JPS61265458A - Refrigerator - Google Patents

Abstract

(57) [Summary] 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 refrigerating machine, in particular a reciprocating drive of a movable body such as a split Stirling cold storage refrigerator by differential pressure across the movable body. Regarding refrigerators such as

[Prior art J A known tin-lit Stirling type refrigerator is shown in Fig. 3 (I).
~(IV). This refrigerator includes a reciprocating compressor (14) and a cold finger section (16). The piston (17) of the compressor (14) pressurizes a refrigerant gas such as helium to cause a curved pressure fluctuation with a sine force. Said pressure fluctuations in the head chamber (8) are transmitted into said cold finger part (18) through a supply pipe (2o).

Split Stirling refrigerators typically have a compressor driven by an electric motor. A variant of this type of refrigerator is the Split Vuill Lumiere type.
eumier) refrigerator. This device uses a thermally driven compressor.

A cylindrical moving body freely reciprocates within the housing of the cold finger section (16) to change the volumes of the greenhouse chamber (22) and cold chamber (2 (7) in the cold finger section (1G). The mobile body (26) includes a regenerative heat exchanger (28).
Other types of heat exchangers are also known, such as stacked poles, which are formed by stacking several hundred side metal screen discs of thin mesh to form a cylindrical matrix. . Helium is passed through the heat exchanger (2) between the hot room (22) and the cold room (24).
8) is allowed to flow freely through the As discussed below, the piston member (30) is located in the gas spring chamber (18) at the end of the cold finger (18) greenhouse chamber.
32) and extends upward from the main body portion of the movable body (26).

The refrigerator shown in Figures 3(I)-(IV) is shown as having two separate chambers of pressurized gas.The working volume of gas forming the working chambers of gas is
14), the gas in the supply pipe (20), and the gas in the hot chamber (22) and the cold chamber (2).
4) and the gas in the heat exchanger (28) of the cold finger section (1B). It is the gas spring chamber (32) that forms the second gas working volume;
The spring chamber (32) is sealed to the working chamber by a piston seal (34) surrounding the drive piston member (30).

Next, the operation of this known split Stirling type refrigerator will be explained. At the time of the cycle shown in FIG. 3(I), the moving body (26) is
6) at the end of the cold chamber in the compressor (14).
) is compressing the gas in the working chamber. compressor(
The compressive movement of the piston (17) of 14) increases the pressure in the working chamber from the lowest pressure to the highest pressure, and this warms the gas in the working chamber. Spring room (3
2) The pressure within is stabilized at a level between the lowest and highest pressure levels within the working chamber. Thus,
At some point, the increasing pressure in the working chamber creates a differential pressure against the drive piston member (30) sufficient to overcome the frictional resistance of the moving object seal (3G) and the piston member seal (32). generate. Then, the piston>' member (30) and the moving body (2B) rapidly rise to the position shown in FIG. Due to this movement of the moving body (26), the gas in the high pressure working chamber at almost ambient temperature is transferred to the heat exchanger (26).
8) and is forcibly guided into the cold room (24). The heat exchanger (28) absorbs the heat of the pressurized gas passing through it, thereby reducing the temperature.

Due to the sine curve drive by Gf (crank shirt), the compressor piston (17) is now in the third
The volume of the working chamber begins to expand as shown in Figure (III).

Due to this expansion, the high pressure helium gas in the cold chamber (24) is further cooled. It is this cooling in the cold compartment (24) that generates a refrigeration effect that maintains a temperature gradient of more than 2000° over the entire length of the heat exchanger (28). At some point in the expansion movement of the piston (17), the pressure in the working chamber drops below the pressure in the spring chamber (32) and the differential pressure is sufficient to overcome the frictional forces of the seal on the piston member (30). acts on The moving body (26) is then driven downward to the position shown in FIG. 3 (1). The location of Figure 3 (IV) is Figure 3 C.
It is also the starting position before reaching position I).

The cooled gas in the cold room (24) is transferred there to a heat exchanger (
28) is forced to pass through a heat exchanger to extract heat from the heat exchanger.

It is known that the phase relationship between the pressure in the working chamber and the movement of the moving body is determined by the braking force of the seals applied to the moving body. For example, if these seals are If there is only frictional resistance, the moving body moves from the lower position shown in FIG. 3 (I) to the upper position shown in FIG. Since the pressure in the spring chamber (32) is brought to a pressure approximately intermediate between the minimum and maximum pressure in the working chamber, the movement of said moving body is This will occur already by the time the compressor piston (17) reaches the middle of its stroke, which will result in compressing a considerable amount of gas in the cold chamber (24) of the cold finger section. Since compressing the gas then means warming the gas, this may have undesirable consequences.

In order to increase the efficiency of the device, the upward movement of said moving body is such that the piston (17) of the compressor is near the end of its stroke as shown in FIGS. 3(1) and 3(n). will be delayed until In this way, almost all the gas is compressed and warmed in the greenhouse chamber (22) of the cold finger section.Then the warmed gas is then simply transferred to the heat exchanger (22) when the mobile body moves upwards. 28).

Thus, the gas currently contained in the cold chamber (24) has been cooled as much as possible before it is further cooled by expansion. Similarly, in the cold chamber of the cold finger section, it is preferable that the gas is expanded as much as possible before being transferred to the greenhouse chamber by the moving body (26); again, the movement of the moving body is must be delayed for pressure changes at .

In the conventional device, the seal (34) and the seal (3B
) were precisely designed and manufactured to apply a predetermined amount of load to the moving object, and thus slow the movement of the moving object by an optimal amount. A major problem with Split Stirling refrigerators is that the braking action of these seals changes as they wear.

Next, we will clarify this problem according to Figure 4.

In the same figure, the horizontal axis is the crank angle 5 of the piston (17).
The vertical axis indicates the displacement of the piston (17) and the displacement of the moving body (26) with respect to the crank angle. Piston (17)
Since the displacement is driven by a crank mechanism (not shown), the displacement is approximately sinusoidal. By the way,
Crank angle θ=0 is the bottom dead center of the piston, and θ=π is the top dead center.

Here, a load force (frictional force) is applied to the moving body in advance by a seal (34) and a seal (36). The displacement is determined by this load force and the pressure conditions in the spring chamber (32) and the greenhouse chamber (22).The solid line in the figure shows the ideal piston (17) that exhibits the best performance of the split Stirling type cooling system. Here, the displacement of the moving body when the load force (frictional force), that is, the braking force applied in advance to the moving body by the seal (34) and the seal (36) changes, will be explained. If the load decreases, the displacement will be as shown by the dashed line.If the load increases too much, the displacement will be as shown by the dashed line.In this way, i
As the load changes, the displacement deviates from the ideal displacement, resulting in a decline in the performance of this refrigerator.

[Problems to be solved by the invention] The conventional split Stirling type refrigerator has a seal (34
) and the seal (3B), the displacement of the moving body was determined by the balance of the load force (frictional force) applied in advance to the moving body and the pressure state of the spring chamber and the greenhouse chamber. , the displacement form of the moving body changes,
Cold 711! It was difficult to maintain the machine's performance over a long period of time.

This invention was made to solve the above problems, and the load force can be adjusted so that the displacement form of the moving body can be maintained in a desired state without being affected by changes over time, so that it can be stabilized over a long period of time. The purpose of this invention is to obtain a refrigerator that can guarantee high operating performance.

[Means for Solving the Problems] The refrigerator of the present invention is provided with a variably controllable load force applying means for applying a second load force to the moving body, in addition to the conventional brake using a seal. This is what I did.

"Operation" In the present invention, the load force applying means allows the mutual relationship between the displacement of the moving body and the displacement of the piston to be always maintained in a constant state.

L Embodiment 1 (81 indicates an embodiment of the present invention, and the same symbols as in FIGS. 3 and 81944 indicate the same functional members. In the figure, (101) is a moving object (2
A piston member protrudes from the lower part of B), the lower end of which is supported by a non-lubricated bearing (110), and a disk-shaped permanent magnet (102) is further attached to the lower part of the piston member.

(111) is a housing provided with the spring chamber (32) and the above-mentioned non-lubricated bearing (110), (103) is a cover plate made of at least a non-magnetic material for sealing the lower part of this housing, and (ctoa) is this housing. A magnetoresistive sensor is attached to the lower surface of the lid plate, (104a) and (LO4b) indicate its electrical input lines, and (104c) indicates a signal input line.

(10G) is one of the members constituting the second load force applying means that is attached to penetrate the side wall of the housing (111) so as to be in orthogonal contact with the piston member (101), and is made of at least a non-magnetic material, A plunger holder that can seal the spring chamber (32), (105) is a winding that surrounds this holder and constitutes an electromagnet, and (108) is a plunger that is inserted into the holder and is made of a magnetic material, with a piston at the tip. A friction body (112) made of ceramic material is fixed so that it can come into contact with the member with rapid lubrication. (109) presses the plunger to the right in the figure without applying voltage to the winding (105), and the piston This is a spring coil spring for keeping the member (101) and the friction body (112) out of contact. (107) is provided around the plunger (108) in order to smoothly move the plunger (108) forward and backward. Tamujunsei guide ring, (105a),
(105b) is the electrical input terminal of the winding (105), (11
3) is a surrounding space (114) surrounding the disk-shaped permanent magnet (102) attached to the lower part of the piston member (101).
) is a communication hole provided to function as a spring chamber (32). (115) is a connecting rod of the piston (17), (11B) is a crankshaft, and (117) is a top dead center detection sensor of the piston (17) attached to the crankshaft.

FIG. 2 shows a block diagram of the electromagnet control device constituting the second load force applying means. In FIG. 0, (119) is Ti
A moving object detection circuit (121) is a moving object detection circuit that outputs a pulse signal only when the 15L resistance sensor (104) detects the bottom dead center of the moving object (approach of the disk-shaped permanent magnet (102)).
) is at the top dead center, the piston detection circuit outputs a pulse signal by the detection sensor (117), (120) is a calculator that calculates the phase difference between both pulses, and (122) is a preset position of both pulses. This control circuit compares the phase difference with the detected and calculated phase difference and performs feedback control of the voltage applied to the ridge portion (118) of the electromagnet.

In this embodiment configured in this manner, the movable body is operated by the reciprocating motion of the piston (17), and operates as a split Stirling type refrigerator, as explained in FIGS. 3 and 4.

Here, the second load force applying means detects whether or not the top dead center of the piston and the bottom dead center of the moving body operate with a predetermined phase while the refrigerator is operating.

When displaced from a predetermined phase difference, the electromagnet winding (105)
The voltage applied to the plunger (108) is controlled by an electromagnetic control circuit as shown in FIG.
The contact load force (frictional force) between the piston member (101) and the friction body (112) can be controlled by changing the electromagnetic force acting on the piston member (101) and the frictional body (112).

[Effects of the Invention] As described above, according to the present invention, the adjustable second braking force is applied to the movable body by the second additional force applying means, and the bottom dead center of the movable body and the top dead center of the piston are Since the load force is controlled so that the phase difference is always at a predetermined value, it is possible to provide a refrigerator that is stable over a long period of time.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention, Fig. 2 is an electrical control circuit diagram thereof, and Fig. 3 CI) to (rV) show the operating form of the cold finger section in a general refrigerator. The figures shown in sequence, FIG. 4, are operation graphs showing the relative relationship between the piston and the moving body. In the figure, (101) is a piston member, (102) is a disk-shaped permanent magnet, (104) is a magnetic resistance sensor, (105) is a winding, (IOEI) is a plunger holder, (108) is a plunger, (112) ) is a friction body. (117) is a top dead center detection sensor. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] (1) A compressor, a housing that communicates with the compressor through a supply pipe, a movable body that reciprocates within the housing, and a gas that contacts opposite end surfaces of the movable body and surrounds the movable body. a gas working chamber and a gas spring chamber separated by a fluid seal; the movable body is driven by a differential pressure between the working chamber and the spring chamber;
In a refrigerator configured to have a phase relationship between the movement of the moving body determined by the braking force applied to the moving body, in addition to the braking force, a second load is applied to the moving body. A refrigerator characterized in that it is equipped with means for applying load force that can be variably controlled. (2) The load force applying means is constituted by a friction body that is electromagnetically operated toward and away from a piston member extending from a moving body. refrigerator. (3) The load force applying means adjusts the second load force based on the detection values of the bottom dead center detection means of the moving body and the top dead center detection means of the piston to maintain the predetermined phase relationship. The refrigerator according to claim 1 or 2, further comprising a control means for controlling the refrigerating machine. (4) The bottom dead center detection means of the movable body is constituted by a permanent magnet provided on a piston member extending from the movable body and a magnetic resistance sensor that detects the approach of the permanent magnet. Refrigerator according to scope 3.