JPH03177752A - Refrigerator - Google Patents

Abstract

PURPOSE:To be able to attenuate the resonance of a single mass system of a spring composed of a piston, movable coil, sleeve and supporting spring, by a method wherein, a compressor chamber located between two cylinder is divided into two by a partition wall, while the two divided chambers are communicated with each other by providing a communication tube. CONSTITUTION:Between cylinders 4a and 4b, a partition wall 29 is provided, and the spaces partitioned by each cylinder, pistons and partitioning wall is temporarily named here as a first compression chambers 30 and 31. The two chamber 30 and 31 are communicated by a communication tube 32. A coupling 3 is connected to the communication tube 32, and communicate the compression chambers 30 and 31 with a high temp. chamber 22 of a cold finger 2. When a vibration having a frequency component equivalent to a resonance frequency of a single degree of freedom system spring and a single mass vibration system spring being constituted by, counting from outside and toward the piston rod, pistons 5a, 5b, movable coils 8a, 8b, sleeves 7a, 7b and support springs 6a, 6b is applied, an operation gas moves between the compression chambers, 30, 31 through a communication tube 32 and the resistance caused by the tube 32 lowers the multiple factors.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention provides, for example, an infrared detection element at an extremely low temperature (for example, 77°C).
This relates to a Stirling refrigerator that cools the refrigerator before and after.

[Conventional technology]

FIG. 3 shows an example of the configuration of a conventional Stirling refrigerator.

In FIG. 3, a Stirling refrigerator is broadly divided into a compressor (1), a cold finger (2), and a connecting pipe (3) connecting these. The compressor (1) has a first cylinder (40 cylinders), a second cylinder (4b), a first piston (5a) and a second piston (5b). Second piston (5
1)) are respectively positioned by support springs (6a), t (61)), and are structured to reciprocate inside the first cylinder (4a)k and the second cylinder (4b).

The first piston (5a) b and the second piston (5b
) each include a lightweight first sleeve (
7a) and a second sleeve (7b) are connected, and a conductor is wound around the sleeves (7a) and (71)) to connect the first moving coil (Sa) and the second moving coil (
8b) is formed. The moving coils (8a), (8b) have first leads (10a), (1ob) and second leads (1ob) extending outward through the wall of the housing (9).
1a) and (11b). These lead wires (10a), (10b), (11a), (1
1b) has a first electrical contact (1b) on the outside of the housing (91).
2a), (12b)b and the second electrical contact (13a)
, (t5b). Inside the housing (9) are permanent magnets (t4a), (14b) and a yoke (15a),
(15'b) are provided, and these constitute a closed magnetic circuit. The moving coils (8a) and t (8b) are connected to a first gap (164) and a second gap (161Q) provided in a closed magnetic circuit consisting of a permanent magnet (L) and a yoke (15).
The structure allows the pistons (5a) and (5b) to reciprocate in the axial direction. Gap (16a), (16
1)) A permanent magnetic field exists in the radial direction transverse to the direction of motion of the moving coils (8a), (8b).

Cylinder (4a), (4b)> and piston (5&)
.

The internal space defined by (5b) is called a compression chamber (5).

The compression chamber ar) is filled with a high-pressure working gas such as helium. The working gas in the compression chamber side flows into the cylinder (
4a) and the gap between the piston (5a), and.

The gap between the cylinder (4a) and the piston (5a) and the gap between the cylinder (4b) and the piston (5b) are filled with seals/l/l/l/ (28a) and (28'b) are provided. The above is the configuration of the compressor (1).

On the other hand, the cold finger (2) is engaged with a cylindrical cold cylinder asb and a resonance spring 0.

It has a displacer (1) that slidably reciprocates within the low temperature cylinder aa. The space inside the low-temperature cylinder αa is divided into two by a displacer rod.

The space above the displacer ■ is called the cold room 0D, and the space below is called the high temperature room. A regenerator (1) and a gas passage hole are provided inside the displacer (A), and the cold room and the high temperature room are connected through the regenerator (to) and the gas passage hole (2). The inside is filled with a cold storage material such as a steel wire mesh. A seal (2) is provided in the gap between the displacer (a) and the low-temperature cylinder so that the working gas does not pass through the gap between the low-temperature cylinder aS and the displacer blade. Each chamber of the cold finger (2) is equipped with a compressor (
Similarly to 1), a high-pressure working gas such as helium is sealed. The above is the configuration of the cold finger (21), the compression chamber α force of the compressor (1) and the high temperature chamber of the cold finger (2).

They communicate via a connecting pipe (3). In addition, the compression chamber (1
? ).

The space inside the connecting pipe (3), the low temperature chamber CD, the high temperature chamber @, the regenerator ■, and the gas passage hole (2) are in communication with each other, bB,
These chambers are collectively called the working chamber (■).

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

Moving coil (8a)? (8b) is an electrical contact (12a3
゜ (12'b), (t3a), (Hb) b and lead i'ii! (10&).

When an alternating current is applied through (10b), (11a), (11b), the moving coils (8a), (
8b), a Lorentz force acts in the axial direction due to interaction with the permanent magnetic field in the gaps (16a) and (16b), respectively.

As a result, piston (5a)* (5b), xleave c7a)t (7b)b moving coil (8a),
The assembly from 81)) moves left and right in the axial direction of the piston (5).

Now the first moving coil (8a) and the second moving coil (8b)
) under the conditions that the characteristics of the 0th moving coil (8a) and the 2nd moving coil ( 8
b) When a sinusoidal current is applied such that the pistons (5a) vibrate in opposite directions with the same amplitude, the piston (5a).

(5b) are cylinders (4a), (4b
) and move back and forth inside the compression chamber αD to the cold room I21).
A sinusoidal wave is applied to the gas pressure in the working chamber.

This sinusoidal pressure wave causes a change in the flow rate of the gas passing through the displacer (2) and the regenerator (2).

The displacer (4) including the regenerator is connected to the piston (5a
).

It reciprocates in the axial direction within the cold finger (2) at the same frequency as (5b) but with a different phase.

Piston (51L), (5b) and displacer ■
When moving with a suitable phase difference, the working gas sealed in the two working chambers constitutes a thermal cycle known as the "inverse Stirling cycle", mainly due to the cold room OD
generates cold heat. Regarding the above-mentioned "reverse Stirling cycle" and its principle of cold generation.

Reference 1'-0ryocoolersJ (G, Wal
ker, PIenum Press, New York
, 1983. PP 117-123). The principle will be briefly explained below.

While the gas in the compression chamber αD compressed by the pistons (5a) and (5b) flows through the connecting pipe (3), the heat of compression is cooled and the gas passes through the gas passage hole (ha) of the regenerator in the high temperature room. ) flows into. The working gas is precooled by the cold energy stored in the regenerator half a cycle before entering the cold room QD. When most of the working gas enters the cold room 211, it begins to expand and generates cold heat in the cold room QD. Working gas is 2
Next, in the reverse order, the cold heat is released into the regenerator and then the flow path is returned to the compression chamber side.

At this time, heat is removed from the tip of the cold finger (2) to cool the outside thereof. In this way, when most of the working gas returns to the compression chamber αD, compression begins again.

Move to next cycle. Through the process described above, the above-mentioned "reverse Stirling cycle" is completed and cold heat is generated.

[Problem to be solved by the invention]

The conventional device as described above has the following problems. A piston, a moving coil.

The assembly consisting of the sleeve is positioned on the support spring, so that it constitutes a spring-mass vibration system with degrees of freedom. FIG. 4 is a model diagram of the above-mentioned vibration system.

In the figure, 2m is the mass of the assembly including each piston, moving coil, and sleeve.

k is the spring constant of the support spring, and fO is the resonance frequency of the vibration system. fO is similar to mk and k.

is shown.

Therefore, if the piston is installed in an environment subject to external vibrations such as an aircraft or vehicle, f = = fo in the direction of the piston axis.
When a vibration having a component of .

An assembly consisting of a first piston, a second moving coil, and a first sleeve, an assembly consisting of a second piston, a second moving coil, and a second sleeve, and a working gas in a compression chamber are integrated into a system. It vibrates with the same period and phase. In this resonance, there is no vibration damping effect due to the working gas in the compression chamber, so the resonance magnification is large and the vibration has a large amplitude.

Therefore, when the vibrations received from the outside become large, the vibrating piston, moving coil, and sleeve collide with the housing or the yoke, resulting in noise and damage to parts.

The object of the present invention is to provide a refrigerator which can attenuate the resonance of a spring-mass system and prevent noise and damage to parts.

[Means to solve the problem]

The refrigerator according to the present invention includes a partition wall that bisects a compression chamber provided between two coaxially arranged cylinders, and a connecting pipe that communicates the two divided compression chambers.
The structure is such that resonance of a spring-mass system constituted by a piston, a moving coil, a sleeve, and a support spring can be attenuated by the resistance force generated when two working gases pass through a communicating pipe.

[Effect]

In this invention, when the piston, moving coil, and sleeve assembly coaxially arranged resonate due to external vibration, 1. Working gas moves from one compression chamber to the other compression chamber through a communication pipe. The connecting pipe is subjected to frictional resistance force and resistance force due to flow bending, and these resistance forces are
As shown in the figure, it acts as a vibration damping force for the vibration model and reduces the resonance magnification, which prevents parts from colliding, thereby preventing noise and damage to parts.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, (1) to (I!, !11-) are exactly the same as the conventional device.A partition wall 4 is provided between the first cylinder (4a) and the second cylinder (4b). 1st
The space defined by the cylinder, the first piston, and the partition wall is called the first compression chamber (2), and the space defined by the second cylinder, the second piston, and the partition wall is called the second compression chamber (2). .

The first compression chamber ω and the second IE compression chamber c) communicate with each other through a communication tube. The connecting pipe (3) is connected to the communicating pipe C3B so that the compressor (13 first compression chamber (2) and second compression chamber OI) and the cold finger [21 high temperature chamber] are communicated with each other. There is.

For such devices, an external piston (5a)
, (51)), the piston (5a) l (5
b) 1 moving coil (8a)l (81)), sleeve (
7a), (7b) and support springs (6a), (6b
) is given a vibration having a frequency component equal to the resonant frequency of a one-degree-of-freedom spring-one-mass vibration system, the first piston (5a), the first moving coil (8
a) b and the first sleeve (assembly consisting of 70 and the second piston (51)), the second moving coil (8b)
As the assembly consisting of the first compression chamber 090 and the second sleeve (7b) vibrates in the same direction, one working gas moves between the first compression chamber 090 and the second compression chamber 090 through the communication pipe 1. At this time, the working gas is subjected to a pipe friction resistance force of the communication pipe and a resistance force due to flow bending, and these resistance forces act as a vibration damping force to lower the resonance magnification. FIG. 2 is a vibration model diagram of the vibration damping mechanism described above. Second
In the figure, 5 m is the mass of the assembly consisting of the first piston, first moving coil and first sleeve, or the assembly consisting of the second piston, second moving coil and second sleeve 7. , represents the spring constant of the first support spring or the second support spring, and C represents the damping coefficient due to the above-mentioned vibration damping force. The above-mentioned vibration damping mechanism will be specifically explained as a phenomenon. A pressure difference occurs between the first compression chamber ω and the compression chamber C(1) of fg2 due to the above-mentioned pipe friction resistance force and resistance force due to flow bending. (5a)l (5b), movable carp A/caa)+ca'b)t sleeve (7a),
(7b) acts in the direction of suppressing the movement of the assembly (and therefore damps vibrations. As a result, the piston ('') l
(5b) l Mobile carp A/(82L).

(ab), sleeves (7a), (7'b) can be prevented from colliding with the housing (91 or yokes (15a), (1sb)), thereby reducing noise and damage to parts.

On the other hand, in 1 normal operation, that is, 3 the process in which the working gas reciprocates between the first compression chamber (2) button, the second compression chamber OD, and the high temperature chamber), the tube friction resistance force is Because the passage is short, it is small, and there is no bend in the flow, so the resistance force that the working gas receives in the communication tube is the same as in the conventional device, so there is no decrease in performance.In the above embodiment, the compressor ( 1
) and the cold finger (21) are separated from each other via the connecting pipe (3).
) may be an integrated Stirling refrigerator that is mechanically strongly coupled, and the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, in a compressor of a refrigerator in which multiple pistons are driven by a magnet and a moving coil, the compression chamber is divided into two by providing a partition between two cylinders, and the two compression chambers are separated into two compression chambers. The piston, which is caused by vibrations from the outside, can be
moving coil.

A spring consisting of a sleeve and a support spring damps the resonance of a mass system, piston, cylinder.

This prevents the sleeve from colliding with the housing or yoke, eliminating noise and damage to refrigerator components during a crash.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a refrigerator according to an embodiment of the present invention, FIG. 2 is a diagram showing a vibration damping model according to the present invention,
FIG. 3 is a sectional view showing a conventional refrigerator, and FIG. 4 is a diagram showing a vibration model of a spring-mass system composed of a piston, a moving coil, a sleeve, and a support spring. In the figure, (1)...compressor, 12>...cold finger, (3)...connecting pipe, (4a). (4b)-=cylinder, (5a), (5b),,
,piston. (6a)) (6b)--Support spring e (7a)t
(7'b)-X IJ-b, (8a), (Bt
))...Possible coil, (9)...Housing,
(14a), (14b), permanent magnet, (15
a), (151))...Yoke, (ISa),
(16b) Gap, compression chamber. ■... High temperature chamber, @... Working chamber 1g3... Partition wall, Seki... First compression chamber, r3B... Second compression chamber, C
13... It is a communication pipe. The same reference numerals in the two figures indicate the same or equivalent parts.

Claims (1)

[Claims] first and second cylinders disposed coaxially with each other; first and second movable coils that face each other and are provided in the magnetic flux created by the magnet and capable of reciprocating motion by flowing an alternating current; a first piston connected to a first moving coil and reciprocating within the first cylinder; a second piston connected to the second moving coil reciprocating within the second cylinder; a piston, a compression chamber partitioned by the first cylinder, the second cylinder, the first piston and the second piston, an elongated cylindrical low temperature cylinder, and an interior of the low temperature cylinder. In the refrigerator, the refrigerator is divided into a low-temperature chamber and a high-temperature chamber, and is equipped with a displacer that slidably reciprocates inside the low-temperature cylinder, and a regenerator provided inside the displacer.
a partition wall provided between the cylinder and the second cylinder that divides the compression chamber into a first compression chamber and a second compression chamber, and communicates the first compression chamber and the second compression chamber. A refrigerating machine characterized by being equipped with a communicating pipe.