JPS6230931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a car air conditioner, and particularly to a control device having an automatic temperature control function. Regarding control.

Conventionally, car air conditioner control devices that have an automatic airflow adjustment function change the voltage applied to the blower motor using a resistor group or variable resistor that is linked one-to-one with the position of an automatically moving temperature adjustment member. It is common practice to adjust the air volume. Further, Japanese Utility Model Publication No. 48-38658 discloses that the rotational speed of a blower motor is changed by giving an output command value of an electric control circuit that commands the position of a temperature control member to a speed control circuit.

By the way, in order to make the temperature controllability of the car air conditioner more stable, it is necessary to change the heat exchange capacity of the heat exchanger installed in the ventilation duct (for example, start, stop, or stop the cooling compressor) even in a stable control state. Rotational speed fluctuations due to onboard engine,
In order to maintain a stable temperature of the required blown air, we compensate for the temperature fluctuations in the cooling water of the vehicle's engine, which is the heating heat source, and the temperature of the air outside the vehicle at that time. It is required to always correct the position of the temperature adjusting member so that the

However, if the conventional control method described above is followed, the amount of air blown is determined in conjunction with the position of the temperature adjustment member, so the amount of air blown changes each time the position of the temperature adjustment member is changed, so the air conditioning feeling The problem arises that it is bad.

In view of the above-mentioned problems, the present invention automatically calculates the required blowing air temperature necessary to maintain the vehicle interior temperature close to its target value according to the air conditioning conditions of the air temperature inside the vehicle interior and outside the vehicle interior. During control, the airflow volume corresponding to this required airflow temperature is calculated and used, and during manual control, the set desired airflow rate is used to improve the air conditioning feeling during both automatic and manual control, and the airflow volume is adjusted to the temperature. To provide a good car air conditioner control device that does not change due to the influence of the actual position of an adjustment member.

FIG. 3 illustrates the configuration of the present invention, which includes a ventilation duct A for sending air toward the vehicle interior, a blower motor B disposed within the ventilation duct to blow air, and the ventilation duct. a heating heat exchanger C and a cooling heat exchanger D disposed in A; and a temperature adjusting means E for adjusting the heating effect of the heating heat exchanger C and the cooling effect of the cooling heat exchanger D. , air conditioning condition detection means F for detecting air conditioning conditions from the air temperature inside the vehicle interior and the air temperature outside the vehicle interior; a first operating means H that adjusts the temperature adjusting means E in accordance with the necessary blowing air temperature and the capacity of the heat exchanger; Air volume setting means I that generates a desired air volume signal in response to a set desired air volume; and automatic air volume determining means J that calculates a blowout air volume in accordance with the required blowout air temperature and generates an automatic air volume signal.
and a manual/automatic switching means K for selecting between the desired air volume signal from the air volume setting means I and the automatic air volume signal from the automatic air volume determining means J, and the air volume selected by the manual/automatic switching means K. A second actuating means L for changing the power supplied to the blower motor B in response to a signal.

In the embodiment of the present invention described below, the main parts of the required blowout air temperature calculation means G, automatic air volume determination means J, and manual/automatic switching means K are realized by the calculation processing of a digital computer.

〔Example〕

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention. In this figure, reference numeral 1 denotes a ventilation duct placed in the front part of the vehicle interior 8, the upstream side of which is branched into an intake port for outside air and an intake port for interior air, and an inside/outside air switching damper (not shown). For example, it is manually switched to select between the intake state of air outside the vehicle interior and the intake state of air inside the vehicle interior. Reference numeral 3 denotes a blower motor, which is energized from an on-vehicle battery when a main switch (not shown) is turned on, and generates an air flow in the ventilation duct 1 from the inside/outside air switching damper 2 toward the passenger compartment 8.

4 is an evaporator as a cooling heat exchanger,
A compressor driven by an on-vehicle engine, an electromagnetic clutch, and other parts (not shown) form a known air cooling system to cool the air flow passing through the ventilation duct 1.

Reference numeral 5 denotes a heater as a heating heat exchanger, which circulates the cooling water of the vehicle engine as a heat source. The heater 5 occupies about half of the cross-sectional area of the ventilation duct 1, and the remaining portion is a bypass passage 6.

Reference numeral 7 denotes an air mix damper as a temperature regulating member, which changes the rate at which the air cooled by the evaporator 4 is reheated by the heater 5 and the rate at which it passes through the bypass passage 6 as it is. The temperature of the air blown into the vehicle compartment 8 is adjusted. The regulated blowing air is blown into the vehicle interior after its blowing direction is changed by an appropriate blowing outlet switching damper (not shown).

10 is a room temperature sensor that outputs an analog electric signal Tr' corresponding to the air temperature inside the vehicle interior 8; 11 is an outside temperature sensor that generates an analog electric signal Tam' that corresponds to the air temperature outside the vehicle interior; 12 is the vehicle interior 8; This is a solar radiation sensor that generates an analog electrical signal Ts' corresponding to the thermal radiation or light amount of solar radiation incident on the solar radiation sensor.

A temperature setting device 13 generates an analog electrical signal Tset' corresponding to the desired temperature set by the occupant. 14 is an air volume setting device, which outputs an analog electrical signal corresponding to the desired air volume manually set by the passenger.
produces W′.

The electrical signals generated by these sensors and setting devices are converted into binary code signals by an analog-to-digital conversion circuit 15.

Reference numeral 16 denotes a changeover switch for the blower motor, which is a manual switch and selects whether the state of adjustment of the air blown from the ventilation duct 1 is automatically controlled or according to the desired air volume set by the air volume setting device.

17 is a digital computer that centrally controls the air volume generated by the blower motor 3 and the position of the air mix damper 7. In the process of performing arithmetic processing according to the control program set in advance in the internal memory, the digital computer 17 Based on the input signal, a temperature control command signal to the air mix damper 7 and an applied voltage control command signal to the blower motor 3 are provided.

This digital computer consists of a so-called microcomputer, which includes a program memory (ROM) that stores an air conditioning control program, a central processing unit (CPU) that performs arithmetic processing according to the program, and various types of devices related to the CPU's arithmetic processing. The main components are a temporary memory (RAM) that can be written and read to temporarily store data, a timing circuit that generates a reference clock pulse for arithmetic processing with a crystal oscillator 17a, and an input/output circuit that adjusts input/output signals. One chip configured in
Consists of LSI (large scale integrated circuit).

Reference numeral 19 denotes a position adjustment actuator for the air mix damper 7, which is composed of an electro-mechanical converter, and works in cooperation with the damper drive circuit 18 to adjust the position of the air mix damper 7 in response to a temperature control command signal from the digital computer 19. Change position. Damper drive circuit 18
For example, a digital-to-analog conversion circuit that converts a digital control command signal indicating the target position of the air mix damper 7 from the digital computer 19 into an analog electrical signal, and the converted analog electrical signal and the downstream part of the ventilation duct 1. and a comparison circuit that generates a damper position increase/decrease signal corresponding to the comparison result with an analog electric signal indicative of the phenomenon blowing temperature from the temperature detector 18a disposed at the temperature sensor 18a.

Reference numeral 20 denotes a blower motor drive circuit that changes the voltage applied to the blower motor in response to an air volume control command signal from the digital computer 19. The blower motor drive circuit is a digital control command signal that converts a digital control command signal indicating a target air volume from the digital computer 19 into an analog electrical signal.
It consists of an analog conversion circuit and a power amplification circuit that amplifies the converted analog electrical signal and applies it to the blower motor.

FIG. 2 shows a control program for arithmetic processing in the digital computer 19. When the main switch is turned on, the digital computer 19 is supplied with power from the on-board battery via a stabilized power supply circuit (not shown), and repeats the arithmetic processing shown in the figure at a cycle of several hundred milliseconds. It should be noted that the figure shows only the parts from step 101 to step 107, which are related to the main points of the present invention, and the rest are omitted.

The control program includes a signal input step 101 that receives signals from each input device. In this signal input step 101, each detection signal of the sensors 10 to 12 converted into a binary code signal by the analog-to-digital conversion circuit 15 and the setting device 13,
14 setting signal is stored in a predetermined location of RAM, and the setting signal from changeover switch 16 is stored.
Store in a specified location in RAM.

In the next calculation step 102, based on the data indicating the environmental conditions in the vehicle interior 8, the airflow from the ventilation duct 1 necessary to maintain the temperature in the vehicle interior close to the set target temperature is determined. The temperature of Ta ₀
Calculate. This calculation is done according to the following equation using experimentally measured constants.

Ta ₀ = Kset×Tset−Kr×Tr −Kam×Tam−Ks×Ts+C However, Tset, Tr, Tam, and Ts are sensor 10,
11, 12 and the value obtained from the setting device 13,
Kset, Kr, Kam, Ks, and C are predetermined constants.

In the next calculation step 103, the necessary position SW of the air mix damper 7 is calculated in order to actually obtain the necessary blowout air temperature Ta ₀ calculated in the calculation step 102 from the ventilation duct 1. This calculation is performed using the following equation, assuming that the actual heat exchange capacity of the evaporator 4 and heater 5, which are heat exchangers, is constant.

SW=(Ta ₀ −Ca)/(Cw−Ca−Co)×D However, Ca and Cw are the fictive temperatures of the evaporator 4 and the heater 5, respectively, and Co and D are predetermined constants.

In the next output step 104, a position control command signal indicating the control target position SW of the air mix damper 7 calculated in the calculation step 103 is given to the damper drive circuit 18.

Note that steps 102, 103, 104 above
For details, refer to JP-A-55-77659.

In the next determination step 105, changeover switch 1
The signal No. 6 is checked from the stored value in the RAM, and it is determined whether manual setting of the air volume is desired.
If you would like to make manual settings based on the judgment results,
Next, the process jumps to replacement step 107. Otherwise, the next air volume calculation step 106 is executed.

In the air volume calculation step 106, the amount of blown air, that is, the air volume, is calculated in accordance with the calculated value of the required blown air temperature Ta ₀ using a predetermined functional formula. Through this calculation, the value Wout of the control air volume is obtained, which is minimum in the intermediate region of the required blowing air temperature Ta ₀ and gradually increases as it goes to the low temperature and high temperature regions. In addition,
ROM can also be used as a data table instead of functional calculations.

On the other hand, in the case of manual setting, in a replacement step 107, the set air volume given by the air volume setting device 14 is replaced as is with the control air volume value Wout.

Air volume value obtained in step 106 or 107
Wout is output as a control command to the blower drive circuit 20 in the next output step 108.

Next, other appropriate program routines 109 described above are executed, and then the program routines previously described are executed again.

The program steps described above are executed repeatedly, and when the environmental conditions of the vehicle interior 8 change, the position of the air mix damper 7 is adjusted accordingly, and the temperature of the air blown into the vehicle interior is appropriately changed. The actual temperature inside the vehicle is maintained at the target temperature. Here, the position of the air mix damper corresponds to a control command from the computer, but since it is corrected by the damper drive circuit 18 in response to the temperature detected by the temperature sensor 18a, the actual blowout temperature is determined in the calculation step 102. It is controlled to almost match the calculated value. On the other hand, the air volume generated by the blower motor 3 is determined in accordance with the calculated required air temperature Ta ₀ in order to almost match the actual temperature of the air blown into the vehicle interior, so the air volume generated by the blower motor 3 is determined based on the operating state of the car air conditioner. Accurate air volume control can be achieved.

Note that when implementing the present invention, as an air volume control method, an air volume sensor may be provided in the ventilation duct 1, and feedback control may be used in which the voltage applied to the blower motor is adjusted so that the detected value matches the control air volume value. .

Further, the air volume-temperature characteristics in calculation step 106 can be changed as necessary.

Further, the correction function in the damper drive circuit 19 may be executed by the computer 17 as disclosed in Japanese Patent Laid-Open No. 77659/1983.

As described above, according to the present invention, the air volume can be switched between automatic and manual, and in automatic control, the appropriate air volume can be automatically controlled in accordance with the required air temperature calculated from the air conditioning conditions. Since the air volume can be controlled based on the actual air conditioning conditions, it is possible to achieve air volume control that accurately corresponds to the air conditioning conditions. Moreover, since the amount of air blown out is calculated in accordance with the above-mentioned required air temperature, it is possible to obtain a comfortable air conditioning feeling without changing the air amount due to the actual position of the temperature control member. There is.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram showing one embodiment of the present invention, Fig. 2 is a flowchart for explaining the arithmetic processing of the digital computer in Fig. 1, and Fig. 3 is a division of the structure of the present invention into functions. FIG. 1... Ventilation duct, 3... Blower motor, 4... Evaporator as a cooling heat exchanger, 5... Heater as a heating heat exchanger, 7... Air mix damper for temperature adjustment, 14... Air setting device (air volume setting means) ),
16... Changeover switch (selection means), 17... Digital computer as control means, 19... Position adjustment actuator (first actuation means), 20... Blower motor drive circuit (second actuation means).

Claims (1)

[Scope of Claims] 1. A ventilation duct for sending air toward a vehicle interior, a blower motor disposed within the ventilation duct to blow air, and a heating heat exchanger disposed within the ventilation duct. a cooling heat exchanger; a temperature adjustment means for adjusting the heating effect of the heating heat exchanger and the cooling effect of the cooling heat exchanger; and air conditioning based on the air temperature inside the vehicle interior and the air temperature outside the vehicle interior. air conditioning condition detection means for detecting the condition; necessary blowout air temperature calculation means for calculating the necessary blowout air temperature necessary to maintain the vehicle interior temperature close to its target value according to the air conditioning condition; A first control unit that adjusts the temperature adjusting means in accordance with the temperature of the blown air and the capacity of the heat exchanger.
an air volume setting means for generating a desired air volume signal corresponding to the set desired air volume; and an automatic air volume determining means for generating an automatic air volume signal by calculating a blowing air volume in accordance with the required blowing air temperature; manual/automatic switching means for selecting the desired air volume signal from the air volume setting means and the automatic air volume signal from the automatic air volume determination means; A car air conditioner control device comprising: second actuating means for changing power supplied to a blower motor.