JPS6390423A - Cloudiness estimating and detecting device for vehicle window - Google Patents

Abstract

PURPOSE:To estimate and detect cloudiness and carry out a favorable cloudiness removing control by sticking a heat insulating material to the inner face of a window glass while providing a cloudiness detecting means for detecting the cloudiness of said window glass in the vicinity of said heat insulating material. CONSTITUTION:A doughnut formed heat insulating material 1 is stuck to the inner face of a front glass 11. Thereupon, at the part of the inner face of the front glass 11 to which the heat insulating material 1 is stuck, heat exchange with the inside air of a vehicle room is shut off. Therefore, the vicinity of the inner face in this part has a temp. close to the outside air temp. and is liable to be clouded. Accordingly, by detecting cloudiness on the inner face of the front glass 11 inside the heat insulating material 1 by means of a light emitting/receiving sensor 2, the generation of cloudiness on the whole front glass 11 can be estimated. Thereby, a comfortable temp. control can be carried out in a condition without cloudiness, preventing the sudden generation of the cloudiness of window due to change in environment, eliminating an invisible condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle window fogging prediction and detection device suitable for preventing the occurrence of fogging on a vehicle window glass.

[Conventional technology]

In order to remove fog that occurs on the windshield of a vehicle, a sensor detects the fog that occurs and a defrost mechanism is activated to remove the fog.

For example, the device disclosed in Japanese Utility Model Application Publication No. 58-9 detects fogging of the windshield by projecting light onto the inner surface of the windshield and using a light emitting/receiving sensor that receives the reflected light.
It is a device that operates the defrost mechanism, and it is a device that operates the defrost mechanism.
The device described in Japanese Patent No. 8608 is a device that detects fog on the windshield using a dew condensation sensor installed on the inner surface of the windshield, and removes the fog by switching control between internal and external air intake.

[Problem that the invention seeks to solve]

In the above conventional technology, after fogging occurs on the vehicle window glass,
This is a device that detects this with a sensor and removes the fog using a defrost mechanism, etc.When fog occurs, it often occurs in a large portion of the windshield of a vehicle at the same time, which can be a major hindrance to vehicle driving. It became.

An object of the present invention is to provide a detection device that predicts the occurrence of fogging on a vehicle window glass in advance.

[Means for solving problems]

The above problem is solved by a vehicle window fogging prediction and detection device that is composed of a heat insulating material attached to the inner surface of the window glass of the vehicle and a fogging detection means for detecting fogging that occurs on the inner surface of the window glass near the heat insulating material. It is resolved accordingly.

[Effect]

Vehicle window fogging occurs when the outside temperature Ta is lower than the vehicle room temperature Tr, the window glass inner surface temperature T, becomes lower than Tr, and the vehicle interior temperature in contact with the window glass inner surface is cooled to T. The dew point Ta is T.

If the temperature is higher, the mechanism is that water vapor contained in the air inside the vehicle condenses on the inner surface of the window glass. That is, Tw and Ta
The high and low temperature compensation will determine whether or not window fogging occurs.

FIG. 5 shows the temperature gradient of the window glass including T and the air near the window glass.

In FIG. 5, (a) is Ta=5℃# Tr=25
This is the temperature gradient on the line AA' when the windshield 11 is not fogged at .degree.

If T in this case is T w i , T w t is T
The temperature is slightly higher than the temperature between a and Tr. (b) and (c) in FIG. 5 pass through the center of the heat insulating material 1 when the donut-shaped heat insulating material 1 is attached to the inner surface of the windshield 11 under the same conditions of Ta and T as in (a). B-B'
Temperature gradient on the edge line and c-c' at a position away from the insulation material 1
This is the temperature gradient on the edge line. BB' on the edge line T, Tax,
If T1 on the C-C' line is Tws, then Tw x <
Tws. This is due to insulation material 1.
Since the inner surface of the windshield 11 is blocked from heat exchange with the air inside the vehicle, the temperature approaches the outside temperature, and this effect extends to the vicinity of the inner surface of the windshield 11 when the heat insulating material is attached. , as a result, T w z becomes closer to the outside temperature.

As described above, Tl12 becomes lower temperature than Tws, so C-C' representing the entire inner surface of the windshield 11
The inner surface of the windshield 11 on the B-B' edge line, which is the inner side of the donut-shaped heat insulating material 1, is more likely to become cloudy than the inner surface of the windshield 11 on one line, and the front inside the donut-shaped heat insulating material 1 By detecting cloudiness on the inner surface of the glass, it is possible to predict that the entire windshield 11 will become foggy.

〔Example〕

An embodiment of the present invention will be described below.

In this embodiment, the present invention is incorporated into a car air conditioner to perform the following two controls.

B) Comfortable Humidity Control By not causing fogging on the windshield 11 during heating and keeping the interior of the vehicle as high as possible in humidity, the feeling of dryness caused by low humidity during heating is improved.

口) Window fogging removal control Windshield 11 is a foggy window that interferes with driving a vehicle.
Predict this occurrence and prevent it from occurring.

The necessity and method of comfortable humidity control will be explained with reference to FIGS. 6 and 7. Figure 6 shows the window fogging generation line with respect to the outside air temperature Ta and the window fogging generation line when the temperature is controlled at Tr = 25°C. is a curved line, and window fogging occurs in the area above this line, and window fogging does not occur in the area below this line.Window fogging does not occur when the car air conditioner blower is in outside air introduction mode, but Ta< In the low temperature range of 1o℃, the humidity is extremely low at 30-5%.

Passengers feel parched. On the other hand, in the inside air introduction mode, even if Ta is at a low temperature, the Tr can be kept at a comfortable humidity of 40 to 60%, but the windows become foggy and operation becomes impossible. Therefore, as shown in FIG. 7, the present invention detects the state of the windshield just before the fogging occurs, and switches between the outside air introduction mode and the inside air introduction mode based on the detection signal, so that the interior of the vehicle interior is changed as shown by the dotted line in FIG. 6. It controls the temperature 'Pr and improves the humidity comfort of the occupants.

Window defogging control uses the present invention to predict and detect the sudden occurrence of windshield fogging caused by sudden changes in the vehicle's humidity and temperature environment, such as sudden rain or snow, or when a large number of passengers are on board. The purpose is to control the mode to best eliminate window fogging, and to prevent the occurrence of an inoperable state due to sudden window fogging. A specific system wiring and piping diagram for realizing the above two controls is shown in FIG. 8, and the window fogging prediction detection sensor section is shown in FIGS. 1 and 2.

The window fogging prediction detection sensor unit is attached to the windshield 11, and its attachment position is preferably behind the room mirror 12 as shown in FIG. This is to ensure that the sensor section does not obstruct the driver's field of vision. The shape of the heat insulating material 1, whose cross-sectional view is shown in FIG. 2, is donut-shaped.
It is preferable to use the glass inner surface of the hollow portion as a cloudy detection surface, because the donut-shaped shape best exhibits the effect of the heat insulating material 1. Note that the material of the heat insulating material 1 is preferably Styrofoam or the like.

The sensor that detects cloudiness on the cloudy detection surface is a light emitting element 2a (such as a light emitting diode) as shown in FIG.
A light film light receiving sensor 2 that combines a light receiving element 2b (such as a phototransistor) and a light receiving element 2b (such as a phototransistor) is preferable. When using this sensor, as shown in FIG. 2, a reflective plate 4 made of mirror-finished metal such as aluminum is attached to the cloud detection surface. Although it is possible to use a dew condensation sensor as another sensor, the optical film light receiving sensor 2 is preferable in terms of fog detection sensitivity and responsiveness.

In the case of the optical film light-receiving sensor 2, the amount of light emitted from the light projecting element 2a is kept constant, and the amount of clouding is detected by the change in the amount of light received by the light receiving element 2b, that is, the output signal.

The eighth embodiment shows an example in which the present invention is incorporated into a car air conditioner system.
It is also explained in the figure.

Compressor 21. Capacitor 22. liquid tank 2
3. A refrigeration cycle consisting of an expansion valve 24 and an evaporator 25, and a blower 26. an intake blower' consisting of an inside/outside air switching door 31 and a negative pressure actuator 41;
Heater core 27. Air mix door 32. Mode switching doors 33, 34 and negative pressure actuators 42, 43, 44
a heater unit consisting of; a register 55 that controls the blower 26; electromagnetic valves 51 to 54 that control the negative pressure actuators 41 to 44; negative pressure @56;
The following items according to the present invention are additionally connected to the conventional car air conditioner system constituted by a control section 57 for controlling the air conditioners 1 to 54.

b) The heat insulating material 1 and the reflective plate 4 attached to the sensor windshield 11,
It also includes a light emitting diode 2a and a phototransistor 2b attached to the heat insulating material 1.

(mouth) Control circuit comparators 61, 62, resistors 71 to 85° transistors 91, 92, Zener diode 93 and relay 9
A circuit consisting of 4.

The operation of the sensor section and control circuit section will be explained below. For the purpose of explanation, the resistance values of resistors 71 to 85 are respectively R.
71 to Rs8. Battery voltage Va is stabilized to a constant voltage Vc by R&δ and Zener diode 93. This Vc passes through R71 and is applied to the light emitting diode 2a, a constant current ip flows, and the light emitting diode 2a projects light with a constant intensity Dl onto the reflecting plate 4. The light reflected by the reflector 4 enters the phototransistor 2b, and the intensity D2 of this light is D2 because aVc, which changes depending on the degree of cloudiness of the reflector 4, is applied to R7z through the phototransistor 2b.
A photocurrent ip proportional to flows, and a voltage Vp is applied across R7x.
occurs. FIG. 9 shows the relationship between this Vp and the degree of sharpness of the reflecting plate 4. As shown in FIG. 9, as the degree of cloudiness of the reflector 4 increases, the reflectance of the four reflectors 4 decreases, and Vp decreases. Comparator 61 and Rf5 to R77 constitute a voltage comparison circuit, and the input signal to this circuit is Vp, R7a, and R74.
The voltage V1 across R74 is obtained by dividing the voltage. When the output of the comparator 61 is HL, the transistor 91 is turned on, and the output is HL.
It turns OFF at o. Similarly, the comparator 62 and R
a s to Raa also constitute a voltage comparison circuit, and the input signals to this circuit are Vp, R7e, ', and the voltage v2 across Rso obtained by dividing Vc by Rao.

When the output of the comparator 62 is H8, the transistor is turned on, and when it is Lo, the transistor is turned off. The variable input of these two voltage comparator circuits is Vp, and the operating characteristics of the above circuits with respect to Vp are shown in FIG. The circuit constants of R7a to R114 are set to provide the above operating characteristics. Operating voltages V P 1 , V P 21 V p s +VP in FIG.
4 represents the multi-value on the curve shown in FIG.
N-OFFL, . The transistor 92 turns ONL when the degree of cloudiness is large; .< OFF when the degree of cloudiness is small. The transistor 91 is connected to the electromagnetic valve 51, and the electromagnetic valve 51 controls the inside/outside air switching door 31.
Set it to the outside air introduction mode. Due to this.

Where the degree of fog is low on the reflector 4 (windshield 11
(immediately before cloudiness occurs), the inside air and outside air introduction modes switch,
A transistor 92 that performs the desired comfortable humidity control is connected to the electromagnetic valves 51 to 54 and a relay 94.
Contact point 4 is connected to the motor of the blower 26 and the magnetic clutch of the compressor 21. transistor 92
is ON, the blow mode is set to defrost, the air mix door is set to full hot, the intake blower is set to outside air introduction mode, the blower is set to HI, and the compressor is set to O.
As a union with N, the fogging elimination ability is maximized. As a result, when the degree of fogging of the reflector 4 is high (a state in which light fogging occurs on the windshield 11), the control state is entered, and the fogging on the windshield 11 is promptly and automatically eliminated, and the objective is achieved. Perform window defogging control.

Note that it is also possible to use a dew condensation sensor as the window glass fogging detection sensor, and this embodiment is shown in FIGS. 3 and 4.

According to the above-described embodiments in which the present invention is applied to a car air conditioner system, it is possible to improve the feeling of dryness caused by extremely low humidity during heating, and also to prevent the windows from suddenly fogging up, thereby eliminating the inability to drive due to window fogging. be able to.

〔Effect of the invention〕

According to the present invention, it is possible to predict and detect vehicle window fogging in advance by utilizing the phenomenon that window fogging occurs early in the vicinity of window glass to which a heat insulating material is pasted, and by incorporating it into a car air conditioner system.

Comfortable humidity control is performed without windows fogging, and window fogging can be prevented even if environmental conditions suddenly change.

Further, the vehicle window fog prevention device according to the present invention only requires adding a heat insulating material 1 to the conventional window fog removal device, and the increase in cost is small compared to the effect.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a vehicle with a window fogging detection sensor installed, Fig. 2 is an enlarged view of the sensor mounting part in Fig. 1, and Fig. 3 is a longitudinal sectional view of a vehicle with another window fogging detection sensor installed. Fig. 4 is an enlarged view of the sensor mounting part in Fig. 3, Fig. 5 is a window glass temperature gradient characteristic diagram that explains the principle of the present invention, Fig. 6 is a diagram of the humidity inside the vehicle against the outside temperature of the vehicle, and Fig. 7 8 is a wiring and piping diagram of a car air conditioner system according to an embodiment of the present invention. FIG. 9 is a circuit characteristic diagram of an embodiment of the present invention. FIG. 10 is a circuit control diagram of an embodiment of the present invention.

Claims (1)

[Claims] 1. A vehicle window fog prediction and detection device comprising: a heat insulating material attached to the inner surface of a window glass of a vehicle; and a cloud detection means for detecting fog generated on the inner surface of the window glass in the vicinity of the heat insulating material.