JPH01269646A - Controller for air conditioner for automobile - Google Patents

Abstract

PURPOSE:To correctly judge cloudiness and remove the cloudiness by determining the cloudiness judgement value from the temperature difference between the window glass inner surface temperature and the car compartment temperature and judging cloudiness by comparing the judgement value and the relative humidity of the inner surface of a window glass and carrying out demist control. CONSTITUTION:A humidity sensor 26 for detecting the relative humidity of the inner surface of a window glass, window inner surface temperature sensor 27 for detecting the temperature of the inner surface of the window glass, and a car compartment temperature sensor 28 for detecting the representative average temperature in a car compartment are installed. The temperature difference of the temperature detected by the temperature sensors 27 and 28 is calculated by a temperature difference calculating means 80, and a cloudiness judgement value setting means 70 determines the judgement value of cloudiness according to the result of the calculation. The cloudiness is determined by comparing the determined cloudiness judgement value and the detected relative humidity in a cloudiness judging means 50, and a drive signal is outputted into the air conditioner equipment from a demist control means 60 according to the result of the judgement, and the demist action is developed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air conditioning control device for reliably detecting cloudiness on the inner surface of a window glass in an automobile air conditioner.

(Prior Art) Automobiles are equipped with a humidity sensor on the inner surface of the window glass in order to prevent the inner surface of the window glass from becoming cloudy.When fogging occurs or is likely to occur, the humidity sensor detects the occurrence of fogging, and demist control is carried out. The configuration is such that an activation signal is sent to the air conditioning equipment to prevent fog from forming.

A humidity sensor is constructed by placing metal oxide semiconductor electrodes facing each other with an appropriate gap between them, and applying a moisture-absorbing material to the surface.The humidity sensor changes resistance due to humidity adhering to the surface. Humidity (relative humidity) was detected from Since the response and detection accuracy of this humidity sensor itself is not good, the judgment value for cloudiness is the stage before predicting the occurrence of cloudy weather, and in reality, fogging occurs when the relative humidity exceeds approximately 60%. Demist control is performed by switching the blowout mode, operating the compressor, switching the suction mode, and increasing the amount of air blown.

As a condition for the occurrence of fogging on the inner surface of a window glass, it tends to occur frequently when the temperature of the inner surface of the glass is low. A humidity sensor and a temperature sensor are provided in the window glass, and the fogging determination value of the humidity sensor is changed depending on the temperature of the inner surface of the window glass, thereby improving the fogging detection accuracy.

(Problems to be Solved by the Invention) Table 1 shows the relationship between the temperature and humidity inside the vehicle, the temperature on the inner surface of the window glass, and the humidity on the inner surface of the window glass.

Table 1 As shown in Table 1, the temperature inside the window glass alone is
Determination of ease of fogging is not sufficient 0 For example, even if the inside surface of the window glass is 15 degrees Celsius, the humidity on the inside surface of the window glass varies greatly depending on the temperature inside the vehicle, and there is a large difference between the temperature inside the vehicle and the temperature on the inside surface of the window glass. It gets more cloudy as you go.

Therefore, changing the judgment value based on the temperature of the inner surface of the window glass being 15°C is extremely effective in the case of 30°C and 50% RH as in the previous example, but it is useless in the case of 20°C and 50% RH. In this case, demist control results in unnecessary power loss.

Further, the relationship between the temperature and humidity inside the vehicle, the temperature on the inner surface of the window glass, and the humidity on the inner surface of the window glass has characteristics as shown in Tables 2 and 3.

Table 2 Table 3 Table 2 shows the case where the difference between the temperature inside the vehicle and the inner surface temperature of the window glass is 10°C, and Table 3 shows the case where the temperature difference is 5°C.

From the above characteristics, it is reasonable to change the cloudiness judgment value based on the temperature difference, especially when the temperature is 10℃ or higher.
Since cloudiness occurs under any conditions, correcting the cloudiness determination value to a low value is effective in increasing the detection speed and preventing the occurrence of cloudiness.

Therefore, it is an object of the present invention to make accurate judgments about cloudiness in view of the above-mentioned characteristics.

(Means for Solving the Problem) As a means for solving the problem, the present invention provides an automobile having an air blowing means, a heat exchange means, an intake mode setting means, and a blowing mode setting means in an air conditioning duct. In a commercial air conditioner, there are a humidity sensor 26 that detects the relative humidity on the inner surface of the window glass, a window glass inner surface temperature sensor 27 that detects the temperature of the inner surface of the window glass, and a vehicle interior temperature sensor that detects the average representative temperature inside the vehicle interior. 28, a temperature difference calculation means 80 for calculating a temperature difference from the window glass inner surface temperature sensor 27 and the vehicle interior temperature sensor 28, and the temperature difference calculation means 80.
a cloudy judgment value setting means 70 for determining a cloudy judgment value based on the calculation result from the cloudy judgment value setting means 70; and a cloudy judgment value setting means 70 for determining cloudiness by comparing the relative humidity detected by the humidity sensor 26 with the cloudy judgment value from the cloudy judgment value setting means 7o. Cloudy determination means 5
0, and a demist control means 60 that outputs a drive signal to the air conditioner that performs demist control based on the determination result of the cloudiness determination means 50.

Further, in addition to the above claims, the temperature difference calculation means 8
Differentiating means 90 is provided for differentiating the calculation effect from zero.

(Function) Therefore, the fogging determination value is changed depending on the temperature difference between the temperature inside the vehicle and the temperature of the inner surface of the window glass, thereby improving the accuracy of determining fogging and performing demist control accurately.

Further, by differentiating the temperature difference between the temperature inside the vehicle and the inner surface temperature of the window glass, it is possible to predict future changes, and the fog judgment value can be determined from the temperature difference and the predicted change.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, the vehicle 1 has an air conditioner 12,
The air conditioner 2 is formed in such a way that an inside air inlet 4 and an outside air inlet 5 are divided into two on the upstream side of an air conditioning duct 3, and an intake door 6 is provided at the divided part. The outside air inlet 5 is selectively opened and closed.

The blower 7 is for sucking air into the air conditioning duct 3 and blowing it to the downstream side, and an evaporator 8 is provided on the downstream side of the blower 7.

The evaporator 8 includes a compressor 9, a capacitor 10,
It is connected to the receiver tank 11 and the expansion valve 12 through piping to form a refrigeration cycle. The compressor 9 uses an automobile engine (not shown) as its drive source, and its drive is controlled on and off by an electromagnetic clutch 9a. A variable capacity device 9b is provided, and the variable capacity device 9b adjusts the discharge capacity. It is designed to be regulated.

This capacity variable device 9b may be a known device that changes the angle of the wobble plate in the case of a wobble type compressor, or changes the discharge capacity by changing the compression start position in the case of a vane type compressor. .

An air mix door 13 is provided on the downstream side of the evaporator 8.
and a heater core 14 are provided.

The air mix door 13 adjusts the ratio of the air sent to the heater core 14 and the air bypassed according to its opening degree, and the air that has passed through the heater core 14 is later mixed with the bypassed air to increase the temperature. adjusted.

The rear end of the air conditioning duct 3 is divided into a defrost outlet 15, a vent outlet 16, and a foot outlet 17, which open into the vehicle interior 18, and mode doors 19a, 19b are installed in the separated parts.
are provided, and the blowing mode can be changed by selectively opening and closing the mode doors 19a and 19b. The defrost outlet 16 opens toward a front window glass 20 that constitutes the vehicle interior 18 .

The above-described internal/external air switching door 6, air mix door 13, and mode doors 19a, 19b are operated by actuators 22a to 22c, respectively, and the actuators 22a to 22c receive outputs from the microcomputer 24 via drive circuits 23a to 23c. Controlled based on signals. Also.

The electromagnetic clutch 9a of the blower 7 and the compressor 9 are similarly controlled by the microcomputer 24 via drive circuits 23d and 23e, respectively.

The microcomputer 24 includes a central processing unit CPU, a read-only memory ROM, and a random access memory RAM.
This is a well-known device that includes a clock generator that generates reference pulses using a crystal oscillator. An A/D converter 25 is connected to the microcomputer 24. The A/D converter 25 receives a humidity signal Th from a humidity sensor 26 provided on the window glass 20 to detect fogging on the window glass 20, a temperature signal from a window glass inner surface temperature sensor 27, and a temperature signal from the window glass inner surface temperature sensor 27. The representative temperature in the vehicle interior from the interior temperature sensor 28 is input. Further, although not shown, signals from the temperature setting device for setting the opening degree of the air mix door 13, the amount of solar radiation, and the temperature inside the vehicle are inputted, and the inputted analog signals are converted into digital signals and the signals are input to the microcomputer. Send on 24th.

The humidity sensor 26 is provided on the inner surface of the window glass 20 to detect the relative humidity in the vicinity thereof, and the window glass inner surface temperature sensor 27 is also provided on the inner surface of the window glass 20 to detect the temperature in the vicinity. Further, a vehicle interior temperature sensor 28 is provided on the instrument panel, and detects the representative temperature within the vehicle interior by sucking the air inside the vehicle interior with an aspirator 29.

Reference numeral 30 denotes an air conditioning status input device, which includes switches for operating the air conditioning system and an air conditioning status display section set by the switches. Namely, mode setting switch, intake door control switch.

Blower control switch, compressor drive control switch,
It also has a display section that displays the intake door, mode, blower rotation speed, etc.

Reference numeral 31 is an operation setting section for automatically or manually controlling the demist, which is composed of a push button switch, etc., and can be set to auto by pressing it or, conversely, to normal auto, and can be canceled by pressing it. It can also be set as follows.

In the above-described configuration, an example of the demist control device will be explained according to the flow shown in FIG. 3.

First, when the demist switch 31 is pressed or is installed in the control device as automatic, demist control is started at a start step 100, the process proceeds to step 101, the vehicle interior temperature Tr is taken in, and the process proceeds to step 102. The window glass inner surface temperature Tg is taken in. Then, the process proceeds to step 103, where the vehicle interior temperature Tr and the window glass inner surface temperature T are determined.
The temperature difference with g is calculated.

Further, the process proceeds to step 105, in which a cloudiness determination value A is determined from the temperature difference using a predetermined map. As shown in Tables 2 and 3, it is preferable to increase the correction value for the cloudy judgment value A as the temperature difference increases, and it is not necessary to correct it when the temperature difference is 5°C or less. . When the cloudy judgment value A is determined, the process proceeds to step 106, where the window glass inner surface humidity Th is taken in, and then, in step 107, this window glass inner surface humidity Th and the step 1
The cloudy judgment value A determined in step 05 is compared, and if the window glass inner surface humidity Th is smaller than the cloudy judgment value A, step 1 is performed.
Proceeding to 08, demist control is not performed.

On the other hand, when the window glass inner surface humidity Th is larger than the cloudy judgment value A, the process proceeds to step 109 and demist control is started, and as described above, the demist control includes switching of the blowing mode, driving the compressor, driving the blower, and controlling the intake. Door switching etc. are performed comprehensively. In this way, by changing the fogging determination value based on the temperature difference between the vehicle interior temperature Tr and the window glass inner surface temperature Tg, it is possible to compensate for the response delay and detection accuracy of the humidity sensor.

FIG. 4 shows the flow of another embodiment. This example differs from the previous embodiment in that after the temperature difference between the vehicle interior temperature Tr and the window glass inner surface temperature Tg is calculated, a step 104 is provided to differentiate the temperature difference calculation. This differentiation makes it possible to predict future changes,
The cloudy judgment value A can be determined from the temperature difference and the predicted change. This improves the timing for accurately determining fog.

(Effects of the Invention) As described above, according to the present invention, the fogging determination value is determined based on the temperature difference between the vehicle interior temperature and the window glass temperature, so that the humidity sensor for detecting fogging on the window glass can be used. Responsiveness and detection accuracy can be compensated, and cloudiness can be determined accurately.

Furthermore, by providing a means of differentiating the temperature difference between the interior temperature of the vehicle and the inner surface temperature of the window glass, it is possible to predict future changes.If this change prediction is incorporated to determine the fog judgment value, fogging can be further reduced. Judgments can be made more accurately.

[Brief explanation of the drawing]

Fig. 1 is a functional block diagram of this invention, Fig. 2 is a configuration diagram of an embodiment of this invention, Fig. 3 is a flowchart of an embodiment corresponding to claim 1 of this invention, and Fig. 4 is a claim of this invention. 3 is a flowchart of an embodiment corresponding to item 2. 2...Air conditioner. 26...Humidity sensor, 271° window glass inner surface temperature sensor, 28... Vehicle interior temperature sensor, 5
0: Cloudy determination means, 60: Demist control means, 7o: Cloudy determination value setting means. 80... Temperature difference calculating means, 90... Differentiating means. Figure 4

Claims (2)

[Claims] 1. An air conditioner for an automobile that has an air blowing means, a heat exchange means, an intake mode setting means, and a blowing mode setting means in an air conditioning duct, the humidity sensor detecting the relative humidity on the inner surface of the window glass, and the temperature on the inner surface of the window glass. a window glass inner surface temperature sensor that detects the average representative temperature of the vehicle interior, a vehicle interior temperature sensor that detects an average representative temperature inside the vehicle interior, and a temperature difference calculation means that calculates a temperature difference from the window glass interior temperature sensor and the vehicle interior temperature sensor. and a cloudy judgment value setting means for determining a cloudy judgment value based on the calculation result from the temperature difference calculating means, and comparing the relative humidity detected by the humidity sensor with the cloudy judgment value from the cloudy judgment value setting means. An automobile air conditioning control device comprising: a cloudy determination means for determining cloudy weather; and a demist control means for outputting a drive signal to an air conditioner that performs demist control based on the determination result of the cloudy determination means. 2. An air conditioner for an automobile that has an air blowing means, a heat exchange means, an intake mode setting means, and a blowing mode setting means in an air conditioning duct, the humidity sensor detecting the relative humidity on the inner surface of the window glass, and the temperature on the inner surface of the window glass. a window glass inner surface temperature sensor that detects the average representative temperature of the vehicle interior, a vehicle interior temperature sensor that detects an average representative temperature inside the vehicle interior, and a temperature difference calculation means that calculates a temperature difference from the window glass interior temperature sensor and the vehicle interior temperature sensor. a differentiating means for differentiating the calculation result from the temperature difference calculating means; a cloudy judgment value setting means for determining a cloudy judgment value based on the output from the differentiating means; It consists of a cloudy determination means that determines cloudiness by comparing it with a cloudy determination value from a cloudy determination value setting means, and a demist control means that outputs a drive signal to an air conditioner that performs demist control based on the determination result of the cloudy determination means. Automotive air conditioning control device.