JPS6227443Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a vehicle air conditioner, and particularly to a control device that adjusts the operating level of a control device that controls on/off of a compressor and controls the opening degree of an air mixer door to save power.

Conventionally, as shown in Japanese Patent Laid-Open No. 51-27245, a compressor is known in which the compressor is not operated in the heater mode and the ventilate mode to save power.

However, when the compressor is stopped in the heater mode as described above, the compressor cannot be driven when dehumidifying the interior of the vehicle, and therefore the inner surface of the window glass cannot be defogged. Additionally, if the compressor is stopped during the ventilate mode when the outside air changes from low to high temperatures, the compressor cannot be driven at all at this time, and therefore the cold air is not blown out, which impairs comfort. It had drawbacks.

The purpose of this invention is to provide a control device that compares the temperature on the evaporator side with a set level and stops the compressor when the temperature on the evaporator side drops to the set level, and increases the set level by a certain value. In this way, the rate at which the compressor is turned off is increased to save power and eliminate the problems caused by the compressor being completely stopped as in the past, and will be explained in detail below using examples. do.

FIG. 1 is a block diagram showing an embodiment of a control device for a vehicle air conditioner according to the present invention. In the figure, 1 is an arithmetic circuit, which is a temperature setting device provided on a temperature control panel (not shown). A signal corresponding to the set temperature TD of 2, a signal corresponding to the vehicle interior temperature tr detected by the vehicle interior temperature sensor 3, a signal corresponding to the outside air temperature ta detected by the outside air sensor 4, and a signal corresponding to the outside air temperature ta detected by the outside air sensor 5. A total signal T is calculated by calculating a signal corresponding to the detected solar radiation temperature ts. This total signal T is expressed as, for example, T=-TD+(tr+ta+ts), and is inversely proportional to the vehicle interior temperature TD, and increases as the temperature TD decreases, and the vehicle interior temperature tr,
It is proportional to the outside air temperature ta and the solar radiation temperature ts, and decreases as the temperature decreases.
The output signal corresponding to the total signal T of the arithmetic circuit 1 is sent to the air mix door control circuit 7 via an adder 6.
The air mix door control circuit 7 controls the actuator 9 for controlling the opening degree θ of the air mix door 8. Further, an output signal corresponding to the total signal T from the arithmetic circuit 1 is supplied to a compressor control circuit 11 via a subtracter 10.
A compressor control circuit 11 turns on and off an electromagnetic clutch 14 which controls a compressor 13 via a switch circuit 12. The above switch circuit 12
is controlled by the controller 15, and the controller 1
5 detects the difference S between the signal corresponding to the set temperature TD from the temperature setting device 2 and the signal corresponding to the vehicle interior temperature tr from the sensor 3, and when this difference S is smaller than the set value P, the switch is activated. The circuit 12 is turned off to stop the compressor, and when it is larger than the set value Q, the switch circuit 12 is turned on to put the compressor in the on mode. However, P<Q.

The air mix door control circuit 7 controls the opening degree θ of the air mix door 8 to a small value, as shown by characteristic F in FIG. As a result, the air mix door 8 is controlled from the heater mode to the cooler mode, so that the mixing ratio of cold air from the evaporator side to the warm air from the heater core is increased. As shown in FIG. 2b, the compressor control circuit 11 compares the signal from the sensor 16 that detects the temperature te on the evaporator side with a set level L1, and when the temperature te falls to the set level L1, an electromagnetic Turn off the clutch 14, stop the compressor 13, and set the set level L slightly higher than the set level L1.
When the above temperature te becomes higher than 2, compressor 1
Turn on 3 again. That is, such on/off control is performed. In this case, the set levels L1 and L2 in the compressor control circuit 11 are controlled so that their values gradually decrease as the total signal T gradually increases, and as a result, when the total signal T decreases, the compressor operating rate increases. The structure is designed to reduce power consumption and save power.

Reference numeral 17 denotes a controller driven by the economy switch 18, which outputs the signal TB to the adder 6 and outputs the signal TB to the air mix door control circuit 7 when the total signal T is within the range of set values m and n. Add this signal TB to signal T, and
This signal TB is sent to the subtracter 10 via the correction circuit 19.
Output. In this case, the signal TB is corrected by the correction circuit 19 to become the signal TC. This signal TC is subtracted from the total signal T supplied to the compressor control circuit 11 by the subtracter 10. That is, if, for example, a total signal TA is output to the air mix door control circuit 7, TA+TB is input to the air mix door control circuit 7 by the function of the adder 6, and TA+TB is input to the compressor control circuit 11 by the function of the subtractor 10. is TA−
TC is input. Here, the above set value m corresponds to the upper limit value θm of the air mix door opening in the intermediate region.The overall signal n corresponds to the lower limit value θm in the intermediate region.
This is a total signal corresponding to n. When the air mix door is set between the intermediate ranges θm to θn, a bilevel mode is set in which the mixing ratio of cold air and warm air is approximately equal.

The operation of the control device for a vehicle air conditioner with the above configuration will be explained using FIGS. 2 and 3.

If the economy switch 18 is currently on, the controller 17 determines the magnitude of the total signal T. Here, when the air mix door 8 is set to a bilevel mode in which the mixing ratio of cold air and warm air is set to be approximately equal, the total signal T is within the range of m and n, so the controller 1
Signal TB is output from 7. At this time, if the magnitude of the total signal T computed by the arithmetic circuit 1 is TA, the above signal TB is added to this total signal TA by the adder 3 and outputted to the air mix door control circuit 7, thereby controlling the air mix door. The opening degree θ of 8 is set smaller than θA by θB, and the air mix door 8 is slightly corrected to the cooler mode side. This slightly increases the mixing ratio of cold air. On the other hand, the signal TB is outputted from the controller 17 as the signal TC via the correction circuit 19, and this signal TC is supplied to the subtracter 10 to generate the total signal.
TA is subtracted by the signal TC and then supplied to the compressor control circuit 11. Therefore, the setting levels L1 and L2 of the compressor control circuit 11 are set to LA.
Since the compressor is raised from LB to LB, the operating rate of the compressor is reduced. In other words, the rate at which the compressor is turned off increases. By increasing the rate at which the compressor is turned off in this way, it is possible to save power. Further, since the mixing ratio of cold air is increased by the increase in the number of times the compressor is turned off, the temperature rise in the vehicle interior can be suppressed to some extent, and there is no risk of impairing comfort. In this embodiment, the difference S between the vehicle interior temperature tr and the set temperature TD is the set value P.
Since the compressor is stopped in the following cases, power saving can also be achieved. If the difference S is greater than or equal to Q, the compressor is set to the on mode, thereby making it possible to bring the temperature tr in the vehicle interior closer to the set temperature TD.

As explained above, according to the control device for a vehicle air conditioner according to the present invention, when the air mix door is set to an opening that controls the mixing ratio of cold air and warm air to be approximately equal, the opening of the air mix door is In addition to correcting towards cooler mode,
Since the operating rate of the compressor is lowered, it is possible to save power while maintaining comfort. Since the compressor is not completely stopped in the heater mode or the ventilate mode as in the conventional case, dehumidification can be achieved in the heater mode and there is no risk of impairing comfort in the ventilate mode.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a control device for a vehicle air conditioner according to the present invention;
FIG. 3 is a flow chart for explaining the operation of the control device for a vehicle air conditioner according to the present invention. 1: arithmetic circuit, 2: temperature setting device, 3: vehicle interior temperature sensor, 4: outside air sensor, 6: adder, 7: air mix door control circuit, 8: air mix door, 10: subtracter, 11: compressor control circuit, 12: switch circuit, 13:
5, 17...controller, 18...economy switch.

Claims (1)

[Scope of utility model registration request] By calculating at least the vehicle interior temperature and the set temperature of the temperature setting device, the calculation means for calculating the overall signal and the evaporator temperature detected by the temperature sensor installed near the evaporator are compared with the set level. a compressor control means that turns off the compressor when the temperature of the evaporator falls to a set level, turns on the compressor when the temperature exceeds the set level, and gradually lowers the set level as the overall signal increases; an air mix door control means for controlling the air mix door to increase the mixing ratio of cold air to warm air as the ratio of cold air to warm air increases; A correction means for reducing the operating rate of the compressor by increasing the set level by a certain percentage, and controlling the air mix door control means to correct the opening degree of the air mix door to an opening degree that increases the mixing ratio of cold air. A control device for a vehicle air conditioner.