JPH06144160A - Wiper control device - Google Patents

Abstract

PURPOSE:To prevent a front window from glaring when the light of a road lamp illuminates the rain drops stuck on the front window at the time of a rainfall at night. CONSTITUTION:When the second detecting means 102 detects that the surrounding of a vehicle is dark and the first detecting means 101 detects the incoming light, the number of actions per unit time of a drive control means 100 is increased by an action number increasing means 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for electrically driven wipers.

[0002]

2. Description of the Related Art Intermittently selected by a wiper switch,
A control device that operates a wiper according to an operation mode such as low speed or high speed is known. In this type of controller,
The number of operations per unit time is preset for each operation mode. If the intermittent operation mode is selected during light rain, for example, the wiper operates intermittently 20 times per minute, and if the low speed mode is selected during normal rain, for example, The wiper operates continuously 45 times per minute, and if the high speed mode is selected during heavy rain, the wiper operates continuously 70 times per minute, for example.

There is also known a raindrop sensing automatic intermittent wiper which senses raindrops, sets the number of times the wiper is operated per unit time according to the amount and impact of raindrops, and drives the wiper intermittently (for example, Nissan New Car Manual Y32-1
(F003669) June 1991). FIG. 5 shows the structure of an automatic intermittent rain wiper wiper. Raindrop sensor 1
Is composed of a piezoelectric element and an amplifier (not shown), and when a raindrop collides with a vibration plate provided on the upper surface of the piezoelectric element, a voltage corresponding to the amount and impact of the raindrop is generated in the piezoelectric element and is amplified and output by the amplifier. . The charging circuit 2 has a built-in capacitor,
The capacitor is charged by the output voltage of the raindrop sensor 1. The terminal voltage Vc of this capacitor is compared with the reference voltage Vo by the comparison circuit 3, and when the terminal voltage Vc of the capacitor exceeds the reference voltage Vo, the comparison circuit 3 outputs an intermittent drive signal to the drive circuit 4. When the drive circuit 4 receives the intermittent drive signal, the drive circuit 4 drives the wiper drive motor 5 to set the wiper to 1
Make them wipe only once. The output of the comparison circuit 3 is connected to a reset terminal (not shown) of the charging circuit 2. When the intermittent drive signal is output, the charge of the capacitor of the charging circuit 2 is discharged and the charging circuit 2 is reset. . Thus, in the raindrop sensing automatic intermittent wiper, the number of times of operation is set to, for example, 3 to 30 times per minute according to the appropriate amount of rain and impact, and the number of times of operation increases when heavy rain occurs, and the number of times of operation decreases when light rain occurs. Become.

[0004]

However, in the above-mentioned conventional wiper control device, the number of operations per unit time is preset for each operation mode regardless of day or night, or according to the amount of raindrops or impact. Since it is set, the number of operations does not change even at night, and there is a problem that when the light of a streetlight enters a windshield with raindrops attached, the raindrops diffract the light and make it dazzling.

An object of the present invention is to prevent raindrops adhering to the front window from being dazzled by the light of a streetlight when it is raining at night.

[0006]

The present invention will be described with reference to FIG. 1, which is a claim correspondence diagram, and the present invention comprises drive control means 100 for operating a wiper in accordance with a set number of operations per unit time. And a first detection means 101 applied to the wiper control device for detecting extraneous light,
Second detection means 102 for detecting that the surroundings of the vehicle are dark
When the second detecting means 102 detects that the surroundings of the vehicle are dark and the first detecting means 101 detects extraneous light, the drive control means 100 increases the number of operations per unit time. The operation number increasing means 103 is provided to achieve the above object.

[0007]

[Operation] When it is detected that the surroundings of the vehicle are dark at the time of nighttime rain and external light is detected, the number of times of operation of the wiper per unit time is increased and the raindrops adhering to the windshield are sufficiently wiped off. To prevent diffuse reflection of extraneous light and secure good visibility.

[0008]

FIG. 2 shows the structure of an embodiment in which the present invention is applied to a raindrop sensing automatic intermittent wiper. It should be noted that the same components as those in FIG. 5 showing the configuration of the conventional wiper control device are designated by the same reference numerals, and differences will be mainly described. The optical sensor 6 is, as shown in FIG. 3, a front differential grill 11 of the vehicle.
The light receiving portion is installed on the upper side so as to face upward, and detects external light such as a street light and outputs a signal of a level corresponding to the light intensity to the reference voltage setting circuit 7. If the light receiving portion of the optical sensor 6 is installed in front of the vehicle while being inclined, the light of the headlight of the oncoming vehicle can also be detected. The light switch 8 is a switch for turning on the headlight, and outputs a turn-on signal to the reference voltage setting circuit 7 when the surroundings of the vehicle are dark and the headlight is turned on. The reference voltage setting circuit 7 sets the reference value Vo of the comparison circuit 3 to the normal value V1 when the signal level output from the optical sensor 6 is lower than a preset value even when the headlight is off or when the headlight is on. When the headlight is on and the output signal level of the optical sensor 6 is equal to or higher than the set value, the reference value Vo is switched to V2 which is lower than V1. That is, when the surroundings of the vehicle are dark and external light is detected, the reference value Vo is switched from V1 to V2.

FIG. 4 is a time chart showing the operation of each part of the embodiment. Now, it is assumed that the wiper is operated in the raindrop detection automatic intermittent mode described above during light rain. At time t1, the surroundings of the vehicle became dark, so the headlights were turned on by the light switch 8, and at time t2
Then, the light of the streetlight is incident on the front window, and the output signal level of the optical sensor 6 exceeds the set value. Further, in order to make the explanation easy to understand, it is assumed here that the amount and impact of raindrops are constant and the raindrop sensor 1 outputs a constant voltage. At this time, the terminal voltage Vc of the capacitor of the charging circuit 2 is boosted at a constant rate of increase. Since the output signal level of the optical sensor 6 is equal to or lower than the set value until time t2 regardless of whether the headlight is turned on or off, the reference value Vo of the reference voltage setting circuit 7 is set to the normal value V1. Therefore, the raindrop sensor 1 outputs a voltage according to the amount and impact of raindrops to charge the capacitor of the charging circuit 2. When the terminal voltage Vc of the capacitor reaches the reference value Vo = V1, the intermittent drive signal is output from the comparison circuit 3 to the drive circuit 4, and the drive circuit 4 drives the wiper drive motor 5 to wipe the wiper only once. . At the same time, the charging circuit 2
The charging charge of the capacitor is discharged and the charging circuit 2 is reset. After that, such a series of operations are repeated,
The intermittent operation of the wiper is performed as shown in FIG.

When the output signal level of the optical sensor 6 exceeds the set value at time t2, the reference voltage Vo of the comparison circuit 3 is switched to V2 lower than V1 by the reference voltage setting circuit 7. As a result, in the comparison circuit 3, the terminal voltage Vc of the capacitor of the charging circuit 2 is compared with V2 lower than V1,
The drive signal is output when the terminal voltage Vc exceeds the reference voltage Vo = V2. That is, as shown in FIG. 4, the output cycle of the drive signal is shortened, and the number of wiper operations per unit time is increased. As a result, raindrops adhering to the front window are sufficiently wiped off, and diffuse reflection of incident light due to raindrops is eliminated.

As described above, when the headlight is turned on at night and the light intensity of the external light exceeds a predetermined level, the number of times the wiper is operated per unit time is increased, so that the windshield adheres to the front window. The raindrops can be wiped off sufficiently to prevent diffuse reflection and ensure a good field of view.

[0012] Normally, at night, raindrops adhering to the front window are less noticeable than at daytime. Therefore, when night is detected with a light switch etc., the number of wiper operations per unit time should be less than that during daytime, and if external light is detected in this state, the number of operations per unit time should be returned to that of daytime. You may

In the structure of the above embodiment, the raindrop sensor 1, the charging circuit 2, the comparison circuit 3 and the driving circuit 2 serve as drive control means, the optical sensor 6 serves as the first detection means, and the light switch 8 serves as the second detection means. The reference voltage setting circuit 7 constitutes the detection means and the operation number increasing means.

Although the present invention has been applied to the raindrop sensing automatic intermittent wiper in the above-described embodiment, the present invention is also applicable to the wiper control device for operating the wiper according to the operation mode selected by the wiper switch described above. The invention can be applied. In that case, if it is detected that the surroundings of the vehicle are dark and external light is detected, switch to the low speed mode when the intermittent mode is set, or switch to the high speed mode when the low speed mode is selected. The number of operations per unit time may be increased.

Further, in the above-described embodiment, it is detected that the surroundings of the vehicle are dark by the lighting operation of the light switch, but an optical sensor may be provided to detect the illuminance around the vehicle.

[0016]

As described above, according to the present invention, the number of times of operation of the wiper per unit time is increased when the surroundings of the vehicle are dark and external light is detected. The raindrops can be wiped off sufficiently to prevent diffuse reflection and ensure a good field of view.

[Brief description of drawings]

FIG. 1 is a complaint correspondence diagram.

FIG. 2 is a block diagram showing the configuration of an embodiment.

FIG. 3 is a diagram showing an installation location of an optical sensor.

FIG. 4 is a time chart showing the operation of the embodiment.

FIG. 5 is a block diagram showing a configuration of a conventional wiper control device.

[Explanation of symbols]

 1 Raindrop Sensor 2 Charging Circuit 3 Comparison Circuit 4 Driving Circuit 5 Wiper Driving Motor 6 Optical Sensor 7 Reference Voltage Setting Circuit 8 Light Switch 11 Front Diff Grill Vo, V1, V2 Reference Voltage Vc Capacitor Terminal Voltage 100 Drive Control Means 101 1st Detecting means 102 second detecting means 103 actuation number increasing means

Claims (1)

[Claims] 1. A wiper control device including drive control means for operating a wiper according to a set number of times of operation per unit time, a first detection means for detecting external light, and detection of dark surroundings of a vehicle. And a second detection unit that detects that the surroundings of the vehicle are dark and the first detection unit detects external light,
A wiper control device comprising: an operation number increasing means for increasing the operation number per unit time by the drive control means.