JPS6241135B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for controlling the capacity of a vehicle cooler.

Conventional car air conditioner temperature control methods are mainly based on the reheat air mix type, which changes the temperature of the air blown into the car by appropriately mixing cold air from the cooler and warm air from the heater, and the reheat air mix type, which changes the temperature of the air blown into the car by appropriately mixing cold air from the cooler and warm air from the heater. It is broadly classified into the blowout thermo type, which maintains a constant temperature of the air blown into the car by turning the compressor on and off.

However, first of all, the reheat air mix type allows automatic room temperature adjustment by automatically operating a damper that mixes cold air and hot air, but since the compressor is always in operation, the amount of heat reheated by the heater is lost during light loads. , there is a lot of waste in terms of power saving and fuel consumption reduction of the vehicle, and the following blowout thermo type does not change the room temperature when the heat load such as outside temperature or solar radiation changes, causing discomfort to the passengers. There are disadvantages such as the trouble of manually changing the blowout temperature setting value and the waste of power consumption of the air conditioner due to overcooling operation.

The present invention was proposed in view of the above circumstances, and an object of the present invention is to provide a method for controlling the capacity of a vehicle cooler that maintains a comfortable room temperature and reduces power consumption. Each room temperature is detected, the temperature of the blowing air is calculated to maintain the room temperature at the set value, the operating rate of the compressor is calculated based on the calculated value of the blowing air temperature, and the rotation speed of the compressor is detected. The present invention is characterized in that the operating rate of the compressor is corrected based on the detected value of the compressor rotational speed, and the compressor is controlled on/off based on the corrected operating rate of the compressor. Here, the operating rate of the compressor is defined as follows.

Compressor operation rate=compressor operation time/compressor operation time+compressor stop time One embodiment of the apparatus used to carry out the method of the present invention will be explained with reference to the drawings. The figure is a block diagram showing the control circuit of Fig. 1, Fig. 3 is a characteristic diagram of the function generator 20 showing the relationship between the difference between the outside temperature and the room temperature set value and the amount of change in the temperature of the blown air, and Fig. 4 is the characteristic diagram of the engine. A characteristic diagram of the function generator 22 showing the relationship between the rotation speed and the compressor operating rate, FIG. FIG. 3 is a characteristic diagram of the pulse generator 27 showing the relationship between the operating rate and the operating time and stop time of the compressor.

First, in FIG. 1, 1 is a vehicle, 2 is a compressor driven by the engine, 3 is a magnetic clutch having an excitation coil 4, 5 is a capacitor, 6 is a receiver tank, 7 is an expansion valve, 8 is an evaporator, 9 1 is a ventilation fan, 10 is a room temperature detector, 11 is a solar radiation detector, 12 is an external temperature detector, 1
3 is an engine rotation speed detector; 14 is a relay that excites the magnetic clutch 3; and 15 is a control device that inputs the outputs of various detectors to control the shutdown rate of the compressor 2. Next, in Figure 2,
16 is a room temperature setter; 17 is a subtracter that subtracts the respective outputs of the room temperature detector 10 and the room temperature setter 16;
8 is a coefficient unit that multiplies the output of the subtracter 17 by a coefficient; 19
20 is a subtractor that subtracts the outputs of the external temperature detector 12 and the room temperature setting device 16, and 20 is a function generator that relates the output of the subtractor 19 to the amount of change in the temperature of the blown air. The amount of change in outlet air temperature ΔTma for the input of the difference ΔTa between temperature and room temperature set value
By outputting , the amount of change in temperature of the blown air required to maintain a constant room temperature when the outside temperature changes is output. 21 is a coefficient generator that multiplies the output of the solar radiation amount detector 11 by a coefficient and relates this to the amount of change in the temperature of the blown air; 22 is a function generator that correlates the output of the engine rotation speed detector 13 with a correction value of the compressor operating rate; As shown in FIG. 4, the amount of change ΔP in the operating rate of the compressor is output in response to the input of the rotation speed N of the compressor. This amount of change △P prevents the cooling capacity of the cooler from changing due to changes in engine speed by changing the operating rate of the compressor. Thus, the cooling capacity is maintained at a predetermined value, and the room temperature is maintained constant. 23 is an adder, 2
4 is a subtracter that subtracts the output of the adder 23 from the output of the room temperature setting device 16, and its output 28 is the evaporator 8 necessary to keep the room temperature constant according to the heat load.
Indicates the temperature setting value of the air blown from. Reference numeral 25 denotes a function generator that associates the outlet air temperature setting value 28 with the operating rate setting value 29 of the compressor 2. As shown in FIG.
By outputting the compressor operation rate P, the compressor operation rate corresponding to the discharge air temperature set value 28 calculated from the outputs of the various detectors 10, 11, and 12 is output. 26 is a subtracter; 27 is a subtracter 26 which generates a pulse with an appropriate on/off time ratio;
With a pulse generator that excites
The shorter duration of the start/stop pulses is set to a certain short time (20 to 30 seconds), and the longer duration is set according to the compressor operation rate setting. It has the function of changing.

In such a device, (1) First, when the external temperature rises, the external temperature detector 12
Since the output of the room temperature setting device 16 does not change, the output of the subtractor 19 also increases, and as shown in FIG. Since the output increases, the output of the subtractor 24, that is, the blowout air temperature set value 28 decreases. As a result, the output 29 of the function generator 25, that is, the compressor operation rate P
increases, as shown in FIG.

At that time, there is no change in engine speed, so
The output of the function generator 22 remains unchanged, and the output of the subtracter 26
The output of the pulse generator 27 increases as the output of the function generator 25 increases.
As shown in the figure, a pulse is generated that increases the operating time ratio of the compressor.

The output change of the pulse generator 27 is caused by the relay 1
4. Since the operating rate of the compressor 2 is increased via the clutch 3 and the cooling capacity is increased, the rise in room temperature is suppressed despite the increase in heat load due to the rise in outside temperature.

When the outside temperature decreases, contrary to the above, the operating rate of the compressor decreases and the cooling capacity decreases, so that the decrease in room temperature is suppressed.

(2) Next, when the amount of solar radiation increases, the output of the solar radiation amount detector 11 increases, which causes the coefficient unit 21 to increase.
The output of the compressor increases, and the operating rate of the compressor increases due to the same effect as in case (1) above.
By increasing the cooling capacity, the rise in room temperature can be suppressed despite the increase in heat load.

When the amount of solar radiation decreases, contrary to the above, the cooling capacity decreases, so the drop in room temperature is suppressed.

(3) When the engine speed increases, the output of the engine speed detector 13 increases, and therefore the output of the function generator 22 increases as shown in FIG. At this time, since the output 29 of the function generator 25 does not change, the output of the subtracter 26 decreases, and the output of the pulse generator 27 changes so that the compressor stop time becomes longer.

When the engine speed increases, the compressor speed also increases, so the cooling capacity increases. However, due to the above action, the compressor operating rate decreases, so in the end, the cooling capacity remains almost unchanged and changes in room temperature are suppressed. It will be done.

Even when the engine speed decreases, the compressor operating rate increases due to the same effect as described above, and the change in cooling capacity is also suppressed.

(4) To explain the case where the compressor operation rate is controlled by detecting the room temperature, when the room temperature is higher than the room temperature set value, the output of the room temperature detector 10 is larger than the output of the room temperature setting device 16, so the subtractor 17
The output of is positive, which is multiplied by a factor in the coefficient multiplier 18, and the output of the adder 23 increases by this amount. Therefore, with the same effect as in (1) above,
The operating rate of the compressor 2 increases, the cooling capacity increases, and the room temperature decreases and approaches the set value. The same effect occurs when the room temperature is lower than the set value.
The cooling capacity will decrease and the room temperature will approach the set value.

As a result of the actions (1), (2), (3), and (4) described above, the room temperature will be maintained at the set value with high accuracy even if the heat load and vehicle speed change. According to this device, the following effects are achieved.

(1) In terms of power savings, the reduction in heat load and increase in vehicle speed increase cooling capacity, and the compressor stop time increases, so the power required for vehicle air conditioning is reduced, resulting in power savings throughout the year. The effect is great.

(2) In terms of improving comfort and operability, the room temperature is automatically maintained at the set value, improving comfort and eliminating the hassle of operation. As shown in FIG. 6, that is, the characteristic diagram of the pulse generator 27,
Since the shorter time period of operation and stop is kept to a certain short time (20 to 30 seconds), the temperature fluctuation of the blown air is kept small and no discomfort is felt.

(3) The control device 15 is composed of many parts, but by replacing these with digital calculation programs using a microcomputer, it is possible to reduce the number of parts, make it smaller and lighter, and lower costs. can.

In short, according to the present invention, the outside temperature, the amount of solar radiation, and the room temperature are each detected, the blowing air temperature is calculated to maintain the room temperature at the set value, and the compressor is operated based on the calculated value of the blowing air temperature. In addition to calculating the ratio, it also detects the compressor rotation speed,
The operating rate of the compressor is corrected based on the detected value of the compressor rotation speed, and the compressor is controlled on/off based on the corrected compressor operating rate, thereby maintaining a comfortable room temperature and reducing power consumption. The present invention is industrially extremely useful because it provides a method for controlling the capacity of a vehicle cooler.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an embodiment of the apparatus used to carry out the method of the present invention, Fig. 2 is a block diagram showing the control circuit of Fig. 1, and Fig. 3 is an external temperature and room temperature set value. Fig. 4 is a characteristic diagram of the function generator 20 showing the relationship between the difference between FIG. 6 is a characteristic diagram of the function generator 25 showing the relationship between the air temperature setting value and the compressor operating rate, and FIG. 6 is a characteristic diagram of the pulse generator 27 showing the relationship between the compressor operating rate and the operating time and stop time of the compressor. DESCRIPTION OF SYMBOLS 1... Vehicle, 2... Compressor, 3... Magnetic clutch, 4... Excitation coil, 5... Capacitor, 6... Receiver tank, 7... Expansion valve,
8...Evaporator, 9...Blower fan, 10
...Room temperature detector, 11...Solar radiation detector, 12...
...External temperature detector, 13...Engine rotation speed detector,
14...Relay, 15...Control device, 16...Room temperature setter, 17...Subtractor, 18...Coefficient unit, 1
9...Subtractor, 20...Function generator, 21...Coefficient generator, 22...Function generator, 23...Adder, 2
4...Subtractor, 25...Function generator, 26...Subtractor, 27...Pulse generator, 28...Subtractor 2
4 output, 29... Operating rate setting value.

Claims (1)

[Claims] 1 Detects the outside temperature, solar radiation, and room temperature, calculates the blowout air temperature to maintain the room temperature at the set value, calculates the compressor operating rate based on the calculated blowout air temperature, and calculates the compressor operating rate. A vehicle for use in a vehicle, characterized in that the number of revolutions is detected, the operating rate of the compressor is corrected based on the detected value of the compressor number of revolutions, and the compressor is controlled to be on/off based on the corrected operating rate of the compressor. Cooler capacity control method.