JPH07315173A - Control circuit of wiper motor - Google Patents

Abstract

PURPOSE:To prevent abnormal noise and reversing noise produced at the time of reversing a wiper wiping motion and overrunning of a wiper immediately before the wiper starts reversing and reduce the abnormal noise at the time of reversing when the amount of rainfall is small. CONSTITUTION:A sliding fixed contact point 7 serailly connecting resistors 23, 24 to constantly open contact points 27, 28 of a relay 6 and conducted at the time when a wiper is within a specified range including a reversing position of a wiping motion of the wiper, a first contact point plate 5 and a second contact point plate 4 are furnished on a wiper motor 1. When the sliding fixed contact point 7 and either of the first contact point plate 5 and the second contact point plate 4 are conducted to each other, a coil 9 of the relay 6 is magnetized, a movable contact point of the relay 6 is switched from constantly closed contact points 25, 26 to the constantly open contact points 27, 28, and the wiper motor 1 is connected to the resistors 23, 24. Consequently, rotational speed of the wiper motor 1 is lowered in the neighbourhood of the wiper reversing, and overrunning and reversing noise are reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper motor control circuit.

[0002]

2. Description of the Related Art A conventional wiper motor control circuit is shown in FIG. FIG. 6 is a schematic circuit diagram showing a control circuit of a conventional wiper motor. The battery power supply terminal 13 is an input terminal 14 of the wiper motor 1 and a contact plate 3 that opens and closes according to the rotation of the auto stop 2.
And a contact point 36 connected to the capacitor and a capacitor 11. The high speed output terminal 16 and the low speed output terminal 15, which are the output terminals of the wiper motor 1, are connected to the high speed drive contact 17 and the low speed drive contact 18 of the wiper switch 12, respectively.

A wiper drive shaft, which rotates via a link mechanism (not shown), is connected to the wiper motor 1.
The wiper makes a wiping motion by the rotation of the wiper drive shaft. At this time, the wiper switch 12 is selected to wipe the wiper at high speed or low speed.

[0004]

However, in the wiper motor 1, the wiper switch 12 is driven by selecting either the high-speed drive contact 17 or the low-speed drive contact 18, but it is always driven at a constant speed. Since the rotation continues, there is a problem that when the wiping movement of the wiper is reversed, a reversing sound is generated due to the influence of the inertial force of the wiper, or an overrun occurs.

In particular, when the high speed drive contact 17 is selected by the wiper switch 12, an overrun phenomenon occurs due to inertial force when the wiper wiping motion is reversed. Therefore, in consideration of the overrun in advance, it is necessary to set a large interval between the opposite edges of the window and the reversal position of the wiper wiping motion, which causes a problem that the wiper wiping range becomes narrow when driven at low speed. . There is also a problem in that the set position of the wiper becomes high and the appearance is poor.

When the low speed drive contact 18 is selected by the wiper switch 12 to drive the wiper motor 1 at a low speed when the amount of rain is small, a reversing sound is particularly noticeable when reversing the wiper wiping motion. There is. The present invention has been made in view of such problems,
An object of the present invention is to provide a control circuit of a wiper motor that reduces an overrun phenomenon due to inertial force that occurs at the time of reversing a wiper wiping motion and reduces a reversing sound that is particularly noticeable at the time of reversing.

[0007]

In order to achieve such an object, the control circuit of the wiper motor of the present invention outputs a detection signal when the wiper is within a predetermined range near the reversal position for reversing the wiper wiping motion. And a deceleration circuit for decelerating the rotation of the wiper motor is connected to the wiper motor via a switching means, and the switching means is configured to output the detection signal from the reversal detection circuit. Is connected to a wiper motor.

The reversal detection circuit rotates integrally with the auto stop of the wiper, and the first and second contact plates provided symmetrically with respect to the rotation center of the auto stop, and the wiper reverses the wiper wiping motion. Which has a sliding fixed contact which comes into contact with either the first contact plate or the second contact plate when it is within a predetermined range near the reversal position, and whichever of the first contact plate or the second contact plate When one of the two contacts with the sliding fixed contact, a current may flow in the inversion detection circuit to serve as a detection signal. Further, the speed reduction circuit may be a circuit including a resistor. The speed reduction circuit may be a circuit that connects the input terminal and the output terminal of the wiper motor to form a closed circuit.

[0009]

In the wiper wiping movement, when the wiper reaches a predetermined range near the reversal position, the reversal detection circuit outputs a reversal detection signal, and the detection means causes the switching means to connect the speed reduction circuit to the wiper motor. Since the rotation of the wiper motor is reduced by the speed reduction circuit, the wiping speed of the wiper decreases in a predetermined range near the reverse position of the wiper, the inertia force of the wiper is reduced, and the overrun due to inertia and the reverse sound when the wiper reverses. Can be prevented. When the reversal detection circuit comprises the first contact plate, the second contact plate and the sliding fixed setting, the automatic stop and either the first contact plate or the second contact plate which rotates physically, and When the dynamic fixed contact comes into contact, an electric current flows and becomes a reversal detection signal indicating that the wiper has reached a predetermined range near the reversal position in the wiper wiping movement. The predetermined range is set by the plate widths of the first and second contact plates.

When the speed reduction circuit is a circuit including a resistance, the rotation speed of the wiper motor is driven by a voltage lower by a voltage drop corresponding to the resistance value of the resistance. That is, when the wiper reaches a predetermined range including the reversal position in the wiper wiping motion, the rotation speed decreases by the amount corresponding to the voltage drop. Therefore, it is possible to prevent the overrun and the reversing sound at the time of reversing the wiper.

When the speed reduction circuit is a circuit that connects the input terminal and the output terminal of the wiper motor to form a closed circuit, the wiper motor is braked and its rotation is decelerated. Therefore, it is possible to prevent the overrun and the reversing sound at the time of reversing the wiper. In this case, it is preferable that the closed circuit is formed just before the reverse position of the wiper, and the predetermined range is preferably a distance that can be passed by the inertial force of the wiper.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a control circuit diagram of a wiper motor according to a first embodiment of the present invention. The same members as those of the related art are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the low speed output terminal 15 and the high speed output terminal 16 which are the output terminals of the wiper motor 1 are connected to the relay 6 which is a switching means. That is, the relay 6 includes the coil 9, the movable contacts 19 and 20, the normally closed contacts 25 and 26, and the normally open contact 2.
7, 28, and the low speed output terminal 15 and the high speed output terminal 16 are movable contacts 19 of the relay 6,
20 are respectively connected. Normally closed contact 25 of relay 6,
26 is connected to the high speed drive contact 17 and the low speed drive contact 18 of the wiper switch 12, while
The normally open contacts 27 and 28 of the relay 6 are resistors 23 and 28, respectively.
It is connected to a high resistance circuit composed of 24.

Normally, the high speed output terminal 16 and the low speed output terminal 15 of the wiper motor 1 are connected to the wiper switch 12 via the movable contacts 19 and 20 and the normally closed contacts 25 and 26 of the relay 6.

The control circuit of the wiper motor of this embodiment is provided with an inversion detection circuit 30. Inversion detection circuit 30
Is composed of a battery power supply terminal 13, a coil 9 of the relay 6, an inversion detector, and a series circuit connected to ground,
The reversal detector comprises an automatic stop 22, a first contact plate 5 and a second contact plate 4 which rotate around the body, and a sliding fixed contact 7. The first contact plate 5 and the second contact plate 4 are arranged at symmetrical positions with respect to the rotation center of the auto stop 22,
Sliding fixed contact 7, first contact plate 5, and sliding fixed contact 7
The second contact plate 4 and the second contact plate 4 have a relative positional relationship and a first contact so that the wiper is closed and conductive when the wiper is within a predetermined range including the lower reversal position and the upper reversal position of the wiping motion. The widths of the plate 5 and the second contact plate 4 are set. Therefore, in the inversion detection circuit 30, when the inversion detector is within a predetermined range including the inversion position of the wiper, the inversion detection circuit 30 is closed and a current serving as a detection signal flows.
As a result, the coil 9 of the relay 6 is excited and the movable contacts 19 and 20 of the relay 6 are normally closed contacts 25 and 26, respectively.
To the normally open contacts 27 and 28.

Next, the operation of this embodiment will be described. During operation of the wiper, when the wiper is not in the predetermined position including the reverse position, that is, when the sliding fixed contact 7 of the reverse detector and the contact plates 4 and 5 are not electrically connected, the reverse detection circuit 3
Since 0 is not closed, the movable contacts 19 and 20 of the relay 6 are
Are connected to normally closed contacts 25 and 26. Then, depending on the selection of the wiper switch 12, a low speed or high speed wiper wiping motion is performed. When the wiper reaches a predetermined position including the reversal position, one of the sliding fixed contact 7 and the contact plates 4, 5 of the reversal detector is brought into conduction, the reversal detection circuit 30 is closed, and the battery power supply terminal 13 A current serving as a detection signal flows from the coil 6, excites the coil 9 of the relay 6, and moves the movable contacts 19 and 20 of the relay 6, respectively.
The normally closed contacts 25, 26 are switched to the normally open contacts 27, 28 to connect the wiper motor 1 to the high resistance circuit including the resistors 23, 24. Therefore, the wiper motor 1 is driven at a voltage lower by the voltage drop due to the resistors 23 and 24, and the rotation speed of the wiper motor 1 is reduced.

FIG. 4 is an operation diagram of the wiper wiping of the control circuit of the wiper motor of this embodiment and the control circuit of the conventional wiper motor, in which the vertical axis represents the wiper wiping speed and the horizontal axis represents the cycle. I am taking it. The wiper wiping motion by the control circuit of the wiper motor of the present embodiment is shown by the dotted line 31.
A solid line 32 shows the wiper wiping movement by the control circuit of the conventional wiper motor. As shown in the drawing, the wiping operation is repeated with the lower reversal position 34 when the wiper starts wiping and the upper reversal position 33 when the wiper finishes the operation of returning to the original position.

In the predetermined range 35, the difference between the dotted line 31 of the wiper wiping motion by the control circuit of the wiper motor embodying the present invention and the solid line 32 of the wiper wiping motion by the control circuit of the conventional wiper motor is shown. Predetermined range 3
5 are preset in the lower reversal position 34 and the upper reversal position 33, respectively, with the reversal positions as the center.
This range is a time determined by the width of the contact plates provided on the first contact plate 5 and the second contact plate 4 shown in FIG.

As for the wiper wiping motion dotted line 31 by the control circuit of this embodiment, the wiper wiping speed sharply decreases within a preset predetermined range 35, and the wiper wiping is performed at the lower reversal position 34 and the upper reversal position 33. The speed becomes zero. After the reversal, the wiper wiping speed gradually increases from zero, and the wiper wiping speed increases when it exceeds a preset predetermined range 35. In this way, since the rotation speed of the wiper motor 1 decreases near the reversal of the wiper, it is possible to reduce overrun and reversal sound due to the inertial force of the conventional wiper.

FIG. 2 is a control circuit diagram of the wiper motor of the second embodiment according to the present invention. The inversion detection circuit 30 is the same circuit as in FIG. The relay 6 includes a relay coil 9, a movable contact 19, a normally closed contact 25, and a normally open contact 2.
7, the normally open contact 27 is connected to the high speed drive contact 17 of the wiper switch 12 via the resistor 23. That is, it is a circuit diagram in which the inversion detection circuit of the present invention is applied only to the circuit that drives the wiper motor 1 at high speed, and the operation of the circuit is the same as in FIG.

The present embodiment is suitable when overrun due to inertial force during high speed operation of the wiper poses a particular problem. FIG. 3 is a control circuit diagram of the wiper motor of the third embodiment according to the present invention. Inversion detection circuit 3
0 has the same circuit as that in FIG. The relay 6 is composed of a coil 9 of the relay, one movable contact 20, a normally closed contact 26 and a normally open contact 28, and the normally open contact 28 is connected to the low speed drive contact 18 of the wiper switch 12 via a resistor 24. Has been done. That is, wiper motor 1 at low speed
2 is a circuit diagram in which the inversion detection circuit of the present invention is applied only to a circuit for driving the circuit, and the operation of the circuit is the same as that in FIG. The present embodiment is suitable when the reversal sound during the low speed operation of the wiper becomes a particular problem.

FIG. 5 is a control circuit diagram of the wiper motor of the fourth embodiment according to the present invention. In this embodiment, the switching unit includes a first relay 40 and a second relay 41. The first relay 40 includes a coil 45 and a movable contact 46.
, A normally closed contact 47 and a normally open contact 48. The normally closed contact 47 is connected to the battery power supply terminal 13. In addition, the second relay 41 includes the coil 50 and the movable contact 5
1, 52, normally closed contacts 53, 54, and normally open contacts 55, 5
6 and the high speed drive contact 57 and the low speed drive contact 58 of the wiper switch 12 are connected to the movable contacts 51 and 52 of the second relay 41, respectively. The normally closed contacts 53 and 54 of the second relay 41 are grounded, and the normally open contacts 55 and 56 are connected to the normally open contact 48 of the first relay 40.

The control circuit of the wiper motor of this embodiment is provided with an inversion detection circuit 60. Inversion detection circuit 60
Are the battery power supply terminal 13, the coil 50 of the second relay 41, the inversion detector, and the coil 4 of the first relay 40.
5 and a series circuit to which ground is connected, and the reversal detector comprises an auto stop 22, a first contact plate 61 rotating to the body, a second contact plate 62, and a sliding fixed contact 63. The first contact plate 61 and the second contact plate 62 are arranged at symmetrical positions with respect to the rotation center of the auto stop 22, and the sliding fixed contact 63, the first contact plate 61, and the sliding fixed contact 63 are provided. The relative positions of the second contact plates 62 are set so that when the wipers are within a predetermined range immediately before the lower reversal position and the upper reversal position of the wiping motion, the second contact plates 62 close and conduct the contacts.

Therefore, in the reversal detection circuit 60, when the reversal detector is within a predetermined range immediately before the reversal position of the wiper, the reversal detection circuit 60 is closed and a current serving as a detection signal flows. As a result, the coil 4 of the first relay 40
5 and the coil 50 of the second relay 41 are excited, and the first
Movable contacts 46, 5 of the relay 40 and the second relay 41 of
1, 52 respectively switch from the normally closed contacts 47, 53, 54 to the normally open contacts 48, 55, 56.

Next, the operation of this embodiment will be described. During the operation of the wiper, when the wiper is not within the predetermined range immediately before the reverse position, that is, the sliding fixed contact 63 of the reverse detector.
Since the reversal detection circuit 60 is not closed when the contact plates 61 and 62 are not electrically connected to each other, the movable contact 46 of the first relay 40 becomes the normally closed contact 47 and the movable contact 51, 52 of the second relay 41. Are connected to normally closed contacts 53 and 54. Then, depending on the selection of the wiper switch 12,
A low speed or high speed wiper wiping exercise is performed.

When the wiper comes within a predetermined range immediately before the reversing position, the sliding fixed contact 63 and the contact plate 6 of the reversing detector are detected.
Either one of 1 and 62 is turned on, and the inversion detection circuit 60
Is closed, a current serving as a detection signal flows from the battery power source 13, the coil 45 of the first relay 40 and the coil 50 of the second relay 41 are excited, and the first relay 40
And the movable contacts 46, 51, 52 of the second relay 41 from the normally closed contacts 47, 53, 54 to the normally open contacts 48, 5 respectively.
It switches to 5, 56. As a result, the wiper motor 1 is separated from the battery power supply terminal 13 and placed in the closed circuit. Therefore, the wiper motor 1 is braked and the rotation speed of the wiper motor 1 is reduced. It is desirable to set the time for forming a closed circuit corresponding to the width of the contact plates 61, 62 to a time that allows passage by the inertial force of the wiper.

In this way, since the rotation speed of the wiper motor 1 decreases near the reversal of the wiper, it is possible to reduce the overrun and the reversal sound due to the inertial force of the conventional wiper. In each of the above embodiments, the case where a mechanical detector including a contact plate and a sliding fixed contact is used as the reversal detector has been described. However, a rotating plate or a wiper is used by using an optical sensor or a magnetic sensor. It is also possible to detect the position of and output the detection signal near the inversion position. It is also possible to detect the vicinity of the inversion position by measuring the time with a timer.

[0027]

As described above, when the wiper motor is connected to the speed reducing circuit for reducing the rotation of the wiper motor through the switching means, and the wiper is within the predetermined range near the reversing position for reversing the wiper wiping motion. Since the switching means connects the speed reduction circuit to the wiper motor when the detection signal from the inversion detection circuit is output, the inversion detection circuit for outputting the detection signal to the wiper motor is provided. Since the wiping speed of the wiper decreases in a predetermined range, there is an extremely excellent effect that it is possible to prevent an overrun due to the inertia of the wiper and a reversing sound at the time of reversing the wiper. Furthermore, since overrun due to the inertia of the wiper can be prevented, the setting position of the reversal position of the window can be brought closer to the molding edge which is the edge, and the wiping range of the wiper can be set wide,
Positioning the tip of the window further forward, that is, even if the inclination of the window is gentle, the degree of freedom in shaping the vehicle can be increased without obstructing the field of view from the occupant.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of the present invention.

FIG. 4 is a comparative diagram showing a graph of wiper wiping speed-cycle of the present invention and a conventional example.

FIG. 5 is a circuit diagram showing a fourth embodiment of the present invention.

FIG. 6 is a control circuit diagram of a conventional wiper motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wiper motor 4,62 2nd contact plate 5,61 1st contact plate 6 Relay (switching means) 7,63 Sliding fixed contact 12 Wiper switch 30,60 Inversion detection circuit 40 1st relay (switching means) 41 Second relay (switching means)

Claims (4)

[Claims] 1. A wiper motor control circuit, comprising a reversal detection circuit for outputting a detection signal when the wiper is within a predetermined range near a reversal position for reversing the wiper wiping motion, and the wiper motor has a wiper motor. A deceleration circuit for decelerating the rotation of the wiper motor is connected via a switching means, and the switching means connects the deceleration circuit to a wiper motor when a detection signal from the inversion detection circuit is output. Control circuit. 2. The reversal detection circuit rotates integrally with an auto stop of a wiper, and first and second contact plates provided symmetrically with respect to a rotation center of the auto stop, and the wiper wipes wiping motion. And a second fixed contact plate, the fixed fixed contact and the second fixed contact plate contacting either the first contact plate or the second contact plate when within a predetermined range near the reverse position. 2. The wiper motor control circuit according to claim 1, wherein a current flows through the reversal detection circuit to generate a detection signal when either one of the above and the fixed fixed contact comes into contact. 3. The wiper motor control circuit according to claim 1, wherein the speed reduction circuit is a circuit including a resistor. 4. The control circuit for the wiper motor according to claim 1, wherein the speed reduction circuit is a circuit that connects an input terminal and an output terminal of the wiper motor to form a closed circuit.