JPS6229243B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a car air conditioner, and in particular, in a control device having an automatic temperature control function, a defroster function for preventing fogging of a window glass that partitions a vehicle interior from the outside. The present invention relates to a control device for a car air conditioner.

Conventionally, in car air conditioner control devices that have a function to automatically adjust the temperature inside the vehicle, the defroster function that blows warm air onto the window glass is generally operated manually by the passenger. In order to quickly eliminate fogging, that is, a decrease in transparency due to dew condensation or frost formation, the deflection damper that changes the direction of air blowing from the ventilation duct to the passenger compartment is set to the defroster blowout state, and the automatic temperature It was necessary to temporarily increase the adjustment target value manually.

In order to eliminate this inconvenience, Japanese Patent Application Laid-Open No. 18142/1983 discloses a method of detecting the state of defroster airflow and uniquely increasing the target value of automatic temperature control.

However, according to this conventional method, the temperature of the blown air increases simply by operating the defroster regardless of the air conditioning status, so if there is no active intention to defog the window glass, This causes a problem in that it disturbs the air conditioning feeling.

In view of the above points, the present invention has been developed to determine the environmental condition of the vehicle interior without raising the temperature of the blown air even when the air blowing direction is switched to the defroster blowing direction, To provide a comfortable control device for a car air conditioner that hardly disturbs the air conditioning feeling by increasing the temperature of blown air when the environment is in an environment where fogging is likely to occur.

In order to achieve the above object, the present invention, as shown in FIG. 3, includes a ventilation duct A for sending air toward the vehicle interior, and a blower motor for generating air flow toward the vehicle interior in this ventilation duct. B and
Cooling heat exchanger C arranged in the ventilation duct
and a heating heat exchanger D, a temperature adjusting means E for adjusting the amount of heat exchanged by the heating heat exchanger D, a deflecting means F for changing the direction of air blowing from the ventilation duct to the passenger compartment, and a desired temperature set by the occupant. A temperature setting device G, an inside temperature sensor H that generates a signal corresponding to the air temperature inside the vehicle interior, an outside temperature sensor I that generates a signal corresponding to the air temperature outside the vehicle interior, and a temperature set by the temperature setting device G. Necessary outlet air temperature calculation means J that calculates the necessary outlet air temperature based on the temperature signal and signals generated by the inside temperature sensor H and the outside temperature sensor I.
, a temperature adjustment operating means K that operates the temperature adjustment means E based on the required blowout air temperature, a switching means L that generates a defroster signal that switches the direction of air blowing into the passenger compartment to a defroster blowout, and a switching means L that responds to the defroster signal. deflection operating means for operating the deflection means F; and a deflection actuation means for operating the deflection means F when receiving the defroster signal, based on a signal from the outside temperature sensor, detecting the possibility that fogging will occur on a window glass that partitions the vehicle interior from the outside. a fogging determining means N for determining; and a blowing air temperature correcting means P for forcibly changing the necessary blowing air temperature upward when the fogging judging means N determines that there is a high possibility that fogging will occur on the window glass. Adopt technical means.

Embodiment FIG. 1 is an overall configuration diagram showing an embodiment of the present invention. In this figure, reference numeral 10 is a ventilation duct arranged at the front part of the vehicle interior, and the upstream side thereof is an intake port for airflow outside the vehicle interior and a ventilation duct located at the front part of the vehicle interior. It is branched into an indoor air intake port, and can be manually switched, for example, to select between the intake state of outside air and the intake state of air inside the vehicle by an inside/outside air switching damper (not shown). . Reference numeral 11 denotes a blower motor that generates an air flow toward the vehicle interior within the ventilation duct 10.

Reference numeral 12 denotes an evaporator as a cooling heat exchanger, which together with a compressor driven by the vehicle engine, an electromagnetic clutch, and other parts (not shown) constitutes a known air cooling device, and controls the airflow passing through the ventilation duct 10. Cooling.

Reference numeral 13 denotes a heater as a heating heat exchanger, which circulates the cooling water of the vehicle engine as a heat source.
The heater 13 occupies about half of the cross-sectional area of the ventilation duct 10, and the remaining portion is a bypass passage.

Reference numeral 14 denotes an air mix damper as a temperature regulating member, which changes the rate at which the air cooled by the evaporator 12 is reheated by the heater 13 and the rate at which it passes through the bypass passage as it is, so that the air is distributed from the ventilation duct 10 to the passenger compartment. Adjust the temperature of the air blown out.

Reference numeral 15 designates one of the blower outlet switching dampers, which selectively opens and closes the defroster outlet 16 and the heater and vent outlet 17 via the ducts 10a and 10b. The blown air whose temperature has been adjusted by the evaporator 12, the heater 13, and the air mix damper 14 is diverted to the blowing direction by the damper 15 and appropriate heater outlets and vent outlet switching dampers (not shown), and is directed into the passenger compartment. It's blown out.

18 is an inside temperature sensor that generates an analog electrical signal Tr' corresponding to the air temperature inside the vehicle; 19 is an outside temperature sensor that generates an analog electric signal Tam' that corresponds to the air temperature outside the vehicle; 20 is input to the vehicle interior 8. This is a solar radiation sensor that generates an analog electrical signal Ts' corresponding to solar thermal radiation or light intensity.

A temperature setting device 21 generates an analog electrical signal Tset' corresponding to the desired temperature set by the occupant. 22 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′. Both of these setting devices are composed of variable resistors, for example.

Electric signals generated by each of these sensors and setting devices are converted into binary code signals by an analog-to-digital conversion circuit 23.

Reference numeral 24 denotes a changeover switch that electrically commands the deflection state of the air outlet switching damper, which is a manual switch, and generates a command signal by the passenger's operation to at least set the air outlet to the defroster.

25 is a digital computer that controls the position of the air mix damper 14, as well as the blower motor 11 and the blower outlet switching damper 15 in response to operation commands from the occupant, according to a control program preset in the internal memory. In the process of performing calculation processing, a position control command signal for the air mix damper 14, an applied voltage control command signal for the blower motor 11, and an air outlet switching damper are generated based on input signals from each sensor and setting device. A position control command signal is given to 15.

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 27 denotes a position adjustment actuator for the air mix damper 14, which is composed of an electro-mechanical converter, and cooperates with the damper drive circuit 26 to adjust the position of the air mix damper 14 in response to a temperature control command signal from the digital computer 25. Change position. Damper drive circuit 2
6 is, for example, a digital-to-analog conversion circuit that converts a digital control command signal indicating the target position of the air mix damper 14 from the digital computer 25 into an analog electrical signal, and a circuit that converts the converted analog electrical signal and the downstream of the ventilation duct 10. It is configured to include a comparison circuit that compares the damper with an analog electrical signal indicating the actual blowing temperature from the temperature detector 26a disposed in the section, and generates a damper position increase/decrease signal corresponding to the result.

A blower motor drive circuit 28 changes the voltage applied to the blower motor 11 in response to an air volume control command signal from the digital computer 25. The blower motor drive circuit is a digital control signal that converts, for example, a digital control command signal indicating a target air volume from the digital computer 25 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.

Reference numeral 29 denotes a position adjustment actuator for the outlet switching damper 15, which is composed of an electro-mechanical converter, and is operated by the digital computer 25 in cooperation with the damper drive circuit 30.
The position of the damper 15 is changed in response to an air outlet opening/closing control command signal from the air outlet, and the defroster air outlet 16 and other air outlets 17 are selectively opened and closed. The damper drive circuit 30 is, for example, a digital computer 2.
It consists of a switching circuit that amplifies the on/off signal from 5.

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 an 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. The figure shows steps from step 101, which is related to the main points of the present invention, in car air conditioner control.
Only the part up to 110 is shown 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-digital conversion circuit 23 and the setting devices 13, 14 are input.
The setting signal from the changeover switch 24 is stored at a predetermined location in the RAM, and the setting signal from the changeover switch 24 is stored at a predetermined location in the RAM.

In the next calculation step 102, the air flow from the ventilation duct 10 necessary to maintain the temperature in the vehicle interior close to the set target temperature is determined based on data indicating the environmental conditions in the vehicle interior. Calculate temperature Tao. This calculation is done according to the following equation using experimentally measured constants.

Tao=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.

For details of the above calculation step 102, reference can be made to Japanese Patent Application Laid-open No. 77659/1983.

In the next determination step 103, the changeover switch 24
Check the stored value of the signal in the RAM to determine whether or not defroster blowing is desired. If the result of this determination is that defroster blowing is desired, then the processes from step 106 onwards are executed.

In the next determination step 106, the value of the outside temperature of the vehicle is used to predict whether or not the window glass will fog up.
It is checked whether Tam is lower than a predetermined reference value D1 (for example, 0°C). Furthermore, in this embodiment, it is additionally checked whether the set air volume value W is larger than a predetermined maximum air volume value Wmax.

As a result of the determination in steps 103, 106, and 107 above, defroster blowing is desired and the outside temperature of the vehicle is
When Tam is lower than a predetermined value and an air volume greater than or equal to the predetermined value is desired, it is determined that there is a high possibility that fogging will occur on the window glass.

Then, in step 108, a calculation step is performed.
The required blowout temperature value Tao calculated in step 102 is set to a predetermined reference value D2 (for example, the air mix damper 14
is set to the maximum value sufficient to completely close the bypass passage of the heater 13). As a result, the temperature of the air blown out from the defroster outlet 16 is fixed at a value higher than the temperature value normally calculated in calculation step 102.

On the other hand, if the result of the determination in steps 106 and 107 is that the vehicle outside temperature Tam is relatively high or the set air volume is relatively small, the temperature change process in step 108 is skipped.

Next, in step 109, the opening/closing command flag Sout of the air outlet switching damper 15 is set to a value (for example, "1") that indicates the defroster air. Note that when it is determined in determination step 103 that defroster blowing is not desired, the process jumps to step 105 and sets the opening/closing command flag Sout to a value other than defroster blowing (for example, "0").

Next, in step 110, each control data obtained through the above processing is applied to each output device. Here, the blower motor 11 generates an air flow according to the signal given by the air volume setting device 22, and the blower outlet switching damper 15
is opened and closed according to a signal given by the changeover switch 24. On the other hand, the air mix damper 14 adjusts the vehicle interior temperature to the value calculated in the calculation step 102 in order to follow the signal given by the room temperature setting device 21 under normal conditions.
The position is controlled based on Tao, and under the specific conditions described above, the position is controlled so that the temperature of the blown air is higher than that based on the temperature fixing process in step 108.

The program steps described above are executed repeatedly, and under normal conditions, when the environmental condition of the passenger compartment changes, the air mix damper 1 changes accordingly.
4 is adjusted to appropriately change the temperature of the air blown into the vehicle interior, thereby maintaining the actual vehicle interior temperature at the target temperature. Note that although the position of the air mix damper corresponds to the control command from the computer, it is corrected by the damper drive circuit 26 in accordance with the temperature detected by the temperature sensor 26a, so the actual blowout temperature is calculated at the calculation step 102. It is controlled to almost match the value calculated in . On the other hand, when the defroster is requested by the passenger, it is determined whether the outside temperature and the desired air volume are likely to cause fogging on the window glass, and the blown air temperature is increased only if fogging is likely to occur. As a result, fogging is quickly removed,
Or the occurrence of cloudy weather is prevented.

In addition, when implementing the present invention, the above-mentioned embodiment may be modified and implemented as described below.

(1) The comparison reference value D1 in step 106 can be selected from values ranging from minus several degrees to plus tens of degrees as necessary.

(2) In addition to the air volume manually set in step 107, if the device has an automatic air volume control function,
The automatically determined air volume value can be compared with a reference value.

(3) The comparison reference value in step 107 is the maximum value.
In addition to Wmax, intermediate values can be used.

(4) Comparing the air volume with the standard value as in (2) and (3) is useful in determining whether or not the occupants have a strong desire for the defroster to blow out.
As in the example above, this is also carried out to prevent frost from forming on window glass (steps
(See explanation of constants in steps 106, 107, and 108) In addition, if the present invention is implemented solely for the purpose of preventing condensation (the constants in steps 106 and 108 may be relaxed compared to those exemplified in the above embodiment), the air volume The determination may be omitted.

(5) In addition to fixing the increase in the blowout air temperature at step 108 to a constant value that provides maximum heating, it is also possible to simply add a fixed amount of increase to the blowout temperature required for temperature control. It may be fixed at a value determined by conditions such as outdoor temperature and air volume, or may be adjusted.

(6) A request for defroster blowout may be issued by the passenger using a manual operation device, or may be automatically determined based on the detected value of a condensation sensor or humidity sensor.

(7) In addition to detecting a request for defroster airflow as a command from the passenger using an electric switch, if the air outlet switching damper is moved by a mechanical actuator or a link mechanism, its mechanical displacement is detected. Can be detected with an electric switch.

(8) Instead of using a digital computer that operates based on a control program, the electrical control system implementing the method of the present invention may also be constructed by combining known electrical circuits and electrical circuit elements each having an independent function. It is possible to realize this.

As explained above, according to the present invention, it is possible to realize control of the temperature of the blowing air in accordance with the environmental conditions in the vehicle interior, and to perform effective defroster blowing while simultaneously controlling the air conditioning feeling. It has an excellent effect of not causing any damage.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an 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 block diagram showing the configuration of the present invention. 1 is a ventilation duct, 3 is a blower motor, 4 is an evaporator as a cooling heat exchanger, 5 is a heater as a heating heat exchanger, 7 is an air mix damper for temperature adjustment, 15 is an outlet switch as a deflection means damper; 25 is a digital computer as a control means;

Claims (1)

[Scope of Claims] 1. A ventilation duct for sending air toward the vehicle interior, a blower motor for generating air flow toward the vehicle interior in the ventilation duct, and a cooling heat disposed within the ventilation duct. A temperature control means for adjusting the amount of heat exchanged between the exchanger and the heating heat exchanger, a deflection means for changing the direction of air blowing from the ventilation duct to the passenger compartment, and a temperature set by the occupant to a desired temperature. a setting device; an inside temperature sensor that generates a signal corresponding to the air temperature inside the vehicle; an outside temperature sensor that generates a signal corresponding to the air temperature outside the vehicle; and a temperature signal set by the temperature setting device and the inside temperature sensor. a necessary blowout air temperature calculation means for calculating a necessary blowout air temperature based on a signal generated by an air temperature sensor and the outside temperature sensor; a temperature adjustment operation means for operating the temperature adjustment means based on the necessary blowout air temperature; a switching means for generating a defroster signal to switch the direction of air blowing into the room to a defroster blowout; a deflection actuation means for actuating the deflection means in response to the defroster signal; a fogging determining means for determining, based on the signal, the possibility that fogging will occur on the window glass that partitions the vehicle interior and the outside; and a fogging determination means determining that there is a high possibility that the window glass will fog up. A control device for a car air conditioner, comprising: a blowout air temperature correction means for forcibly increasing the required blowout air temperature.