JP2692747B2 - Reversible rotating wiper device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversible rotary wiper device in which a wiper blade for wiping a wind surface of a vehicle, for example, a vehicle is driven by a wiper motor capable of forward and reverse rotation.

[Conventional technology]

With a reversible rotation type wiper device that does not use link motion, the wiping angle is difficult to be constant due to the frictional force of the wind surface, and the wiping angle depends on whether the glass surface is wet due to rain or dry. There was a problem that it caused fluctuations.

[Problems to be solved by the invention]

Therefore, it is desirable to control the current supplied to the wiper motor to make the wiping angle constant so that the wiping angle necessary and sufficient for the vehicle is always constant even if the coefficient of friction of the glass surface varies. .

For this reason, the present invention does not use a reciprocating rotation mechanism by a link mechanism, that is, a mechanism that converts a rotational movement into a reciprocating wiping movement using a link, and in a wiper device of a type that performs normal and reverse rotation of a wiper motor. The purpose is to keep constant.

(Configuration of the present invention)

In order to achieve the above-mentioned object, the present invention provides a wiper blade for wiping the window of a vehicle, a wiper motor for normal rotation and reverse rotation for driving the wiper blade, and a forward rotation current and a reverse rotation current for the wiper motor. A drive circuit for supplying, position detection switch means that operates in accordance with the movement of the wiper blade, and that outputs a signal at one side reversal command position and the other side reversal command position of the wiper blade,
The wiper is provided with control means for controlling the drive circuit based on a signal from the position detection switch means, whereby the wiper wiper passes through the one side inversion command position and the other side inversion command position by respective slip angles. In the reversible rotation type wiper device in which the blade reciprocates and reciprocates, the control means includes
The measuring means has a measuring means for measuring a wiping command angle passage time at which the wiper blade passes the wiping command angle between the one-side reversing command position and the other-side reversing command position detected by the position detecting means. A control signal is generated from the control means to the drive circuit so that the slip angle becomes larger as the measured time becomes longer, and the total angle of the slip angle on the one side and the other side and the wiping command angle is constant. It is designed to approach the value.

[Action]

In the present invention, for example, the time taken for the wiper blade to pass through the designated wipe angle specified by the position detection means constituted by a cam switch or the like is measured, and the longer this time is (the too small if left alone) the slip angle The current supplied to the wiper motor is controlled so that As a result, when the wind surface is wet due to rain, for example, the frictional force between the wind surface and the wiper blade is small, so that the time required to pass the wiping command angle is shortened. And
In this case, the current supplied to the wiper motor is cut off earlier so that the slip angle becomes smaller. Therefore, normally, when the wind surface is wet due to rain, the frictional force is small, so the tendency for the slip angle to increase can be forced to approach a certain value by cutting off the current supplied to the wiper motor early. It will be possible.

On the other hand, when the wind surface is dry, on the other hand, the time taken for the wiper blade to pass the wiping command angle becomes long. In this case, in a normal state, the slip angle tends to be small, but in the present invention, the time for passing the wiping command angle becomes longer as the wind surface is dry, so the slip angle becomes large. A drive signal is output from the control means to the drive circuit so that a reversible rotary wiper device having a wiping angle that is almost constant regardless of whether the wind surface is dry or wet can be obtained.

〔The invention's effect〕

According to the present invention, a wiper device having a substantially constant wiping angle can be provided, so that a necessary field of view can always be ensured and it can contribute to safe driving of a vehicle.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described.

FIG. 1 is a wiper blade in the wiper device of the present invention.
10 illustrates the wiping angles of 10, and schematically shows that the slip angles exist on both sides of the cam signal angle that forms the designated wiping angle defined by the cam switch that forms the position detecting means. Next, FIG. 2 is an electric circuit diagram of the wiper device of the present invention, and FIG. 3 is a cam signal in the electric circuit diagram.
6 is a timing chart showing how the blade behaves in synchronization with the cam signal. FIG. 4 is a flow chart of the microcomputer of the circuit shown in FIG. In FIG. 2, reference numeral 1 is a wiper switch, 2 is a wiper controller, which is provided with a one-bit microcomputer 2a and a drive circuit 2b which are control means. The drive circuit is a direct-current motor in a wiper motor 3 capable of forward and reverse rotation. It is a well-known one that supplies a forward rotation current and a reverse rotation current to 3a, and has a relay having a plurality of switching contacts and a plurality of transistors for controlling the relay to be in an excited state. The wiper motor 3 is a cam switch which constitutes a DC motor 3a forming a wiper motor body and a position detecting means which rotates together with an output shaft of the wiper motor.
3b.

Reference numeral 5 is a battery, one end of which is connected to the wiper controller 2 to supply power to the drive circuit 2b and the microcomputer 2a. The minus side of the other end of the battery is connected to a brush 3b ₂ which is in sliding contact with the surface of the cam switch. In addition to the brush of the cam switch, another brush 3b ₁ is provided so as to face each other, and the other brush is connected to the microcomputer 2a to guide the signal from the cam switch to the microcomputer 2a. It is like this.

In FIG. 3, the relationship between the movement of the wiper blade and the signal from the cam switch that constitutes the position detection switch means will be described.

By the drive circuit 2b, the forward current is supplied to the DC motor 3a, the wiper blade begins to forward, the cam signal when a certain time has elapsed at time t _1, inverted from positive to negative, that is, the second In the figure, since the metal pattern of the cam switch rides on both the brushes 3b ₁ and 3b ₂ and the negative potential of the battery is introduced to the wiring 6, the cam signal is inverted from brass to negative at time t ₁ . . That is, the stop command is issued. However, the wiper blade continues to rotate in the normal direction, that is, continues to run idle, and the electric brake is applied to start braking in the middle of this, but the wiper blade completely stops after moving by a predetermined slip angle V ₂₁ . The time of this complete stop is indicated by t ₂ . Next, at time t ₃ , a reverse current is supplied from the drive circuit 2b to the DC motor 3a, and reverse rotation is started. When the reverse rotation is performed to some extent, the signal of the cam switch is inverted from minus to plus again. This time is t ₄ , and the rising timing of the cam signal from minus to plus at this time corresponds to the counting start time by the measuring means inside the microcomputer. Next, when the reverse rotation continues for a while and reaches time t ₅ , the wiper blade reaches the lower reverse command position which is the other side in FIG. 1, and the signal of the cam switch reverses from positive to negative. This is the time t _5.
In this way the wiper blade even if the, will continue to empty run continued the reversal, the middle of the sky run That is, at time t _6, including electric braking is heard in between t ₆ from the time t _5, the wiper blade is completely Stop. Then, when the time t ₇ is reached, the wiper blade starts to rotate forward by the forward rotation current from the drive circuit 2b, and after a predetermined amount of forward rotation is performed, the wiper blade is again on one side of FIG. Since the inversion command position on the side is reached, the signal of the cam switch is inverted from minus to plus. This time is indicated by t ₈ .

Rising from the above-mentioned cam signal to minus, that is, the time from the upper reversal command position to the negative reversal of the cam signal which is the lower reversal command position is the time when the wiper blade passes the wiping command angle,
That is, it corresponds to the wiping command angle passage time. In other words, the length of the period during which the wiper blade idles is determined according to the length of this time. In other words, the magnitude of the slip angle passage time is determined.

Specifically, in order to increase the slip angle, that is, to increase the idling time, it is performed after the stop command is issued, that is, by shifting the timing at which electric braking starts from time t ₁ . Further, in order to shorten the idling time, that is, to reduce the slip angle, the timing from the time t ₁ until the electric braking starts is set early. Also, at the other slip angle, that is, the slip angle V ₂₂ between the reverse rotation and the forward rotation,
Empty run starts from the time t _5, to set the slip angle by shifting the timing at which the braking begins to listen. And
The setting of the slip angle is controlled by the timing of the drive signal output from the microcomputer to the drive circuit 2b.

Next, the operation of the microcomputer 2a will be described based on the flowchart shown in FIG. In this flowchart, initial setting is performed in step 101,
Next, at step 102, the signal from the cam switch 3b,
That is, the signal from the wiring 6 is read. For example, the rising inversion signal of the cam signal from minus to plus at time t ₄ in FIG. 3 is read. This gives you step 10
3 starts time measurement, measures the time of the next cam inverted signal in step 104, i.e. from the positive at time t ₅ to come inverted signal to the negative. And time
When it reaches t ₅ , as shown in step 105, the time measurement by the measuring means is ended. This measured time is T _1, that is, the wiping command angle passage time is T _1, and then the step
As shown by 106, 107 and 108, it is determined what time region this time T ₁ corresponds to. Where Ta, Tb, Tc
Td is the time obtained from each experiment, and Ta <Tb <
Tc <Td.

If YES is determined in any of the steps 106, 107, 108, the processes of steps 109, 110, 111 are performed, respectively. That is, it means that the time T ₁ is larger as going from step 106 to step 108, that is, the friction on the glass surface is larger and the dryness is larger, and in this case, the idle running time is set to be larger. . That is, the slip angle is set to increase. And step 10
At 9, the free running time is given at which the slip angle (passing time) is small. Further, in step 110, the free-running time at which the slip angle becomes Vb of medium is provided. Further, in step 111, the free running time at which the slip angle becomes Vc is given. The setting of such idle running time, specifically, the timing control of the operation of the electric braking by the drive signal given from the microcomputer 2a of FIG. 2 to the drive circuit 2b is performed.

It should be noted that the supply of the forward rotation current of the DC motor 3a by the drive circuit and the supply of the reverse rotation current which is the current in the opposite direction to the DC motor 3a, and the configuration in which the armature of the DC motor is short-circuited and the electric brake is applied are well-known. Although omitted, the switching relay in the drive circuit switches between forward rotation current and reverse rotation current and shorts the armature. Switching of this relay is controlled by turning on / off a transistor that supplies current to the solenoid of the relay. .

As described above, after the electric brake of the DC motor 3a is controlled by the drive signal supplied from the microcomputer to the drive circuit, the microcomputer 2a
Outputs a motor inversion signal to the drive circuit 2b. That is,
Step 112 is executed. That is, the wiping operation of the wiper blade is continuously performed, such as the normal rotation after the stop after the reverse rotation, the normal rotation after the stop, and the reverse rotation again.

In the above flow chart, the stratification of the time T ₁ is set to three stages. However, the more the stratification is increased at any stage, the finer and more accurate the control becomes possible.

Further, needless to say, the cam switch can use various other limit switches without using the pattern electrodes as shown in FIG. Further, although the wiping command angle set by the cam switch is set to one fixed value in the above-mentioned embodiment, this may be set freely, and the point is that the wiping command angle is set with respect to the set wiping command angle. The wiping angle of the wiper blade having a certain relationship may be controlled so as to be obtained regardless of the wetness or dryness of the window. If such control is performed, a predetermined desired wiping angle corresponding to the wiping command angle set by the cam switch means or the like can always be obtained, and front view is secured regardless of whether it is raining or dry. It will be.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing a wiping range of a wiper blade of the present invention wiper device, FIG. 2 is an electric circuit diagram in one embodiment of the present invention wiper device, and FIG. 3 is used in FIG. FIG. 4 is a time chart for explaining the correspondence between the signal from the cam switch and the normal, stopped and reverse rotation states of the wiper blade, and FIG. 4 is a flowchart showing the processing in the microcomputer used in FIG. 10 ... wiper blade, 3 ... wiper motor, 3a ... DC motor constituting a wiper motor body constituting a part of the wiper motor, cam switches constituting the position detecting means forming part of the 3b ... wiper motor 3, 3b _1, 3b ₂ ... cam A brush in the switch, 2b ... A driving circuit, 2a ... A microcomputer constituting a control means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mikiharu Tomita 3 Iyama, Shinomemachi, Anjo City, Aichi Prefecture, inside Anjo Electric Co., Ltd. (72) Seiji Ishikawa, 1 Toyota Town, Toyota City, Aichi Prefecture, inside Toyota Motor Co., Ltd. (72) Inventor Tetsuya Yasuda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (56) Reference JP 62-265049 (JP, A)

Claims (1)

(57) [Claims] 1. A wiper blade for wiping a window of a vehicle, a wiper motor main body that rotates in the normal and reverse directions to drive the wiper blade, a drive circuit for supplying a normal rotation current and a reverse rotation current to the wiper motor main body, and the wiper. The wiper blade operates in accordance with the movement of the blade, and outputs a signal at one side reversal command position and the other side reversal command position of the wiper blade, and the drive circuit based on the signal from the position detection switch means. A reversible rotation type in which the wiper blade reciprocates and reciprocates after passing the one-sided reversal command position and the other-sided reversal commanded position by the slip angles of the one side and the other side, respectively. In the wiper device, the control means includes one side inversion command position detected by the position detection switch means and the other side. The wiper blade has a measuring means for measuring a wiping command angle passing time of a wiping command angle between a rotation command position and the wiping blade, and the longer the time measured by the measuring means, the larger the slip angle. A drive signal is generated from the control means to the drive circuit so that the wiping angle, which is the total angle of the slip angles on the one side and the other side and the wiping command angle, approaches a constant value. Reversible rotation type wiper device.