JPS59173670A - Refrigerant flow controller for 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 The present invention relates to a refrigerant flow rate control device for a refrigerator that performs electrical control.

Conventionally, as this type of control device, as shown in Fig. 1,
There was a thermostatic expansion valve installed between the condenser and evaporator in the refrigeration cycle. This expansion valve is provided with a refrigerant port/co and a refrigerant E1/3 in the valve body l/, and a spindle/l having a valve body part for controlling the opening degree of the valve port/da inside the valve body l/. , spindle l! A spring 16 that applies a spring force to r is housed. One end of the spindle /3 is connected to a diaphragm /g installed inside the temperature-sensitive cylinder chamber 77.

The spindle 13 is moved by the vertical movement of the diaphragm 1g, and the opening degree of the valve port III is controlled.

The conventional refrigerant flow control device for a refrigerator configured as described above thermally and indirectly senses the vaporized state of the refrigerant, and further converts this into pressure and operates it mechanically. This has the disadvantage that the response is delayed, causing the valve to open too much and a hunting phenomenon.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and uses a new control method that is completely different from that of thermostatic automatic expansion valves to achieve quick response to the refrigerant vaporization state. The purpose is to provide a highly accurate refrigerant flow rate control device for a refrigerator.

That is, the refrigerant flow control device for a refrigerator according to the present invention includes a detector that electrically determines the gas-liquid state of the refrigerant flowing in the pipe near the outlet of the evaporator of the refrigeration cycle; A controller that controls a duty ratio at a frequency, and an expansion valve that is provided between a condenser and an evaporator of a refrigeration cycle and that proportionally controls a refrigerant flow rate based on the average output current of the controller. It is a feature.

Hereinafter, an example of a refrigeration cycle equipped with a refrigerant flow rate control device according to the present invention will be described in Section 2. This will be explained using figures.

In this refrigeration cycle, high-temperature, high-pressure refrigerant gas discharged from the compressor is condensed and liquefied in the condenser, passed through the expansion valve 23, which opens the proportional solenoid valve, and is made low-temperature and low-pressure to the evaporator 24'. It is sent to the evaporator, where it is evaporated and vaporized, and then sucked into the compressor again.

In Fig. 2, ko S and ko are temperature detectors, the temperature sensor ko S is installed in the evaporator koku to detect the evaporation temperature of the refrigerant, and the temperature detector ko t is installed in the compressor, 2/ The temperature of the suction refrigerant gas is detected, and a signal representing the humidity difference between the two re-tested temperatures, that is, the degree of superheat, is input to the controller-7.

The controller is configured to control the refrigerant flow rate by outputting a duty ratio at a constant frequency to the expansion valve 3 in response to an input signal thereto.

The structure of the expansion valve 23 will be explained with reference to FIG. The body 31 of the expansion valve 3 has a valve seat 3/3 for controlling the refrigerant flow rate.
A and bearing parts for three needle pulps are formed, refrigerant pipes 3// provided at the bottom of body 3/ are connected to the evaporator body, refrigerant pipes provided horizontally, and 3// are connected to the condenser. It is connected to here. Pipe 3 at the top of the above body 3/
6 is fixed and protrudes above the body 31, the core 33 is fitted and fixed to the upper part of the pipe 36, and a spring 3D is interposed between the lower part of the core 3S and the upper part of the plunger 33 to press it downward. . The plunger 33 is fitted into the lower part of the pipe 3 so as to be movable in the vertical direction.
3 is fastened with a threaded portion provided at the top of the three needle pulps. At the upper end of the core 3S is a case 3 shaped like an inverted bowl.
9 is fastened with 3/3 screw, and the bobbin 3 is inside the case 3q.
The electromagnetic coil 3g attached to the pipe 7 is inserted, and the bobbin 37 is fitted onto the outer periphery of the pipe 36. The lower end opening of the case 39 is closed by an end wall member 310, and the outer circumference of the end wall member 310 is fixed to the lower edge of the case 39, and the pipe 36 is fitted into a through hole having the same diameter as the end wall member 310. ing.

Next, the operation of the device configured as described above will be explained. Take the refrigerant flowing out from the condenser, refrigerant pipe 3/
/ into the cylindrical space in the body 31 and the valve seat J/a
reach the top. Note that at this time, the inside of the pipe 36 is also filled with refrigerant. With this ζ, when power is not supplied to the electromagnetic coil 3g, the spring, ? With lI, the three needle pulps press against the body 31 and the valve seat, ? Since it is joined to /a,
The expansion valve, 23, is closed to prevent refrigerant flow. When power is supplied from the controller 27 to the electromagnetic coil 3g, the end wall member 310. A magnetic flux flows through a magnetic path formed by the case 3g, the core 3S, and the plunger 33, and the plunger 3J connects the core 3. Attraction force and spring according to the power supply current towards tK? Move to a position where the spring force of 4C is balanced. Along with this movement, the three needle pulps move and are disconnected from the valve seat j/a, and the refrigerant is communicated from the cylindrical space in the body 31 through the valve seat 3/a to the evaporator body. It flows out into 31 refrigerant pipes. Since the amount of refrigerant flowing out depends on the amount of movement of the needle pulp 3.2, the amount of refrigerant can be controlled by the amount of movement of the plunger 33 in accordance with the current. In addition, the needle pulp 32, which moves according to the current of the electromagnetic coil 3g, is supported by the body 31 and moves along the circumferential wall of the inner hole of the bearing part, so there is a frictional force between the three needle pulps and the body 31. This causes hysteresis in the amount of movement of the needle valve 3.2 relative to the current. For this reason, the electromagnetic coil 3g is supplied with power by controlling the average output current by controlling the duty ratio □ of a constant frequency using the controller Koku, and the sliding friction force between the 3 needle pulps and the body 31 is controlled by the dither effect. The amount of movement of the three needle pulps can be accurately controlled with respect to the average output current, and the refrigerant flow rate control device can be improved at low cost.

As explained above, the present invention electrically detects the gas-liquid state of the refrigerant flowing near the outlet piping of the evaporator, linearly and proportionally controls the refrigerant flow rate using the duty ratio at a constant frequency, and reduces the load on the evaporator. The present invention has the advantage that a refrigerant flow rate control device for a refrigerator that can control the refrigerant flow rate with high accuracy and responsiveness in response to fluctuations can be provided at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an example of a conventional thermostatic automatic expansion valve, FIG. 2 is a configuration diagram of a refrigerant cycle equipped with a refrigerant flow rate control device according to the present invention, and FIG. 3 is a refrigerant flow rate control device according to the present invention. It is a front sectional view showing an expansion valve of. //... Valve body, /2... Refrigerant inlet, /,? ...
Refrigerant outlet, /R...valve port, /S...spindle, /
A...Spring, /ri...Temperature-sensitive tube chamber, lza...-
diaphragm, -1...compressor, -1...condenser,
3...Expansion valve, Koku...Evaporator, K-S, Colo...
・Temperature detector, body...controller, 31...body,
3/a... Valve seat, 3.2... Needle valve, 33
...Plunger, 3D...Spring, 3S...
Core, 36...pipe, 37...bobbin, 3g...
- Electromagnetic coil, 39... Case, 3/θ... End wall member, 3//, 3/Co... Refrigerant piping. Agent: Makoto Kuzuno - (and 1 other person) Procedural amendment hearing (voluntary) 26 Name of invention Refrigerant flow control device for refrigerator 3 Relationship to the case of the person making the amendment Patent applicant address: 2 Marunouchi, Chiyoda-ku, Tokyo Eye 2; 3
Name Title (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 6° Subject of amendment (1) Column 6 of detailed explanation of the invention in the specification, Contents of amendment (1) Page 6, line 17 of the specification [Refrigerant flow control device]
If it says, "accuracy of the refrigerant flow rate control device" is corrected.

Claims (1)

[Claims] A detector that electrically determines the gas-liquid state of the refrigerant flowing through the pipe near the outlet of the evaporator of the refrigeration cycle, a controller that controls the duty ratio at a constant frequency according to the signal from this detector, and the refrigeration cycle. A refrigerant flow rate control device for a refrigerator, comprising: an expansion valve that is provided between the condenser and the evaporator to proportionally control the refrigerant flow rate based on the average output current of the controller.