JP3053461B2 - 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 which is suitably implemented for a vehicle and drives a wiper blade at a wiping interval suitable for a rainy condition.

[0002]

2. Description of the Related Art A so-called automatic wiper control device for controlling a wiper operation based on an output of a raindrop sensor integrates a value based on an output from the raindrop sensor, and when the integrated value becomes equal to or greater than a predetermined threshold value, The wiping operation of the wiper blade is started at the earlier of the time when a predetermined intermittent time has elapsed after the end of the previous wiping operation of the wiper blade or the earlier.

The intermittent time is, for example, when the wiper blade is in a high-speed continuous operation state, a low-speed continuous operation state, an intermittent operation state of 1.5 seconds, hereinafter, an intermittent operation state of 3 seconds, 6 seconds, 12 seconds, and 24 seconds. It consists of seven steps for selection.

In a typical prior art, when the integrated value is equal to or more than the threshold and the wiper blade is driven, the elapsed time from the end of the previous wiping operation to the time when the wiper blade is equal to or more than the threshold is set. When the intermittent time is within 80% of the intermittent time, the step is changed by one step so that the next intermittent time is shortened. When the elapsed time exceeds 80% of the set intermittent time,
The next intermittent time step is held in the current intermittent time step.

On the other hand, if the integrated value does not exceed the threshold value even after the set intermittent time has elapsed, and the wiper blade is driven when the set intermittent time has elapsed, the The integrated value at the time is 1 / th of the threshold.
If it is less than 2, the step is changed by one step so that the next intermittent time becomes longer. When the integrated value is equal to or more than １ ／ of the threshold value, the next intermittent time step is held at the current intermittent time step.

[0006]

As described above, in the prior art, the step change of the intermittent time is performed only one step at a time, so that a sudden rainfall condition such as when passing through a tunnel or under an overpass is required. If it changes, the step change of the intermittent time cannot follow, and the driver feels strange. In particular, when escaping after traveling for a long time under a tunnel or under an overpass, the intermittent time is set to a long step, so that it takes a long time to change the step to a low-speed continuous operation state or a high-speed continuous operation state. Cost. On the other hand, if the next intermittent time is immediately made to correspond to the step corresponding to the current integrated value or the elapsed time in order to improve the delay of the response as described above, the detection range of the raindrop sensor is extremely narrow. As a result, the intermittent time becomes unstable, giving the driver discomfort.

An object of the present invention is to provide a wiper control device that can change the step of the intermittent time with good responsiveness and without a sense of incongruity.

[0008]

According to the present invention, there is provided a raindrop sensor for detecting a rainfall state, and a drive means for reciprocatingly driving a wiper blade for removing raindrops adhering on the surface to be wiped on the surface to be wiped. The value based on the output from the raindrop sensor is integrated, and when the integrated value is equal to or greater than a predetermined threshold value, and the integrated value remains less than the threshold value, and after the previous wiping operation of the wiper blade is completed, Control means for outputting a drive signal indicating that the wiper blade should be driven to the drive means at the earlier of the time when the determined intermittent time has elapsed, and a plurality of stages corresponding to the plurality of intermittent times, respectively. When the driving signal is output, when the integrated value is less than a predetermined value, the step is changed by one step so that the intermittent time becomes longer, When the intermittent time corresponding to the further step is set as the next intermittent time, or when the integrated value is equal to or more than a predetermined threshold and the elapsed time after the end of the previous wiping operation is within the predetermined time, Intermittent time setting means for selecting a step corresponding to the elapsed time from among the plurality of steps so that the intermittent time becomes shorter, and setting an intermittent time corresponding to the selected step as a next intermittent time; And a wiper control device.

[0009]

According to the present invention, the control means integrates a value based on the output from the raindrop sensor, and when the integrated value becomes equal to or greater than a predetermined threshold value, and the integrated value remains less than the threshold value. A drive signal is output to the driving means at the earlier of the time when the predetermined intermittent time set by the intermittent time setting means has elapsed after the end of the previous wiping operation of the wiper blade. The driving unit drives the wiper blade to reciprocate on a surface to be wiped such as a windshield in response to the drive signal to remove raindrops and the like attached to the surface to be wiped.

The intermittent time is, for example, a seven-step intermittent operation of the wiper blade representing a high-speed continuous operation, a low-speed continuous operation, an intermittent operation of 1.5 seconds, and the following intermittent operations of 3, 6, 12, and 24 seconds. It consists of steps.

An intermittent time setting means is provided in connection with the control means. The intermittent time setting means may be an integrated value at the time when the drive signal is output or a value that has elapsed since the end of the previous wiping operation. Set the next intermittent time based on time.

That is, when the wiper blade is driven due to the lapse of the intermittent time, the intermittent time setting means sets the intermittent time to a predetermined value, for example, less than の of the threshold value. The intermittent time step is changed by one step so that the intermittent time becomes longer. When the value is equal to or more than the above value, the step is held.

On the other hand, when the integrated value is equal to or larger than the threshold value and the wiper blade is driven, the elapsed time from the end of the previous wiping operation is a predetermined time, for example, 80% of the set intermittent time. When it is within, select a step corresponding to the elapsed time among the steps of the plurality of steps so as to shorten the intermittent time,
The intermittent time corresponding to the selected step is set as the next intermittent time. When the elapsed time exceeds the 80%, the step is held.

Therefore, even if the vehicle escapes from a tunnel or under an elevated road and becomes in a relatively heavy rainfall state, the intermittent time is quickly reduced, and the driver does not feel uncomfortable.
When the rainfall decreases and the intermittent time increases, the intermittent time is changed step by step. Therefore, even if the intermittent time varies due to the narrow detection range of the raindrop sensor, it is not affected. The intermittent time can be stabilized without changing the intermittent time as desired.

[0015]

FIG. 1 is a block diagram showing an electrical configuration of a wiper control device 1 according to one embodiment of the present invention. This wiper control device 1 is used for a vehicle, and when an automatic wiper switch 2 is turned on, a control circuit 3 drives and controls a wiper motor 5 as a driving unit in response to an output from a raindrop sensor 4. This is a so-called automatic wiper control device that performs a wiping operation by reciprocally displacing a wiper blade that does not operate on a windshield.

The raindrop sensor 4 includes, for example, a pair of light receiving and emitting elements, and detects an amount of rainfall based on a change in a light receiving level due to a raindrop passing through an optical path formed by the light receiving and emitting elements. It is a raindrop sensor of a formula. The output of the raindrop sensor 4 is input to the control circuit 3 and is shaped into a rectangular wave pulse by the waveform shaping circuit 11, and is realized by a microcomputer or the like. The processing circuit is a control means and an intermittent time setting means. 12 is input. The output of the automatic wiper switch 2 is input to the processing circuit 12 after noise components such as so-called chattering are removed by a waveform shaping circuit 13.

Each circuit in the control circuit 3 including the processing circuit 12 is connected to the constant voltage circuit 29 from the power supply line L2.
, Power is supplied from the battery 23. The processing circuit 12 integrates the output of the raindrop sensor 4 when the power is supplied from the constant voltage circuit 29 and the auto wiper switch 2 is turned on, and the integrated value M
1 is greater than or equal to a predetermined threshold value RP, or a time point at which a predetermined intermittent time WOT has elapsed from the end of the previous wiping operation of the wiper blade while the integrated value M1 remains less than the threshold value RP, whichever is earlier. At this time, the wiper motor 5 is driven.

The intermittent time WOT can be selected, for example, into seven steps as shown in Table 1. Therefore, when the first step is selected, the wiper motor 5 is set to a high-speed continuous operation state, when the second step is selected, the wiper motor 5 is set to a low-speed continuous operation state, and when the third step is selected, 1.5 seconds. It is set to an intermittent operation state, and thereafter, 3 seconds in the fourth step, 6 seconds in the fifth step,
The intermittent operation state is set to 12 seconds in the sixth step and 24 seconds in the longest seventh step.

[0019]

[Table 1]

Each of the steps is set based on the time WCT from the end of the previous wiping operation of the wiper blade until the integrated value M1 becomes equal to or greater than the threshold value RP when the integrated value M1 is equal to or greater than the threshold value RP. Is done. Further, when the integrated value M1 is less than the threshold value RP even after the elapse of the intermittent time WOT, each of the steps is set based on the integrated value M1 at the elapse of the intermittent time WOT.

That is, for example, the intermittent time WOT of 80
% Within the time WUP, the integrated value M1 is equal to the threshold RP
As described above, the step of the intermittent time WOT is set as follows in correspondence with the time WCT, and the intermittent time is changed to be shorter.

First, from the current intermittent time WCT, as shown in Table 2, when the time WCT is within the range of 1 to 8 seconds, the step of the next intermittent time WOT is directly set. Therefore, for example, when the current time WCT is longer than 1.2 seconds and equal to or shorter than 2 seconds, the next intermittent time WOT is set to the third step of 1.5 seconds, and the time W
When CT is longer than 2 seconds and not longer than 4 seconds, the intermittent time W
OT is set to the fourth step of 3 seconds, and time WCT is 4
When the time is longer than 8 seconds and less than 8 seconds, the intermittent time WOT is 6
It is set to the fifth step in seconds.

[0023]

[Table 2]

When the current time WCT is less than 1.2 seconds and longer than 8 seconds, as shown in Table 3,
If it is within the time WUP that is 80% of the intermittent time WOT, the step is set one step lower, otherwise the step is held.

[0025]

[Table 3]

On the other hand, if the integrated value M1 is less than the value MDN which is 1/2 of the threshold value RP at the time when the intermittent time WOT has elapsed, the step of the intermittent time WOT is increased by one step. I do. FIG. 2 shows the threshold values for such stepwise step change. If the integrated value M1 is equal to or greater than the value MDN when the intermittent time WOT has elapsed, the step is held. By performing the above-described operation of updating the intermittent time WOT and the operation of integrating the output of the raindrop sensor 4, the automatic wiper control is realized.

When the wiper motor 5 is driven at a low speed, the processing circuit 12 outputs a drive signal from the output terminal P2 to the line L3. This drive signal is applied to the base of the transistor Tr2 via the resistor R3 and the bias resistor R4. The emitter of the transistor Tr2 is grounded, and the collector is connected to the power supply line L2 via the relay coil 27 of the relay 26.

On the other hand, the relay switch 2 of the relay 26
8 has two individual contacts 28a and 28b, one of which is connected to the power line L2 and the other of which is connected to the common contact 30c of the cam switch 30 via the line L4. I have. The common contact 24c of the relay switch 24 of the relay 21 is connected to the common contact 28c of the relay switch 28, and one individual contact 24a of the relay switch 24 is connected to the low-speed power input terminal 5a of the wiper motor 5. .

When the wiper motor 5 is driven continuously at high speed, the processing circuit 12 outputs a drive signal from the output terminals P1 and P2 to the lines L1 and L3. The drive signal for the line L1 is input to the base of the transistor Tr1 via the resistors R1 and R2, and the drive signal for the line L3 is input to the base of the transistor Tr2 via the resistors R3 and R4.

The transistor Tr1 has an emitter grounded and a collector connected to the relay coil 22 of the relay 21.
To the power supply line L2. The other individual contact 24b of the relay switch 24 of the relay 21 is
It is connected to a high-speed power input terminal 5b of the wiper motor 5.

In connection with the wiper motor 5, a cam switch 30 is provided.
When the wiper blade is at the initial position, the individual contact 30a is electrically connected, the wiper motor 5 is started, the wiper blade starts wiping operation, and when the wiper blade is separated from the initial position, the individual contact 30b is electrically connected. When the blade finishes the wiping operation and returns to the initial position again, it is electrically connected to the individual contact 30a.

The individual contact 30a is grounded together with the ground terminal 5c of the wiper motor 5, and the individual contact 30b is
It is connected to the power supply line L2. Common contact 3
0c is connected to the individual contact 28a of the relay switch 28 via the line L4,
The potential 0c is detected by the processing circuit 12 from the line L5 via the signal processing circuit 31. Processing circuit 12
Determines from the detected potential of the common contact 30c whether or not the wiper blade is performing the wiping operation.

Therefore, when driving the wiper motor 5 at a low speed, the processing circuit 12 outputs a drive signal from the output terminal P2 to the line L3. As a result, the transistor Tr2 is turned on, the relay coil 27 is excited, and the contacts 28b and 28c of the relay switch 28 are turned on.
Therefore, the battery 23 via the power line L2
Is supplied to the low-speed power input terminal 5a of the wiper motor 5 from the contacts 28b and 28c via the contacts 24c and 24a of the relay switch 24.

When the wiper motor 5 is activated in this way and the cam switch 30 is switched from the individual contact 30a to the individual contact 30b, and then the wiper blade returns to the initial position, the cam switch 30 is switched from the individual contact 30b to the individual contact 30a again. , The processing circuit 12 stops outputting the driving signal. As a result, the brake current flows to the low-speed power input terminal 5a of the wiper motor 5 through the contacts 30a and 30c, the contacts 28a and 28c of the relay switch 28, and the contacts 24c and 24a of the relay switch 24, and the wiper motor 5 stops. I do.

When the wiper motor 5 is driven at a high speed, the processing circuit 12 outputs a drive signal from the output terminals P1 and P2.
Are conducted, the relay coils 22 and 27 are both excited, the relay switch 24 is conducted to the individual contact 24b, and the relay switch 28 is conducted to the individual contact 28b. Thus, the electric power from the battery 23 is supplied to the high-speed power input terminal 5b of the wiper motor 5 via the relay switches 28 and 24.

The processing circuit 12 detects whether or not the wiper blade has returned to the initial position from the output voltage level of the cam switch 30. Until the wiper blade returns to the initial position, the processing circuit 12 outputs the signal from the output terminals P1 and P2. Continue to derive drive signals. Thus, the wiper motor 5 can be driven at a low speed and a high speed.

Further, a counter 32 is built in the processing circuit 12, and the counter 32 is connected to the output terminal P.
At the point in time when the output of the drive signal from 2 is stopped, the timer operation is started, and the intermittent time WOT is counted. The counter 32 is reset when the integrated value M1 becomes equal to or larger than the threshold value RP, and when the intermittent time WOT elapses while the integrated value M1 remains less than the threshold value RP.

FIG. 3 is a flowchart for explaining the automatic wiper control operation. Auto wiper switch 2
Is conducted, the process proceeds to step n1, where initialization processing such as initialization of the integrated value M1 and the time WCT and setting of an initial value of the intermittent time WOT are performed. In step n2, the output signals of the raindrop sensor 4 are integrated.

In step n3, it is determined whether or not the integrated value M1 is equal to or larger than the threshold value RP. If not, in step n4, the count value WCT of the counter 32 is incremented by 1 and updated. In step n5, it is determined whether or not the count value WCT has become equal to or longer than the intermittent time WOT. If not, that is, if the integrated value M1 is less than the threshold value RP and the intermittent time WOT has not elapsed, the step n5 is executed. Returning to n2, the integration operation is repeated.

In step n5, the count value W
When CT is equal to or longer than the intermittent time WOT, step n6
It is determined whether or not the integrated value M1 is less than a value MDN that is 1/2 of the threshold value RP. If so, the process proceeds to step n7, and the next step of the intermittent time WOT increases by one step. Is done. In step n6, when the integrated value M1 is equal to or greater than the value MDN, the process proceeds to step n8, and the next step of the intermittent time WOT is held as it is.

In step n3, when the integrated value M1 is equal to or more than the threshold value RP, the process proceeds to step n10, and the count value WCT at the time when the value exceeds the threshold value RP is determined.
Is determined to be within the time WUP, which is 80% of the intermittent time WOT. If not, the process proceeds to step n8, and if so, the process proceeds to step n11 and subsequent step reduction processing.

In step n11, it is determined based on Table 2 whether or not the current time WCT is longer than 1.2 seconds and equal to or shorter than 2 seconds.
In step 2, the next intermittent time WOT is set to 1.5 seconds in the third step, and if not, the process proceeds to step n13.
In Step n13, the time WCT is longer than 2 seconds and 4
It is determined whether it is less than or equal to seconds. If so, the next intermittent time WOT is set to 3 seconds of the fourth step in step n14, and if not, the process proceeds to step n15. In step n15, it is determined whether or not the time WCT is longer than 4 seconds and equal to or shorter than 8 seconds. If so, in step n16, the next intermittent time WOT is set to 6 seconds in the fifth step. Step n
At step 17, the step of the next intermittent time WOT is changed so as to be reduced by one step from the current step.

Thus, steps n7, n8, n1
Next intermittent time WO at 2, n14, n16 and n17
When the step T is selected, the next intermittent time WOT is set to the selected step at step n21. In step n22, the integrated value M1 and the count value WCT are reset to zero.

In step n23, a drive signal is output from the terminals P1 and P2 of the processing circuit 12, and the wiper motor 5 is started. In step n24, it is determined whether or not the common contact 30c of the cam switch 30 has been switched to the individual contact 30b, that is, whether or not the wiper blade has left the initial position and has started the wiping operation. Move on to In step n25, it is determined whether or not the common contact 30c of the cam switch 30 has been switched to the individual contact 30a, that is, whether or not the wiping operation has been completed.
Move on to In step n26, after the output of the drive signal is stopped and the wiper motor 5 is stopped, the process returns to step n2.

As described above, the wiper control device 1 according to the present invention
When the intermittent time WOT is shortened, the integrated value M
The next intermittent time W corresponding to the elapsed time WCT from the end of the previous wiping operation when 1 becomes equal to or greater than the threshold value RP
Since the OT is set, the intermittent time WOT can be followed with good responsiveness even when the vehicle escapes from a tunnel or under an overpass and is in a heavy rainfall state, and the driver can feel light and comfortable without discomfort. Wiper operation can be realized. Also, when changing the intermittent time WOT to be longer, 1
Since the change is performed step by step, it is possible to prevent a sudden step change due to the narrow detection range of the raindrop sensor 4 and realize a stable wiper operation without giving the driver any discomfort.

[0046]

As described above, according to the present invention, the wiper blade is driven when the integrated value is equal to or greater than the threshold value, and the elapsed time from the end of the previous wiping operation at that time is within a predetermined time. Sometimes, the intermittent time is shortened by one or more steps until the step corresponding to the elapsed time.
Even if you get out of a tunnel or under an overpass and get into heavy rainfall, the intermittent time will be shortened with good responsiveness.

On the other hand, when the amount of rainfall decreases, the intermittent time undesirably changes with respect to the fluctuation of the detection result due to the narrow detection range of the raindrop sensor, and the driver becomes unfriendly. It is possible to eliminate a problem that gives a pleasant feeling.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of a wiper control device 1 according to one embodiment of the present invention.

FIG. 2 is a diagram illustrating a threshold value of a step change of an intermittent time WOT.

FIG. 3 is a flowchart illustrating an automatic wiper control operation.

[Description of Signs] 1 Wiper control device 2 Auto wiper switch 3 Control circuit 4 Raindrop sensor 5 Wiper motor 12 Processing circuit 30 Cam switch 32 Counter

Claims (1)

(57) [Claims] 1. A raindrop sensor for detecting a rainfall state, a driving means for reciprocally driving a wiper blade for removing raindrops adhered on a surface to be wiped on the surface to be wiped, and an output from the raindrop sensor. And a time when the integrated value is equal to or greater than a predetermined threshold value, and a time when a predetermined intermittent time has elapsed since the end of the previous wiping operation of the wiper blade while the integrated value remains less than the threshold value. Control means for outputting a drive signal indicating that the wiper blade should be driven to the drive means at the earlier one of the following; and a plurality of steps corresponding to a plurality of intermittent times, respectively, wherein the drive signal When the integrated value is less than a predetermined value at the time when is output, the step is changed by one step so that the intermittent time becomes longer, and the step corresponding to the changed step is performed. The intermittent time is set as the next intermittent time, or when the integrated value is equal to or more than a predetermined threshold and the elapsed time from the end of the previous wiping operation is within the predetermined time, the intermittent time is short. Intermittent time setting means for selecting a step corresponding to the elapsed time from among the plurality of steps, and setting an intermittent time corresponding to the selected step as a next intermittent time. Wiper control device.