JPH0562365U - Sensor device in auto wiper device - Google Patents

Abstract

(57) [Summary] [Construction] A windshield wiper 1 is provided with a capacitance type raindrop sensor that detects when raindrops adhere to the windshield glass 1 and activates the wiper. A temperature sensor for detecting the glass temperature is provided in order to prevent the glass from operating. The film-shaped sensor electrodes 31 and 32 that form the raindrop sensor 3 are provided at the glass bonded portion of the laminated glass that forms the windshield glass 1, and the temperature sensor 4 is formed in a film shape. It is installed at the glass joint. [Effect] A raindrop sensor and a temperature sensor are embedded in the windshield glass, and both sensors can be reliably protected from the outside without disturbing the wiping operation of the wiper. The temperature sensor can detect the glass temperature in the same environment as the raindrop sensor, and the wiper operation during freezing can be reliably prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sensor device used in an automobile auto wiper device.

[0002]

[Prior Art]

 Conventionally, an electrostatic capacitance type raindrop sensor having a pair of sensor electrodes is provided on the windshield glass of an automobile, and raindrops are detected from the change in capacitance between the sensor electrodes that occurs when raindrops adhere to the windshield glass. There is known an automatic wiper device that detects and operates the wiper automatically.

By the way, if the outer surface of the windshield glass freezes, the electrostatic capacitance between the sensor electrodes of the raindrop sensor changes in this case as well. An automatic wiper device has also been proposed in which a temperature sensor for detecting is provided so that the operation of the wiper by the raindrop sensor is stopped when the glass temperature is below a predetermined temperature.

[0004]

[Problems to be solved by the device]

 In the case of the above, the raindrop sensor and the temperature sensor are attached to the outer surface of the windshield glass, and these sensors are covered with a protective film. If it breaks, the protective function of the sensor is impaired, while thickening the protective film hinders the wiping action of the wiper. The present invention has been made in view of the above points, and an object thereof is to provide a sensor device capable of reliably protecting the sensor without disturbing the wiping operation of the wiper.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention pays attention to the fact that a laminated glass in which two glasses are joined is used as a windshield glass, and a film-like sensor electrode constituting a raindrop sensor is interposed at the glass joining portion. In addition to the above, the temperature sensor formed in a film shape was interposed in the glass joint.

[0006]

[Action]

 Both the raindrop sensor and the temperature sensor are installed in the glass joint part and embedded in the windshield glass, so that both sensors are reliably protected from the outside world, and the wiping action of the wiper is not disturbed by both sensors. . In this case, the temperature sensor may be integrated into the sensor electrode at the terminal portion or the like, which can reduce the number of sensor terminals for external extraction and simplify external wiring. Further, the signal processing circuit connected to the raindrop sensor or the temperature sensor may be formed as an IC chip and provided in the glass joint portion, whereby the digital signal from the signal processing circuit can be taken out to the outside. Compared to the case where the analog signal from the sensor is output to the outside, the wiper is less likely to malfunction due to disturbance factors such as variations in the resistance value of the external wiring.

[0007]

【Example】

 Referring to FIG. 1, reference numeral 1 denotes a windshield glass on the front side of an automobile, and raindrop sensors 3 are provided in a plurality of regions of the windshield glass 1 wiped by a wiper 2.

As shown in FIG. 2 and FIG. 3, the windshield glass 1 is formed by heating and pressing the outside glass 1a and the inside glass 1b by sandwiching an intermediate film 1c made of a transparent insulating material such as polyvinyl butyral. It is composed of laminated glass that is adhered to each other by.

The raindrop sensor 3 is composed of a capacitance-type sensor in which a pair of comb-teeth-shaped sensor electrodes 31 and 32 are arranged in parallel with a constant gap between them, and an intermediate film 1 c and The electrode forming material such as ITO (isodium tin oxide) is attached to the inner surface of the exterior glass 1a, which is the bonding surface of the, in a transparent thin film by vacuum deposition, sputtering, printing, etc. When the outer glass 1a and the inner glass 1b are formed and bonded to each other via the intermediate film 1c as described above, the raindrop sensor 3 is embedded in the glass bonding portion. A thin-film temperature sensor 4 made of a heat-sensitive material whose resistance value changes in response to heat of SiC or the like is provided on the inner surface of the outside glass 1a, which is located near the sensor electrodes 31 and 32. At the time of glass bonding, the temperature sensor 4 is embedded in the glass bonding portion like the raindrop sensor 3.

The raindrop sensor 3 is connected to an external signal processing circuit 5 via terminal portions 31a and 32a connected to the sensor electrodes 31 and 32, and the temperature sensor 4 also has a pair of thin film-shaped terminal portions 4a and 4b. Is connected to the signal processing circuit 5. The signal processing circuit 5 includes an oscillator 51 that generates a signal having a frequency corresponding to the capacitance of the raindrop sensor 3, a frequency-voltage converter 52, and a rainfall determination circuit 5a including a switching element 53, and a temperature sensor 4. It is composed of a temperature judgment circuit 5b having a comparator 54 for discriminating a voltage change due to the resistance change of the above, and an AND circuit 5c for inputting signals from the both judgment circuits 5a and 5b. When the level signal is output, the wiper motor 7 is operated via the control circuit 6.

When raindrops adhere to the outer surface of the windshield glass 1, the capacitance between the pair of sensor electrodes 31 and 32 of the raindrop sensor 3 changes, the oscillation frequency of the oscillator 51 changes, and the converter 52 The switching element 53 is turned off via this, and a high level signal is output from the rainfall determination circuit 5a. On the other hand, when the glass temperature is lower than a predetermined temperature (for example, 0 ° C.), a low level signal is output from the temperature determination circuit 5b. Without this, a low level signal is output from the AND circuit 5c, and the wiper motor 7 does not operate. Therefore, the operation of the wiper is prevented when the outer surface of the windshield glass 1 is frozen.

By the way, the windshield glass 1 may be hand-wipe during warm-up operation after the engine is started. At this time, if the wiper is activated, it interferes with the hand-wiping work. Therefore, in this embodiment, a predetermined time has elapsed from the engine start. Sometimes, means 8 for outputting a high level signal is provided, and the output signal is input to the AND circuit 6a provided in the control circuit 6 together with the output signal from the AND circuit 5c, and the high level signal is output from the AND circuit 6a. When it is output, the wiper motor 7 is operated via the wiper drive circuit 6b provided in the control circuit 6, and thus the wiper is prevented from operating until a predetermined time elapses after the engine is started. Although not shown, when the vehicle is started, the wiper operation may be controlled only by the output signal of the rainfall determination circuit 5a regardless of the glass temperature.

FIG. 4 shows another embodiment, in which a terminal portion 31b branched from a terminal portion 31a for the electrode is formed at the end portion of one sensor electrode 31 of the raindrop sensor 3 and the end portion is formed. The temperature sensor 4 is integrally incorporated in the middle of the child portion 31b. The temperature sensor 4 is formed by chemically depositing a heat sensitive material in a thin film form on the inner surface of the exterior glass 1a when forming the sensor electrodes 31, 32 on the inner surface. According to this configuration, there is an advantage that the terminal portion 31a of the sensor electrode 31 is shared with one terminal portion of the temperature sensor 4 and the number of terminals can be reduced. The temperature sensor 4 can be composed of a thin film SiC thermistor or a thin film platinum heat sensitive element. Especially, the latter has advantages such as stability of resistance value and large output.

Further, in the above embodiment, the signal processing circuit 5 is arranged outside the windshield glass 1, that is, on the vehicle body side. However, the signal processing circuit 5 shown in FIG. As shown in FIG. 5, the circuit 5 may be provided in the glass bonding portion of the windshield glass 1 together with the sensors 3 and 4.

According to this, the output terminal 5d of the signal processing circuit 5 is connected to the control circuit 6, and the operation of the wiper can be controlled by the digital signal from the circuit 5, as in the above embodiment. The wiper malfunction due to a disturbance factor such as a variation in the resistance value of the external wiring is less likely to occur as compared with a case where an analog signal from each of the sensors 3 and 4 is transmitted to an external signal processing circuit. In the figure, 5e and 5f are a power supply terminal and a ground terminal connected to the ignition switch, respectively.

[0016]

[Effect of the device]

 As is clear from the above description, according to the first aspect of the present invention, both the raindrop sensor and the temperature sensor are provided in the glass joint portion of the windshield glass, so that both sensors can be installed without disturbing the wiping operation of the wiper. It is possible to reliably protect the environment from the outside, and the temperature sensor can detect the glass temperature in the same environment as the raindrop sensor, and the operation of the wiper during freezing can be reliably prevented.

Further, according to the invention of claim 2, the number of terminals of the sensor can be reduced to simplify the external wiring, and according to the invention of claim 3, the external extraction signal is digitized to cause the disturbance factor. It is possible to prevent malfunction of the wiper due to.

[Brief description of drawings]

FIG. 1 is a perspective view of a front portion of an automobile showing a layout of a raindrop sensor.

FIG. 2 is a perspective view of a main part of a windshield glass equipped with the device of the present invention.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a perspective view of a main part showing another embodiment of the device of the present invention.

FIG. 5 is a perspective view of a main part showing still another embodiment of the device of the present invention.

[Explanation of symbols]

1 Windshield glass 3 Raindrop sensor 31, 32 Sensor electrode 4 Temperature sensor 5 Signal processing circuit

Claims (3)

[Scope of utility model registration request] 1. A windshield glass is provided with a capacitance type raindrop sensor and a temperature sensor for detecting a glass temperature,
In an automatic wiper device that controls the operation of a wiper based on signals from both sensors, a film-like sensor electrode that constitutes the raindrop sensor is provided at a glass joint portion of laminated glass that constitutes windshield glass. At the same time, the temperature sensor formed in the form of a film is provided in the glass bonding portion, and a sensor device in an auto wiper device. 2. The sensor device in an automatic wiper device according to claim 1, wherein the temperature sensor is integrally incorporated in the sensor electrode. 3. The sensor device in the automatic wiper device according to claim 1, wherein a signal processing circuit connected to the raindrop sensor and the temperature sensor is provided in the glass bonding portion.