JPH11245773A - Windshield wiper driving controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with an inflow checking diode for a reverse connecting current due to a counter electromotive force to be generated at the time of being set up in a high mode, in this windshield wiper driving controller. SOLUTION: A combination switch 9 sets up an operating mode of a wiper motor 1, and at the time of setting up an intermittent mode, two power elements 10 and 11 are turned on or off by an integrated circuit 8, thereby intermittently driving the motor 1. A connecting terminal 14 of the power element 11 is connected to an Lo terminal, 6 via a switch means 13 added to the combination switch 9. When this combination switch 9 is set up in a Hi mode, counter electromotive force is produced in the Lo terminal 6, but since the connecting terminal 14 of the power element 11 is insulated from the Lo terminal 6 by the switch means 13, such a possibility that the reverse connecting current might flow into the power element 11 is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiper drive control device having a power semiconductor element for operating a wiper of a vehicle or the like intermittently at regular intervals when the amount of rainfall is small.

[0002]

2. Description of the Related Art Conventionally, a drive control circuit for controlling the intermittent operation of a wiper generally uses a relay as a means for interrupting power supply to a wiper motor. Therefore, not only does the relay generate noise during intermittent operation, but also the contacts are opened and closed, which causes a problem in durability. Therefore, for example, as disclosed in Japanese Patent Publication No. 7-41822,
When the first field-effect power element connected in series with the wiper motor is turned on and off to perform energization control to make a contactless state, and when this power element is turned off to shut off energization, the second electric field connected in parallel with the wiper motor There is a type in which an effect type power element is turned on to perform power generation braking for releasing a current generated by a wiper motor charged by a power motor rotating by inertia.

[0003] The wiper drive control device shown in FIG. 4 has substantially the same configuration and operation as the above-described conventional device, but further advances the circuit integration into an IC. In FIG. 1, reference numeral 1 denotes a wiper motor, on which a contact 2a, 2b of a wiper motor switch 2 is provided as a rotation detecting means on a cam plate for reducing the rotation thereof, and is normally closed on the contact 2b side. 3 is a vehicle battery, 4 is an ignition (IG
N) Power switch interlocked with the key switch, 5 is a washer motor, 6 is a Lo terminal, 7 is a Hi element, and 8 is a control I
C circuit, 9 is a combination switch, 10 is a field effect power element (Nch type MO) for driving a wiper motor.
SFET) and 11 are field effect power elements (Pch type MOS FET) for stopping the wiper motor.

The combination switch 9 is turned off (O
FF), intermittent (INT), Lo, and Hi, a composite switch for instructing the setting of the wiper operation mode in four stages and the operation of the washer (WASH). The control IC circuit 8 includes a combination switch 9, power elements 10, 11, It is connected to a wiper motor switch 2, a Lo terminal 6, a washer motor 5 and a power switch 4 as a power supply means, and detects rotation of the wiper motor 1 and controls on / off of the power elements 10 and 11.

[0005]

However, in the conventional device of FIG. 4 described above, the problem is that when the combination switch 9 is switched from "Hi" to "Lo",
A back electromotive force is generated at the Lo terminal 6, which causes a reverse connection current to flow into the power element 10. Therefore, it is necessary to insert a diode 12 to prevent the reverse connection current, which leads to a complicated circuit configuration and an increase in cost. It is a point that is.

An object of the present invention is to provide a wiper drive control device provided with a reverse connection current inflow prevention means which solves the above-mentioned problems of the prior art.

[0007]

In order to achieve the above object, a wiper drive control device according to the present invention includes a wiper motor for driving a wiper of a vehicle or the like, and a wiper motor connected in series to supply power to the wiper motor. Power supply means for performing the following operations; a first power semiconductor element for driving the wiper motor connected in series to the wiper motor; a second power semiconductor element for stopping the wiper motor connected in parallel to the wiper motor; A combination switch for setting a stepwise wiper operation mode, and a control connected to the combination switch and the power supply means for detecting rotation of the wiper motor and controlling on / off of the first and second power semiconductor elements. Means for switching the first power semiconductor when a predetermined wiper operation mode is switched A switch means for preventing the flow of reverse connection current to the child, further comprising a a gist.

[0008]

FIG. 1 is a schematic circuit diagram showing an embodiment of the present invention, FIG. 2 is a timing chart for explaining the operation thereof, and FIG. 3 is an exploded perspective view.

In FIG. 1, the same reference numerals as those in FIG. 4 denote the same or similar circuit components. In particular, in the present invention, a switch means 13 for preventing the inflow of reverse connection current is added to the combination switch 9 and the switch is added. Means 1
3 is connected between the Lo terminal and the connection element 14 of the power blocks 10 and 11.

Next, the operation of the above configuration will be described. If the combination switch 9 is set to the intermittent mode (INT) with the power switch 4 closed,
The i terminal 7 is opened and the terminal 7a is energized, so that an instruction to generate an intermittent operation is given to the control IC circuit 8.
The control IC circuit 8 always detects the wiper motor switch 2 and responds to the detection signal to control the power elements 10, 1
1 to control the rotation of the wiper motor 1. That is, when the wiper motor switch 2 is on the 2a side, the power element 10 is turned off to cut off the power supply to the wiper motor 1, and the power element 11 is turned on to release the generated current generated by the inertial rotation of the wiper motor 1. The braking is performed, and the wiper motor 1 is stopped immediately.

On the other hand, the wiper motor switch 2
Is on the contact 2b side, the power element 10 is turned on, the power motor 1 is energized, the power element 11 is turned off, and the wiper motor 1 rotates. Thus, when one rotation of a cam plate (not shown) corresponding to one stroke of the wiper blade is completed, the contact of the wiper motor switch 2 closes to the contact 2a. The above operation is repeated to perform the intermittent operation of the wiper as indicated by T3 in FIG.

Next, the combination switch 9 is set to Hi.
When the mode is set, the Hi terminal 7 is grounded and energized without passing through the power element 10 to perform a high-speed operation of the wiper as indicated by T1 in FIG. At this time, a back electromotive force Vr is generated at the Lo terminal 6 as shown in the figure. However, the connection terminal 14 of the driving power element 11 is L
The o terminal 6 is insulated from the o terminal 6, and the Lo terminal 6 is connected to the battery 3. Therefore, the reverse connection current is prevented from flowing into the power element 11.

When the combination switch 9 is set to Lo
When set to the mode, the Hi terminal 7 is opened and
The o terminal 6 is grounded, and the wiper motor 1 performs a low-speed operation of the wiper as indicated by T2 in FIG.

When the combination switch 9 is set to the off mode (OFF), the wiper motor 1 is stopped as shown at T4 in FIG. 2 in which the stop power element 10 is turned on as in the intermittent mode.

[0015]

As is clear from the above description, according to the present invention, a diode for preventing the inflow of reverse connection current is not required, and only a switch means is required. It will be cheaper.

[Brief description of the drawings]

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

FIG. 2 is a timing chart for explaining the operation of the embodiment.

FIG. 3 is an exploded perspective view showing a state when a combination switch is turned upside down in the drawing showing the embodiment.

FIG. 4 is a circuit diagram of a conventional wiper drive control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wiper motor 2 Wiper motor switch 3 Battery 4 Power switch 5 Washer motor 6 Lo terminal 7 Hi terminal 8 Control IC circuit 9 Combination switch 10 Driving power element 11 Stopping power element

Claims (2)

[Claims] 1. A wiper motor for driving a wiper of a vehicle or the like, power supply means connected in series to the wiper motor and supplying power to the wiper motor, and a drive motor for driving a wiper motor connected in series to the wiper motor. A first power semiconductor element, a second power semiconductor element connected in parallel to the wiper motor for stopping the wiper motor, a combination switch for setting a plurality of stages of a wiper operation mode, the combination switch, and power supply Control means for detecting rotation of the wiper motor and controlling on / off of the first and second power semiconductor elements; and switching back to the first power semiconductor element when a predetermined wiper operation mode is switched. Switch means for blocking the inflow of connection current. Wiper drive control device. 2. The wiper drive control device according to claim 1, wherein said switch means is provided in said combination switch.