JPH0729588B2 - Automatic wiper device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic wiper device for wiping a windshield of an automobile with a wiper blade.

BACKGROUND ART In a typical prior art, a light path between a light emitting element and a light receiving element that receives light from the light emitting element is interrupted by rain, snow, or the like passing through the light path. This is detected by the light receiving element, the output from this light receiving element is integrated, and when the integrated value reaches a predetermined value, the wiper blade is driven by the motor to wipe the windshield of the automobile. Is configured.

Problems to be Solved by the Invention In such a prior art, depending on the mounting positions of the light emitting element and the light receiving element, the size of the raindrop detection range by the optical path, and the like, even if the rain condition is constant, The detection frequency and sensitivity vary. In addition, during natural rain, the state of rainfall may change in a short time. As a result, in the above-described prior art, the time interval at which the wiper blade is driven fluctuates finely, which causes the driver to feel uncomfortable.

An object of the present invention is to provide an automatic wiper device in which the time interval of driving the wiper blade is adjusted so as to give a comfortable feeling, and the window or the like is wiped by the wiper blade.

Means for Solving Problems The present invention provides a raindrop detecting element for detecting raindrops, an integrating means for integrating the output of the raindrop detecting element, a wiper blade for wiping a window and the like, and a driving means for driving the wiper blade. The control means measures the elapsed time from the drive time of the wiper blade, measures and stores the time interval for each drive, and resets the integrating means according to the drive of the wiper blade by the drive means. Then, in response to the integrated value from the integrating means, (a) when the integrated value becomes equal to or more than a predetermined first discrimination level within the previous time interval, the previous time interval and the first discrimination level from the previous drive. When the time difference from the time required to reach is equal to or greater than a predetermined value SU, the time interval is set short, and (b) the integrated value is smaller than the first discrimination level at the time when the previous time interval has elapsed. When the time is less than the second discrimination level, the time interval is set to be long, and (c) when the integrated value becomes equal to or higher than the first discrimination level within the time interval of the previous time, the time discrimination between the previous time interval and the first discrimination level from the previous drive is performed. When the time difference from the time to reach is less than the value SU, the time interval is set to the same as the previous time, and (d) when the integrated value is equal to or higher than the second discrimination level at the time when the previous time interval has elapsed. An automatic wiper device comprising: a control means for setting the time interval to be the same as the previous time.

Operation According to the present invention, the control means resets the integrating means in response to the drive of the wiper blade by the drive means for driving the wiper blade, and the time interval for activating the drive means is set in advance. When one of a plurality of values is selected and set, and (a) when it is faster than the previous timing, that is, when the time interval is set to be short, the integrated value is the first discrimination value at the time before the previous operation timing. When the time is equal to or higher than the level and the time difference between the previous time interval and the time from the previous drive to the first discrimination level in this time is the value SU or more, and (b) the time is delayed from the previous timing, that is, When the time interval is set long, the integration delay is less than the second discrimination level, which is smaller than the first discrimination level, even at the previous operation timing, (c, d) In other cases, the wiper blade is driven at the same time interval as the previous time interval.

Therefore, for example, in the case where the vehicle is traveling in a rainy place, when the vehicle enters the tunnel, the rise of the integrated value becomes extremely slow, and therefore the wiper blade is driven undesirably. Therefore, it is possible to prevent the wiper blade from being wiped dry, so that the wiper blade is comfortable and the damage to the window glass and the wiper blade due to the wiper blade wiper can be prevented.

Embodiment FIG. 1 is a block diagram of an embodiment of the present invention. The raindrop detection element 1 is provided so as to be exposed to the outside of the automobile, and has a light emitting element 2 such as a light emitting diode and a light receiving element 3 that receives light from the light emitting element 2. When rain, snow, or the like passes through the light path between the light emitting element 2 and the light receiving element 3, the light to the light receiving element 3 is blocked by the raindrops. The light emitting element 2 is driven by the modulation signal from the drive circuit 4. The output from the light receiving element 3 is envelope-detected by the detection circuit 5.

The output waveform derived from the detection circuit 5 to the line 6 is the second waveform.
As shown in FIG. (1), the raindrop detection element 1
A pulse is obtained each time a raindrop passes through the optical path of. The integrating circuit 7 integrates the detection output from the line 6. The integration circuit 7 derives an integrated output via a line 8 to a processing circuit 9 realized by a microcomputer or the like.

The integrated output of the integrating circuit 7 is as shown in FIG. 2 (2), and the pulsed detection output is integrated every time a raindrop passes through the optical path.

The processing circuit 9 receives this integrated output and outputs it to the wiper motor.
Activate 10. As a result, the wiper motor 10 wipes the windshield, which is the window of the automobile, with the wiper blade 11 only once, as shown in FIG.
By driving the wiper motor 10, the integrating circuit 7 is reset. Reference numeral Ta in FIG. 2 (3) indicates the previous time interval each time the wiper blade 11 is driven.

The operation of setting a long time interval for driving the wiper blade 11 in the processing circuit 9, that is, setting the time interval later than the previous timing will be described. The processing circuit 9 activates the wiper motor 10 at one selected time interval from a plurality of predetermined time intervals T0, T1, T2, T3, .... For convenience of explanation, the previous time interval is set to T1, for example. The integrated output of the integrator circuit 7 rises with the passage of time as shown by the line l1. Here, in order to perform level discrimination of the integrated value, a first discrimination level R1 and a second discrimination level R2 smaller than the first discrimination level R1 are determined. If the integrated value is a value M1 that is less than the second discrimination level R2 at the time when the previous time interval T1 has elapsed with the passage of time, the current time interval is set to a value T2 that is larger than the previous time interval T1. (T1 <T2). That is, as shown in FIG. 4, the wiper blade is driven intermittently, the previous time interval is indicated by reference numeral T1, and the integration is performed at time t2 after the time interval T1 from the time t1 thereafter. When the value is less than the second discrimination level R2, the current time interval T2 is set and the time interval T2 is set.
At the time t3 when is elapsed, the processing circuit 9 causes the wiper motor 10
Is activated to drive the wiper blade 11 by the wiper motor 10.

In this way, when the integrated value of the integrating circuit 7 gradually rises with time, such as when a vehicle enters a tunnel during rain, the time interval of the wiper blade 11 is set to be long. That is, the wiper blade 11 can comfortably wipe the window glass without operating the wiper blade 11 excessively frequently.

Therefore, the wiper blade 11 does not need to be wiped unnecessarily, so that the wiper blade 11 is comfortable, and the window glass and the wiper blade can be prevented from being damaged by the wiping.

Referring to FIG. 5, it is assumed that the time interval of the last wiping operation of wiper blade 11 is T1, for example. It is necessary to set a short time interval for driving the wiper blade 11 when the vehicle comes out of a tunnel on a rainy road while the vehicle is running. At time t4, which is less than the elapsed time T1 from the time when the wiper blade 11 is driven by the wiper motor 10, it is assumed that the integral value becomes equal to or higher than the predetermined first discrimination level R1 as shown by the line l2. At this time, the previous time interval T1 and the time ΔT (= T1−t4) from the previous drive to the first discrimination level R1 are calculated. When this time difference ΔT is equal to or greater than the predetermined value SU, the time interval is set to a value T0 shorter than the previous time interval T1, and the operation timing is accelerated in this way. That is, as shown in FIG. 6, the wiper blade 11 is driven by the wiper motor 10, the last time interval is T1, and the last wiper blade is
When the integrated value reaches the first discrimination level R1 at time t6 when time T4 has elapsed from the driving time t5 of 11 and the time difference ΔT (= T1−T4) is equal to or greater than a predetermined value SU, the previous time interval T1 Set a shorter time interval T0. In this way, the wiper blade 11 is driven by the wiper motor 10 at the time t7 when the time interval T0 has elapsed from the time t5.

Therefore, referring to FIG. 7, as shown by the line l1a of the integral value of the integrating circuit 7, in the range A where the integral value is less than the second discrimination level R2 at the time when the previous time interval, for example, T1 has elapsed. , Set the time interval to a large value T2. Further, as shown by the line l2a, in the region B in which the integrated value reaches the first discrimination level R1 within the previous time interval T1 and the time difference is equal to or more than the predetermined value SU, the time interval is set to the previous time interval T1. Set to a shorter value T0. In the remaining area C, the current time interval is set to the same value as the previous time interval T1. That is, in this area C, (a) the previous time interval
When T1 has elapsed, the integrated value is equal to or higher than the second discrimination level R2, or (b) the integrated value is equal to or higher than the first discrimination level R1 within the previous time interval T1, and the time difference ΔT from the previous time. Is less than a predetermined value SU, and in these cases (a) and (b), the time interval is set to be the same as the previous time.

Here, the time intervals T0, T1, T2, T3, ... Of the wiper blade 11 are
It is determined as follows with reference to FIG. That is, the allowable range is obtained from the operation interval of the wiper blade 11 according to the feeling of feeling of the driver of the automobile, and the time interval is set within this allowable range. If the upper limit + X% of the human sense is shown by l3 and the lower limit -Y% line is shown by l4, the allowable range is the range D surrounded by the lines l3,4. It may be X = Y = 30. For example, in human feeling, 14
When it is desired to drive the wiper blade 11 with a feeling of ~ 26 seconds, the actual time interval of the wiper blade 11 is set to 20 seconds. In this way, even if the time interval is set to 20 seconds, it does not seem that the time interval of the wiper blade 11 is short or fast in the rain within the allowable range D of human feeling. In this way, the respective values of the time intervals T0, T1, T2, T3, ... Are set so that the human feeling is continuous. Therefore, the configuration of the processing circuit 9 can be simplified.

The above-mentioned second discrimination level R2 is set to a common constant value for each set time interval T0, T1, T2, T3, as shown in FIG. 9 (1). As another embodiment of the present invention, the second discrimination level R2 may be individually set to different values for each time interval T0, T1, T2, T3, .... The above predetermined value SU
Are time intervals T0, T1, T2, T3, as shown in FIG. 9 (2).
It is set so that it will become a large value with the increase of. This makes it possible to drive the wiper blade 11 so that the human feeling is continuous, and it becomes comfortable.

Next, FIG. 10 is a flow chart for explaining the operation of the processing circuit 9. Step n1 is moved to step n2, and when power is turned on, it is moved to step n3.
Initialization is performed at n3, and the integrated value M is obtained at step n4.
And resetting the measurement time T to zero. Step n5
Now, the integration operation is performed by the integration circuit 7, and the step
At n6, it is judged whether the time lapse T from the last drive time of the wiper blade 11 is equal to or more than the previous time interval (for example, T1 as described above), and if not, the process proceeds to step n7, where the integral value M is It is determined whether or not the first discrimination level R1 or higher is reached, and if not, the process proceeds to step n8 and the elapsed time T
To count.

When it is determined in step n6 that the elapsed time T has become equal to or longer than the previous time interval T1, the process moves to step n9 and the operation described with reference to FIGS. 3 and 4 described above can be performed. In step n9, it is determined whether the integrated value M is equal to or higher than the second discrimination level R2. If not, that is, if the integrated value is less than the second discrimination level R2, the process proceeds to step n10 to set the time interval to the previous time interval. Set to a value T2 that is larger than T1. In step n9, the integrated value M is the second
When it is at the discrimination level R2 or higher, the process moves to step n11, and the current time interval is left as the previous time interval T2. In step n12, wiper blade 11 is connected to wiper motor 1
It is driven by 0 to wipe the window glass.

In step n6, the elapsed time T is the previous time interval.
It is less than T1 and the integrated value is first in step n7.
If it is determined that the discrimination level is R1 or higher, the step
Moving to n13, the action of shortening the time interval may be performed as described in connection with FIGS. 5 and 6 above. At step n13, the time difference ΔT between the previous time interval T1 and the time T from the previous drive until the first discrimination level R1 is reached is calculated. At step n14, it is judged whether or not this time difference ΔT is equal to or larger than a predetermined value SU, and when the time difference ΔT is equal to or larger than the value SU, the process proceeds to step n15, and this time interval is set to the previous time interval T1 in order to accelerate the operation timing. Set to a smaller value T0. If it is determined in step n14 that the time difference ΔT is less than the value SU, step n1
Move to 6 and keep the operation timing as it is, that is, the current time interval is the previous time interval T1. In this way, the wiper blade 11 is driven at step n12.

INDUSTRIAL APPLICABILITY The present invention can be widely applied not only to wipe the windshield of an automobile, but also to wipe other windows with a wiper blade.

Effect As described above, according to the present invention, when the amount of rainfall decreases, for example, the time interval of driving the wiper blade is not affected by the decrease, and therefore the time interval changes frequently. It can be prevented. Further, even when the amount of rainfall increases, the time interval is not affected by the degree of increase. Therefore, the time interval for driving the wiper blade can be adjusted so as to give a comfortable feeling, and the wiper blade can be prevented from being wiped dry.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation of this embodiment, and FIG. 3 is an operation when the wiper blade 11 is driven later than the previous timing. FIG. 4 is a graph for explaining the drive interval of the wiper motor 10 in the state of FIG. 3, FIG. 5 is a graph for explaining the operation when the timing is made faster than the previous timing, and FIG. 5 Wiper motor 10 in the state shown in FIG.
FIG. 7 is a graph showing a driving interval of the wiper blade 11, FIG. 7 is a graph showing a time interval of the wiper blade 11, and FIG. 8 is a set time interval.
FIG. 9 is a diagram for explaining the principle of setting T0, T1, T2, T3, ...
FIG. 10 is a graph showing the lapse of time between the second discrimination level R2 and SU at a predetermined value, and FIG. 10 is a flow chart for explaining the operation. 1 ... Raindrop detection element, 4 ... driving circuit, 5 ... detection circuit, 7 ... integration circuit, 9 ... processing circuit, 10 ... wiper motor, 11 ... wiper blade, R1 ... first discrimination level,
R2 …… Second discrimination level, T0, T1, T2, T3 …… Time interval

Claims (1)

[Claims] 1. A raindrop detecting element for detecting raindrops, an integrating means for integrating the output of the raindrop detecting element, a wiper blade for wiping a window and the like, a driving means for driving the wiper blade, and a control means. The elapsed time from the drive time of the wiper blade is measured, the time interval for each drive is measured and stored, the integrating means is reset according to the drive of the wiper blade by the driving means, and the integration from the integrating means is performed. In response to the value, (a) when the integrated value becomes equal to or more than a predetermined first discrimination level within the previous time interval, the time interval between the previous time and the time from the previous drive until the first discrimination level is reached. When the time difference is equal to or greater than the predetermined value SU, the time interval is set to be short, and (b) the integrated value is less than the second discrimination level that is smaller than the first discrimination level at the time when the previous time interval has elapsed. When the time interval is set to be long and (c) the integrated value becomes equal to or higher than the first discrimination level within the last time interval, the time interval between the previous time and the time from the previous drive to the first discrimination level is reached. When the time difference is less than the value SU, the time interval is set to the same as the previous time, and (d) when the integrated value is equal to or higher than the second discrimination level at the time when the previous time interval has elapsed, the time interval is the same as the previous time. An automatic wiper device, comprising: