JPS6387561A - Refrigerator - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a refrigerator having a displacer, such as a Stirling refrigerator.

[Conventional technology]

FIG. 2 shows an example of the configuration of a conventional Stirling refrigerator. The Stirling refrigerator shown in FIG. 0 is called a split type Stirling refrigerator and is a typical example of a Stirling refrigerator.

In FIG. 2, a split type Stirling refrigerator is composed of a thick compressor (1) and cold fingers (12), and a connecting pipe (3) that connects them.

The compressor (1) includes a cylinder (4) and a piston (5).

The piston (5) is driven by an electric motor (not shown) through a connecting rod (6) and a crank (7) to reciprocate inside the cylinder (4). A cylinder head (
8] is attached, and the internal space defined by the cylinder (4), the piston (512, and the cylinder head (8) is called a compression chamber (9). The piston (5) such as the crank (71) The driving mechanism member is housed in a housing α1, and the space within the housing α, which is partitioned from the compression chamber (9) by the piston (5), is called the bulk chamber αυ.The cylinder (41, tI The cylinder head 8) and the housing α value are joined together to maintain airtightness with the outside, and the compression chamber (9) and the bulk chamber 0υ inside are filled with, for example, helium.

It is filled with high-pressure working gas such as hydrogen. A piston ring a3 is installed on the side surface of the piston (5) to prevent the working gas from passing through the gap between the piston (5) and the cylinder (4).
is installed. Further, the outer surface of the cylinder (4) is provided with fins 0 for increasing heat dissipation to the outside.The above is the configuration of the compressor (1).On the other hand, the cold finger 12+ has a cylindrical shape. It has a low-temperature cylinder α knob, and a displacer (1!19) that slideably reciprocates inside the low-temperature cylinder α core.

The space inside the low temperature cylinder α4 is divided into two by the displacer αS, and the space inside the low temperature cylinder α4 is divided into two by the displacer αS.
The space above 9 is a cold room αG, and the space below is a high temperature room α
Call it η. Inside the displacer α9, there is a reproducing a(L
8 and a flow path (19), the low temperature chamber αe and the high temperature chamber αη communicate with the regeneration HQ8 via the flow path +1'J, and the regenerator (18 includes, for example, a copper wire mesh). The low temperature cylinder α is filled with cold storage material ■ such as
A seal ring Qυ is fitted into the side of the displacer 9 to prevent the working gas from passing through the gap between the displacer 4 and the displacer α9.

A control cylinder @ is located at the bottom of the cold finger (2).
A control piston attached to the lower end of the displacer α9 passes through the high temperature chamber a and the control cylinder ■ and projects into the bowl chamber. The control cylinder ■ and the control piston Q
A seal ring 4 is attached to the control cylinder to prevent the working gas from passing through the gap 4. Each chamber of the cold finger (2) described above is made of helium, for example, like the compressor +11.

0 or more in which high-pressure working gas such as hydrogen is sealed is a cold finger (2-in configuration), and the compressor +11
The compression chamber (9) of the cold finger (2) and the high temperature chamber αη of the cold finger (2) communicate with each other via the connecting pipe (3). Also.

The compression chamber (9), the space inside the connecting pipe (3), the low temperature chamber e, the high temperature chamber r1η, the regeneration HQδ and the flow path 19 are in communication with each other, and these chambers are integrated as a whole. and is called the working space.

The operation of the conventional refrigerator configured as described above will be explained. By reciprocating inside the cylinder (4), the piston (5) gives a sinusoidal wave to the gas pressure in the working space, from the compression chamber (9) to the cold room, in particular. On the other hand, since the volume of the parque chamber αυ is sufficiently larger than the stroke volume of the piston (5), the internal gas pressure does not change much even when the piston (5) reciprocates.

The seal ring (c) attached to the control cylinder of the cold finger (2) provides almost complete sealing against short-period pressure changes, such as pressure waves in the gas in the opposite working space, but against long-term pressure changes. If you look at it, the sealing is incomplete, so
The gas pressure in the control chamber is maintained approximately at the average value of the gas pressure in the working space.

FIGS. 3 to 6 explain the operating principle of the conventional device in the order of the refrigeration cycle.

In one process of the cycle shown in Figure 3, the compressor fi
The + piston [5] is located below in the cylinder (4), and the displacer α9 of the cold finger (2) is located above the cold cylinder α4. During the transition from FIG. 3 to FIG. 4, the piston (5) rises and compresses the gas in the working space. The heat generated by this compression is transferred to the cylinder (5
) is emitted to the outside from the fin Q3 on the outer periphery. At the time point 8 in FIG. 4, the gas pressure in the working space is greater than the gas pressure in the control chamber.

The downward force generated on the control piston QIJ due to this differential pressure overcomes the static friction force of the seal rings QD and (c) and begins to move the displacer aS downward.

As shown in FIG. 5, it is moved to the lower part of the low temperature cylinder a4. As the displacer a9 moves, the gas in the high temperature room αη passes through the regenerator and moves to the low temperature room aS.

At this time, the cold storage material (2) filled in the regenerator absorbs heat from the gas passing through it and lowers the temperature of the gas. In the process from Fig. 5 to Fig. 6, the piston +5) of the compressor (1) descends and expands the gas in the working space, and this expansion causes the temperature of the gas in the cold room αθ to further drop, causing the upper part of the cold finger to drop. Absorbs heat from the surrounding area. This endothermic action plays a role in cooling the object to be cooled as a refrigerator. In the working space, the pressure decreases due to the expansion of the gas, so at the time of Fig. 6, the gas pressure is greater in the control chamber than in the working space.This differential pressure causes the control piston Q4 to move upward. The applied force overcomes the static friction force of the seal rings cI)g and @, and begins to move the displacer a5 upward.
It is moved to the upper part of the low temperature cylinder I as shown in FIG. As this displacer (1!19) moves, the low temperature gas in the low temperature chamber passes through the regenerator Q8.

Cold heat is stored in the cold storage material ■ in the barrel of the regenerator α, and the gas itself flows into the high temperature chamber αD with a temperature increase of 1.

Refrigerating motion is performed by repeating the above-described cycle.

Since the conventional refrigerator is configured as described above, it is necessary to manually adjust the input terminal when the temperature of the cold finger (2) deviates from a predetermined cooling temperature.

[Problem 6α to be solved by the invention] Jumei's refrigerator had the following drawbacks. That is,
During operation of the refrigerator, if the cooling temperature at the tip of the cold finger deviates from the predetermined temperature range that is originally intended due to changes in the environmental temperature, etc., the rotation speed of the compressor (1) can be adjusted manually. I had to. Moreover, in order to make this adjustment, the temperature at the tip of the cold finger must be measured, so if the infrared image sensor is being cooled at the tip of the cold finger, obtaining one image information must be temporarily interrupted. There was a problem that it was indispensable.

The present invention was made with the aim of improving this drawback, and the spring constant of the bimetal spring connected to the displacer changes depending on the environmental temperature, thereby changing the stroke of the displacer.

The changed stroke is detected by the position detection means.

Displacer supplementary control means provides more precise stroke control. As a result, the cooling temperature of the refrigerator can be automatically adjusted.

[Means for solving problems]

The refrigerator according to the present invention includes a bimetallic spring whose spring constant changes depending on the temperature and which changes the stroke of the displacer according to the external temperature, a position detection means for detecting the stroke of the displacer, and a displacer that supplementally controls the movement of the displacer. Supplementary control means, lI'
ii) A supplementary control output determining means is provided for determining the output of the displacer supplementary controlling means based on the position detecting means.

[For production]

In the third aspect of the invention, when the temperature of the cold finger deviates from a predetermined temperature, the bimetal spring changes the stroke of the displacer, the position detection means detects the stroke of the displacer, and the displacer supplementary control means further detects the stroke of the displacer. Perform precise stroke control. As a result, the cooling temperature can be automatically adjusted.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention. In the figure, each part of the compressor (1) and the connecting pipe (3) are the same as those shown in the conventional device shown in Figure 2. A bimetallic spring frame is installed between the control piston and the wall of the control room, and an electromagnetic coil is provided around it as supplementary control means for the displacer.It is also equipped with position detection means and supplementary control output determination means. The control piston Q4 is also made of a magnet in this embodiment. All other parts are the same in this embodiment.

゛ Displacer αS is the pressure difference between the cold room ae and the control room ■.

It is driven by the elastic force of the bimetal spring and the magnetic force of the displacer supplementary control means.

Now, assume that bimetal spring 4 has a constant spring constant of 1 at a constant temperature T1. temperature from T1 to T
When increasing to 2, the average diameter of the coil becomes larger, and the spring constant at that time becomes smaller. It is assumed that when the bimetal spring is installed between the piston @ and the control chamber Q, the displacer α9 is driven with a stroke S1, which is twice T1. Now, if the temperature rises to the surface T2, 2 becomes smaller and the stroke of the displacer QS becomes thicker.Furthermore, the stroke length is detected by the position detection means, and if the stroke is not suitable, the supplementary output determination means The displacer supplementary control means (support) provides supplementary driving force or braking with the output determined according to (1).As a result, the stroke of the displacer can be controlled to cool within a desired temperature range at a certain external temperature.

〔Effect of the invention〕

As described above, the present invention includes a bimetal spring that controls the movement of the displacer.

The stroke length of the displacer is controlled by the spring constant changing in accordance with the temperature, and furthermore, by the functions of the position detection means, supplementary limit output determination means, and displacer supplementary control means, the stroke length of the displacer is controlled at any external temperature. The stroke of the displacer can be accurately controlled to achieve cooling within the cooling temperature range. As a result, the refrigeration capacity can be automatically adjusted without any complicated work.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the present invention; FIGS.
The figure shows a conventional refrigerator. In the figure, (1) is compression fi, +21 is cold finger, +31 is connecting pipe, α9 is displacer, ae
04 is a cold room, 04 is a control piston, r2n is a bimetallic spring, @ is a supplementary control means for a displacer, 0 is a position detection means, and ■ is a supplementary control output determination means. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] a cylinder with a temperature difference at both ends; a displacer that moves reciprocally within the cylinder to expand the working gas; and a displacer that encloses one end of the high temperature side of the displacer and connects one end of the low temperature side of the displacer and one end of the low temperature side of the cylinder. A bimetal spring whose spring constant changes in response to temperature and controls the movement of the displacer within the control chamber or the low temperature chamber that is partitioned and generates refrigeration and absorbs heat from the outside, and the displacer. position detection means for detecting the position of the displacer, supplementary displacer control means for supplementary control of the movement of the displacer, and supplementary control output determining means for determining the output of the supplementary displacer control means based on the output of the position detection means. Freezer.