JPH04100758A - Control device for pressing force variable type wiper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a variable pressing force type wiper in which the pressing force of the wiper blade is changed by changing the tension of a spring by changing the forward and reverse directions of the motor. , relates to a device that automatically controls reverse rotation.

[Conventional technology]

FIG. 4 is a sectional view for explaining the general structure of the wiper device.

A wiper arm 1 supports a wiper blade (not shown). On the other hand, the arm head 2 is fixed to the wiper shaft 3 and rotates back and forth together with the back and forth rotation of the wiper shaft 3 around its axis.

The wiper arm 1 is connected to the arm head 2 by a pivot shaft 4.
In FIG. 4, the glass surface 5 is located below the wiper arm 1.

A coil spring 8 is stretched between a spring hook 6 provided on the wiper arm 1 and a spring hook 7 provided on the arm hood 2, and applies a rotational force in a direction to bring the wiper arm 1 closer to the glass surface 5. . Reference numeral 9 denotes a link to which the coil spring 8 is interposed and engaged so as not to interfere with the spring hook 7.

In the wiper device for a vehicle, the wiper arm 1
Therefore, it is desired that the force with which a wiper blade (not shown) is pressed against the glass surface 5 can be adjusted. The reason is as follows.

If this pressing force is excessive, a large amount of driving force is required and the rubber ribbon (not shown) of the wiper blade is prematurely worn out, so it is undesirable that the pressing force is excessive. However, when the wind is strong or when the vehicle is traveling at high speed, the wind pressure exerts a force that lifts the wiper blade from the glass surface, so it is necessary to increase the pressing force.

Further, when the wiper device is not used for a long period of time, it is desirable to keep the pressing force small in order to prevent the wiper blade from being pressed against the glass surface and permanently deformed while the wiper device is not in use.

Japanese Patent Application Laid-Open No. 159161/1984 is a known wiper device in which the pushing force of the wiper blade can be adjusted by operating the motor by operating a switch on the motor from the driver's seat.

FIG. 5 is a bottom view shown as FIG. 1 in the above-mentioned publication, and shows the wiper arm in one embodiment of the above-mentioned known technology.

In this example, two coil springs 3a and 3b are provided. One end of the coil spring 8a is attached to the wiper arm 1 via a hook 6, and the other end is attached to the arm head 32 via an L-shaped lever 40.

33 is a small electric motor (so-called geared motor) having a built-in reduction gear means. The output shaft 34 is installed aligned with the reference vAs, and a male screw member 35 for a feed screw is fixed concentrically to the output shaft 34.

On the other hand, a prismatic rod-like member 37 is constructed, and this is connected to the reference line S.
Support with bushing 38 so that they are aligned. This bushing 38 is provided with a square hole, which allows the rod-like member 37 to slide in the direction of the reference line S, and restricts rotation about 8 degrees around the reference line.

A female screw member 36 is connected to one end of the rod member 37 and is screwed into the male screw member 36, and the rod member 37 is engaged with the L-shaped lever 40.

A sliding electrode 44 is attached to the rod-shaped member 37 or the female threaded member 36 integrally connected thereto, and brought into sliding contact with the printed circuit 43.

As the rod-shaped member 37 reciprocates in the direction of the reference line S, the sliding electrode 4
4 slides on the surface of the printed circuit 43 to switch the electric circuit and control the rotation of the geared motor 33.

By appropriately setting the printed circuit 43, the rotation biasing force of the wiper arm 1 (the pressing force of the wiper blade)
Switch to two levels of strength and weakness.

FIG. 6 shows a motor (guard motor) 33 in a known example.
The system? FIG. 2 is an explanatory diagram of the I1 mechanism.

In the figure, BT is a battery, SW is a 2-circuit, 2-contact manual switch with 7 switches, and Da and Db are diodes.

The sliding electrode 44 (FIG. 6) has three contacts 44a.

44b and 44c, and moves to the left and right in the figure in conjunction with the rotation of the motor 33. That is, as the tension of the spring 8a changes, it moves to the left and right in the figure as the wiper pressing force changes. 44-1 is moved to the leftmost position I,
Reference numeral 44-2 indicates a state in which the object has been moved to the rightmost position (3).

The three contacts 44a, 44b, 44c
Conductive patterns 43a, 43b along the path of
, 43c are provided.

When the sliding electrode 44 is in position I, the pressing force is minimum,
It is maximum when it is at position ■. Further, when the R terminal side of the motor 33 is at 10, the motor 33 rotates forward to increase the pressure, and when the L side is at 10, the motor 33 rotates in the reverse direction to reduce the pressure.

Now, when the pressing force is the minimum, if contacts a, 33+bl, and b3 of switch SW are turned on, the ten poles of battery BT →
Electricity is supplied through the R terminal of the motor 33 - the L terminal of the motor 33 - the conductive pattern 43a - the sliding electrode 44 - the conductive pattern 43b - the diode Da - the battery BT, and the motor 33 rotates forward and the sliding electrode 44 moves to the right of the diagram.

Along with this, the pressing force of the wiper blade increases.

Further, when the motor 33 continues to rotate in the normal direction and the sliding electrode 44 reaches the position ■ and separates from the conductive pattern 43b, the motor 3
3, the current in the forward rotation direction is cut off and the motor stops.

When the switch SW is switched from the stopped state as described above to turn on the contacts a2, a,..., bz, the motor 33 is reversed and the sliding contact 44-2 moves to the left. Along with this, the wiper pressing force decreases.

[Problem to be solved by the invention]

In the conventional control device described above, the wiper pressing force is increased or decreased remotely by the driver's manual operation, so it requires a high level of experience to operate it to obtain the appropriate pressing force. Requires skill.

ii. Since the wiper blade (rubber ribbon) is operated manually, if the wiper blade (rubber ribbon) is continued to be used with an unnecessarily large pressing force due to forgetfulness, ignorance, carelessness, etc., the wiper blade (rubber ribbon) will wear out prematurely.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an automatic control mechanism that can automatically switch the wiper pressing force to three levels depending on the vehicle speed.

[Means to solve the problem]

To achieve the above object, the present invention provides a device for controlling a motor of a variable pressing force wiper that changes the pressing force of a wiper blade by forward and reverse rotation of a spring tension adjusting motor, in which a moving contact in which four contacts are electrically connected to each other; a conductive pattern disposed along four paths through which each of the four contacts passes; and a conductive pattern and the motor. a diode circuit connected between the motor, a 4Mi relay contact inserted and connected in the drive circuit of the motor, four relay circuits that drive each of the four sets of relay contacts, and the four 4 F- controlling each of the relay circuits of
F circuit, a reset OR circuit connected to each of the above four F-F circuits, a trigger circuit connected to the above OR circuit and F-F circuit, and outputs a pulse with a frequency proportional to the vehicle speed. a frequency-voltage conversion circuit that converts the pulses into voltage; two comparison circuits each having a different reference voltage and receiving the voltage signal output from the conversion circuit; and the trigger circuit. The present invention is characterized in that it includes a polarity inversion circuit inserted and connected between the first part and each of the comparison circuits.

[Operation] According to the above configuration, the voltage signal obtained by converting the output signal of the vehicle speed sensor activates the relay via the F-F circuit, and cooperates with the conduction pattern and the moving contact (sliding contact). The wiper pressure can be automatically switched to three levels: strong, medium, 9-low, depending on the vehicle speed.

Since this action does not involve any human operation, there is no risk of premature wear due to human error.

[Embodiment] FIG. 1 is an explanatory diagram showing one embodiment of a wiper control device according to the present invention.

33 is a motor for adjusting the tension of the wiper,
When electricity is applied from the R terminal to the L terminal, it rotates in the normal direction, increasing the spring tension and increasing the wiper pressing force. At the same time, the movable contact 21 moves to the right in the figure.

The illustrated position I is the left end position, the minimum wiper pressing force, and the position ■
is the rightmost position and the wiper pressing force is maximum.

The position ■ is an intermediate position, and the wiper pressing force is a standard value.

The above moving contact 21 has four contacts 21a to 21d.
are interconnected and conductive.

When the movable contact 21 moves between the illustrated positions (1) and (2), the four contacts 21a to 21d each move to the left and right in the figure, creating four trajectories.

Conductive patterns 22a are formed along the trajectories of the above four stripes.
~22d is provided. However, at position I, the conductive pattern 22c is a moving contact)2
No contact continuity to 2c.

At position 1■, the conductive pattern 22d is connected to the moving contact 2.
No contact conduction to 1.

Further, at position (3), the conductive pattern 22a does not contact the movable contact 21 and is not electrically conductive. Therefore, in this example, the conductive pattern 22a is divided into two conductive patterns 22a-, 22a-, and 22a-.
It consists of 2a-z.

23 in the figure is a relay circuit, and A/1 to D/I are 1
A relay with two contacts in the circuit, a - d are the contacts.

9 in the figure is a diode circuit, which includes diodes D1 to
Consists of D4.

These diodes are connected between said conductive pattern and the relay contacts.

Reference numeral 24 in the figure indicates a flip-flop circuit (F-F circuit) consisting of IC@ to ICz, which respectively control the relays A/1 to D/1.

25 is an OR circuit, and 26 is an initial reset circuit.

27 is a vehicle speed sensor that outputs pulses with a frequency proportional to the vehicle speed. This pulse is generated by a frequency-voltage conversion circuit (FV)
It is converted into a voltage signal at 28.

ref++ refz are reference voltages, respectively, and are compared with the above voltage signals by comparators CM, CMZ.

The second is a chart showing the relationship between vehicle speed and vehicle speed sensor output frequency.

FIG. 3 is a chart showing conversion characteristics in the frequency-voltage conversion circuit (FV) 28.

Looking at the above figures 3 and 2 in the backward calculation direction, the results are as follows.

The output voltages V, , V on the vertical axis of FIG. 3 correspond to the reference voltages ref, ref2 shown in FIG. 1, respectively.

These voltages V, , V2 correspond to converted values of frequencies f, , f, on the horizontal axis in FIG. 3, respectively.

When these frequencies fJ and fz are applied to the vertical axis in FIG. 2, they correspond to the vehicle speeds S, , S2 on the horizontal axis, respectively.

The outputs of the comparators CM, CM, are connected to C- of the trigger circuit 29 via polarity inverting circuits IC, , IC, respectively.
given to the R circuit.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

In the trigger circuit 29, the time constant of the CR circuit consisting of C, R, is T1, the time constant of the CR circuit consisting of C2, R, is T2, the time constant of the CR circuit consisting of C3, R3 is T3, and C4 , R4 is the time constant of the CR circuit consisting of T4.
As, T,=T2=T,=T.

Set it so that

CR consisting of C5 and Rs of the initial reset circuit 26
Let the time constant of the circuit be T5, and let T5>>T+.

First, when the vehicle speed is O and the switch SW is turned on, the outputs of the comparators CM, CM2 become "L", and the trigger circuit C
The outputs of the trigger circuits C1 and R3 also become "L".

For this reason, ICs and IC,. Output Q also becomes "L", and relays B/1 and C/1 do not operate.

On the other hand, IC and Icy are inverter circuits, and when their inputs are "L", the output becomes "HI+".

Therefore, the trigger circuits C2 and R2 and C4 and R4 operate and output positive pulses T, , T4.

The positive pulse of T2 is transmitted to the S terminal of IC7, and IIc,
is in the set state. Further, the positive pulse of T4 is transmitted to one input of IC3 of the OR circuit, and its output also outputs a positive pulse, and is also transmitted to the S terminal of IC11, so that IC1 becomes in the cent state.

However, since VCG is transmitted to C6 and R1 of the initial reset circuit 26 at the same time as the ON operation of the switch SW, a positive pulse of T is output and IC4 to IC of the OR circuit are output.
, and each output is transmitted to one side input of IC8~I
It is transmitted to the R terminal of C, .

As mentioned above, <Ts >>T+ -Tz =Ts =T
Since it takes a long time to transmit the "H" level to the R terminal side, IC, and IC, are reset, their respective outputs become L'', and relays D/1. Relay A/1
doesn't work either.

In this way, all relays A/1-D/1 do not operate,
These contacts a to d are on the NC side as shown in FIG. 1, and both terminals of the motor 33 are grounded and stopped.

The moving contact 21 is stopped at position T.

The above state continues until the vehicle speed increases and reaches SI.

Next, when the vehicle speed is greater than or equal to 31 and less than 82, the output of the frequency voltage conversion circuit (FV) 28 becomes greater than or equal to ■1 and less than ■2, and the output of the comparison circuit CM becomes "H" and the output of the comparison circuit CM2 becomes "H".
It becomes “L”.

Since the output of CM is “L”, the above explanation (vehicle speed S
, less than) as well as IC,. , IC, , is kept at "L", and relay C/1 . Relay A/1 does not operate, and its contacts c and a remain on the NC side.

On the other hand, since the output of the comparator circuit CM becomes "HII", I
The output of C, becomes "L", the trigger circuit 02 becomes in a discharge state, the output of C2 and R2 remains "L",
The output of IC also becomes "L", relay D/1 does not operate, and contact d remains on the NC side.

As mentioned above, when CM becomes "H", the "H" level is transmitted to the S terminal of IC,t through C8, and the I
The outputs of C and □ become "H", activating relay B No. 1, and the contact point S is switched to the No side.

Note that even if CM maintains the 11 HII level, charging of C0 ends after T1, so the subsequent input to the S terminal of ICI□ becomes "L".

As mentioned above, when the contact switches to the No side, Vcc→
Contact b → Mortar 33 → Conductive pattern 22b → Moving contact 21 → Conductive pattern 22a-+ → Diode D2 →
Electricity is applied through the path from contact a to ground, the motor 33 rotates forward, and the wiper pressing force begins to increase.

At the same time, the moving contact 21 starts moving from position I toward position ■.

When the movable contact 21 reaches position (2), it separates from the conductive pattern 22a-+, the current is cut off, and the motor 33 stops. In this way, the wiper pressing force is in an intermediate state between weak and strong.

Next, a case where the vehicle speed becomes S2 or higher will be described.

The output voltage of the frequency voltage conversion circuit (FV) 28 becomes 72 or more, and the outputs of the comparison circuits CM, CMt both become "H".

The output of CM is already “H” and the contact is No.
side, contact d maintains the NC side.

When CM becomes "H", the output of IC2 becomes "L++", and 04 of the trigger circuit becomes a discharge state, C4 and R4.
The output of the IC remains “L”.

Since both human powers become "L", their output also becomes "L".

Therefore, the input of IC, , remains "L", relay A/1 does not operate, and contact a remains on the NC side.

On the other hand, when CM2 goes "H", the "H" level goes through C8. is transmitted to the S terminal of the IC,. The output becomes "H", relay C/1 is activated, and contact C is switched to the No side.

Incidentally, even if CM maintains "H", charging of C3 ends after T, so the subsequent input to the S terminal of IC becomes "L".

When the contact C switches to the No side as described above, the motor 33 is energized in the forward rotation direction (since the contact C maintains the No side), the wiper pressing force begins to increase further, and the movable contact 21 moves to the position H. start moving towards.

When the moving contact 21 reaches position ■, the conductive pattern 2
When the motor 33 moves away from 2d, the current is cut off and the motor 33 stops.

In this way, the wiper pressing force becomes strong.

Next, a case where the vehicle speed is decelerated from a state of 32 or more to a state of less than 32 and 51 or more will be described.

The output of the comparator circuit CM is up to the HH level, and the outputs of the trigger circuits C1.R+ and C2.R2 remain at "L".

On the other hand, the output of the comparison circuit CM2 switches from "H" to "L". At this time, C3 of the trigger circuits C3 and R3 is in a discharge state, and the output remains at "L".

On the other hand, when the input of the IC switches from "H" to "L", its output switches from u L n to "IIH''", and the trigger circuit C4/R4 outputs the "H" level for the time T4, and the output of the IC changes from "H" to "L". Transfer to one input.

Since the other input of M Icx is “L”, the IC,
For example, a 14-width positive trigger is output.

This positive trigger output signal is transmitted to the S@ terminal of rc, , and at the same time, is transmitted to one input terminal of IC6.

Since the other input terminals of the ICs, IC6 are "L", these IC4, IC6 output a 14-width positive trigger.

As a result, r c, , is set, and the output terminal Q is “H”.
At the same time, the ICs and ICs are set and output "L".

At this time, the input of the IC is not changing, so the output is “
It remains at "L".

As a result, relay A/1 is activated and contact a
is on the NC side, relays B/1 to D/1 are inactive, and contacts b-d are on the NC side.

As a result, the motor 33 is energized in the reverse direction, the pressing force on the wiper blade begins to decrease, and the movable contact 21 begins to move from position (2) toward position (2).

When the moving contact 21 reaches position (2), it separates from the conductive pattern 22a-2! The power is cut off and the motor 33 stops. In this state, the wiper pressure is strong.

It is between weak and weak.

Next, a case where the vehicle speed is decelerated from 51 or more to less than 31 will be described.

The outputs of the comparison circuits CM, CM2 both become "L".

CM2 is already at "L".

On the other hand, since the output of CM switches from "°H゛°→"L," C0 of the trigger circuit becomes in a discharge state, and C, -R,
The output of remains “L”.

As mentioned above, the output of CM becomes L, and IC becomes “
L'' is output.For this reason, the trigger circuits C2 and R2 are 12
Outputs a positive trigger of width. This positive trigger is simultaneously transmitted to the S terminal of IC, and to one input of IC.

Since the other input of the above IC3 is already “L”, the I
Cs outputs a 12-width positive trigger and transmits it to the S terminal of XC, , and IC.

to one input of the IC.

As a result, IC,,IC,,is in the set state,rc,.

I C,, becomes a reset state, and relay A/1. D
/1 is operating state, relay B/1. C/1 becomes inactive, contacts a and d switch to the NC side, and contacts S and C switch to the NC side.

Therefore, the motor 33 is energized in the reverse direction, the wiper pressing force begins to decrease, and the movable contact 21 begins to move toward position I.

When the movable contact 21 reaches the position I2, the movable contact 21 separates from the conductive pattern 22d, the current is cut off, and the motor 33 stops. In this way, the wiper blade pressing force automatically becomes weak.

In addition, the IC shown in the figure is S from vehicle speed less than 31.

When it becomes less than S5 after becoming above (less than SZ),
Further, when IC and □ go from S2 or more to less than 32 (S+ or more) and then become S2 or more, the respective contacts are switched to prevent a short circuit caused by the moving contact 21.

〔Effect of the invention〕

As explained above, according to the control device of the present invention, the wiper pressing force is automatically increased or decreased depending on the vehicle speed.

This can prevent troubles caused by human operational errors, especially premature wear of the wiper blade rubber ribbon due to excessive pressing force.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of a control device according to the present invention. FIGS. 2 and 3 are characteristic charts of the vehicle speed sensor and the frequency-voltage conversion circuit in the above embodiment, respectively. FIG. 4 is an explanatory diagram of the structure of the wiper. FIG. 5 is a bottom view showing a known technique of a wiper pressing force adjustment device, and FIG. 6 is a circuit diagram thereof. 21... Moving contact, 21a-21d... Contact, 22a-1+ 22a-t, 22b-22
d-... Conductive pattern, 23... Relay circuit, 24...
...FF circuit, 25...OR circuit, 26...initial reset circuit, 27...vehicle speed sensor, 28...
・Frequency voltage conversion circuit, 29... trigger circuit, 30・
...Polarity inversion circuit. 10・r

Claims (1)

[Scope of Claims] 1. In a device for controlling a variable pressing force wiper motor that changes the pressing force of a wiper blade by forward and reverse rotation of a spring tension adjusting motor, the four wiper motors move as the tension of the spring changes. a moving contact whose contacts are electrically connected to each other; a conductive pattern arranged along four paths through which each of the four contacts passes; and a movable contact that is connected between the conductive pattern and the motor. four sets of relay contacts inserted and connected in the drive circuit of the motor; four relay circuits that drive each of the four sets of relay contacts; and each of the four relay circuits. Four F・
F circuit, a reset OR circuit connected to each of the above four F/F circuits, a trigger circuit connected to the above OR circuit and F/F circuit, and outputs a pulse with a frequency proportional to the vehicle speed. a frequency-voltage conversion circuit that converts the pulses into voltage; two comparison circuits each having a different reference voltage and each receiving a voltage signal output from the conversion circuit; 1 and a polarity reversal circuit inserted and connected between each of the comparison circuits.