JP2792221B2 - Control device for variable pressure wiper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a motor for a variable pressing force type wiper in which the tension of a spring is changed by forward and reverse rotation of a motor to change the pressing force of a wiper blade. The present invention relates to a device for automatically controlling forward and reverse rotation.

[Conventional technology]

FIG. 4 is a cross-sectional view for explaining a 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 reciprocates together with the reciprocation around the axis of the wiper shaft 3.

The wiper arm 1 is pivotally attached to an arm head 2 by a pivot 4.
Is located below the glass surface 5.

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 head 2, and the wiper arm 1 is placed on the glass surface 5.
It is energizing the turning power in the direction to approach. Reference numeral 9 denotes a link interposed and attached so that the coil spring 8 does not interfere with the spring hook 7.

Thus, in the vehicle wiper device, it is required that the force for pressing the wiper blade (not shown) against the glass surface 5 by the wiper arm 1 can be adjusted.
The reason is as follows.

If the pressing force is excessive, a large driving force is required, and a rubber ribbon of the wiper blade (both not shown)
It is not desirable that the pressing force be excessive, since this will cause early wear. However, on the other hand, when the wind is strong or the vehicle runs at high speed, the wind pressure exerts a force to lift the wiper blade from the glass surface, so that it is necessary to increase the pressing force.

When the wiper device is not used for a long period of time, it is desirable to reduce the pressing force in order to prevent the wiper blade from being pressed against the glass surface and being permanently deformed during a pause.

Japanese Patent Application Laid-Open No. 63-159161 discloses a wiper device capable of adjusting the pressing force of a wiper blade by operating a motor switch in a driver's seat to operate the motor.

FIG. 5 is a bottom view shown as FIG. 1 in the above publication and shows a wiper arm according to an embodiment of the above-mentioned known technique.

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

Reference numeral 33 denotes a small electric motor (a so-called geared motor) incorporating a reduction gear unit. The output shaft 34 is set in alignment with the reference line S, and a male screw member 35 for a feed screw is fixed to the output shaft 34 concentrically.

On the other hand, a prismatic rod-like member 37 is formed, which is
It is supported by bush 38 so that it is aligned. This bush 38
Is provided with a rectangular hole, which allows the rod member 37 to slide in the direction of the reference line S and restricts rotation about the reference S.

A female screw member 36 is connected to one end of the rod member 37 and screwed to 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 screw member 36 provided integrally with the rod-shaped member 37 and brought into sliding contact with the printed circuit 43.

With the reciprocation of the rod member 37 in the reference line S direction, the sliding electrode 44
Slides on the surface of the printed circuit 43 to switch its electric circuit, and controls the rotation of the geared motor 33.

The print circuit 43 is set arbitrarily and the biasing force of the wiper arm 1 (the pressing force of the wiper blade) is set.
Is switched to two levels.

FIG. 6 shows a motor (geared motor) 33 in a known example.
FIG. 4 is an explanatory diagram of a control mechanism of FIG.

The illustrated BT is a battery, SW is a two-circuit, two-contact manual switch, and Da and Db are diodes.

The sliding electrode 44 (FIG. 6) has three contacts 44a, 44b, 44
and moves left and right in the figure in conjunction with the rotation of the motor 33. That is, the spring 8a moves right and left in the figure with a change in the wiper pressing force with a change in the tension of the spring 8a. 44 _-1 to state that moved to the left end position I, 44 _-2 is the state moved to the right end position II, respectively show.

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

When the sliding electrode 44 is at the position I, the pressing force is minimized,
Maximum when in position II. Further, when the R terminal side of the motor 33 is +, the motor 33 rotates forward to increase the pressure, and when the L side is +, it reversely rotates to decrease the pressure.

Now, when the pressing force is minimum, the contact a _{1 of the} switch SW
When a ₃ , b ₁ and b ₃ are turned ON, the positive electrode of the battery BT → the R terminal of the motor 33 → the L terminal of the motor 33 → the conductive pattern 43 a → the sliding electrode 44 → the conductive pattern 43 b → the diode Da → the negative of the battery BT The motor 33 rotates forward and the sliding electrode 44
Moves to the right in the figure. Accordingly, 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 II and is separated from the conductive pattern 43b, the energization in the normal rotation direction of the motor 33 is cut off and stopped.

Turned ON contact a ₂ and a _3, b ₂ and b ₃ by operating switching the switch SW from the stopped state as described above, the motor 33
Sliding contacts 44 _-2 moves to the left, which together with the wiper pressing force decreases reversed.

[Problems to be solved by the invention]

In the control device according to the prior art described above, i.Since the increase / decrease of the wiper pressing force is performed remotely by the driver's manual operation, it is necessary to have advanced experience and Requires skill.

ii. Due to manual operation, continued use of the wiper blade (rubber ribbon) if the pressing force is unnecessarily increased due to forgetting, ignorance, or carelessness will cause early wear of the wiper blade (rubber ribbon).

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

[Means for solving the problem]

As a configuration for achieving the above object, the present invention relates to a device for controlling a motor of a pressing force variable wiper that changes a pressing force of a wiper blade by forward and reverse rotation of a spring tension adjusting motor, A moving contact in which three contacts that move along with each other are connected to each other; a conductive pattern disposed along three paths through which each of the three contacts passes; A diode circuit connected therebetween; three sets of relay contacts inserted and connected in the motor drive circuit; three relay circuits for driving each of the three sets of relay contacts; F that control each of the relay circuits
An F circuit, one timer circuit, a reset OR circuit connected to each of the two FF circuits, a comparison circuit, and an OR for transmitting a rising signal to the FF circuit
OR for transmitting a falling signal of the comparison circuit to the FF circuit
A circuit, an OR circuit for transmitting both rising and falling signals of the comparison circuit to the timer circuit, a trigger circuit for converting a continuous signal output from the comparison circuit into a trigger pulse, and a part of the trigger circuit. A polarity inversion circuit interposed between each of the comparison circuits, a vehicle speed sensor that outputs a pulse having a frequency proportional to the vehicle speed, a frequency-voltage conversion circuit that converts the pulse into a voltage, Receiving the voltage signal output from the circuit,
And two comparison circuits each having a different reference voltage.

[Action]

According to the above configuration, the relay signal is operated via the FF circuit by the voltage signal obtained by converting the output signal of the vehicle speed sensor, and cooperates with the conduction pattern and the moving contact (sliding contact). The wiper pressing force can be automatically switched among three levels of strong, medium and weak according to the vehicle speed.

Since this operation does not involve any manual operation, there is no possibility of causing early wear due to a human error.

〔Example〕

FIG. 1 is an explanatory view showing one embodiment of a wiper control device according to the present invention.

33 is a motor for adjusting the wiper tension,
When power is supplied from the R terminal to the L terminal, the terminal rotates forward to increase the spring tension, and the wiper pressing force increases. At the same time, the moving contact 21 moves rightward in the figure.

The position I shown is the left end position, and the wiper pressing force is
II is the rightmost position, which is the maximum wiper pressing force. And position
III is the intermediate position and the wiper pressing force is the standard value.

The moving contact 21 has a structure in which three contacts 21a to 21c are mutually connected and conductive.

When the moving contact 21 moves between the position I and the position III shown in the figure, the three contacts 21a to 21c move to the left and right in the figure, respectively, to form three trajectories.

Each of the conductive patterns 22a follows the three trajectories.
To 22c. However, at the position I, the conductive pattern 22a is
No contact conduction to

In the position II, the conduction pattern 22c is
No contact conduction to

Further, at the position III, the conduction patterns 22a and 22c do not make contact with the moving contact 21. Therefore, in this embodiment the conductive pattern 22a _-1 by dividing the conductive pattern 22a the 22
a- _2, and the conductive pattern 22c is divided to form the conductive patterns 22c- ₁ and 22c- ₂ .

23 is a relay circuit, and A / 1 to C / 1 are one circuit 2
Contact relays, a to c, are the contacts.

The illustrated 9 is a diode circuit, diodes D ₁ ~
Consisting of D _4.

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

24 shown is made of IC ₈ ~IC ₉ a flip-flop circuit (F · F circuits), each of said relay A / 1 through C / 1
Is controlling.

50 is a timer circuit, which is composed of IC _{10 and} has a relay B / 1
Is controlling.

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

Reference numeral 27 denotes a vehicle speed sensor which outputs a pulse having a frequency proportional to the vehicle speed. This pulse is applied to the frequency-to-voltage converter (FV) 28
Is converted into a voltage signal.

ref ₁ and ref ₂ are reference voltages, respectively, and the comparators CM ₁ and C
By M ₂ it is compared with the voltage signal.

FIG. 2 is a chart showing a relationship between a vehicle speed and a vehicle speed sensor output frequency.

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

3 and 2 in the backward calculation direction are as follows.

The output voltages V ₁ and V _{2 on the} vertical axis of FIG. 3 are voltages corresponding to the reference voltages ref ₁ and ref ₂ shown in FIG. ₁ , respectively.

These voltages V ₁ and V ₂ are respectively represented by the frequency f on the horizontal axis in FIG.
_1, corresponds to the converted value of f _2.

When these frequencies f ₁ and f ₂ are applied to the vertical axis of FIG. _2, they correspond to the vehicle speeds S ₁ and S ₂ on the horizontal axis, respectively.

The outputs of the comparators CM ₁ and CM ₂ are supplied to the CR circuit of the trigger circuit 29 directly or via the polarity inversion circuits IC ₁ and IC ₂ , respectively.

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

In the trigger circuit 29, the time constant of the CR circuit composed of C ₁ and R ₁ is T ₁ , the time constant of the CR circuit composed of C ₂ and R ₂ is T _2, and C ₃ ,
The time constant of the CR circuit consisting of R ₃ is T _3, and the CR consisting of C ₄ and R ₄
The time constant of the circuit as T _4, set such that _{T 1 = T 2 = T 3} = T 4.

C ₅ of initials reset circuit 26, the time constant of the CR circuit consisting of R ₅ and T _5, and T ₅ >> T _1.

The IC ₁₀ is an IC of a timer circuit and outputs an “H” level for a predetermined time TW when a trigger pulse is input. The time TW is set so as to be sufficient for the moving contact 21 to move from the cut of the conduction pattern (for example, between 22a- ₁ and 22a- ₂ ) to the conduction pattern.

First, when the switch SW is turned on when the vehicle speed is 0, the comparator
The outputs of CM ₁ and CM ₂ become “L”, and the outputs of the trigger circuits C ₁ and R _{1 and} the outputs of the trigger circuits C ₃ and R ₃ also become “L”.

Therefore, the output Q of the IC ₈ also becomes "L", and the relay A / 1 does not operate.

Meanwhile, IC ₁ and IC ₂ is an inverter circuit, the output becomes "H" when the inputs are "L".

Therefore, the trigger circuits C ₂ and R ₂ and C ₄ and R ₄ operate,
Outputs positive trigger pulses of T ₂ and T ₄ .

These positive pulses are transmitted to the S terminal of IC ₉ via IC ₅ , and the IC ₉ is set. Since the output of the IC ₉ is set to “H” and the relay C / 1 is activated, these pulses are simultaneously transmitted to the I terminal of the IC ₁₀ via the IC ₃ and the IC ₁₀ is set to “ H "and relay B / 1 is activated.

However, Vcc is transmitted because it is transmitted to the C ₅ · R ₅ of initials reset circuit 26 simultaneously with the ON operation of the switch SW, a positive trigger pulse T ₅ is output to the R terminal of the IC _10, the respective output It is transmitted to the R terminal of the IC ₈ ~IC _9.

As described above, since T ₅ >> T ₁ = T ₂ = T ₃ = T ₄ , the transmission time of the “H” level to the R terminal is long, so that IC ₈ and IC ₁₀ are reset, and their outputs are “L” and relay A /
1-Relay C / 1 does not work.

In this way, all the relays A / 1 to C / 1 do not operate, and these contacts a to c are connected to the NC side as shown in FIG.
33 is grounded at both terminals and stopped.

 The moving contact 21 is stopped at the position I.

Above state is continued through until just before the vehicle speed reaches the S ₁ increases.

Then, when the vehicle speed is less than S ₁ or S _2, the output of the frequency voltage converter (FV) 28 becomes less than V ₁ or V _2, the output of the comparator circuit CM ₁ is "H", the same CM ₂ The output becomes “L”.

Since the output of CM ₂ is "L", the trigger circuit _{C 3 · R 3, C 4} ·
The output of R ₄ is kept at "L".

On the other hand, since the output of the comparison circuit CM ₁ becomes “H”, the output of IC ₁ becomes “L”, C _{2 of} the trigger circuit is discharged, and C ₂
· Output of R ₂ will remain in "L", the output of the IC ₅ also becomes "L", also not operate relay C / 1, contact c remains NC side.

Then, "H" level to the S terminal of the pulse of T ₁ when the the CM ₁ as a becomes "H" through C ₁ · R ₁ is via the IC ₄ IC ₈ is transmitted, the output of the IC ₈ is It becomes “H” and the relay A / 1 operates. I of the IC ₁₀ via the pulse IC ₃ T ₁ at the same time
The output is transmitted to the terminal, the output of which is at the level "H" during the time TW, and the relay B / 1 is operated at the same time. As a result, the contact a switches to the NO side, the contact b switches to the NO side for the time TW, and the contact c maintains the NC side.

As described above, when the contact a is switched to the NO side, Vcc → contact a → conductive pattern 22b → moving contact 21 → conductive pattern 22c ₋₁ (during this time, the contact b also conducts in parallel) → diode D ₄ → motor 33 → contact c → Electricity is supplied through the ground path,
The motor 33 rotates forward and the wiper pressing force starts to increase.

At the same time, the moving contact 21 starts to move from the position I toward the position III.

After time TW from the start of the movement, the contact b is cut off, but the conduction through the energization patterns 22b and 22c- ₁ is maintained, so that the motor 33 continues to rotate, and the moving contact 21 moves rightward in the figure. . When the moving contact 21 reaches the position III and separates from the conductive pattern 22c- ₁ , the motor 33 stops. In this way, the wiper pressing force is in a state intermediate between weak and strong.

Next, description will be made of a case where the vehicle speed becomes S ₂ or more.

The output voltage of the frequency voltage converter (FV) 28 becomes V ₂ or more, the output of the comparator circuit CM _1, CM ₂ are both "H".

Comparison circuit CM ₁ output already becomes "H", since no intact changing, C ₁ trigger circuit 29 is in a fully charged state, the output of C ₁ · R ₁ remains "L". On the other hand, C ₂ continues to be in a discharged state, and the output of C ₂ · R ₂ also remains “L”.

By comparison circuit CM ₂ is switched to "H" to "L", the output pulses of constant T ₃ is the time from the trigger circuit C ₃ · R _3, it is transmitted via the IC ₄ to the S terminal of the IC _8.

The IC ₈ is set when switching to the "H" from the output of the "L" comparison circuit CM _1, the output becomes to "H". Output Again for T ₃ pulse is inputted maintains "H", the relay A / 1 keeps the operating state.

On the other hand, since the IC ₁₀ is returned to "L" after the time TW, when again outputs "H" during the time TW by a trigger pulse of constant T _3, the time relay B / 1 is actuated.

When the comparison circuit CM ₂ switches from “L” to “H”, the output of IC ₂ changes from “H” to “L”, C _{4 of the} trigger circuit 29 is discharged, and the output changes to “L”. keep. Therefore, the input of the IC ₅ becomes both "L", also its output to "L", IC ₉
Does not change, its output remains at "L" and relay C / 1 does not operate.

As a result, the contact a keeps the NO side, and the contact b becomes the time TW
Is switched to the NO side, and the contact c is maintained at the NC side.

Therefore, Vcc → contact a → contact b → motor 33 → contact c
→ Electricity is applied via the ground, the motor 33 rotates forward, and the wiper pressing force starts to further increase.

At the same time, the moving contact 21 starts to move toward the position II.

After a time TW from the start of the movement, the contact b is switched to the NC side, during which the moving contact 21 comes into contact with the conductive pattern 22c- ₂ , and the energization is continued.

When the moving contact 21 reaches the position II, the conductive pattern 22
Power is cut off at a distance from c- ₂ , and the motor 33 stops.

 Thus, the wiper pressing force is in a strong state.

Next, description will be made of a case where the vehicle speed is decelerated from S ₂ or more states than S _2, to S ₁ or more states.

The output of the comparator circuit CM ₁ remains "H" level, the output of the trigger circuit C ₁ · R ₁ and C ₂ · R ₂ remains "L".

On the other hand, the output of the comparator circuit CM ₂ is switched to "L" to "H". At this time, the output of the trigger circuit C ₃ · R ₃ remains “L” due to the discharge state of C ₃ .

On the other hand, when the input of IC ₂ switches from “H” to “L”, the output switches from “L” to “H”, and the trigger circuit C ₄・ R ₄
And outputs the time the "H" level of T ₄ is transmitted to one input of IC _5.

The other input of the IC ₃ is "L", the IC ₃ outputs a positive trigger T ₄ width.

As a result, IC ₉ is set, and its output becomes “H”,
Relay C / 1 is activated.

IC ₁₀ outputs “H” for the time TW and relays the same time.
B / 1 operates.

Further, since T ₄ pulses are transmitted via the IC ₆ to the R terminal of the IC ₈ simultaneously, the IC ₈ output is reset switches to "L" to "H", the relay A / 1 at the same time non Activated.

As a result, Vcc → contact c → motor 33 → diode D
₂ → conductive pattern 22a _-2 → moving contact 21 → conductive pattern 22b (during this time, contact b is conducted in parallel) → contact a
→ Conduction is performed in the order of grounding, the motor 33 rotates in the reverse direction, the pressing force of the wiper blade starts decreasing, and the moving contact 21 starts moving from the position II toward the position III.

When the moving contact 21 reaches the position III, the power is cut off from the conductive pattern 22a- ₂ , and the motor 33 is stopped. In this state, the wiper pressing force is intermediate between strong and weak.

Next, description will be made of a case where the vehicle speed is decelerated to below S ₁ from S ₁ or more.

The outputs of the comparison circuits CM ₁ and CM ₂ both become “L”. CM ₂ is already “L”.

On the other hand, the output of the CM ₁ is switched to the "H" → "L", C 1 trigger circuit is a discharge state, the output of C ₁ · R ₁ keeps the "L".

As described above, the output of CM ₁ becomes “L”, and IC ₁ outputs “H”. Therefore, the trigger circuit C ₂ · R ₂ outputs a positive trigger having a width of T ₂ . This positive trigger is applied to one input of IC ₅ and IC ₃
To one input at the same time.

As described above, the outputs of the trigger circuits C ₁ · R ₁ , C ₃ · R ₃ , and C ₄ · R ₄ are all “L”. Therefore, T _{2 is obtained} from each output of IC ₅ and IC _3.
Are output, and the S terminal of IC ₉ and the I terminal of IC ₁₀ are output, respectively.
And is transmitted to the R terminal of IC ₈ via IC ₆ .

However, setting and resetting of IC ₉ and IC ₈ are performed by the comparison circuit.
When the output of CM ₂ has switched from “H” to “L”, it has already been switched, IC ₉ has already output “H”, and IC ₈ has already output “L”, and relay C / 1 has been activated. State, relay A / 1 remains inactive.

On the other hand, since the IC ₁₀ is returned to "L" after the time TW, and outputs "H" during the re-time TW by T ₂ pulse, the time relay
B / 1 operates.

As a result, the contact c is maintained at the NO side, the contact a is maintained at the NC side, the contact b is switched to the NO side for the time TW, and energized in the order of Vcc → contact c → motor 33 → contact b → contact a → ground. As the motor 33 rotates in the reverse direction, the wiper pressing force starts to decrease, and the moving contact 21 starts moving toward the position I.

After a time TW from the start of the movement, the contact b is switched to the NC side, but the movement of the motor 33 is continued because the moving contact 21 is in contact with the conductive pattern 22a- ₁ during that time.

When the moving contact 21 reaches the position I, the moving contact
21 is separated from the conductive pattern 22a- ₁ , the power is cut off, and the motor 33 stops. In this way, the wiper blade pressing force automatically becomes weak.

The function of IC ₄ and IC ₅ is such that when the output of the comparison circuit CM ₁ or CM ₂ changes when the vehicle speed increases or decreases, the former (IC ₄ )
A signal for setting C ₈ and resetting IC ₉ is output, and the latter (IC ₅ ) is for setting a signal to IC ₉ and outputting a signal for resetting IC ₈ .

The IC ₃ always outputs a signal when the output of the comparison circuits CM ₁ and CM ₂ changes.

〔The invention's effect〕

As described above, according to the control device of the present invention, the pressing force of the wiper can be automatically switched between strong, medium, and weak in accordance with the vehicle speed, and a trouble due to a human operation error, particularly, an excessive pressing force. Premature abrasion of the wiper blade rubber ribbon.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of a control device according to the present invention. FIG. 2 and FIG. 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 view of the structure of the wiper. FIG. 5 is a bottom view showing a known technique of the wiper pressing force adjusting device, and FIG. 6 is a circuit diagram thereof. 21: Moving contacts, 21a to 21c: Contacts, 22a- ₁ and 22a
_-2 , 22b, 22c _-1 , 22c _-2 ... 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 reversal circuit 50
... Timer circuit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60S 1/32

Claims (1)

(57) [Claims] An apparatus for controlling a motor of a variable pressing force wiper for changing a pressing force of a wiper blade by forward and reverse rotations of a motor for adjusting a spring tension, wherein three contacts that move according to a change in the tension of the spring. Moving contacts that are electrically connected to each other, conductive patterns disposed along three paths through which each of the three contacts passes, and a diode circuit connected between the conductive patterns and the motor. And three sets of relay contacts interposed and connected in a drive circuit of the motor; three relay circuits for driving each of the three sets of relay contacts; and controlling each of the three relay circuits. Two F ・
An F circuit, one timer circuit, a reset OR circuit connected to each of the two FF circuits, a comparison circuit and an OR circuit for transmitting a rising signal to the FF circuit; An OR circuit for transmitting a falling signal of a comparing circuit to the FF circuit, an OR circuit for transmitting both rising and falling signals of the comparing circuit to the timer circuit, and a continuous signal output from the comparing circuit. A trigger circuit for converting into a trigger pulse, a part of the trigger circuit, a polarity inversion circuit interposed between each of the comparison circuits, and a vehicle speed sensor for outputting a pulse having a frequency proportional to the vehicle speed; A frequency-to-voltage conversion circuit that converts the pulse into a voltage; and two comparison circuits that receive a voltage signal output from the conversion circuit and have different reference voltages, respectively. You The control unit of the pressing force control wiper.