JPH0737858B2 - refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to, for example, an infrared detection element at an extremely low temperature (for example, 77
Before and after K) Stirling refrigerator to cool.

[Conventional technology]

 FIG. 2 shows a configuration example of a conventional Stirling refrigerator.

In FIG. 2, the Stirling refrigerator is roughly divided into a compressor (1), a cold finger (2) and a connecting pipe (3) connecting them. The compressor (1) comprises a cylinder (4) and a piston (5). The piston (5) is positioned by the spring (17) and reciprocates inside the cylinder (4).

A lightweight sleeve (6) made of a non-magnetic material is connected to the piston (5), and a conductor is wound around the sleeve (6) to form a coil (7). The movable part (8) is composed of an assembly consisting of a piston (5), a sleeve (6) and a coil (7).
Call. The coil (7) is connected to lead wires (10) and (11) that pass through the wall of the housing (9), and these lead wires have electrical contacts (12) and (13) on the outside of the housing (9). To have. Permanent magnet (14) in the housing (9)
And a yoke (15), which form a closed magnetic circuit. The coil (7) is a gap (1) provided in a closed magnetic circuit composed of a permanent magnet (14) and a yoke (15).
The structure is such that it can reciprocate in the axial direction of the piston (5) within 6). Within the gap (16) there is a permanent magnetic field in the radial direction transverse to the direction of movement of the coil (7).

The internal space partitioned by the cylinder (4) and the piston (5) is called a compression chamber (18). The compression chamber (18) is filled with a high-pressure working gas such as helium. The above is the configuration of the compressor (1).

On the other hand, the cold finger (2) has a cylindrical low temperature cylinder (19) and a displacer (20) slidably reciprocating in the low temperature cylinder (19). The space inside the low temperature cylinder (19) is divided by the displacer (20). The space above the displacer (20) is called the low temperature chamber (21) and the space below it is called the high temperature chamber (22). A regenerator (23) and a gas passage hole (24) are provided inside the displacer (20), and the low temperature chamber (21) and the high temperature material (22) are passed through the regenerator (23) and the gas passage hole (24). The regenerator (23) is in communication and is filled with a regenerator material (25) such as a copper wire mesh. A seal (26) is provided on the side of the displacer (20) so that the working gas does not pass through the gap between the low temperature cylinder (19) and the displacer (20).
Each chamber of the cold finger (2) is filled with a high-pressure working gas such as helium as in the compressor (1). The above is the configuration of the cold finger (2), the compression chamber (18) of the compressor (1) and the cold finger (2).
The high temperature chamber (22) is communicated with the high temperature chamber (22) via the connecting pipe (3). Further, the compression chamber (18), the space inside the connecting pipe (3), the low temperature chamber (21), the high temperature chamber (22), the regenerator (23), and the gas passage hole (24) are in communication with each other. The entire room is collectively called the working room (27).

The operation of the conventional refrigerator configured as described above will be described.

When an alternating current is applied to the coil (7) through the electrical contacts (12), (13) and the lead wires (10), (11), the coil (7) interacts with the permanent magnetic field in the gap (16). Due to the action, Lorentz force acts in the axial direction. As a result, the movable part (8) reciprocates in the axial direction of the piston (5). The piston (5) reciprocates inside the cylinder (4), so that the working chamber (27) from the compression chamber (18) to the low temperature chamber (21) is reached.
A sinusoidal wave is applied to the gas pressure of. Due to the change in the flow rate of the gas passing through the displacer (20) and the regenerator (23) due to the sinusoidal pressure wave, the displacer (20) including the regenerator (23) has the same frequency and different phase as the piston (5). To reciprocate in the cold finger (2) in the axial direction.

When the piston (5) and the displacer (20) move with an appropriate phase difference, the working gas enclosed in the working chamber (27) constitutes a thermodynamic cycle known as the "reverse Stirling cycle", and mainly Generate cold heat in a low greenhouse (21). For the above-mentioned "reverse Stirling cycle" and the principle of cold heat generation, see "Cryocoolers" (G. Walker,
Plenum Press, New Yorl, 1983.PP 177-123). The principle will be briefly described below.

The heat of compression of the gas in the compression chamber (18) compressed by the piston (5) is cooled while flowing through the connecting pipe (3), so that the high temperature chamber (22), the regenerator (23), and the gas passage hole (24). ) Flow into. The working gas is pre-cooled in the regenerator (23) by the cold heat stored before the half cycle and enters the low temperature chamber (21). When most of the working gas enters the low temperature chamber (21), expansion starts and cold heat is generated in the low temperature chamber (21). The working gas then returns through the flow path and enters the compression chamber (18) while releasing cold heat to the regenerator (23) in the reverse order. At this time, heat is taken from the tip of the cold finger (2) to cool the outside.

In this way, when most of the working gas returns to the compression chamber (18), compression starts again and moves to the next cycle. By the process as described above, the "reverse Stirling cycle" is completed and cold heat is generated.

[Problems to be Solved by the Invention]

The conventional device as described above has the following problems. In a refrigerator in which a piston is driven by such a permanent magnet and a coil, the stroke of the reciprocating motion of the movable portion including the piston, the sleeve, and the coil is converted according to conditions such as current, environmental temperature, and heat load. Therefore, in the conventional device, depending on the operating conditions of the refrigerator,
When the piston driving force becomes excessive and the stroke amount increases, the moving part collides with a member such as a cylinder, a housing, a permanent magnet, a yoke, etc., causing vibration and noise, and causing loss or destruction of parts. was there.

The present invention has been made to solve the above problems, and it is an object of the present invention to prevent vibration and noise due to collision of a movable part, and to prevent parts from being damaged or broken.

[Means for Solving the Problems]

The refrigerator according to the present invention is made of rubber for limiting the stroke of the reciprocating motion of the movable part to a member such as a cylinder, a housing or a yoke where the movable part may collide, and cushioning the shock at the time of collision. It is equipped with a stopper.

[Action]

In the refrigerator according to the present invention, since the stroke of the reciprocating motion of the movable portion including the piston, the sleeve and the coil is limited by the rubber stopper, the piston or the coil is directly collided with another member, resulting in loss of parts. Alternatively, destruction can be prevented, and vibration and noise due to collision can be extremely reduced.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention. In the figure, (1) to (27) are exactly the same as the conventional device. This invention limits the stroke of a movable part (8) consisting of a piston (5), a sleeve (6), and a coil (7), and rubber stoppers (28) and (29) for buffering the impact at the time of collision.
Mounted on the cylinder (4) and the housing (9). Therefore, even if the piston (5) is given an excessive force from the coil, the piston (5) collides with the stopper (28) on the top dead center side, and the piston (5) and the cylinder (4) directly contact each other. There is no collision. On the other hand, at the bottom dead center side, the piston (5) collides with the stopper (29), and the piston (5) or coil (7) and the housing (9) do not collide directly. The impact generated when the piston (5) collides with the stoppers (28) and (29) is buffered by its elasticity because the stoppers (26) and (29) are made of rubber, and thus the piston (5) and the cylinder (4). Will not be damaged or destroyed, and the vibration and noise generated during a collision will be small. Therefore, in the refrigerator according to the present invention, the movable part (8) does not directly collide with other members in the compressor such as the cylinder (4), the housing (9), the permanent magnet (14), and the yoke (15). It is possible to prevent the parts from being damaged or broken, and to minimize the generation of vibration and noise. Although the rubber stoppers (28) and (29) are attached to the cylinder (4) and the housing (9) in the above-mentioned embodiment, there is a possibility that the movable portion (8) may directly collide with, for example, a permanent magnet. Even if it is attached to any other member in the compressor such as the magnet (14) and the yoke (15), the same effect as in the above-described embodiment can be obtained. In the above embodiment, the cold finger (2) and the cylinder (4) are separated from each other via the connecting pipe (5), but the separate refrigerator is used. For example, two opposing cylinders (4) ) And a piston (5) to form a compression chamber (18), an opposed two-cylinder type refrigerator, or a single cylinder in which the cold finger (3) and the cylinder (4) are mechanically strongly coupled. A body-type refrigerator may be used, and the same effect as that of the above-described embodiment can be obtained.

As described above, according to the present invention, in a compressor of a refrigerator in which a piston is driven by a permanent magnet and a coil, a movable part may directly collide, for example, a cylinder, a housing, a permanent magnet, a yoke, or the like. The simple method of attaching a stopper to another member limits the stroke of the moving part that fluctuates depending on the current, environmental temperature, and amount of heat applied, preventing damage and destruction of refrigerator components due to collision of the piston and cylinder, and collision. The generation of vibration and noise can be made extremely small.

[Brief description of drawings]

FIG. 1 is a sectional view showing a refrigerator according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional refrigerator. In the figure, (1) is a compressor, (2) is a cold finger,
(3) is a connecting pipe, (4) is a cylinder, (5) is a piston, (6) is a sleeve, (7) is a coil, (8) is a movable part, (9) is a housing, (10) and (11). Is the lead wire,
(12) (13) electrical contacts, (14) permanent magnet, (15) yoke, (16) gap, (17) spring, (18) compression chamber, (19) cold cylinder, ( 20) is a displacer,
(21) is a low temperature room, (22) is a high temperature room, (23) is a regenerator,
(24) is a gas passage hole, (25) is a regenerator material, (26) is a seal, (27) is a working chamber, and (28) and (29) are stoppers. The same reference numerals in the drawings indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takeshi Miyazawa, 730 Kamimachiya, Kamakura City, Kanagawa Mitsubishi Electric Engineering Co., Ltd., Kamakura Plant (56) Reference JP2-44159 (JP, A) JP3 -36469 (JP, A)

Claims (1)

[Claims] 1. A cylinder, a permanent magnet and a coil provided in a magnetic flux formed by the permanent magnet and capable of reciprocating movement by passing an alternating current, and a piston connected to the coil and reciprocating in the cylinder. A compression chamber partitioned by the cylinder and the piston, a low-temperature cylinder, a displacer that divides the interior of the low-temperature cylinder into a low-temperature chamber and a high-temperature chamber, and slidably reciprocates inside the low-temperature cylinder, In a refrigerator equipped with a regenerator provided inside a displacer and a connecting pipe that connects the high temperature chamber and the compression chamber, reciprocating motions of the piston and the coil are limited, and other constituent members of a movable part are provided. A refrigerator provided with a stopper for buffering a collision with the refrigerator.