JP2941657B2 - Wiper control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper control device and, more particularly, to a wiper control device for injecting a washer liquid onto a glass surface and interlocking a wiping motion of the wiper.

[0002]

2. Description of the Related Art Conventionally, when the glass surface becomes dirty, the washer liquid is ejected and the wiper is caused to perform a reciprocating wiping motion to wipe off the dirt. Further, after the washer liquid is ejected, the number of times of reciprocating wiping of the wiper arm is determined. There is a washer-linked wiper control device that is operated a number of times to wipe out dripping or remaining liquid.

However, depending on the set number of reciprocating wiping motions of the wiper arm performed after the washer liquid is ejected as described above, the liquid on the glass surface can be wiped off in a small number of times because the liquid on the glass surface is easy to dry in fine weather. When the set number of times is small, the washer liquid may remain on the glass surface after the wiping is completed.
In such a case, there is a disadvantage that the wiper switch must be operated again so as to perform the washer interlocking and the wiper arm wiping operation again. In addition, if the number of times of wiping after the washer liquid is ejected is set so that sufficient wiping is performed in rainy conditions, there is a disadvantage that an extra wiping operation is performed even after complete wiping in fine weather.

[0004]

In order to cope with the above-mentioned difference in weather, it is conceivable to perform control based on the wiping time. In this case, a certain threshold is set,
When the operation is performed for an earlier wiping time, it can be determined that the glass surface is wet, and when it is later, it can be determined that the glass surface is dry. However, even when water droplets are not attached, the wiping speed is high at high humidity, and the threshold value must be changed under the conditions of temperature and humidity, which complicates the control.

In view of the problems of the prior art, a main object of the present invention is to always perform an extra wiping motion under various conditions when the wiper arm is caused to perform a wiping motion in conjunction with the washer liquid ejection. It is an object of the present invention to provide a wiper control device capable of wiping a residual liquid without any problem.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided, in accordance with the present invention, a method for ejecting a washer liquid onto a glass surface while operating a washer switch, thereby interlocking a reciprocating wiping motion of a wiper arm and a corresponding washer. What is claimed is: 1. A wiper control device comprising: a wiper arm configured to continuously perform the wiping motion a plurality of times even after a switch is released; a wipe time detector for detecting a wipe time of the wiper arm; and a reciprocating wipe time after the release of the washer switch. The wiper arm in the reciprocating wiping motion in an earlier mode, and when the rate of change of the current wiping time of the wiper arm with respect to the previous wiping time is greater than or equal to an upper threshold greater than 1, the mode is changed to a mode in which the reciprocating wiping time is slower. Means for controlling the wiper arm to make a reciprocating wiping motion. It is achieved by providing a wiper control system.

[0007]

[Action] After the washer liquid is ejected, every time the reciprocating wiping motion is performed once, the remainder of the washer liquid is removed, and the reciprocating wiping time increases as the resistance between the washer liquid and the glass surface increases. The change rate of the round-trip wiping time with respect to the previous time is larger than 1. When the liquid is gradually removed, the above change rate does not change so much, but when the liquid remains at the previous wiping but the liquid is almost completely removed at the current wiping, the change rate is changed. Therefore, the last wiping time can be determined by determining that the rate of change has significantly changed by an upper threshold value greater than 1.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention.

FIG. 1 is a main part circuit diagram of a washer-linked wiper control device to which the present invention is applied. A wiper blade 3 attached to a free end of a wiper arm 2 driven by a wiper motor 1 to reciprocally swing is urged against a glass surface (not shown) with a predetermined pressing force. As shown in FIG. 1, the drive of the wiper motor 1 is controlled by a motor drive control circuit 4.
, A mode selection signal of the wiper switch 5 is input, and the motor 1 is controlled in a wiper operation mode corresponding to the mode selection signal.

The wiper switch 5 has a high-speed wiping mode (HI) with a short reciprocating wiping time for wiping the wiper arm 2 at a high speed, and a low-speed low-slope wiping time for a wiping motion at a lower speed than the high-speed wiping mode HI. The wiping mode (LO) and the intermittent wiping mode (INT) having the same wiping speed as the low-speed wiping mode LO but having a longer reciprocating wiping time for performing the wiping motion at the stop position with an arbitrary pause time are selected. In addition to having a wiper operation switch unit for obtaining, a washer switch unit for appropriately selecting a washer mode (W) for jetting a washer liquid onto a glass surface. When the washer mode W is selected by the wiper switch 5, the washer liquid jetting device 6 is operated in response to the selection signal, and the washer liquid is jetted to the glass surface by a pump (not shown), and the wiper arm 2 is linked. The motor drive control circuit 4 is controlled to perform the wiping motion in the low-speed wiping mode LO.

The wiper motor 1 is connected to a pulse generation circuit 7 for detecting the drive current and shaping the ripple to obtain a rotation pulse. The motor rotation pulse signal from the pulse generation circuit 7 is supplied to the first and second flip-flops FF1, FF2.
The signal is input to the AND circuit AD1 and branched from both flip-flops FF1 and FF2 to the second AND circuit AD2.
Is entered. Both AND circuits AD
A pulse signal of a predetermined frequency from the clock circuit CLK is input to 1 · AD2 in parallel with each of the input signals.

The pulse signal from the pulse generation circuit 7 branches before the first flip-flop circuit FF1 and is input to the counter circuit CNT. When the motor rotation pulse signal reaches, for example, 256 pulses, the counter A signal is output from the circuit CNT to the reset terminal of the second flip-flop FF2 to reset the second flip-flop FF2. The counter circuit CNT and the first flip-flop circuit FF1 are reset by a stop position detection signal from an auto stop switch STSW for detecting that the wiper arm 2 has reached a predetermined stop position.

Output signals from the AND circuits AD1 and AD2 are separately input to the wiping time detection circuit 8. The first AND circuit AD1 outputs a clock pulse signal from the clock circuit CLK until the motor rotation pulse reaches 256 pulses,
The second AND circuit AD2 outputs a clock pulse signal from the clock circuit CLK until the first flip-flop FF1 is reset by the stop position detection signal. In the wiping time detection circuit 8, the first AND circuit AD
1 and a determination of the stop position of the wiper arm 2 based on the presence or absence of the continuous input of the clock pulse signal via the second AND circuit AD2, the wiper arm 2 undergoes one reciprocating wiping motion. Time is calculated.

Then, a wiping time signal from the wiping time detecting circuit 8 is input to a change rate calculation control circuit 9 as means for calculating a change rate and controlling the change of the wiping mode. The change rate calculation control circuit 9 stores and updates the input wiping time as a previous value every time the wiping time signal is input from the wiping time detection circuit 8, and calculates a change rate of the current input wiping time with respect to the previous value. , Compared with the upper and lower thresholds described below,
A motor drive control signal is output to the motor drive control circuit 4 as appropriate according to the result.

FIG. 2 is a flowchart showing the control according to the present invention. In step ST1, the washer mode W is selected by the washer switch section of the wiper switch 5, and when it is detected that the selection operation of the washer switch section has been canceled (washer ejection completed), the process proceeds to step ST2, and in step ST2, low-speed wiping is performed. Mode L
A wiping motion by O is performed.

In the next step ST3, it is determined whether or not the number of wiping is equal to or more than a predetermined number. Thereby, the upper limit of the number of times of wiping after the washer liquid is ejected is determined. If it is determined in step ST3 that the predetermined number has not reached the upper limit, the process proceeds to step ST4.

In step ST4, as described above, the change rate of the current wiping time required for one reciprocation calculated by the wiping time calculation control circuit 8 with respect to the previous time and the lower limit threshold α (for example, 0.
98). If the rate of change is below the threshold α,
This is the case where the wiping speed is faster than the previous time, and it can be determined that the amount of liquid adhering to the glass surface has further increased, and the process returns to step ST3 to continue the wiping operation up to a predetermined number of times. If the change rate is larger than the threshold value α, the wiping speed may be lower than the previous time, and the process proceeds to step ST5 to make the determination.

In step ST5, the change rate of the current wiping time required for one reciprocation with respect to the previous time is compared with an upper limit threshold β larger than 1 (for example, 1.03). Change rate is threshold β
In the case described above, the wiping speed is much slower than the previous time, and it can be determined that the amount of the liquid adhering on the glass surface has suddenly decreased.
In step 6, an intermittent wiping motion is performed in an intermittent wiping mode INT which is a mode in which the reciprocating wiping time is slow. In the present embodiment, the intermittent wiping mode INT is performed in step ST6. However, this is the case where the intermittent wiping mode INT is performed before the washer interlocking operation, for example, the wiper operation is not performed. In this case, the stop mode may be set by detecting the position of the operation switch.

If the rate of change is smaller than the upper limit threshold β in step ST5, it means that the rate of change is between the upper and lower thresholds since step ST4 has been passed. It can be determined that the wiping operation has been performed without any error, and the process returns to step ST3 to continue the wiping operation up to a predetermined number of times.

Next, FIG. 3 shows experimental data for observing a change in the rate of change with the passage of the number of wiping operations after the washer liquid is ejected. In FIG. 3, the horizontal axis represents the number of times of wiping, and the vertical axis represents the rate of change of the current wiping time required for one round trip with respect to the previous wiping time. As shown in FIG. 3, the change rate is substantially 1 during the washer ejection and the washer interlocking in the low-speed wiping mode LO. After the washer ejection is stopped, the remaining amount of the liquid decreases each time wiping is performed, so that the rate of change increases each time as shown in the figure. In FIG. 3, to see the change in the rate of change,
This shows a case where wiping is continued even after the liquid is completely wiped.

As shown in FIG. 3, the rate of change is 1.0
After crossing 3, it returns to 1. Change rate is 1.
When the value exceeded 03, the liquid was almost completely wiped from the glass surface at the time of the previous time. Thereafter, the rate of change gradually decreases, which indicates that the rate of change is approaching 1 because the amount of one wiping is small and gradually approaches the completely wiped state.

When the rate of change is close to 1, for example, when the washer liquid is applied to the glass surface at the time indicated by Tw, the resistance decreases and the wiping speed increases, so that the rate of change as indicated by the imaginary line is obtained. Is greatly reduced. The experimental value is 0.
Since it is about 95 to 0.96, the above-mentioned step ST4
Was set to 0.98.

In this embodiment, the change in the wiping time for each reciprocation is observed. However, the control is performed by detecting the wiping time for each one-way route or detecting the wiping time in a specific range. Can also.

[0024]

As described above, according to the present invention, since the state of the residual liquid on the glass surface is determined based on the current change rate of the wiping time with respect to the previous time, the determination is made based on the absolute value of the wiping time. However, it is possible to always appropriately control the number of times of wiping the remaining liquid after the washer interlocking operation without being affected by the difference in weather conditions.

[Brief description of the drawings]

FIG. 1 is a main part circuit diagram of a washer-linked wiper control device to which the present invention is applied.

FIG. 2 is a flowchart showing control based on the present invention.

FIG. 3 is a diagram showing a change in the change rate of the wiping time as the number of wiping passes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wiper motor 2 Wiper arm 3 Wiper blade 4 Motor drive control circuit 5 Wiper switch 6 Washer liquid ejection device 7 Pulse generation circuit 8 Wiping time calculation control circuit

Claims (1)

(57) [Claims] 1. A wiper liquid is spouted onto a glass surface while a washer switch is being operated to interlock a reciprocating wiping movement of a wiper arm, and the wiper arm is continuously wiped a plurality of times even after the operation of the washer switch is released. A wiper control device configured to detect a wipe time of the wiper arm in a predetermined range, a change rate of a current wipe time of the wiper arm with respect to a previous wipe time, and the washer switch. After the operation is released, the wiper arm is reciprocated in the mode in which the wiping time is short, and when the rate of change is equal to or greater than the upper limit threshold greater than 1, the wiper arm is reciprocated in the mode in which the reciprocating wiping time is slow. Control means for controlling the wiper control as described above.