JPS58112852A - Mode control device for operation of wiper - Google Patents

Abstract

PURPOSE:To select the operation mode of a wiper on the basis of the level of a difference signal by only taking out the vibration corresponding to the impact of raindrops on the basis of the difference between sensors. CONSTITUTION:A rainfall amount sensor 20 detects the impact of raindrops as the vibration containing the vibration of a car body. A vibration sensor 22 detects the vibration of the car body only. These sensors 20 and 22 are connected to a differential amplifier 23 as a difference signal detector, and on the basis of the output difference between these sensors 20 and 22, an output corresponding only to the vibration corresponding to the impact of raindrops is taken out. The differential amplifier 23 is connected to a rectification circuit 25 via an AC amplifier 24, and the rectification circuit 25 is connected to a comparator 27 via a smoothing circuit 26. The comparator 27 is connected to a wiper operation mode selection circuit 28 to obtain an operation signal of each wiper operation mode in accordance with the level of the output of the smoothing circuit 26.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a vehicle wiper with various drive modes, such as intermittent,
This relates to a wiper drive mode control device that selectively switches between low speed and high speed modes.

Conventionally, the driver or the like manually operated a switch to select the wiper drive mode depending on the situation.

However, it is very cumbersome to operate the switch every time the amount of rainfall or vehicle speed changes, and the location where the changeover switch is attached cannot be changed to a large extent, reducing the degree of freedom in vehicle outfitting.

Therefore, a device has been proposed that can automatically select the wiper drive mode. According to this, for example, as shown in Figure 1111 (-a sensor that detects the impact force of raindrops as vibration)?
'1 is supplied to a bandpass filter 3 via an AC amplifier 2. The output of the bandpass filter 3 is supplied to a rectifier circuit 5 via an amplifier 4, and the rectifier circuit 5
The output of is processed by an adder 6 when there is a plurality of sensors 1. The output of this adder 6 is smoothed by a smoothing circuit 7 and compared
81:.

compared to a predetermined setting level. In response to the output of the comparator 8, the wiper drive circuit 9 is selectively activated, and the wiper is driven in, for example, intermittent, low speed, and high speed modes.

. Further, as the sensor 1, for example, one shown in FIG. 2 was used. In the drawing, reference numeral 10 indicates a plate on which raindrops fall, and one end of the plate 10 is fixed to a support member 111, and this support member 11 is fixed to a damper 12 made of an elastic member.
The damper 12 is also generally cut in order to damp the high frequency component of the vibration of the vehicle body 13, and the support member 11 has a small elastic coefficient and a large mass. things are selected. Note that FIG. 3 shows the vibration characteristics of the sensor l, and shows the so-called resonance frequency fo) at the peak value of the vibration curve H of the support member 11.
4〆T, and its vibration curve H shifts to a lower frequency region than the vibration curve S of the vehicle body 13. Here, 4 is the elastic modulus, and 4 is the mass. In addition, the support plate 10 has a large elastic coefficient 4 and a large mass m so as to separate its resonance frequency f1 from fa in order to separate it from the vibration components (Ill*H, S) of the support member 11 and the vehicle body 13. I choose something small. Note that the vertical axis in FIG. 3 represents vibration acceleration.

FIG. 4 shows changes in waveforms at each check point -9 of the raindrop signal obtained from sensor 1, &), and (z). The signal obtained by the sensor 1 is a vibration signal Lr corresponding to the impact force of raindrops, that is, the frequency of rain, and the vehicle speed (Fig. 4 (a)). )reference).

When the signal from the sensor 1 is supplied to the bandpass filter 3, vibration components of the vehicle body 13 are removed (see FIG. 6). The output of the rectifier circuit 5 is as shown in FIG. 4(a), and the smoothing circuit 7 obtains a signal as shown in FIG. 4(d). ! The signal level in Figure J4 (d) is proportional to the impact force of the raindrop.

However, in such a conventional device, the sensor 11 and the sensor 12 are interposed, and the signal from the sensor 1 is processed by the bandpass filter 3. However, there was a problem in that only specified parts could be used.Also, it took a lot of effort to select the frequency band of the frequency filter 3 so that it matched the 12 frequency characteristics (-). It was also troublesome.Further(:, Danno(12 with raindrops 4:) When exposed, it deteriorated over time and the frequency characteristics of absorbing high frequency components were also likely to change.

Note that there is also a conventional device configured to omit the bandpass filter 3 and process the signal from the sensor I. According to this, a plate 10 is provided as a receiver for resonating vibrations caused by raindrops C2 in an ultrasonic region, and this receiver includes a plate 101 and an ultrasonic vibration element made of ceramic, for example, that generates a signal with an attenuated waveform according to the resonance. Attach.

However, in order to absorb vibration components in the ultrasonic range caused by vibrations of the vehicle body 13, it is necessary to attach an ultrasonic absorbing member such as a damper 12 to such a conventional device.

In addition, in order for the receiver to cause the plate 10 to resonate in the ultrasonic range, the mass of I: must be made small. This results in a lower frequency.In other words, stable operation cannot be achieved.

This invention was made in view of the above-mentioned problems of the conventional technology, and includes a rainfall sensor and a rainfall sensor installed in a portion of the vehicle body corresponding to the wiper surface to detect the impact force of raindrops as vibration including vehicle body vibration. The system is equipped with a vibration sensor that extracts only the vehicle body vibration, and the difference between the outputs of each sensor is taken to extract only the vibration corresponding to the impact force of raindrops, and each wiper drive mode is selected based on the magnitude of this difference signal. An object of the present invention is to provide a wiper drive mode control device.

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

FIG. 5 to FIG. 9 are diagrams for explaining the present invention in detail. First, to explain the configuration, the reference numeral in the figure is a rainfall sensor, and this rainfall sensor is installed at a portion of the vehicle body 21 corresponding to the wiper wiper surface (not shown), and detects the impact force of raindrops as vibration including vehicle body vibration. It is something to do.

Further, reference numeral 22 is a vibration sensor, and this vibration sensor 2
2 dissipates only the vibrations of the vehicle body 21. Add each sensor.

n is a differential signal detector @234: is connected, and the difference between the outputs of each sensor and the output of 22 (from 2), the output corresponding only to the vibration corresponding to the impact force of raindrops is extracted. The differential amplifier n is connected to a rectifier circuit 25 through an AC amplifier, and this rectifier circuit is connected to a comparator circuit through a smoothing circuit. The wiper drive mode selection circuit is connected to a wiper drive mode selection circuit from which drive signals for various wiper drive modes are obtained depending on the magnitude of the wiper drive mode, and a windshield motor M (not shown) for driving the wiper is connected to this circuit path.

For example, the precipitation quantum addition is shown in Figure 6 (&), (b)
, As shown in (0), piezoelectric method (Fig. 6 (a))
, photoelectric method (Fig. 116(b)), magnetoelectric method (Fig. 6(C)
)) etc. are fine. The rainfall sensor 20A according to the piezoelectric method is equipped with a portion 4 of the vehicle body 21 corresponding to the wiper wiped surface: an abbreviated support portion 19 is attached, and one end of the support member 29 is fixed to the rising portion of the support member 29. The bridge is 30m long on both the top and bottom sides of the plate, and a strain gauge G such as a piezoelectric element is fixed to the bridge.Of course, the bridge is a plate (
(capital) is installed to catch raindrops.

The photoelectric rainfall sensor 20B has a light-emitting part and a light-receiving part on the lower surface between the plates, and the receiver optically detects vibrational displacement caused by raindrops on the plate by changing the amount of reflected light.
It is designed to be detected. The other configurations are the same as those of the piezoelectric type, so the explanation will be omitted.

The magneto-electromagnetic rainfall sensor 20C has a coil Cx attached to the lower surface 1 of the receiving plate (9), and a magnet structure is fixed to the support part 19 at a position facing the coil CL, so that the induction generated in the coil CL is fixed. It is designed to detect changes in electromotive force. The other configurations are the same as those of the photoelectric type, so the explanation will be omitted.

On the other hand, the vibration sensors 22A, 22B, and 22C are shown in FIG.
), (b).

As shown in (0), each of the above-mentioned rainfall sensors 2OA, 2
0B.

Although it has a similar configuration corresponding to 20C,
The receiver is covered with a cover B to prevent raindrops from hitting the board. The vibration sensors 22A, 22B, and 22C are installed at positions where vibration components similar to those of the vehicle body 21 detected by the rainfall sensors 20m, 20B, and 20C can be obtained.

Next, a more detailed embodiment constructed based on the block diagram of FIG. TS5 will be described with reference to FIG. Connected to this power supply terminal Vco are two strain gauges G1 in series that form a rainfall sensor and two strain gauges G in series that form a vibration sensor 22. is grounded.

The connection point of each strain gauge G connected to the rainfall sensor is connected to a resistor R.
1 to the non-inverting input terminal of the voltage comparator M1 of the differential amplifier n, and the connection point of each strain gauge G of the vibration sensor n is connected to the inverting input terminal via a resistor R2. . An external resistor Rs is connected between the inverting input terminal and the output terminal of the voltage comparator M1, and the output terminal of the voltage comparator A2 of the reference voltage generating circuit 31 is connected to the non-inverting input terminal via a resistor. has been done. The inverting input terminal and output terminal of this voltage comparator A2 are short-circuited, and the non-inverting input terminal is connected to a voltage dividing resistor Rs +
This voltage dividing resistor Rs p R6 is connected to the connection point of R6.
One end is connected to the power supply terminal vCC, and the other end is grounded.

The output terminal of the voltage comparator A1 is connected to the non-inverting input terminal of the voltage comparator 5 in the AC amplifier 24 via the capacitor C1. Output terminal I: connected, and the inverting input terminal of voltage comparator A5 is connected to the output terminal via resistor R8. ? is connected.

The output terminal of the voltage comparator As is connected to the diode D of the rectifier circuit 25.
1 cathode C: connected, and its anode is connected to the inverting input terminal of the voltage comparator A4 via a resistor Rho. Further, the anode of the diode D2 is connected to the cathode of the diode D1, and the cathode is connected to the resistor Ra.
The other end of the resistor R11 is connected to the connection point of the resistor Ry + Re (:, connected to the non-inverting input terminal C of the voltage comparator A4. The inverting input terminal of the voltage comparator A4 An external resistor R+2 is connected between the output terminal and the output terminal.

The output terminal of the voltage comparator A4 is connected to one end of the resistor R+i of the smoothing circuit 26, and in addition to this resistor R15, the smoothing circuit includes a resistor R+4*R+a and capacitors C2, Cs,
C4 is a so-called capacitor input type, and the connection point of resistor R+s and capacitor C4 is connected to the non-inverting input terminal of voltage comparator A5 via resistor R14, and each connection point of capacitor C2r Cs + Ca (2 is connected to one end of the resistor R11. Also, the inverting input terminal and output terminal of the voltage comparator & are short-circuited.

The output terminal of voltage comparator As is connected to comparator 2 via resistor R17.
A resistor R1s is connected between the non-inverting input terminal and the output terminal of the voltage comparator No. 7. The inverting input terminal of the voltage comparator is connected to the grounded capacitor C5 (one sliding terminal - 2
The sliding terminal l on the ground side of the variable resistance hole having - is connected. One end of the variable resistor (2) is connected to the power supply terminal Vccl, and the other end is grounded via the resistor R1. The output terminal of the voltage comparator Muro is connected to the transistor T via the resistor R20.
Its 21 pin is grounded, and its collector is connected to the power supply terminal 2 through the excitation coil of the 1st relay R. This first relay R
The excitation coil of YI is connected in parallel with the excitation coil of the second relay RY, and the power supply terminal Vca is connected to the collector of the transistor T2 via the excitation coil of the third relay RYi.

The output terminal of this transistor T2 is grounded, its base is connected to the output terminal of the voltage comparator A7 via a resistor R21, and a resistor R2 is connected between the output terminal of and the non-inverting input terminal of the transistor T2.
2 are connected. In addition, the non-inverting input terminal of the voltage comparator A/ is connected to one end (two terminals) of the resistor R17 via the resistor R2m, and its inverting input terminal is connected to the high-voltage side sliding terminal of the variable resistance hole and the grounded capacitor C6. has been done.

The symbol M is a wiper motor for driving the wiper, and the high voltage side terminal of the motor M is connected to the voltage 11[H, and the downstream low speed mode terminal is normally closed for the third relay RYs in the wiper drive mode selection circuit. It is connected to one end of the normally open contact - of the second relay 8η via contact &5.

One end of this normally open contact is the normally closed contact S of the first relay RYi.
It is connected to one input end of the intermittent amplifier via h. Further, the other input terminal of the intermittent amplifier 32 is connected to the anode of the diode Ds via the normally closed contact Sc2 of the second relay. The intermittent amplifier 32 is connected to a power source B, and its output end is connected to an auto-stop switch A1g for intermittent mode. Furthermore, one end of the normally open contact 8os of the third relay 81 is connected to the high-speed mode terminal 1: on the other downstream side of the motor M, and the other end is connected to one end of the normally closed contact 8e+ of the first relay 81. ing. Further, the output terminal of a transistor Ti is connected to the power supply B, its collector is connected to the power supply terminal Vca, and its base is connected to the anode of a diode D4 via a resistor R24.

The cathode of this diode D4 is connected to the cathode of the diode D5 and is also grounded via the wiper switch W1.

Next, the action will be explained.

First, when you need to wipe the wiper, close the wiper switch.

Figure 119 False 1-: As shown 4: The signal at the check point (a) obtained by adding the rainfall amount sensor has the vibration component Po of the vehicle body 21 and the impact force 4 of the raindrops, which is a resonating vibration component.

In addition, as shown in FIG. 9 (b) 4: vibration sensor 22 (=
The signal at the check point ←) is only the vibration component Po of the vehicle body 21. In this way, when the outputs of the sensors 20 and 22 are supplied to the differential amplifier 23, a signal corresponding only to the vibration component due to the impact of the raindrops (at the check point signal) is obtained.Differential amplifier 23
The resistances R1-R2 are respectively ros resistance Rs + R4
are respectively rl, the output of the differential amplifier n is
2el>+O E. Here, ・1 is the output voltage of vibration sensor n, ・
2 is the output voltage of the rainfall sensor, and E is the reference voltage obtained from the reference voltage generation circuit 31.

In this way, the output of the differential amplifier 23 is amplified by the AC amplifier 24 and full-wave rectified by the rectifier circuit. This rectified signal becomes a DC level signal at the smoothing circuit, and the magnitude of this level V is proportional to the magnitude of the vibration component corresponding to the impact force of the raindrop.

When the output level V of the smoothing circuit is small, that is, when the impact force of the raindrops is small, the voltage comparator is used.

Since the voltage at the non-inverting input terminal of A7 is small, each relay RYi e RY2 # R' in the wiper drive mode selection circuit diagram
None of Ys operates. Therefore, intermittent amplifier 3
2 is activated, and the wiper motor M rotates intermittently at a predetermined period due to the action of the switch 42. That is,
The wiper operates in intermittent mode.

Next, when the output level V of the smoothing circuit increases due to an increase in rainfall, etc., the potential at the non-inverting input terminal of the voltage comparator rises, an output is obtained from the output terminal, and transistor T1 is turned on. . Therefore, the excitation coils of the first relay RL and the second relay RY2 are excited, the normally closed contacts ac1+Sc2 are opened, and the normally open contacts 8G2 are closed, so that the operation of the intermittent amplifier 32 is stopped. That is, since the normally closed contact 8a+ remains closed, the wiper motor M
is connected to the low speed mode terminal, and the wiper is driven at low speed.

Then, when the amount of rainfall further increases and the output level V of the smoothing circuit further increases, the potential at the non-inverting input terminal of the voltage comparator A7 rises, so that an output is obtained from its output terminal and the transistor T2 is turned on. Therefore, the third relay R
The exciting coil of Ys is excited and the normally closed contact SC! When I opens, the normally open contact So5 closes. That is, the wiper motor M is connected from the low speed mode terminal to the high speed mode terminal Ht, and the wiper is driven at high speed.

As explained above, according to the present invention, a rainfall amount sensor that detects the impact force of raindrops as vibration that includes vehicle body vibration, a vibration sensor that extracts only vehicle body vibration, and a rainfall A difference signal detector extracts an output corresponding only to the vibration that compensates for the impact force of raindrops based on the difference between the outputs of the volume sensor and the vibration sensor, and a drive signal for various wiper drive modes is generated according to the output of this difference signal detector. Since the system is equipped with a comparator, the driver can automatically select the wiper drive mode (two wiper drive modes) whenever the amount of rainfall or vehicle speed changes during rain while the vehicle is running. In addition, the sensor does not require a damper to attenuate high frequency components of vehicle body vibration.Therefore, there is no need for troublesome considerations such as matching the frequency characteristics between the damper and the bandpass filter as in conventional devices. Furthermore, since the rainfall sensor and the vibration sensor can be formed with similar configurations, there is no need to consider each other's characteristics, and mass production is easy.Also, there is no need to take into account the characteristics of each other, and mass production is easy.Also, it is easy to mass-produce the rain sensor and the vibration sensor, which tend to change over time, such as the damper in conventional devices. Since there is no need to provide a device, it is possible to provide a highly durable and stable device.

[Brief explanation of the drawing]

1 to 184 illustrate a conventional device. FIG. 1 is a block diagram of the wiper drive device, and FIG.
The figure is a schematic configuration diagram of the senna, Figure 3 is a frequency characteristic diagram of various vibration accelerations obtained by the sensor, Figure 4 (a),
(b), (c), (d) are check points (b), (b), (y), (
s), and FIGS. 5 to 9 are diagrams for explaining the present invention in detail. FIG. 5 is a block diagram of the wiper drive mode control device, and FIG.
b) and (c) are schematic configuration diagrams showing each embodiment of the rainfall sensor, and Fig. 6 (- indicates one based on a piezoelectric system, 116
Figure 6) shows the photoelectric method: = based, Figure 6 (c) shows the magnetoelectric method: C = based, and Figure 7 (a), (
b) and (c) are schematic configuration diagrams showing each embodiment of the vibration sensor, in which Fig. 117 (1) is based on the piezoelectric method, Fig. 7 (b) is based on the photoelectric method, and Fig. 817 (a) is the one based on the photoelectric method. FIG. 188 is a block diagram of FIG. Check points (a), (b), (c) in Figure 8
Figure 9 (B) shows the output signal of the rainfall sensor, Figure 9 (B) shows the output signal of the vibration sensor, and Figure 9 (C) shows the output signal of the differential amplifier. It is. First, 20A, 20B, 20C... Rainfall Senna, 21
...Vehicle body, 22.22A, 22B, 22C...
・Vibration sensor, differential amplifier (difference signal detector),
Sae: AC amplifier, 5: Rectifier circuit, 26: Smoothing circuit, 27: Comparison circuit, 4: Wiper drive mode selection circuit. Applicant Nissan Car Five Body Co., Ltd.

Claims (2)

[Claims] (1) A rainfall sensor installed in the vicinity of the wiper wiper surface of the vehicle body detects the impact force of raindrops as vibration including vehicle body vibration, a vibration sensor that extracts only vehicle body vibration, and each of the above-mentioned rainfall sensor and vibration sensor. A difference signal detector that extracts an output corresponding only to the impact force of the raindrop 4: slowing vibration based on the difference in output, and a comparator that obtains drive signals for various wiper drive modes according to the output of the difference signal detector. A wiper drive mode control device comprising: (2) The difference signal detector is a differential amplifier, and the output of the differential amplifier is rectified by a rectifier circuit via an AC amplifier, and the output of the rectifier circuit is passed through a smoothing circuit to provide different comparison levels. Type C: The wiper drive mode control device according to claim 1, wherein the wiper drive mode control device is supplied to a plurality of operating comparison circuits, and supplies the output of each comparison circuit to operate the wiper drive mode selection circuit. .