JPH039387B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an expansion valve device for a refrigerator.
For example, it is suitable for use in a refrigerator such as a cooling system in which two evaporators are installed in parallel in a refrigeration cycle, and the flow of refrigerant into one of the two evaporators is cut off depending on the state of use. .

Conventionally known cooling systems of this type, such as automotive cooling systems, are equipped with evaporators at the front and rear of the vehicle interior, and a solenoid valve is used to supply refrigerant to the rear evaporators, which are auxiliary activated depending on usage conditions. However, such cooling systems require a special solenoid valve as a part of the refrigeration cycle, making them expensive. In addition, there were other drawbacks such as an increase in the number of piping connections.

The present invention has been made in view of the above points, and the expansion valve itself is closed by forcibly cooling the charge gas sealed in the temperature-sensitive cylinder of the expansion valve using a cooling device such as a thermoelectric element. It is an object of the present invention to provide an expansion valve device for a refrigerator which eliminates the need for a solenoid valve, eliminates piping connection to a refrigeration cycle, has an extremely simple structure, and is inexpensive.

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows an embodiment in which the present invention is applied to an automobile cooling system having evaporators at the front and rear parts of the vehicle interior. 2 is a condenser, 2a is a cooling fan thereof, 3 is a liquid receiver, 4 is an expansion valve, 4a is an expansion valve device of the present invention, and an internal space formed in a housing 30a of the expansion valve device 4a. A thermoelectric element 20 is placed in the middle of the capillary 12b that continuously communicates with the inside of the temperature sensing tube 12a.
The cooling side of the 5 and 5a are evaporators arranged in parallel, one evaporator 5 is arranged in the front part of the passenger compartment of the automobile, and the other evaporator 5a is arranged in parallel.
is located at the rear of the vehicle interior. 6,6a
is an electric blower that blows cold air into the passenger compartment.
Reference numerals 8, 9, and 9a are manually operated switches arranged at appropriate positions in the vehicle interior, 10 is a fuse, and 11 is a power storage battery. Here, the temperature-sensitive cylinder 12a of the expansion valve device 4a of the present invention to be used, the capillary 12b, and the internal space 30a reaching the upper part of the diaphragm 13 provided in the internal space 30a of the housing 30 are filled with the same refrigerant as that in the refrigeration system. It is filled with saturated gas refrigerant of 4Kg/cm ² G. On the expansion valve 4 side, there is also an internal space 30 where the saturated gas refrigerant reaches the temperature sensing tube 14, the capillary 14a, and the upper part of the diaphragm 15 of the expansion valve 4.
It is enclosed in a. Valve bodies 16 and 17 are connected to the diaphragms 13 and 15, respectively.

The thermoelectric element 20 serves as a cooling device for the sealed gas refrigerant, and has a structure as shown in FIG. In FIG. 2, the capillary 12b is made of a copper tube, and the heat absorbing plate 20a of the thermoelectric element 20 is in direct contact with the outer peripheral surface of the capillary 12b. Further, a cooling plate 21 made of metal such as aluminum or iron is disposed around the outer periphery of the capillary 12b so as to cover it, and a heat insulating material 22 is disposed on the outside of this cooling plate 21. A case member 23 made of resin is disposed on the outside. Thermoelectric element 20
A heat dissipation fin 20c made of metal such as copper, aluminum, iron, etc. is closely disposed on the heat dissipation plate 20b, and the fin 20c and the case member 23 are connected with mounting screws 24. A bracket part 23a is integrally molded on the case member 23, and this bracket part 23a is connected to the evaporator 5 by means of a tapping screw 25.
It is fixed to a resin case 26 for housing a.

Next, the operation of the device of the present invention with the above configuration will be explained. When the switches 9 and 9a are turned on, the electric blowers 6 and 6a are rotating, but when the switch 8 is not turned on, the thermoelectric element 20 is not energized, so the expansion valve device 4a functions as a normal expansion valve. It works the same way. That is, in the expansion valve device 4a, the saturated gas refrigerant sealed in the temperature-sensitive tube 12a condenses in the temperature-sensitive tube 12a portion where the temperature is lowest, so that the saturated pressure corresponding to the temperature-sensitive tube temperature is applied to the diaphragm 13 of the expansion valve 4a. The pressure change causes the diaphragm 13 to be displaced to adjust the valve opening, thereby controlling the refrigerant flow rate so as to keep the degree of superheat of the refrigerant at the outlet of the evaporator 5a constant. And the evaporator 5a
The cooled air is also blown toward the rear of the vehicle interior by the electric blower 6a. Here, if the switch 8 is turned on when the rear cold air is not needed, the thermoelectric element 20 is energized and the capillary 12b is turned on.
Since the gas refrigerant inside the temperature sensing cylinder 12a condenses at this point, the pressure above the diaphragm 13 decreases, and the expansion valve device 4
The valve body 16 of a is closed by the force of a spring (not shown), and the supply of refrigerant to the evaporator 5a at the rear of the vehicle interior is stopped. This allows the refrigerant to flow only into the evaporator 5 at the front of the vehicle interior.

In addition, in the embodiment described above, the capillary 1
Although the thermoelectric element 20 is used as a cooling device for forcibly cooling the thermoelectric device 2b, any means can be used as long as it can provide a cooling effect with a quick response.

In addition, the cooling point is a capillary 1 with a small heat capacity.
2a, but it may be placed above the expansion valve diaphragm.

Further, in the above-described embodiments, an example was described in which the device of the present invention was applied to an automobile cooling device, but it can also be widely applied to household cooling devices, refrigerators, and the like.

As described above, in the device of the present invention, the expansion valve can be kept in a closed state by forcibly cooling the sealed gas in the temperature-sensitive cylinder of the gas charge type expansion valve. This has the excellent effect of providing an inexpensive refrigerator that does not require a special solenoid valve on the inlet side of the refrigerator.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing an embodiment of a refrigerator equipped with an expansion valve device according to the present invention, and FIG. 2 is a detailed structural diagram of the main part of FIG. 1. 4a... Expansion valve device, 5a... Evaporator, 12a
... Temperature sensing tube, 12b... Capillary, 13... Diaphragm, 16... Valve body, 20... Thermoelectric element forming a cooling device.

Claims (1)

[Claims] 1. A compressor that takes in, compresses, and discharges refrigerant, a condenser that condenses the refrigerant discharged from the compressor, and a plurality of evaporators arranged in parallel that evaporates the refrigerant. an expansion valve that is arranged upstream of at least one evaporator among the plurality of evaporators and controls the flow rate of refrigerant supplied to the evaporator and reduces the refrigerant pressure; a temperature sensing cylinder whose internal pressure changes according to the refrigerant temperature on the outlet side of the evaporator; a housing having a space inside to which the pressure of the temperature sensing cylinder is transmitted; a diaphragm that operates; a valve body whose opening degree is controlled by the operation of the diaphragm to control the refrigerant flow rate and reduce the refrigerant pressure; a capillary that communicates and connects the temperature sensing tube and the internal space; The charge gas sealed in the hot cylinder, the internal space, and the capillary is provided with a cooling device that forcibly cools the charge gas at a location that is not thermally in contact with the refrigerant circulating in the refrigeration cycle. Expansion valve device for refrigerators.