JPS62166108A - Method and apparatus for controlling air conditioner for automobile - Google Patents

Abstract

PURPOSE:To provide comfortable humidity and temperature while saving power by providing a refrigerant flow controlling valve controlled by temperature and humidity in a compartment in a refrigerant flow path between an evaporator and a variable capacity compressor. CONSTITUTION:Humidity and temperature in a compartment are sensed respectively by sensors S1, S2 and sent to the input of a control unit 20 which generates the control signal output to an electromagnetic valve 3. For example, when the humidity and temperature are less than set values respectively, the electromagnetic valve 3 is closed. Thus, only a bypass pipe path 6 provides a refrigerant flow path, resulting in the pressure loss and the reduction of suction pressure of a variable capacity compressor 5. Thus, the small capacity compressor 5 can be provided to reduce the power consumption while the temperature of an evaporator 1 is raised to correct the humidity and temperature. The compressor is reversely operated when the humidity and temperature are raised. Thus, power can be saved and amenity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control method and device for an air conditioner for an automobile.

(Prior art and its problems) Conventionally, automotive air conditioners (hereinafter referred to as air conditioners) use variable capacity compressors that internally sense the suction pressure of refrigerant and automatically adjust the discharge capacity continuously. In the evaporator, the temperature of the evaporator was kept constant near the freezing temperature, and the air cooled here was then reheated by a heater, and the temperature was adjusted by the amount of reheating.

Therefore, although temperature control is possible, since the temperature of the evaporator is always near the freezing temperature, the amount of air dehumidification is always at its maximum, and as a result, the humidity inside the vehicle may drop too much, causing damage to the eyes and throat of the passengers. It was a stimulus to such things. Furthermore, even when dehumidification is not necessary, the inefficient operation of cooling the air by -degrees and then reheating it to adjust the temperature has been a problem.

(Object of the Invention) The present invention was made in view of the above-mentioned problems, and by providing a means for changing the temperature of the evaporator, it is possible to always obtain comfortable humidity and temperature, and to save power. It is an object of the present invention to provide a control method and device for an air conditioner for an automobile that enables efficient operation.

(Structure of the Invention) In order to achieve the above object, a first invention provides an automobile equipped with a variable capacity compressor that internally senses the suction pressure of refrigerant discharged from an evaporator and automatically adjusts its own discharge capacity. In the air conditioner for a car, a control valve capable of controlling the refrigerant flow rate is provided in the cold bag flow path between the evaporator and the compressor, and the control valve is electrically controlled according to the humidity and temperature conditions in the car, The second invention is configured to control the discharge capacity of the compressor, and the second invention includes a variable capacity compressor that internally senses the suction pressure of refrigerant discharged from the evaporator and automatically adjusts its own discharge capacity. In the air conditioner for a vehicle, the control valve is provided in a refrigerant flow path between the evaporator and the compressor to control the refrigerant flow rate, and a humidity sensor and a temperature sensor that detect the humidity and temperature in the vehicle interior. , and a control unit that electrically controls the control valve based on signals from the humidity sensor and the temperature sensor.

(Embodiment) Below, one embodiment of the present invention will be explained based on the drawings. Figure 1 shows the overall configuration of the present invention. 1b is an inlet 3 of a solenoid valve 3 (control valve) that opens and closes a refrigerant flow path via a pipe 2;
The outlet 3b of the solenoid valve 3 is connected to the suction port 5a of the compressor 5 via a conduit 4. Further, a bypass pipe 6 is provided between the pipe 2 and the pipe 4 to bypass the electromagnetic valve 3.

The compressor 5 is a so-called internal sensing type variable capacity compressor that internally senses the suction pressure of refrigerant gas and continuously and automatically adjusts the discharge capacity. Compressors with this configuration are well known, so details thereof will be explained below. is omitted.

The discharge port 5b of the compressor 5 is connected to the inlet 9a of the condenser 9 via a pipe 8, and the outlet 9b of the condenser 9 is connected to the inlet 11a of the receiver 11 via a pipe 10. An outlet 11b of the liquid receiver 11 is connected to an inlet 13a of a temperature-sensitive expansion valve 13 via a conduit 12.

An outlet 13b of the temperature-sensitive expansion valve 13 is connected to an inlet 1a of the evaporator 1 via a conduit 14. The temperature sensing portion 13c of the temperature-sensitive expansion valve 13 is disposed in contact with the outer peripheral surface of the conduit of the outlet 1b of the evaporator 1, and is connected to the main body of the expansion valve 13 via the conduit 13d.

The temperature-sensitive expansion valve 13 is configured to sense the degree of superheating of the refrigerant gas at the outlet 1b of the evaporator 1, and to control the flow rate of refrigerant flowing into the evaporator 1 by opening and closing to maintain the degree of superheat constant. ing.

In the air passage 16, a blower motor 17 is disposed on the upstream side of the evaporator 1, that is, on the outside air or inside air intake side 16a, and an air mix door 18 and a heater core 19 are disposed on the downstream side.

20 is a control unit to which a humidity setting device 21 and a vehicle interior humidity sensor S1 are connected in series, and a temperature setting device 22 and a vehicle interior temperature sensor S2. An outside air temperature sensor S19 and a solar radiation sensor S4 are connected in series. Further, an evaporator temperature sensor S0 and an acceleration switch 23 attached to an accelerator pedal or the like are connected to the control unit 20, and a reheat motor actuator 24 for opening and closing the air mix door 18 is also connected. The solenoid valve 3 is connected to a control unit 2o, and is configured to open and close the refrigerant flow path based on signals from the various sensors.

(effect) First, the humidity inside the car and the temperature inside the car are set.

When the vehicle temperature becomes lower than the temperature, the vehicle interior humidity sensor S1 and vehicle interior temperature sensor S2 detect this and send a signal to the control unit 20. Based on the signal, the control unit 20 sends a signal to close the solenoid valve 3. When the electromagnetic valve 3 is closed, the only refrigerant flow path is the bypass pipe 6, which causes a pressure loss and reduces the suction pressure of the compressor 5. Since the compressor 5 is a variable capacity compressor as described above, the capacity is reduced in order to maintain the suction pressure at the original pressure. Therefore, the power of the compressor 5 is reduced, and the pressure inside the evaporator 1 increases, so that the temperature of the evaporator 1 also increases. As a result, the amount of dehumidification and the amount of cooling in the evaporator 1 are reduced, and low humidity and low temperature inside the vehicle are improved. Note that in this case, the air mix door 18 is closed (in the direction indicated by the 'arrow' in the figure). That is, evaporator 1
This is because the humidity and temperature inside the vehicle are increased by increasing the temperature of the vehicle, so there is no need for reheating.

Next, if the humidity and temperature inside the vehicle become higher than the set values from this state, the evaporator temperature sensor S0. The in-vehicle humidity sensor S1 and the in-vehicle temperature sensor S2 detect this, and the solenoid valve 3 is opened via the control unit 20. As a result, the suction pressure of the compressor S increases and the capacity increases, so the pressure and temperature of the evaporator 1 decreases, and dehumidification and cooling are performed.

Note that when the humidity in the vehicle interior is high and the temperature is low, the electromagnetic valve 3 is opened to lower the temperature of the evaporator 1, and the air mix door 18 is opened by the motor actuator 24 (in the direction of arrow B in the figure).

As a result, after being sufficiently dehumidified and cooled in the evaporator 1, it is reheated in the heater core 19 to raise the temperature.

As described above, the opening/closing of the electromagnetic valve 3 and the opening/closing of the air mix door 18 are controlled according to the humidity and temperature conditions in the vehicle interior, so that the humidity and temperature in the vehicle interior are automatically adjusted to maintain a comfortable level at all times. .

Note that when the acceleration switch 23 attached to the accelerator pedal or the like is activated, the solenoid valve 3 becomes idle and the capacity of the compressor 5 is reduced, thereby improving the acceleration of the vehicle by saving power. I can do it. In addition, if an economy switch is provided in parallel or independently with this acceleration switch 23, 1. By operating it from the driver's seat, it is possible to obtain the same effects as the acceleration switch 23 (power saving, fuel saving).

Furthermore, a water temperature switch for detecting the temperature of the engine cooling water is provided in parallel with or independently of the acceleration switch, and when the water temperature rises, the water temperature switch operates to close the solenoid valve 3, thereby reducing the capacity of the compressor 5. If this is done, the amount of heat dissipated by the condenser 9 is reduced, and the amount of heat exchanged by the radiator increases accordingly, making it possible to lower the temperature of the engine cooling water.

(Effects of the Invention) As explained above, the first invention provides an automotive air compressor equipped with a variable capacity compressor that internally knows the suction pressure of refrigerant discharged from an evaporator and automatically adjusts its own discharge capacity. In the conditioning system, a control valve capable of controlling the refrigerant flow rate is provided in the refrigerant flow path between the evaporator and the compressor, and the control valve is electrically controlled according to the humidity and temperature conditions inside the vehicle, thereby controlling the compression. The second invention is a variable capacity compressor for automobiles which internally senses the suction pressure of refrigerant discharged from an evaporator and automatically adjusts its own discharge capacity. In the air conditioner, a control valve provided in a refrigerant flow path between the evaporator and the compressor to control the refrigerant flow rate, a humidity sensor and a temperature sensor that detect the humidity and temperature in the vehicle interior, and the humidity sensor. Since the configuration includes a sensor and a control unit that electrically controls the control valve based on a signal from the temperature sensor, the cooling capacity of the evaporator can be adjusted by controlling the discharge capacity of the compressor. .

Therefore, the problem of excessive dehumidification is eliminated, and the desired comfortable humidity and temperature can always be obtained, and the inefficient operation of once cooling and then reheating to adjust the temperature is improved, saving power and fuel consumption. can be achieved.

[Brief explanation of drawings]

The figure is an overall configuration diagram showing an embodiment of the present invention. 1... Evaporator, 3... Solenoid valve (control valve), 5...
Variable capacity compressor, 6... Bypass pipe line, 20... Control unit, So... In-vehicle humidity sensor, S2...
・In-vehicle temperature sensor.

Claims (2)

[Claims] 1. In an automotive air conditioner equipped with a variable capacity compressor that internally senses the suction pressure of refrigerant discharged from an evaporator and automatically adjusts its own discharge capacity, a refrigerant flow path between the evaporator and the compressor. A control valve capable of controlling the flow rate of refrigerant is provided in the vehicle, and the control valve is electrically controlled according to the humidity and temperature conditions inside the vehicle, thereby controlling the discharge capacity of the compressor. How to control an air conditioner. 2. In an automotive air conditioner equipped with a variable capacity compressor that internally senses the suction pressure of refrigerant discharged from an evaporator and automatically adjusts its own discharge capacity, a refrigerant flow path between the evaporator and the compressor. a control valve provided to control the flow rate of refrigerant; a humidity sensor and a temperature sensor that detect humidity and temperature inside the vehicle; and a control that electrically controls the control valve based on signals from the humidity sensor and temperature sensor. A control device for an air conditioner for an automobile, characterized by comprising a unit.