JPH0899606A - Push-press force controller of wiper - Google Patents

Abstract

PURPOSE: To provide the push-press force controller of a wiper which can prevent generation of the partial wear and damage of a blade, the twist of an arm and the scratches on a glass surface and by which the durability of the wiper can be ensured. CONSTITUTION: The controller in the title is provided with a wiper arm which makes reciprocating motion by reversing between both ends of a wiping area, a push-press force regulation actuator provided so that the push-press force to the front window glass surface F of the wiper arm can be changed, a motor current detector 28 for detecting the motor current of a motor 1 for driving in rotation the wiper arm and a control means 22 for controlling the operation of the push-press force regulation actuator so that the push-press force may be reduced when the change amount of the detected motor current exceeds its set value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressing force control device mounted on a wiper for a vehicle, and more particularly to a pressing force control device for a wiper capable of varying a pressing force on a windshield within a wiping area of the wiper.

[0002]

2. Description of the Related Art Hitherto, a wiper has been used to wipe off water drops and the like adhering to the windshield of a vehicle.
This wiper is equipped with a motor, and the rotation of the motor is replaced with pivot rotation within a fixed rotation angle by using a linkage mechanism. Further, the wiper blade at the rotating end of the arm head integrally attached to the pivot is reciprocated within a constant rotation angle to wipe off water droplets and the like in the fan-shaped wiping area to ensure the driver's visibility. There is. By the way, when the blade floats during the wiping operation of the wiper, it hinders securing the front field of view and impairs the safety, so that the blade is normally configured to come into sliding contact with the glass surface with sufficient pressing force. . That is, the arm head and the wiper arm are pin-joined, and a tension spring is installed between the arm head and the wiper arm. Further, the blade on the wiper arm side rotatable about the pin is pressed and biased toward the glass surface by the spring force of the tension spring. As a result, the blade is pressed against the glass surface with a predetermined pressing force so that the blade can always slide on the glass surface.

However, when the blade is pressed against the glass surface with a sufficient pressing force in the wiping area of the wiper, the wiper blade can be surely prevented from floating, but the excessive pressing force causes the wiper blade to be worn and deteriorated so that the wiper blade has a predetermined durability. Cannot be ensured, the wiper blade cannot be reliably inverted in the inversion regions at both ends of the wiping region, or noise at the time of inversion becomes excessively large. A device for varying the pressing force of such a wiper has been proposed. For example, 5-5
According to Japanese Patent Laid-Open No. 65-65, when a judder is detected by a load detection device for a wiper blade, a pressing force adjusting motor equipped on the arm head is driven to increase or decrease the pressing force of an arm head connected to the motor. , I try to eliminate Jada.

Further, Japanese Utility Model Publication No. 2-93164 discloses that
The motor mounted on the arm head is connected to the wiper arm via a screw mechanism, a lever and a coil spring, and the control unit drives the motor to adjust the current pressing force to a pressing force equivalent to the vehicle speed. Furthermore, actual Kaihei 4
JP-A-136978 discloses a wiper control device that controls the pressing force of a wiper blade to increase in accordance with a decrease in water repellency detected by a water repellent performance detecting means.

[0005]

If the glass surface of the window equipped with the wiper is not wet and is dry, driving the wiper causes the following problems. That is, when the wiper is driven on the dried glass surface, there is a problem that the glass surface is scratched by the sand or the like attached thereto. Further, when the wiper is driven when the glass surface is dried, there is a problem that the frictional resistance applied to the blade is greatly increased and the blade rubber is unevenly worn or damaged. Moreover, if this state is prolonged, the durability of the motor may be adversely affected by a sudden increase in load, and the wiper arm may be twisted.

In order to eliminate such inconvenience, the conventional technology of Japanese Utility Model Laid-Open No. 5-565 capable of eliminating judder, the technology of Japanese Utility Model Laid-Open No. 2-93164 capable of setting a pressing force corresponding to the vehicle speed, Even if the technique of Japanese Utility Model Laid-Open No. 4-136978 which increases the pressing force according to the decrease in water repellency is not used, it is not an appropriate measure. Moreover, in the technique of Japanese Utility Model Laid-Open No. 4-136978, the pressing force is set on the premise that it is raining. Therefore, when the wiper is operated during non-rainfall, the frictional resistance applied to the blade is greatly increased, and the blade rubber However, the problem of uneven wear and damage is not solved at all.

Therefore, the objects of claims 1 to 3 are:
An object of the present invention is to provide a wiper pressing force control device capable of preventing uneven wear and breakage of a blade, twisting of an arm, and scratches on a glass surface and ensuring durability of a wiper. Claim 2
Particularly, it is also an object to secure the durability of the wiper by reducing the pressing force according to the increase in load. A third object of the present invention is to reliably prevent the reduction of the pressing force of the wiper particularly during rainfall.

[0008]

According to the first aspect of the present invention,
A wiper arm that reciprocates by reversing between both ends of the wiping region, a pressing force adjustment actuator that is capable of changing the pressing force of the wiper arm on the windshield, and a current of a motor that rotationally drives the wiper arm. And a control means for controlling the operation of the pressing force adjusting actuator so as to reduce the pressing force when the amount of change in the detected motor current exceeds a set value. And

According to a second aspect of the present invention, in the pressing force control means for the wiper according to the first aspect, the control means is configured to increase the reduction amount of the pressing force according to the increase amount of the change amount of the motor current. It is characterized by being done. Claim 3
According to the invention described in claim 1, the wiper pressing force control means further comprises rainfall detection means for detecting the presence or absence of rainfall, and the control means changes the motor current when the presence of the rainfall is detected. It is characterized in that the control of the pressing force based on the quantity is stopped.

[0010]

According to the present invention, the pressing force adjusting actuator provided so that the pressing force of the wiper arm against the windshield can be changed, and the motor current detecting means detects the current of the motor for rotationally driving the wiper arm. Then, when the control means detects that the amount of change in the motor current exceeds the set value, the operation of the pressing force adjusting actuator is controlled so as to reduce the pressing force.

According to a second aspect of the present invention, the control means of the pressing force control means of the wiper of the first aspect increases the reduction amount of the pressing force in accordance with the increase of the variation amount of the motor current. Claim 3
The pressing force control means of the wiper according to claim 1, in particular, the presence or absence of rainfall is detected by the rainfall detection means, and the control means is
When the presence of rainfall is detected, the control of the pressing force based on the amount of change in the motor current is stopped.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The wiper pressing force control device shown in FIGS. 1 and 2 is installed in a wiper device for a passenger car (not shown). The wiper device here converts the rotation of a wiper motor (hereinafter simply referred to as a motor) 1 into reciprocation within a constant rotation angle by an interlocking mechanism 2 and transmits it to a pair of left and right pivot shafts 3, 3 arranged in the vehicle width direction. . A head 4 is integrally connected to each pivot shaft 3, and a wiper arm 5 is pin-connected to a pivot end side of the head 4 via a hinge pin 6, and a spring is provided between the wiper arm 5 and the hook 8 on the head 4 side. 9 is erected. The wiper blade 7 is pin-coupled to the rotating end of the wiper arm 5, and the wiper blade 7 at the rotating end of the wiper arm 5 rotates around the hinge pin 6 in accordance with the pulling force of the spring 9, and the glass surface F It is pressed in the direction (the lower side of the paper surface in FIG. 2). An accommodating portion 10 is recessed inside the head 4 (on the lower side of the paper surface), and an actuator 11 and a pressing motor 12 for sliding the hook 8 in the longitudinal direction X of the head are disposed therein.

The actuator 11 has a pressing motor 1 at one end.
2 is connected to the feed screw 14, a slide member 16 with a screw that is screwed to the feed screw 14, a pin 19 is connected to the slide member 16 with a screw via a link 19, and the first guide groove 15 on the head 4 is connected. Slide block 17 slidably locked to
And a hook 8 that is pin-connected to the slide block 17. The threaded sliding member 16 is prevented from rotating by being formed with an inner thread that is screwed into the feed screw 14 and being engaged with a second guide groove 18 formed in the head longitudinal direction X to prevent rotation. Is configured to be slid on.

The pivot shaft 3 is pivotally supported by the vehicle body side pivotal support portion B1, and the above-mentioned interlocking mechanism 2 is connected to the back surface side of the pivotal support portion B1. The accommodating portion 1 is provided in the vicinity of the pivot shaft 3 of the head 4.
0 and a facing portion of the vehicle body side pivotal support portion B1 are communicated with each other, and a guide hole 20 is formed through the guide hole 20, and an extension line 21 is drawn out from the pressing motor 12 that drives the actuator 11. The extension line 21 is a controller. 22 is connected via a drive circuit 31. The pressing motor 12 is a well-known stepping motor that can rotate forward and backward, and is connected to the controller 22 via a drive circuit (excitation signal generation circuit) 31.

The pressing motor 12 slides the slide block 17 in the head longitudinal direction X according to the amount of rotation of the motor. As the slide block 17 slides, the pulling force of the spring 9, that is, the pressing force of the wiper blade 7 against the glass surface F is increased or decreased. The interlocking mechanism 2 is provided with a tandem type link that moves a pair of left and right wiper blades 7 in the same direction, and the link system is configured such that the left and right wiper blades 7 can be reciprocally driven in respective predetermined fan-shaped wiping areas E. Is used.

The head 4 to the wiper blade 7 connected to each pivot shaft 3 are constructed in the same manner on the left and right sides, and here only one side will be mainly described. Since the motor 1 needs to overcome the load regulated by the pressing force of the blade and the arm length to be driven, a motor having a sufficient output and a predetermined reduction mechanism is selectively used. This motor 1 is a well-known DC motor, and is connected to a power supply 26 via a well-known auto park circuit 24 and a switching circuit 25 for stopping at a fixed position. In particular, a current detector for detecting a drive current Im of the motor 1. 28 is attached. A switching signal is input to the switching circuit 25 from the wiper switch 27.

The wiper switch 27 is a three-stage changeover switch and is selectively changed over to the OFF, Lo and Hi positions. When the wiper switch 27 is OFF, the current supply to the motor 1 is cut off. A high current can be passed through the motor 1 to switch the rotation of the motor 1 between low and high stages. At the OFF position, the auto park circuit 24 operates, and the wiper blade 7 is moved to the retracted position where the driver's view is not obstructed and stopped. Controller 2
Reference numeral 2 is a well-known microcomputer, the main part of which is configured to output a rotation angle signal θb of the wiper blade 7 in addition to the current value Im signal from the current detector 28 and the wiper switch 27 signal to the input / output circuit. Corner sensor 30,
Detection signals are input from the inversion zone sensor 32, the raindrop sensor 33, and the like, and a rotation signal dn is output to the drive circuit 31 of the pressing motor 12.

Here, the reversal zone sensor 32 is formed by a limit switch, and is arranged opposite to the link of the interlocking mechanism 2 so as to output an ON signal in the reversal zone dθ (see FIG. 1) at one end in the wiping zone. The inversion area sensor 32 is configured to output an ON signal in the inversion area dθ including the inversion position A. The controller 22 controls the pressing force control program as shown in FIG. 6 and the pressing force calculation map m1 (see FIG. 4).
(See FIG. 5) and the pressing force reduction amount calculation map m2 (see FIG. 5) are stored, and in particular, the following functions are provided.

As a control means, the controller 22 controls the operation of the pressing force adjusting actuator 11 so as to reduce the pressing force P (-dp) when the detected change amount dI of the motor current Im exceeds the set value α. Further, the control means is
Control is performed so as to increase the pressing force reduction amount −dp in accordance with the increase in the motor current change amount dI. Further, the control means is
When the presence of rainfall is detected, the control of the reduction -dp of the pressing force P based on the change amount of the motor current Im is stopped. Next, the operation of the pressing force control device for the wiper will be described with reference to the wiper control program shown in FIG.

When the controller 22 is driven when the engine key (not shown) is turned on, and when step s1 is reached, the output of the wiper switch 27 indicates that the switch is off or L
It is determined whether the position is o or Hi, and if it is OFF, switching to Lo or Hi is waited for, and the process proceeds to step s2 at Lo or Hi. In step s2, the rotation angle sensor 30
Further, the rotation angle signal θb of the wiper blade 7 is input, the signal SA of the reverse position A is input from the reverse area sensor 32, the value of the storage area for sequentially storing each signal is updated, and the process proceeds to step s3. At step s3, the rotation angle signal θb,
The rotation angle position of the wiper blade 7 is obtained based on each signal of the reverse position signal SA.

It should be noted that interrupt processing of a rotation angle calculation routine (not shown) is executed each time the rotation angle signal θb is input, and the B'position (reversal area sensor 3) before the reversal position A, which is the reference position, is executed.
2 is issued at the time t1 from the OFF → ON signal),
The addition of θb is repeated to calculate which position in FIG. 4 the current rotation angle position is. Next, the pressing force calculation map m
The pressing force P corresponding to the wiper rotation angle θb of 1 is calculated, and the process proceeds to step s4. The pressing force P is increased / decreased to a desired value for each rotation angle θb. Here, the reversal positions A and A ′ are set.
The pressing force is lowered to a low value P2 in the vicinity of the reversal region dθ to facilitate the reversal of the blade.

At steps s4 and s5, the current motor current Im is fetched, a change amount dI which is a deviation between the present value and the previous value is calculated, and it is judged whether or not the dI exceeds the set value α. If not, step s8
Proceed to. At step s6, it is judged from the output of the raindrop sensor 33 whether or not it is raining. If it is raining, the process proceeds to step s8, and if it is dry, the process proceeds to step s7. In step s7, since the current change amount dI is large and it is during drying, the reduction value −dp of the pressing force P corresponding to dI is calculated as the pressing force reduction amount calculation map m2.
(See FIG. 5), and the process proceeds to step s8. In this case, the pressing force reduction amount calculation map m2 shows the current change amount dI.
Is set so that the decrease value −dp is increased by a larger value. As a result, the larger the current change amount dI, that is, the larger the frictional resistance, the more the pressing force P can be reduced.

When the process proceeds from step s5 to s7 to step s8, the set pressing force Pn corresponding to the present rotation angle θb is converted into the value of the rotational speed position of the step motor. That is, here, the feed screw 1 that rotates together with the step motor
4, the spring 9 is connected via the threaded sliding member 16, and the pressing force of the wiper blade 7 is increased or decreased in accordance with the pulling force, so that the reference value of the pressing force P (here, the minimum value is P2). The reference rotational position of the pressing motor 12 that can obtain the above is preset. Therefore, the deviation of the rotational speed position corresponding to the set pressing force Pn of this time with respect to the reference rotational position is calculated, and the rotational signal ± dn that is the increase / decrease value of the rotational speed of the pressing motor capable of eliminating the deviation is set. dn is output to the drive circuit 31. As a result, the pressing motor 1
The pulling force of the spring 9 is increased or decreased via 2 to adjust the pressing force P to the currently set pressing force Pn, and the process proceeds to step s9. After that, the control ends when the engine key is turned off. If not, the process proceeds to step s1 in the next control cycle.

As described above, in the wiper pressing force control device of FIG. 1, after the pressing force P corresponding to the rotation angle θb of the wiper blade is obtained, the motor current Im of the wiper motor exceeds the set value α, and the rainfall. When it is not time, the reduction value −dp of the pressing force P equivalent to dI is obtained, the pressing force P is reduced and corrected by the same value, and the wiper blade is driven with the updated set pressing force Pn. When the friction resistance of is large, the pressing force can be reduced, and the uneven wear of the blade,
Prevents damage, twisting of the arm, and scratches on the glass surface, and ensures the durability of the wiper. Moreover, the motor current Im
Since the reduction amount -dp of the pressing force is increased according to the increase of the change amount dI of, the pressing force can be reduced as the frictional resistance between the glass surface and the wiper blade increases. Further, the pressing force P is not reduced and corrected at the time of rainfall to secure the pressing force at the time of rainfall,
It is possible to reliably prevent the blade from floating.

[0025]

As described above, according to the first aspect of the invention, when the amount of change in the motor current exceeds the set value, the pressing force is controlled so that the frictional resistance between the glass surface and the wiper blade increases. When the frictional resistance between the glass surface and the wiper blade is large, the pressing force can be reduced, preventing uneven wear of the blade, damage, twisting of the arm, scratches on the glass surface, and durability of the wiper. Can be secured.

According to the invention of claim 2, in addition to the effect of claim 1, in particular, since the reduction amount of the pressing force is increased according to the increase of the change amount of the motor current, the pressing force is reduced according to the increase of the load. The durability of the wiper can be secured.

According to the invention of claim 3, in addition to the effect of claim 1, in particular, when the presence of rainfall is detected, the control of the pressing force based on the amount of change in the motor current is stopped, so the pressing force is reduced during rainfall. However, it is possible to reliably prevent the wiper blade from floating.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of essential parts of a wiper pressing force control device as an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part of a wiper arm portion used in the wiper pressing force control device of FIG.

3 is a characteristic diagram showing the operation of a motor and a reversal zone sensor used in the wiper pressing force control device of FIG. 1 over time.

4 is a characteristic diagram of values in a pressing force calculation map used in the pressing force control device for the wiper in FIG. 1. FIG.

5 is a characteristic diagram of values in a pressing force reduction amount calculation map used in the pressing force control device for the wiper in FIG. 1. FIG.

6 is a flowchart of a pressing force control program used in the pressing force control device for the wiper in FIG. 1 Motor 2 Interlocking Mechanism 3 Pivot Axis 4 Head 5 Wiper Arm 7 Wiper Blade 9 Spring 11 Actuator 12 Push Motor 22 Controller 28 Current Value Detector 30 Rotation Angle Sensor 33 Rain Drop Sensor-dp Reduction Amount Im Motor Current F Glass Surface X Head Longitudinal direction

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Saiki 5-3-8 Shiba, Minato-ku, Tokyo, Mitsubishi Motors Corporation

Claims (3)

[Claims] 1. A wiper arm that reciprocates by reversing between both ends of a wiping region, a pressing force adjusting actuator that is capable of changing the pressing force of the wiper arm on a windshield, and the wiper arm that rotates. Motor current detection means for detecting the current of the motor to be driven, and control means for controlling the operation of the pressing force adjusting actuator so as to reduce the pressing force when the amount of change in the detected motor current exceeds a set value. A pressing force control device for a wiper characterized by being provided. 2. The wiper pressing force control device according to claim 1, wherein the control means is configured to increase the pressing force reduction amount in response to an increase in the change amount of the motor current. Wiper pressing force control device. 3. The wiper pressing force control device according to claim 1, further comprising rainfall detection means for detecting the presence or absence of rainfall, wherein the control means changes the motor current when the presence of the rainfall is detected. A pressing force control device for a wiper, which is configured to stop controlling the pressing force based on the amount.