JPS604004B2 - Control method for vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of controlling an air conditioner for a car, particularly to controlling a blower.

Conventionally, as shown in FIG. 1, an air conditioner for a car has a blower 1 that introduces air from inside and outside the car, a cooler 2 consisting of an evaporator that cools the air from the blower 1, and a cooler 2 downstream of the cooler 2. It is equipped with a heater 3 located on the side, and an air mix door 4 located in front of the heater 3 to adjust the mixture of cold air and waist air.

The air mix door 4 has a relationship 8 adjusted by an actuator 5, and a transducer 6 that controls the actuator 5 adjusts the negative pressure from the negative pressure source 8 to the actuator 5 depending on the magnitude of the output E of the control circuit 7. , the suction amount of the rod 52 is adjusted against the compression springs 5 and 5. The control circuit 7 is based on the comparison value W between the signal S from the outside air temperature detection sensor, the inside air temperature detection sensor, etc., which is a temperature detection section, and the signal S2 from the cabin temperature setting section, as shown in FIG. 2c. The characteristic output E is sent out, and the opening degree of the air mix door 4 is set to 8.
Adjust. On the other hand, a power supply voltage is supplied to the blower 1 via an air volume control section 9, and the resistance value of the air volume control section 9 is varied by movement of the actuator 5. That is, when the outside temperature is high, such as in summer, the coefficient a of the door 4 becomes 0 (full cooler mode) as shown in FIG.
The rotational speed of the blower 1 becomes maximum as shown in FIG. 2b. Here, when the vehicle room temperature falls to a predetermined value, the function 8 of the door 4 gradually increases, and following this, the rotation speed R of the blower 1 decreases, and when a reaches an approximately intermediate position, the rotation speed R becomes low. Become. 8 becomes even larger from this position, opening degree 8
When becomes maximum (full heater mode), the rotation speed R becomes high again. That is, when the outside temperature is high, such as in summer, the output E from the control circuit 7 initially sets the full cooler mode so that the opening degree 8 becomes 0, and the blower 1 is operated at high speed accordingly. When the vehicle room temperature drops to a certain value, the control circuit 7 sends an output E to raise the vehicle room temperature higher than when the vehicle is fully cooled, and the mix door 4 and the blower 1 start operating at the same time. However, when the conventional control circuit 7 sends out the output E to raise the vehicle room temperature higher than when the vehicle is fully cooled, the mix door 4 immediately
During this time, the cold air that has been cooled uniformly by the cooler 2 is heated by the heater 3, creating a vicious cycle, which adds an unreasonable load to the cooling cycle that drives the cooler 2, and also reduces the blowout temperature. Changes become rapid.

The present invention inputs signals from at least a blower, an air mix door that adjusts the mixing ratio of cold air and warm air, a vehicle interior temperature setting section, and a temperature detection section, and adjusts the air mix door to the maximum level in accordance with the magnitude of the input. In an air conditioner for a car cocoon, the control circuit has a control circuit that controls from the cooling opening to the heating opening and also continuously controls the rotation speed of the entrusted fan from the maximum rotation speed to the low rotation speed. The air mix door is held at the maximum cooling opening until the rotation speed of the blower decreases from the maximum rotation speed and reaches a predetermined rotation speed. This method prevents undue stress from being applied to the cooling cycle and gradually reduces the temperature change of the air outlet temperature, thereby eliminating discomfort for the occupants.This will be explained in detail below using examples. do.

FIG. 3 is a block diagram showing an embodiment of the control method for an air conditioner for a vehicle according to the present invention. In the figure, 10 indicates a signal S. This circuit 10 is a control circuit that sends out an output having the characteristics shown in FIG.
A signal is sent to the air mix door control actuator 12 via the transducer 11 whose operating level is set to E2, and a signal is sent to the blower 1 via the drive circuit 13 whose operating level is set to E. Sent out.

In the above configuration, when the outside temperature is high such as in summer as shown in FIG. However, when the vehicle temperature decreases, the comparison value W between the signals S and S2 changes, and the output E of the control circuit 10 becomes larger. (increasing command signal).

As a result, the drive circuit 13 is operated to reduce the rotational speed of the blower 1. This reduction in the rotational speed of the blower 1 provides a certain degree of temperature increase effect based on the load. Since the airmic door 4 is not opened at this stage, it is possible to eliminate the unreasonable situation in which the cold air cooled by the cooler 2 is heated by the heater 3, and the load on the cooling cycle of the cooling chamber 2 can be reduced. Since the wind does not suddenly blow out from the waist, changes in the temperature of the car's room temperature can be alleviated. Next, when the car room temperature further decreases and the output of the control circuit 10 reaches E2, the transducer 11 starts operating and the air mix door 4 is gradually opened, so that the cold air is partially heated by the heater 3, causing the car room temperature to rise. will be carried out. Note that at this stage, the rotational speed of the blower 1 is low to some extent, so the heating rate of the cold air is small, so that the negative impact of the cooling cycle of the cooler 2 can be further reduced, and the level difference in the temperature change of the air outlet can be reduced. At this time, the air volume by the blower is 80%
It is desirable to control the air mix door only after the air leakage level has decreased. As explained above, according to the present invention, in an air conditioner including at least an air blower and an air mix door that controls the mixing ratio of cold air and waist air, the air mix door is set to supply the maximum ratio of cold air. Due to the current situation, when driving the air mix door to increase the air flow rate, the number of revolutions of the blower must be reduced beforehand. This makes it possible to reduce the burden on the cooling cycle of the cooler, and also to slow down the temperature change in the air outlet temperature, which can cause the inconvenience of suddenly blowing air from the full cooler mode. can be resolved.

In addition, the blower changes continuously from the maximum rotation speed to the low rotation speed, and this change is a change that maintains the temperature inside the vehicle constant, which improves the feeling of the passengers and also reduces the amount of air blown out. There is no sudden change and the feeling of cooling is not impaired.

[Brief explanation of the drawing]

FIG. 1 is a simplified configuration diagram showing an example of a conventional air conditioner;
Figures 2a, b, c, d, and e are diagrams showing the operating characteristics of the air mix door and the blower with respect to the output of the control circuit, and Figure 3 is a block diagram showing an embodiment of the method for controlling an air conditioner according to the present invention. be. 1...Blower, 2...Cooler, 3...Heater, 4
...air mix door, 10...control circuit, 1 1
...Transducer, 12... Actuator, 13
...Drive circuit. Figure 2 Figure 3 Figure 1

Claims (1)

[Claims] 1. Input signals from at least the blower, the air mix door that adjusts the mixing ratio of cold air and warm air, the cabin temperature setting section, and the temperature detection section, and adjust the air mix door from the maximum cooling opening depending on the magnitude of this input. In a vehicle air conditioner having a control circuit that controls the rotation speed of the blower in the heating opening direction and continuously controls the rotation speed of the blower from the maximum rotation speed to the low speed rotation direction, the control circuit controls the rotation speed of the blower to the maximum rotation speed. The air mix door is held at the maximum cooling opening until it reaches a predetermined rotation speed, and at this time, the rotation speed of the blower is gradually decreased from the maximum rotation speed to maintain the vehicle room temperature at a constant temperature. A method for controlling a vehicle air conditioner, characterized in that: