirling engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability and reliability of a Stirling heat instrument and stabilize actuation gas pressure even with the operation over a long period of time by reducing leakage of working gas of the Stirling heat instrument. SOLUTION: A reciprocating driving mechanism is disposed in a housing 2 for converting driving force of a motor 6 to a reciprocating motion. The housing 2, a compression chamber cylinder block 19, and expansion chamber cylinder blocks 20, 20' are manufactured with cast iron JIS FC300 containing a less amount of carbon and having fine crystal grains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Stirling refrigerating machine which can be used for refrigeration in industrial fields such as food distribution, environmental testing, medical care, biotechnology and semiconductor manufacturing, or in any industrial field such as household equipment. The present invention relates to a Stirling engine used for a generator, an air conditioning engine, and the like.

[0002]

2. Description of the Related Art In recent years, as a refrigeration system that substitutes CFCs for global environmental problems, the operating temperature of the refrigeration system is wider than that of conventional refrigeration systems. , Low-temperature liquid circulators, low-temperature thermostats, thermostats, heat shock testers, freeze dryers, temperature characteristic testers, blood / cell storage devices, cold coolers, and various other types of cooling and heating devices. A Stirling refrigerator has been in the spotlight as a refrigerator that can be applied to cold heat equipment, is compact, has a high coefficient of performance, and has good energy efficiency.

In such a Stirling refrigerator, working gas flows between a compression chamber (high-temperature chamber) and an expansion chamber (low-temperature chamber) of a working cylinder such as a compression cylinder or an expansion cylinder, and flows along this flow path. The heat exchanger for heat absorption (low-temperature side heat exchanger) and the heat exchanger for heat radiation (high-temperature side heat exchanger) are arranged to exchange heat with the cold refrigerant and the heat radiation refrigerant, respectively.

[0004] The Stirling refrigerator includes a housing having a drive mechanism such as a motor and a crank, and a sealed operating cylinder that is assembled to the housing. A lid or the like is detachably fixed to the housing via a resin or a rubber seal for the purpose of maintenance or the like, and the inside thereof is held in a semi-sealed state. The working cylinder is connected to the housing via a resin, a rubber seal, or the like. Conventionally, these housings and working cylinders are formed of a casting material such as a casting FC250 usually used as a compressor housing.

In a Stirling engine, as opposed to a Stirling refrigerating machine, a pressurized working gas is sealed and a pressure difference generated between a high temperature chamber and a low temperature chamber in a cylinder heated by a combustor or the like. This is a device that reciprocates a piston and takes out the reciprocating driving force as an energy source. This Stirling engine has high thermal efficiency and excellent quietness, and has recently attracted attention as an energy-saving and environmentally compatible engine. This Stirling engine also has a housing having a generator and a crank mechanism and a cylinder block, and these are also formed of the same casting material as the Stirling refrigerator.

[0006]

By the way, in a Stirling refrigerator, a working gas is sealed in a working cylinder such as a compression cylinder or an expansion cylinder and a housing in a high pressure state. (An operation of about 30,000 to 50,000 hours is required at present, and an operation time of about 100,000 hours is required in the future).

However, the working gas leaks through the wall of the working cylinder or the housing formed by casting.
As will be described later, this is considered to be caused by the fact that the working gas in the high pressure state is passed through the pores of the metal structure of the casting. For example, including helium at 25 kg / cm ² , including such a working gas leak from the working cylinder and the housing and a gap between the housing and the working cylinder or the like.
Even if the working gas pressure is sealed at about the same level, there is a problem that the working gas pressure is reduced by about several kg / cm ^{2 in} one year due to leakage of the working gas.

An object of the present invention is to solve such a conventional problem.
In Stirling refrigerators and Stirling engines,
It is an object of the present invention to prevent leakage of a working gas from a housing or a wall of a working cylinder, stabilize a working gas pressure even after a long operation, and improve durability.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a housing provided with a reciprocating drive mechanism for converting a driving force of a motor into a reciprocating motion, and an air-tightly coupled housing. In a Stirling refrigerator having a working cylinder block constituting a working cylinder including a compression chamber and an expansion chamber, one or both of the housing and the cylinder block are formed of a casting, and the casting is FC300. A Stirling refrigerator is provided.

The working cylinder has two cylinders, a compression cylinder and an expansion cylinder, and the working cylinder block comprises a compression cylinder block forming the compression cylinder and an expansion cylinder block forming the expansion cylinder. It is characterized by being.

In order to solve the above-mentioned problems, the present invention provides a housing in which a rotational force extracting mechanism for converting a reciprocating motion of a piston into a rotational force is provided, and the housing is air-tightly coupled to the housing, and the piston reciprocates. In a Stirling engine having a working cylinder block constituting a moving working cylinder, one or both of the housing and the cylinder block are formed of a casting, and the casting is formed of F
A Stirling engine characterized by being C300.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments with reference to the drawings. FIG. 1 is a diagram illustrating the overall structure of a Stirling refrigerator 1 according to the present invention. The housing 2 of the Stirling refrigerator 1 is integrally formed of a casting, and the inside thereof is semi-sealed. The interior of the housing 2 is partitioned into a motor chamber 4 and a crank chamber 5 by a partition wall 3.

A motor 6 capable of normal and reverse rotation is disposed in the motor chamber 4.
An opening for maintenance is formed, and a lid 7 for hermetically sealing this opening is fixed by a bolt or the like via a metal seal 8 in FIG. An opening for a motor power supply is formed in the top wall 9 of the motor chamber 4,
A terminal cover 11 having this opening hermetically closed and having a power supply mounting terminal 10 attached thereto is detachably attached via a metal seal 8.

An opening for a bearing is formed at an end of the crank chamber 5, and a bearing mounting lid 12 provided with a bearing on an inner surface so as to hermetically close the opening is detachably attached via a metal seal 8. Have been. Further, openings are formed at the bottom of the crank chamber 5 for charging and maintenance of the equipment, and the bottom cover 1 is sealed so as to hermetically seal these openings.
3 is detachably attached via a metal seal 8.

The crank chamber 5 is provided with a crankshaft 14 driven by a motor 6 for converting the rotation of the motor 6 into reciprocating motion, two connecting rods 15 and two cross guide heads 16. The drive mechanism of the machine 1 is configured. The two crank portions 17 and 18 of the crankshaft 14 are formed with a phase difference so that the crank portion 17 moves ahead of the crank portion 18 when the motor 6 rotates forward. As this phase difference, a phase difference of about 90 degrees is generally adopted.

A compression cylinder block 19 is fixed to the upper part of the crank chamber 5 via a metal seal 8 in an airtight manner with respect to the housing 2. The compression cylinder block 19 has an opening 23 for communicating with the expansion cylinder. Further, on the compression cylinder block 19, an expansion cylinder block 20 is hermetically fixed by bolts or the like via a metal seal 8.

The compression cylinder block 19 and the expansion cylinder blocks 20, 20 'constitute a compression cylinder 21 and an expansion cylinder 22, which are working cylinders of the Stirling refrigerator 1, respectively. As the working gas, for example, helium, hydrogen, nitrogen, or the like is sealed in the compression cylinder 21, the expansion cylinder 22, and the housing 2. A compression piston 26 reciprocates in the compression cylinder 21. The upper part (compression space) of this space is the high temperature chamber 24, in which the working gas is compressed to a high temperature.

The compression piston rod 25 connects the compression piston 26 and the cross guide head 16 and extends through the compression cylinder 21 and an oil seal 29 in a through hole in the top wall of the crank chamber 5. Since the sliding direction of the reciprocating compression piston 26 is reversed at the top dead center and the bottom dead center, the speed becomes zero, and the speed is slow near the top dead center and the bottom dead center, and the change amount of the volume per unit time is also small. When moving from the bottom dead center to the top dead center and from the top dead center to the bottom dead center, the speed becomes the maximum at each intermediate point, and the compression piston 26 per unit time
The amount of change in volume due to the movement of is also maximum.

The expansion piston rod 27 connects the expansion piston 28 and the cross guide head 16, and the expansion cylinder 22 and an oil seal 29 in a through hole in the top wall of the crank chamber 5.
Extends through. This expansion cylinder block 20,
The expansion piston 28 reciprocates in the space 20 ', and the upper part (expansion space) of this space is a low-temperature chamber 30, in which the working gas expands to a low temperature. The expansion piston 28
It moves ahead of the compression piston 26 by a phase of 90 degrees.

The expansion cylinder blocks 20, 20 'include:
A manifold 31 through which the working gas flows in and out of the compression space of the compression cylinder 21 is provided so as to communicate therewith. Further, a heat exchanger 32 for heat radiation (high-temperature side heat exchanger) 32 and a regenerator 3
The heat exchanger 3 and the cooling heat exchanger (low-temperature side heat exchanger) 34 are arranged in an annular shape so as to communicate with each other sequentially. Heat exchanger for heat radiation 3
Numeral 2 is connected to a radiator (radiator) 36 via a cooling water circulation pipe 35 and a cooling water pump P1, and is configured to circulate cooling water. Near the upper end of the compression cylinder block 19, a communication hole 23 that connects the high-temperature chamber 24 and the manifold 31 is formed.

In the Stirling refrigerating machine 1 having such a configuration, the working gas is contained in the housing 2, the compression cylinder 21 and the expansion cylinder 22 as described above.
For example, helium, hydrogen, nitrogen and the like are sealed in a high pressure state. In the present invention, as described above, the housing 2, the compression cylinder block 19, and the expansion cylinder block 2
By interposing the metal seal 8 between the joints 0 and 20 ', the leakage of the working gas from the gap between the joints can be suppressed and the amount of leakage can be reduced.

By the way, in the housing 2, which is generally formed of a casting of FC material, and in working cylinder blocks such as the compression cylinder block 19 and the expansion cylinder blocks 20, 20 ', the working gas passes through the metal structure of the casting. Leaks by minute amounts. The present inventors have investigated the mechanism of this leak, and as a result, working gas such as helium,
It has been determined that leakage is caused by flake graphite and crystal grain boundaries, which are materials of the housing and the working cylinder block.

The inventors of the present invention have conducted intensive studies on preventing leakage of working gas from the housing and the working cylinder block based on the analysis results. As a result, the housing 2, the compression cylinder block 19 and the expansion cylinder block have been studied. As a material of No. 19, attention was paid to FC300, which is a casting having a smaller amount of carbon and making crystals finer, and came to think of forming with this material.

In the Stirling refrigerator according to the present invention, the housing 2, the compression cylinder block 19 and the expansion cylinder blocks 20, 20 'were manufactured by casting FC300. Stirling refrigerator housing 2, compression cylinder block 19 and expansion cylinder block 2
0, 20 'is cast FC250 (1.0E-E-0.5 ~
E-0.4 units) compared to FC300
When manufactured at (1.0 to 3.0E-06), the leak amount of helium was remarkably reduced.

The operation of the Stirling refrigerator 1 of the embodiment having the above-described configuration will be described. The motor 6 rotates the crankshaft 14 in the forward direction, and the crank portions 17 and 18 in the crank chamber 5 rotate with a phase shift of 90 degrees. A cross guide head 16 is connected via a connecting rod 15 rotatably connected to the crank portions 17 and 18.
Reciprocates. A compression piston 26 and an expansion piston 28 connected to the cross guide head 16 via a compression piston rod 25 and an expansion piston rod 27, respectively.
Reciprocate with a phase difference of about 90 degrees from each other.

While the expansion piston 28 is moving slowly near the top dead center in advance, the compression piston 26 moves rapidly toward the top dead center near the middle to compress the working gas. The compressed working gas flows into the heat dissipation heat exchanger 32 through the communication hole 23 and the manifold 31. The working gas radiated to the cooling water by the radiating heat exchanger 32 is supplied to the regenerator 33.
And flows into the low-temperature chamber (expansion space) 30 through the cooling heat exchanger 34, where it expands rapidly and generates cold heat. The head of the expansion cylinder 21, that is, the cold head 43 is cooled to a low temperature.

Then, in the cold head 43, the cold refrigerant in contact with the cooling fins 44 is cooled. When the expansion piston 28 moves from the bottom dead center to the top dead center, the compression piston 26 moves from the intermediate position to the bottom dead center, and the working gas passes from the low-temperature chamber 22 through the cooling heat exchanger 34 to the regenerator 33. Into the regenerator 33. The cold stored in the regenerator 33 is reused to cool the working gas sent from the high temperature chamber 24 through the heat radiating heat exchanger 32 again as described above.

Then, the cold refrigerant cooled in the cold head 43 cools various cold utilization devices. For example, the cold refrigerant is sent to a cold refrigerant pipe in a cold utilization device such as a freezer, and performs freezing or cooling in the cold utilization device. It is circulated back to the cold head 43 and cooled again. The cooling water exchanged in the heat-radiating heat exchanger 32 flows from the cooling-water circulation line 35 to the radiator 36, where it is cooled by the cooling fan 45, and is again cooled.
Cycle to 2.

In the Stirling refrigerating machine 1 according to the present invention, the housing 2, the compression cylinder block 19 and the expansion cylinder blocks 20, 20 'are connected to a casting FC30.
Since it was manufactured according to 0, it is possible to prevent the working gas from leaking through the casting wall of these members.

The embodiments of the present invention have been described based on the embodiments. However, the present invention is not limited to the above embodiments, and various embodiments can be made within the technical scope described in the claims. Needless to say. For example, in the above embodiment, the motor and the reciprocating drive mechanism are formed integrally, but may be separate bodies.

In the above embodiment, the Stirling refrigerator has been described, but a Stirling engine may be used.
In the case of a Stirling engine, a generator is provided in the housing instead of the motor, and a rotational force extracting mechanism (crank mechanism) for converting reciprocating motion of the piston into rotational force is provided. When the cylinder block attached to the housing is similarly manufactured using the casting FC300, the leakage of the working gas can be prevented as in the case of the Stirling refrigerator.

[0032]

The Stirling refrigerating machine and the Stirling engine according to the present invention have the above-described structures.
To prevent leakage of working gas through the walls of the housing, compression cylinder block, expansion cylinder block, etc., to stabilize the working gas pressure even after long-term operation, and to improve the durability and reliability of Stirling refrigerators and Stirling engines. Can be.

[Brief description of the drawings]

FIG. 1 is an overall view illustrating a Stirling refrigerator according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stirling refrigerator 1 2 Housing 3 Motor room 5 Crank room 6 Motor 7 Cover 8 Metal seal 11 Terminal cover 12 Bearing mounting cover 13 Bottom cover 14 Crankshaft 19 Compression cylinder block 20, 20 'Expansion cylinder block 21 Compression cylinder 22 Expansion block 26 compression piston 28 expansion piston 29 oil seal 32 heat exchanger for heat dissipation 33 regenerator 34 heat exchanger for cooling

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Goo Nakazaki 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Takashi Inoue 2-chome Keihanhondori, Moriguchi-shi, Osaka No. 5-5 Sanyo Electric Co., Ltd. (72) Ryosuke Kaiji 2-5-5 Keihan Hondori, Moriguchi City, Osaka Pref. Sanyo Electric Co., Ltd. (72) Inventor Takeo Komatsubara Keihanmoto, Moriguchi City, Osaka 2-5-5, Sanyo Electric Co., Ltd. (72) Inventor Dai Dai Kanai 2-5-5, Keihan Hondori, Sanyo Electric Co., Ltd., Moriguchi City, Osaka (72) Inventor Takayuki Mizuno Moriguchi, Osaka Prefecture 2-5-5 Keihan Hondori Sanyo Electric Co., Ltd. (72) Inventor Kazuya Sato 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Eiji Fukuda Osaka Moriguchi 2-5-5 Keihan Hondori Sanyo Electric Co., Ltd. (72) Inventor Yasuo Sakamoto 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Hiroshi Nishikawa Osaka 2-5-5 Keihanhondori, Moriguchi City, Sanyo Electric Co., Ltd. (72) Inventor Denji 2-5-5, Keihanhondori, Moriguchi City, Osaka Prefecture, Sanyo Electric Co., Ltd.

Claims (3)

[Claims] 1. A housing in which a reciprocating drive mechanism for converting a driving force of a motor into reciprocating motion is provided, and an operation forming an operating cylinder airtightly coupled to the housing and including a compression chamber and an expansion chamber. In a Stirling refrigerator having a cylinder block, one or both of the housing and the cylinder block are formed of a casting, and the casting is FC300. 2. The operating cylinder has two cylinders, a compression cylinder and an expansion cylinder. The operating cylinder block is composed of a compression cylinder block forming the compression cylinder and an expansion cylinder block forming the expansion cylinder. The Stirling refrigerator according to claim 1, wherein the Stirling refrigerator comprises: 3. A housing provided with a rotational force extracting mechanism for converting a reciprocating motion of a piston into a rotational force, and an operating cylinder airtightly coupled to the housing to constitute an operating cylinder in which the piston reciprocates. A Stirling engine having a block, wherein one or both of the housing and the cylinder block are formed of a casting, and the casting is FC300.