JPH0650201B2 - Chiller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a gas cycle engine, and more particularly to a cooler that produces cryogenic temperature.

[Conventional technology]

FIG. 3 is a cross-sectional side view of a conventional cooling machine disclosed in, for example, Japanese Patent Publication No. 54-28980. In FIG. 3, reference numeral 1 is a cylinder in which a piston 2 and a free displacer 3 which reciprocate in different phases are housed. A cooler 5 is housed in the compression space 4 between the working surface of the piston 2 and the lower working surface 3 a of the free displacer 3. The upper working surface 3b of the free displacer 3 bounds an expansion space 6, which together with the compression space 4 constitutes the working space. The regenerator 7 provided in the free displacer 3 communicates with the working medium below through the lower central hole 8 and with the upper working medium through the upper central hole 9 and the radial circulation duct 10. Further, the freezer 11 faces the expansion space 6 as a heat exchanger for heat exchange between the expanded cold working medium and the object to be cooled. Seals 12 and 13 are provided between the piston 2 and the wall of the cylinder 1, and seals 14 and 15 are provided between the free displacer 3 and the cylinder 1. The piston 2 is provided on its underside with a lightweight sleeve 16 made of a non-magnetic and non-magnetizable material such as hard paper or aluminum. Sleeve 1
A conductor is wound around 6 to form a movable coil 17, and the movable coil 17 has lead wires 18 and 1 extending to the outside through a wall of a housing 20 hermetically connected to the cylinder 1.
9 are connected. These leads 18, 19 have electrical contacts 21, 22 outside the housing 20, respectively. The moving coil 17 enables reciprocating movement in the annular gap 23 in the axial direction of the piston 2, and an armature magnetic field exists in the annular gap 23, and the force line of this magnetic field is the moving coil 1.
7 extends radially across the direction of movement of 7. In order to obtain the permanent magnetic field in the lower part of the housing 20,
An annular permanent magnet 24 having magnetic poles on the upper and lower sides, a soft iron annular disk 25, a solid soft iron cylinder 26 and a soft iron circular disk 27 are provided. Permanent magnet 24 and soft iron part 2
5, 26 and 27 cooperate with each other to form a closed magnetic circuit, that is, a closed magnetic force line circuit. Further, the closed magnetic circuit, the movable coil 17, the lead wires 18 and 19, the electrical contacts 21 and 22, and the annular gap 23 constitute a linear motor 28 as a whole.

The piston 2 is provided with a support spring 29 composed of a relatively soft coil spring, which secures the fixed center position of the piston 2. Further, both ends of the support spring 29 are fitted around the first projection 30 provided on the lower surface of the piston 2 and the second projection 31 fitted on the soft iron cylinder 26 so that upper and lower ends thereof are fitted and locked so as not to move laterally. The lower surface of the free displacer 3 is supported on the stage of the cylinder 1 by an elastic member 32 composed of a coil spring to limit the stroke of the free displacer 3.

Next, the operation of the cooler configured as described above will be described.

The electric contacts 21, 22 and the lead wire 1 are attached to the moving coil 17.
When an alternating current is made to flow via 8 and 19, due to the interaction between the permanent magnetic field in the annular gap 23 and the current in the movable coil 17,
The vertical Lorentz force acts, and as a result, the assembly including the piston 2, the sleeve 16 and the movable coil 17 starts to vibrate. Due to the vibration of the piston 2, the compression space 4
When the volume changes, the working gas enclosed in the working space consisting of the compression space 4, the expansion space 6, the cooler 5, the regenerator 7, and the breather 11 is compressed and expanded, and the pressure of the gas fluctuates. . Further, this pressure fluctuation causes a cyclical fluctuation of the pressure difference between both ends of the heat accumulator 7, and as a result, the free displacer 3 moves at the same frequency as the piston 2 but in a different phase due to the resonance of the pressure difference and the elastic member 32. Like

When the piston 2 and the free displacer 3 move in different phases, the working gas (for example, helium) in the working space constitutes a thermodynamic cycle known as the reverse Stirling cycle, and produces cold in the expansion space 6. generate.

[Problems to be solved by the invention]

The conventional cooler has the piston 2 and the housing 2 as described above.
Since the 0 side was connected by the relatively soft support spring 29, when the direction of gravity acting on the piston 2 changes depending on the mounting direction of the cooler, the center position of the piston 2 deviates from the set position, and the operation of the cooler is performed. There was a problem that the piston 2 collided with the cylinder 1 and generated an abnormal noise and sometimes was destroyed. Further, when the cooling machine receives a large acceleration due to the vibration from the outside, the same problem as described above occurs.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a highly reliable cooling machine that is not easily affected by the mounting direction of the cooling machine and external acceleration.

[Means for solving problems]

According to the present invention, in the cooling machine as described above, the housing containing the linear motor and the piston or the reciprocating portion of the linear motor have a spring constant. However, k: spring constant of support spring (kgf / mm) m: total mass of assembly (piston, linear motor reciprocating part) (kg) Smax: relatively rigid support spring with maximum allowable stroke of piston (mm) Are linked by.

[Action]

In the cooler according to the present invention, since the piston is supported by the relatively rigid support spring 29 having the spring constant of the formula (1), the piston is substantially constant regardless of the direction of gravity or external acceleration. It is possible to realize a highly reliable cooler that maintains the center position of the piston and does not have a collision of the piston with the cylinder.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, the same reference numerals as those in FIG. 3 indicate the same or corresponding portions, and in this embodiment, the piston 2 is provided with a relatively rigid support spring 29, which is different from the conventional example. That is, the spring constant of the support spring 29 is However, k: spring constant of support spring (kgf / mm) m: total mass of assembly (piston, linear motor reciprocating part) (kg) Smax: maximum allowable stroke of piston (mm) Support spring 29 is piston 2 The fixed center position of is secured. Both ends of the support spring 29 are locked so as not to move laterally, and are arranged around the first protrusion 30 and the second protrusion 31. An elastic member 32 formed of a relatively rigid coil spring is provided below the free displacer 3 to limit the stroke of the free displacer 3. That is, the spring constant is Where kd: spring constant of elastic member (kgf / mm) md: total mass of displacer and regenerator (kg) Sdmax: displacer 3 with a relatively rigid elastic member 32 having a maximum allowable stroke (mm) of displacer
Are supported on the stage of the cylinder 1.

The structure of this embodiment other than that described above is the same as the conventional one shown in FIG.

Next, the operation of this embodiment will be described.

The electric contacts 21, 22 and the lead wire 1 are attached to the moving coil 17.
When an alternating current is passed through 8 and 19, a vertical Lorentz force acts on the movable coil 17 due to the interaction between the permanent magnetic field in the annular gap 23 and the current, and as a result, the piston 2, the sleeve 16 and the movable coil 17 move. The assembly of coils 17 begins to vibrate. When the volume of the compression space 4 changes due to the vibration of the piston 2, the working gas enclosed in the working space is compressed and expanded, and the pressure of the gas fluctuates. Further, this pressure fluctuation causes a cyclical fluctuation of the pressure difference between both ends of the regenerator 7, and as a result, the free displacer 3 has the same frequency as the piston 2 due to the resonance of the pressure difference and the elastic member 32.
And it will move in different phases.

When the piston 2 and the free displacer 3 move in different phases, the working gas (for example, helium) in the working space constitutes a thermodynamic cycle known as the reverse Stirling cycle, and produces cold in the expansion space 6. generate.

Then, how the support spring 29 in this embodiment acts on a change in the mounting direction of the cooler will be described with reference to FIG. In FIG. 2, when the cooler is mounted so as to receive downward gravity, the support spring 2
9 is deflected by the gravity of the assembly composed of the piston 2 and the like. As a result, the center position of vibration of the piston 2 is m / k from the center position (line of FIG. 2 (b)) when there is no gravity.
Only move down as shown by the line. On the other hand, when the gravity is upward, that is, when the cooler is installed in the opposite manner to that of FIG. 1, the center position of the vibration of the piston shifts upward by m / k as indicated by the line for the same reason. Therefore, regardless of the mounting direction, in order for the piston 2 not to collide with the cylinder 1 and to perform a stable reciprocating motion, from FIG. It is necessary to be. On the contrary, the spring constant k of the support spring 29 is By doing so, equation (3) is established, and a stable cooler irrelevant to the mounting direction can be obtained.

Furthermore, in the above embodiment, the support spring 29 of the piston 2 is
Not only is the spring relatively stiff to satisfy the expression (1), but the elastic member 32 of the free displacer 3 is also an elastic member satisfying the expression (2), so that the movement of the displacer 3 also increases in stability. There is an effect that a more reliable cooler can be obtained.

In the present invention, the elastic member of the free displacer may be the same as the conventional one, and the housing and the reciprocating motion part of the linear motor are connected by the support spring having a spring constant of the above formula, and the reciprocating motion part is connected. The piston may be fixed to.

〔The invention's effect〕

As described above, according to the present invention, the compression space kept at a relatively high temperature during the operation, the expansion space kept at a relatively low temperature during the operation, the cooler, the heat storage device communicating with the both spaces,
And a working space consisting of a space inside the freezer and
The volume of the compression space is changed by the movement of a piston driven by a linear motor or the piston and the displacer, and the volume of the expansion space is changed by the movement of the displacer. By operating in a different phase, the working gas existing in the working space undergoes a thermodynamic cycle to generate cold heat,
Since the spring constant of the support spring is configured so as to satisfy the formula (1), a stable operation and a highly reliable cooling machine can be obtained, and the cooling machine can be used in any mounting direction, and the usage of the cooling machine is expanded. There is an effect.

[Brief description of drawings]

FIG. 1 is a sectional side view showing a cooler according to an embodiment of the present invention, FIG. 2 is an explanatory view showing the action of a support spring in FIG. 1, and FIG. 3 is a sectional side view of a conventional cooler. . 1 is a cylinder, 2 is a piston, 3 is a displacer, 4
Is a compression space, 5 is a cooler, 6 is an expansion space, 7 is a heat storage device,
11 is a freezer, 20 is a housing, 28 is a linear motor, 29 is a support spring, 30 is a first protrusion, and 32 is an elastic member. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Kashiwamura 8-1-1 Tsukaguchi Honcho, Amagasaki City, Hyogo Sanryo Electric Co., Ltd. Central Research Laboratory (56) Reference JP-A-50-145952 (JP, A) ) JP-A-62-13965 (JP, A)

Claims (2)

[Claims] 1. A compression space maintained at a relatively high temperature during operation,
It has an operating space consisting of an expansion space that is kept at a relatively low temperature during operation, a cooler, a heat storage device, and a space inside the freezer that communicate with both spaces, and the volume of the compression space is driven by a linear motor. That is changed by the movement of the piston or the movement of the piston and the displacer, the volume of the expansion space is changed by the movement of the displacer, by moving the piston and the displacer in different phases, In a cooler in which the working gas present in the working space undergoes a thermodynamic cycle to generate cold heat, the housing containing the linear motor and the piston or the reciprocating part of the linear motor have a spring constant, However, k: Spring constant of support spring (kgf / mm) m: Total mass of assembly (piston, linear motor reciprocating part) (kg) Smax: Maximum allowable stroke of piston (mm) By relatively rigid support spring Cooler characterized by being connected. 2. The displacer is connected to a cylinder containing the displacer by an elastic member, and the spring constant of the elastic member is However, kd: spring constant of elastic member (kgf / mm) md: total mass (kg) of displacer and heat accumulator Sdmax: maximum allowable stroke (mm) of displacer.