JPS59153611A - Air conditioner for vehicles - Google Patents

Abstract

PURPOSE:To make the clouding produced on a windowpane inside eliminable with certainty, by controlling an air conditioner on the basis of not only a main cause producing the clouding inside a car room but also that producing it outside the car room. CONSTITUTION:This air conditioner is provided with a clouding discriminator circuit 20, which finds size of the outside signal of a dew drop sensor 7 to be installed in a windowpane inside and discriminates for whether clouding occurs or not, and in time of clouding occurring, selects an H signal to be fed to a terminal 9 at a selector circuit 8, then feeds this signal to a clouding removal command circuit 11. Also, it is provided with an operation circuit 18 into which each output signal out of an outside temperature sensor 4 and a temperature sensor 19 detecting temperature at the outer surface side of a windowpane is inputted. This operation circuit 18 is below the specified valve of the outside temperature (for example, a temperature of 19 deg.C), and set in motion by the H signal of an AND circuit 16 in time of operation in the said command circuit 11. And, when a temperature difference obtainable from outputs of both sensors 4 and 19 is above the fixed valve (about 2-3 deg.C), it controls the said command circuit 11 and holds the temperature difference into a clouding removal mode.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioner for a vehicle, and particularly to a device for removing fog generated on the inner surface of a window glass.

Conventionally, fogging on the inner surface of a vehicle's window glass has been detected using a dew condensation sensor or a humidity sensor that detects the humidity of the air in the vehicle interior, and the interior/exterior air switching door is controlled to introduce dry outside air into the vehicle interior. A method has been proposed to clear up the cloudy weather. (Utility Model Application Publication No. 57-163409) However, in a device like this that detects the cause of fogging in the 1z vehicle interior and clears the fog, as long as the cause of fogging such as rain exists, the cloudy weather will clear once, but When the weather becomes clear, the factors that cause fogging change, and in order to detect clear weather, the mode is canceled and fogging occurs again, and the vehicle air conditioner is set to a mode that clears the fog, for example by setting the inside/outside air switching door. Since the outside air introduction mode is set, a hunting condition is caused, which makes driving difficult, and the air conditioning condition is hindered, resulting in a loss of comfort.

An object of the present invention is to eliminate the above-mentioned drawbacks by controlling a vehicle air conditioner based not only on the factors that cause fogging inside the vehicle interior but also on the factors that cause fogging outside the vehicle interior. This will be explained in detail using an example.

FIG. 1 is a block diagram showing an embodiment of a vehicle air conditioner according to the present invention, in which 1 is a temperature setting device 2.
set temperature TD, vehicle interior temperature tr detected by the inside air sensor 3, and outside air temperature ta detected by the outside air sensor 4.
This is an air conditioning control device that controls the air conditioning controller 5 based on the following. The air conditioning controller 5 is composed of an inside/outside air switching door, a compressor for cooling the evaporator, a blower for introducing inside and outside air, a heater core, a mode switching door, etc., and the air is blown into the passenger compartment from the air outlet of the air conditioning controller 5. The temperature setting device 2 operates to set the temperature of the air to the set temperature TD of the temperature setting device 2.

6 is a defogging control device, which includes a fogging determination circuit 20 that determines the magnitude of the output signal tm of a dew condensation sensor 7 provided on the inner surface of the window glass, determines whether fogging has occurred, and controls the selection circuit 8; It has °. This judgment circuit 20 selects and outputs the signal H (high level) supplied to the terminal 9 by the selection circuit 8 when it is cloudy, and selects the signal supplied to the terminal 10 when it is sunny. control to output.

The output signal from the selection circuit 8 is the fog removal command circuit 1.
1. The output from the defogging command circuit 11 is supplied via a selection circuit 12 to a defogging setting circuit 13 in the cooler mode or to a defogging setting circuit 14 in the heater mode.

The defogging setting circuit 13 operates in cooler mode.
By driving the compressor constituting the air conditioning controller 5 and controlling the inside/outside air switching door to introduce a portion of outside air, it operates to lower the absolute humidity in the vehicle interior and clear fog. In addition, the dew condensation removal setting circuit 14 is configured to set the mode switching door for controlling the blowing direction to the defrost blowout mode when in the heater mode (the rotational speed of the blower is increased by the aluminum and the inside/outside air switching door is set to the outside air introduction mode). In other words, the mode is set such that air is blown out to the inner surface of the window glass.The selection circuit 12 is controlled by an outside air temperature determination circuit 15, and this outside air temperature determination circuit 15 determines that the outside air temperature La is high. When the air conditioning controller 5 operates in the cooler mode, a signal from the defogging command circuit 11 is supplied to the defogging setting circuit 13, so that when the outside temperature ta is low, the air conditioning controller 5 operates in the heater mode. In such a case, the output from the defogging command circuit 11 is controlled to be supplied to the defogging setting circuit 14.In addition, the outside air temperature determination circuit 15 is controlled so that the output from the defogging command circuit 11 is supplied to the defogging setting circuit 14.In addition, when the outside air temperature [a is as low as 19 degrees Celsius or lower, 1.AND circuit A signal of H is output to the AND circuit 16.A signal from the flag setting circuit 17 which is set by the output signal from the defogging command circuit 11 and latches the signal of H is input manually to the AND circuit 16. The AND circuit 16 outputs an H signal to the arithmetic circuit 1B when the outside temperature is below 19°C and the defogging command circuit 11 operates and the output of the flag setting circuit 17 becomes H, when the AND condition is satisfied. The arithmetic circuit 18 is based on this AND circuit 16.
T=ta+α−tg based on the outside air temperature ta detected by the outside air sensor 4 and the temperature tg detected by the temperature sensor 19 that detects the temperature on the outer surface side of the window glass. (α=2~3°C) and the signal T7'l<T obtained by the above calculation.
When the condition ≧0 is satisfied, an H signal is supplied to the terminal 10 of the selection circuit 8, and when the above condition is not satisfied, a reset signal is output to the flag setting circuit 17 to reset the flag setting circuit 17.

Normally, when a vehicle runs in the rain, the surface side of the window glass gets wet and evaporates, which removes heat, so the temperature difference between the outside surface temperature tg and the outside air temperature ta becomes lower than when it is a sunny day. The above constant α is set to T7 when the weather is sunny! Set so that l<T<0.

Therefore, when it rains, the temperature tg of the outer surface of the window glass becomes lower than the outside air temperature ta, so T≧0.

The operation of the vehicle air conditioner of the present invention having the above configuration will be explained below using the flowchart shown in FIG. First, the air conditioning control device 1 sets the set temperature T of the temperature setting device 2.
D. The air conditioning controller 5 is controlled based on the vehicle interior temperature tr, etc. to set the interior of the vehicle to a comfortable temperature. In other words, normal control is performed. The flag setting circuit 17 of the defogging control device 6 is set in a reset state in advance. Here, when fogging occurs on the inner surface of the window glass, the fogging determination circuit 20 detects this and controls the selection circuit 8, and the H signal supplied to the terminal 9 of the selection circuit 8 is sent to the fog removal command circuit 11. Control the output. As a result, the defogging command circuit 11 is turned off, and a signal from the command circuit 11 is supplied to the selection circuit 12. On the other hand, if the outside air temperature ta is high, the outside air temperature determination circuit 15 causes the selection circuit 12 to operate in the illustrated state, that is, so that the output signal from the defogging command circuit 11 is supplied to the defogging setting circuit 13. Therefore, the fog removal setting circuit 13 operates to turn on the compressor constituting the air conditioning controller 5, and sets the inside/outside air switching door to a mode in which a portion of the outside air is introduced, thereby lowering the absolute humidity in the vehicle interior and clearing the fog. Further, if the outside air temperature ta is low, the outside air temperature determination circuit 15 controls the selection circuit 12 and operates so that the output signal from the defogging command circuit 11 is supplied to the defogging setting circuit 14. Removal setting circuit 14
operates to increase the speed of the blower of the air conditioning control ta5, set the inside/outside air switching door to the outside air introduction mode, and set the mode switching door to the defrost blowing mode to blow warm air onto the inner surface of the window glass to clear the fog.

When such a defogging operation is performed, the flag setting circuit 17 is set by the defogging command circuit 11, and its output signal becomes H. When the fog on the inner surface of the window glass clears, the fog determination circuit controls the selection circuit 8 to switch its movable contact to the terminal 10 side, so that the output signal from the calculation circuit 18 is output to the defogging command circuit 11. works.

Here, the temperature ta detected by the outside air temperature determination circuit 15
For example, when the temperature is below 19°C, an H signal is input from the outside air determination circuit 15 to one input terminal of the AND circuit 16,
Further, since the H signal is input from the flag setting circuit 17 to the other input terminal of the AND circuit 16, the AND circuit 16
The AND condition is satisfied, and the arithmetic circuit 18 is driven by the H output signal of the AND circuit 16. Arithmetic circuit 18
Then, T is calculated to determine whether T≧0 or T<O. In the case of rain, since T≧0, an H signal is output to the terminal IO of the selection circuit. Therefore, the H signal is input to the defrosting command circuit 11, and based on this, the defogging setting circuit 13
Or, by controlling the defogging setting circuit 14, the air conditioning controller 5
to keep it in a defogging mode. On the other hand, T<
When it is O, an L (low level) signal is output to the input terminal 10 of the selection circuit 8, so the defogging command circuit 11 does not operate. Also, at this time, the flag setting circuit 17 is reset to L. On the other hand, when fogging has not occurred on the inner surface of the window glass in advance, the defogging command circuit 11 does not work, and the output signal of the flag setting circuit 12 is L, or when the outside air temperature is 20°C or higher, the outside air temperature determination circuit is sent to the AND circuit 16. When the output signal supplied from the selector circuit 15 is L, the arithmetic circuit 18 does not work, and the L signal is supplied to the terminal 10 of the selection circuit 8, so that the defogging command circuit 11 does not operate. As a result, the air conditioning control R5 does not perform the dew condensation removal operation.

According to the present invention, when fogging occurs on the inner surface of the window glass, the air conditioning controller 5 is driven in a mode that removes the fogging on the inner surface of the window glass, so that the fogging on the inner surface of the window glass is removed. be able to.

When there is an external factor that causes fogging on the inner surface of the window glass, that is, when the temperature tg of the outer surface of the window glass is lower than the outside temperature ta, the air conditioning controller 5 is maintained in a mode that removes fogging. Therefore, fogging will not occur again on the inner surface of the window glass. Therefore, since the defogging mode does not occur intermittently, airflow changes and abnormal noises do not occur, and wear and tear on the air conditioning controller can be reduced.

Note that in this embodiment, the defogging operation is not performed when the outside temperature is 20°C or higher.When the outside temperature is as high as 20°C or higher, the air conditioning controller 5 is operated in cooler mode. As a result, the temperature inside the vehicle becomes low, and as a result, the temperature of the window glass is low, and therefore the temperature tg of the outside surface of the window glass is also low. Therefore, even when it is sunny, the arithmetic circuit 18 determines the cause of rainy weather. This is because it may cause malfunction.

In the present invention, the defogging control device 6 is configured using a microcomputer, and this microcomputer includes a fogging determination circuit, a defogging command circuit 11, a selection circuit 12, and so on. Outside air temperature determination circuit 15. It may also be provided with functions such as the arithmetic circuit 18.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a vehicle air conditioner according to the present invention, and FIG. 2 is a flow chart for explaining its operation. 1... Air conditioning control device, 5... Air conditioning control machine, 6...
Defogging control device, 7...fogging determination circuit, 8, 12.
...Selection circuit, 11...Fog removal command circuit, 13.1
4... Defog removal setting circuit, 15... Outside air temperature determination circuit, 18... Arithmetic circuit.

Claims (1)

[Claims] determining means for determining fogging based on a signal from a dew condensation sensor provided on an inner surface of a window glass; a setting means for setting an air conditioning controller to a defogging mode based on a signal from the determining means; and the air conditioning control. When the machine is set to defogging mode, it detects the outside air temperature and the temperature on the surface side of the window glass, and removes the above fogging when the temperature difference between the outside air temperature and the temperature on the surface side of the window glass is higher than a certain value. 1. An air conditioner for a vehicle, comprising: arithmetic control means for controlling the means to maintain an air conditioning controller in a defogging mode.