JPS58126213A - Air conditioning apparatus for automobile - Google Patents

Abstract

PURPOSE:To generate cooling capacity which is balancing to a heat load in a car cabin by changing the amount of cooling medium step by step by switch controlling a switching valve which is connected to 2 inlet sides by help of a compressor composed of coaxial 2 cylinders each of which has its own displacement of cooling medium different from each other. CONSTITUTION:A cooling cycle is composed in such a way that, cooling medium emitted from a rolling piston type variable performance compressor 1 composed of coaxial 2 cylinders is returned to the inlet of each cylinder through a condenser 2, a receiver dryer 3, an expansion valve 4, and a cooler 5. Switching valves 7a, and 7b are prepared in the pipes connected to the inlet of each cylinder, and each valve 7a, and 7b is switch-controlled in accordance with the heat load in a car room. That is, when the heat load is high, both valves 7a, 7b are opened, and a rated cooling capacity can be fulfilled. When the heat load is lowered, the valve 7a is opened, and the valve 7b is closed. When the heat load is lowered more, the valve 7a is closed, and the valve 7b is opened, and the cooling capacity is lowered step by step.

Description

[Detailed description of the invention] This invention relates to an air conditioner for automobiles.

By operating the on-off valve connected to the suction side of a coaxial 2-cylinder compressor with different refrigerant push times, the amount of refrigerant is changed in stages, creating a refrigerant capacity that is particularly suited to the heat load inside the vehicle. The present invention relates to an air conditioner for an automobile characterized by the following.

Generally, in automobile air conditioners, after the heat load inside the vehicle has decreased, the cooling overload occurs.

The compressor was repeatedly turned on and off, which shortened the life of the compressor and was also uncomfortable for the driver.

Conventionally, the configuration is as shown in FIG.

That is, in the figure, (1) is the compressor, and (2) is the condenser.

(3) is receiver dryer 14) Fi expansion valve, f5
1ij cooler. In a closed-loop refrigeration cycle in which these are connected in series, the refrigerant that has been made high temperature and high pressure in the compressor (11) is converted to high pressure and low temperature in the condenser (2).

After eliminating pulsating flow with the register bag 3), it is expanded with the expansion valve (4) and heat is absorbed with the cooler (5).

However, in this configuration, as shown in FIG.

As the ON and OFF cycles occur, the air outlet temperature rises and falls, but since the air volume of the in-car proa is almost constant, the temperature inside the car also rises and falls with the ON/Oyν cycle, causing temperature fluctuations. Also, the shock at ON/077 was quite large and unpleasant for the driver.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and uses a coaxial two-cylinder compressor with different refrigerant displacement amounts for each cylinder, and connects on-off valves to the two suction sides. The purpose is to change the amount of refrigerant in stages by operating the system to achieve a cooling capacity of 9% commensurate with the heat load inside the vehicle.

An embodiment of the present invention will be described below with reference to the drawings. Third
The figure shows a compressor for an automobile air conditioner according to the present invention, which has a coaxial two-cylinder structure, has two inlets and one outlet, and has different cylinder displacements.・It is a piston type variable capacity compressor. FIG. 2 shows a refrigeration cycle of an air conditioner for an automobile according to the present invention.

(6) From the compressor shown in Fig. 8, the air flows through the condenser (2), receiver/dryer (0), expansion valve (4), and cooler (5) to the compressor. , the on-off valve connected to the suction pipe with the larger displacement of the cylinder is (7a), and the on-off valve connected to the suction pipe with the smaller displacement is shown as (7b).

In the refrigeration cycle configured as above, when the heat load inside the vehicle is high, both the on-off valves (71!L) (7b) are opened and the rated cooling capacity is produced, but the heat load inside the vehicle decreases. Create a circuit where *(7a) is t-open and *(7b) is closed to reduce the amount of refrigerant and cooling capacity slightly. When the heat load inside the vehicle further decreases, a circuit is created that closes ('a) and opens I (7b), further reducing the amount of refrigerant and lowering the cooling capacity. If the heat load inside the vehicle is lower than that, clutch ON * 0 IPIF control will be performed with (7a) closed and (7'b) open, but the refrigeration cycle will not be controlled (Fig. 4). By comparison,
077 The time will be longer and the shock will be less. Figure 5 shows the heat load inside the vehicle and the cooling capacity over time, and the cooling capacity can be controlled according to the heat load inside the vehicle.

As described above, according to the present invention, a rolling piston type variable capacity compressor is used, which has two inlets and one outlet due to the coaxial two-cylinder structure, and the displacement of the cylinders is different. When two on-off valves are connected to the opening and operated, the cooling capacity is controlled in four stages, reducing the cooling capacity to match the heat load inside the vehicle, and enabling low input and continuous operation of the compressor. compressor OIJ,
0FIF shock is also drastically reduced, and the temperature inside the car is kept constant, which has great effects, such as reducing the driver's discomfort.

[Brief explanation of drawings]

Fig. 1 is a refrigerant circuit diagram showing a conventional air conditioner for automobiles, and Fig. 2 is a diagram of the present invention! Fig. 3 is a diagram showing a rolling piston type variable capacity compressor; Fig. 4 is a diagram showing the conventional vehicle interior heat load and cooling capacity over time. Figure S is a characteristic diagram showing the relationship between the heat load inside the vehicle and the cooling capacity according to an embodiment of the present invention.In the figure, (1) is the compressor, (2) is the Fi condenser. , (3) is the receiver dryer, (4) is the expansion valve, (the powder is the cooler, (6) is the
) Fi milling piston variable capacity compressor 1 (7
a) and (7b) are on-off valves. In addition, in FIG. 9, the same reference numerals indicate the same or corresponding parts. Agent Makoto Kuzuno

Claims (1)

[Claims] A variable capacity compressor is used, which has a coaxial two-cylinder structure, has two suction ports and one discharge port, and has different cylinder displacements. A compressor, a condenser, a receiver/dryer, and two on-off valves are installed inside the engine compartment, and a cooler and expansion valve are installed inside the engine compartment, and each is connected to piping to form a refrigeration cycle, which runs the main engine of the car. For power sources, there are two on-off valves. Both open, one open, the other closed, vice versa, one closed,
Open the other and close both, in other words, clutch OFF.
An air conditioner for an automobile characterized in that the amount of refrigerant entering the compressor is changed in four stages by performing a stepwise operation, thereby producing a cooling capacity commensurate with the heat load in the vehicle interior.