JPS62199521A - Fog removal device for vehicle - Google Patents

Abstract

PURPOSE:To maintain the visibility through a window glass continuously by detecting environment around a vehicle so as to judge a condition which makes the window glass foggy whereby actuating a fog removal means before having fogs. CONSTITUTION:When an air conditioning switch 75 is turned on, output signals from a rain sensor 2, an outside air temperature sensor 3, and a cabin temperature sensor 4 are inputted into a control circuit 1. And when the output X from the rain sensor 2 is greater than a set value Xp corresponding to the number of rain drops for high humidity, the outside air temperature Tout is compared with the cabin temperature Tin. And in case of Tout>=Tin, the difference Tx between the two is computed so as to be compared with a set value Tp based on the temperature difference in and out of a vehicle which meets the necessary condition for having fogs programmed in advance for the case of humidity Xp. If the comparison indicates Tx>=Tp, as a window glass is suspected to become foggy, a compressor 5 is driven so as to prevent possible fogging.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for automatically removing fog from a vehicle window.

[Conventional technology]

It is important for vehicle windows to be de-fogged for safety reasons, and for this reason dew condensation sensors are installed on the window glasses.
A device has been proposed that automatically removes fog from window glass by detecting dew condensation and controlling the operation of a defogger or a defogger, such as an air conditioner. (JP-A-55-59041, JP-A-55-6394
(No. 0 and Japanese Unexamined Patent Publication No. 59-75852) This is as shown in FIG. 8, for example. That is, a pair of Ag pastes on a ceramic substrate 21)
22. Measure the insulation resistance between the wires by baking 23, and check the insulation resistance change due to dew condensation.

A sensor 20 for detecting a dew condensation state is provided on the inside of a vehicle interior of a window glass 10. The computer 30 controls the fog removal device 40 according to the output of the sensor 20 to remove fog from the window glass. Further, as a dew condensation detection sensor for detecting cloudiness, there is also a sensor that measures temperature changes due to dew condensation using a thermistor or the like.

[Problem that the invention seeks to solve]

However, this kind of conventional (dust removal device)

Since the system detects dew condensation on the window glass, the defogging device is activated after the window glass becomes foggy, which delays fogging and obstructs visibility.Therefore, improvements were desired.

Therefore, one object of the present invention is to operate a fog removing means before cloudiness occurs, thereby preventing fogging from occurring and ensuring good visibility.

[Means for solving problems]

Therefore, the present invention is characterized in that the vehicle environment is detected, the state in which fogging occurs on the window glass is determined, and the fogging removal means is activated before fogging occurs.

Specifically, as shown in FIG. 1, the vehicle fog removal device of the present invention includes, as a means for detecting the vehicle environment, a humidity detecting means, an outside air temperature detecting means for detecting the air temperature inside and outside the vehicle, and an indoor air temperature detecting means for detecting the air temperature inside and outside the vehicle. and temperature detection means.

Based on the signals from these detection means, a control means for determining the fogging state and activating the fogging removing means before the fogging occurs.

[Effect]

As a result, due to defogger or air conditioning equipment,
Heating or dehumidification is performed to remove fog that occurs on both the inside and outside of the window glass.

〔Example〕

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

FIG. 2 is an overall configuration diagram of an embodiment of the present invention.
In the figure, reference numeral 1 denotes a control circuit of a vehicle air conditioner, which corresponds to a control means mainly composed of a microcomputer. The control circuit 1 is connected to a battery 6 and supplied with power, and controls the operation of various actuators and relays that control the air conditioner as is known.

Here, 9 items not related to the present invention are described.

Illustrations are omitted and only two related to the present invention are shown.

Only relays 70,74 are shown.

When energized by a signal from the control circuit 1, the relays 70, 74, respectively, switch the corresponding switches 72, 74, respectively.
The switches 72 and 76 are turned on, and the switches 72 and 76 are turned off when the power is not supplied. The relay 70 is a main relay, and the relay 74 is a relay for stopping the operation of the cooler compressor 5. The cooler compressor 5 corresponds to fog removal means.

The switches 72 and 74 are connected in series with each other and are inserted in a path where the electromagnetic clutch 71 is connected to the battery 6. Here, the electromagnetic clutch 71 is, as is known,
It is inserted between the drive shaft of the cooler compressor 5 and the engine output shaft in an air conditioner and selectively connects nine wheels. In this case, both shafts are disconnected and the operation of the cooler compressor 5 is stopped.

On the other hand, the control circuit 1 is configured to receive various signals necessary for the above-mentioned control.

Here, illustrations of items not directly related to the present invention are omitted, and only items directly related to the present invention are air conditioner switch 75. Rain sensor 2. Outside temperature sensor 3. Only the vehicle room temperature sensor 4 is shown.

The air conditioner switch 75 is a switch that is turned on when operating the air conditioner.

Further, the rain sensor 2 corresponds to a humidity detecting means, and detects the humidity in the outside air using raindrops, and outputs a signal according to the number of raindrops. The outside air temperature sensor 3 corresponds to outside air temperature detection means, and the vehicle room temperature sensor 4 corresponds to indoor temperature sensing means, and outputs signals corresponding to the inside and outside air temperatures of the vehicle. be.

Here, the installation position and structure of the rain sensor 2 applied to this embodiment will be explained based on FIGS. 3 to 6.

FIG. 3 shows the installation position of the rain sensor 2.

It is attached to the outside of the window glass 80 of the vehicle.

Note that the rain sensor 2 is made colorless and transparent, and does not obstruct the view at all even if it is installed on the window glass 80.

FIG. 4 is an enlarged front view showing the electrode structure of the rain sensor 2, and FIG. 5 is an enlarged sectional view of the rain sensor 2.

As is clear from FIGS. 4 and 5, in the rain sensor 2, the pair of comb-teeth electrodes 11.12 are
lb, 12a, and 12b are engaged with each other. The comb-teeth electrodes 11 and 12 are provided by depositing or sputtering a transparent conductor made of Inzc+(Sn) on the window glass 80 to a thickness of about 1 micron.

The insulating protective film 81 is made of Al2O! A dielectric material made of.

It is formed by vapor deposition or sputtering so that the thickness on the comb-teeth electrodes 11 and 12 is about a fraction of a micrometer.

As a result, stray capacitances are formed between each comb-teeth electrode 11.12, and these stray capacitances are shown as Cl-Cm and C3-C1 in FIGS. 5 and 6. Among these stray capacitances C3 to C7, Cs to Cma are:
Each comb tooth portion 11a, llb, 12a of the comb tooth electrode 11.12
, 12b, the capacitance varies greatly depending on whether or not raindrops are attached to the insulating protective film 81 covering the capacitors 12b and 12b.

For example, when raindrops adhere to the insulating protective film 81 covering the comb teeth portions 12a and lla, the stray capacitance Cs becomes larger than when no raindrops adhere thereto.

This is because the dielectric constant of raindrops is larger than that of air. Therefore, the capacitance between the comb-teeth electrodes 11 and 12 changes depending on the number of raindrops that adhere to the rain sensor 2. In other words, the capacitance of the comb-teeth electrodes 11 and 12 is the same as that of the rain sensor 2.
The size increases approximately in proportion to the number of raindrops that land on it.

Furthermore, as shown in FIG. 3, the outside temperature sensor 3 and the vehicle room temperature sensor 4 are connected to the hood lock support (
The vehicle room temperature sensor 4 is disposed at a location outside the vehicle that is not affected by heat from the engine, such as at a vent (not shown) of an air conditioner in the vehicle interior. Both of these sensors use known thermistors, and detect changes in temperature as changes in the resistance of the thermistor.

It outputs signals corresponding to the temperature of the air inside and outside the vehicle.

FIG. 7 shows the main program of the microcomputer, and the operation of the apparatus will be explained below according to this program.

When this program is started, first, step 101
In this step, a known initialization process is performed.

Next, in step 111, it is determined whether the air conditioner switch 75 is turned on.

If the air conditioner switch 75 is turned on.

In step 112, known air conditioning control is performed, and if the air conditioner switch 75 is not turned on, in step 113, the air conditioning control in step 112 is stopped.

When the air conditioner switch 75 is turned on,
After the process of step 112 described above is executed, the processes of step 120 and subsequent steps are executed.

In step 120, the output X of the rain sensor 2 is determined.

The output Tout of the outside temperature sensor 3 and the output Tin of the vehicle room temperature sensor 4 are input.

In step 130, a set value X corresponding to the output X of the rain sensor 2 and the pre-programmed number of raindrops for high humidity
If X≧xp, the process proceeds to step 140.

If <x<xp, return)) In step 140, the outside temperature 7out and the vehicle interior temperature T
Compare with in, and if ToutkTin, step 14
Proceed to step 1 @ (Return if Tout<Tin) In step 141, the difference Tx between 'l'out and Tin is determined, and the process proceeds to step 150, where the air temperature inside and outside the vehicle is calculated under the pre-programmed fogging conditions at humidity X9. A comparison is made with a set value Tp based on the difference, and if Tx≧Tp, it is determined that the condition is such that fogging occurs on the window glass 80, and the process proceeds to step 160.

(Return if T x < Tp) In step 160, it is determined whether or not the cooler compressor 5 is in the on state. If the determination is negative, in step 170, the cooler compressor 5 is driven before fogging occurs on the window glass 80. Let me.

, to secure the visibility of the window glass 80 by preventing the occurrence of fire. (Return if on) Here, step 12
Steps 0 to 150 correspond to the part of the claims that determines that a state where fogging can occur, and steps 160 to 17LJ' correspond to the part of activating the fog removing means. Note that the above-mentioned setting values may be determined as appropriate depending on the capabilities of the cloud removal means, control means, and the like.

According to this embodiment, since the humidity outside the vehicle is detected using a rain sensor, it is possible to effectively remove fog caused by high temperature outside air especially during rain.

In other words, with a rain sensor.

As mentioned above, since humidity is detected by the change in stray capacitance depending on the number of raindrops, if the humidity is not high enough to cause cloudiness during light rain, the stray capacitance is small, and therefore the output signal is small and does not unnecessarily drive the cooler compressor and cause a decrease in engine output, etc. On the other hand, with a device that detects humidity based on resistance changes and temperature changes, even in light rain conditions where the humidity is not high enough to cause fogging, once a raindrop happens to hit the sensor, the resistance and temperature will change suddenly. This is because a large difference occurs between the output signal and the output signal before raindrop contact, and the cooler compressor is unnecessarily driven.

Furthermore, according to the two embodiments, since the cooler compressor is controlled by detecting the temperature difference between the inside and outside of the vehicle, the driver can decide whether to use the heater or the cooler during rainy seasons (spring, autumn). Even if you are having trouble making a choice, the cooler compressor is automatically activated when the condensation temperature of the outside air becomes higher than the temperature of the cooler outlet inside the vehicle, so the temperature inside the vehicle does not rise due to high temperature outside air. In addition to removing dust, the temperature inside the vehicle can be maintained at an appropriate level, and the driver is not burdened with making choices.

Although the five specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and includes various embodiments within the scope of the claims. As the fog removal means, a heater or a defogger may be used instead of the cooler compressor.

In addition, the humidity and the temperature difference between the inside and outside of the vehicle are not set to a fixed value, but are programmed based on the difference between the humidity and the temperature inside and outside the vehicle. It is also possible to control the fog removal means by calculating various fog generation conditions from the air temperature.

Furthermore, sensors for detecting humidity may be provided inside and outside the vehicle for control.

〔Effect of the invention〕

As described above, according to the present invention, the vehicle environment is detected, the humidity inside the vehicle is lowered by introducing high-humidity outside air, and the window glass is It is possible to maintain good visibility at all times, contributing to safe driving without putting a burden on the driver.

[Brief explanation of drawings]

FIG. 1 is a corresponding diagram of the claims. Figure 2 is 2
FIG. 1 is an overall configuration diagram of an embodiment of the present invention. 3 to 6 show the rain sensor in the above embodiment, and FIG. 3 is a diagram illustrating the installation position. FIG. 4 is an enlarged front view showing the electrode structure, FIG. 5 is an enlarged sectional view of the rain sensor, and FIG. 6 is an equivalent circuit diagram of the rain sensor. FIG. 7 is a diagram showing a flowchart of the main program of the microcomputer in the control circuit in the above embodiment. FIG. 8 is a diagram showing a conventional technique. i --------1 Control circuit (control means) 2 --- Rain sensor (humidity detection means) 3 ------1 Outside temperature sensor (outside temperature detection means) 4
−・−Car room temperature sensor (indoor temperature detection means) 5・・−
---Applicant of cooler compressor (fog removal means)
Toyota Motor Corporation Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) Humidity detection means that detects humidity and outputs a signal according to the humidity; outside temperature detection means that detects the outside air temperature of the vehicle and outputs a signal according to the outside air temperature; and an indoor temperature detection means that outputs a signal according to temperature; a fog removal means that removes fog from a vehicle window glass; an output signal of the humidity detection means; an output signal of the outside air temperature detection means; and an output signal of the outside air temperature detection means. and control means for determining, based on the output signal of the detection means, that the window glass is in a state where fogging may occur, and for operating the fog removal means before fogging occurs on the window glass. A fog removal device for a vehicle, characterized in that: