JPH0241952A - Water droplet removing device for vehicular rear view mirror - Google Patents

Abstract

PURPOSE:To reduce power consumption per unit duration of time by composing in such a way to install vibrating means on rear view mirrors arranged on both the left and right sides and to selectively drive one of them at a specified time interval. CONSTITUTION:A side mirror is repeatedly inflected when an oscillating circuit 60 is connected and alternating current is supplied to a ultrasonic 31 rigidly secured at about the middle of the mirror. If a frequency is selected in the vicinity of the lowest resonnant frequency of the mirror increased by an integral number, standing waves of a large oscillation are generated. Since water droplets are removed by use of the standing waves, water droplets can be efficiently removed with a little power consumption. When the operator of a vehicle operates the left side driving button 73a, water droplets on the left side mirror alone are removed. When the right side driving button 73b is operated, water droplets on the right side mirror alone are removed. When both driving buttons 73a, 73b are not operated, water droplets on both the left and right sides are removed in turn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a device for removing water droplets adhering to so-called vehicle rearview mirrors, such as fender mirrors and door mirrors.

(Prior Art) A conventional device of this type is disclosed in Japanese Patent Application Laid-Open No. 59-8548 (see FIG. 12). In this device, a vibrating means 2 is fixed to a mirror 1, and the vibrating means 2 is vibrated by a driving means 3 to remove water droplets attached to the mirror 1.

When mirror l vibrates, if there are water droplets attached to the reflective surface of mirror l, the water droplets are excited by the vibration of mirror l,
removed from mirror 1.

Further, the above-mentioned publication discloses that the driving means 3 is operated at regular intervals in order to eliminate wasteful power consumption.

(Problems to be Solved by the Invention) However, in the conventional device, since the left and right mirrors 1 are driven simultaneously, there is a problem in that the power consumption per unit time is large.

Therefore, the technical challenge of the present invention is to reduce power consumption per unit time.

[Structure of the invention]

(Means for solving the problem) The technical means taken to achieve the above-mentioned technical problem is a vibration excitation device that is attached to a vehicle rearview mirror and vibrates the mirror to remove water droplets attached to the mirror. In a water droplet removing device having a drive means for driving the vibrating means, and a timer means for operating the driving means at predetermined time intervals, the driving means is improved, and either one of the vibrating means is selectively driven.

(Function) According to the above-mentioned technical means, since either one of the vibration means is selectively driven, power consumption per unit time is reduced.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 is a perspective view of a vehicle side mirror 10 to which the water droplet removing device of this embodiment is applied, as viewed from the front left seat of the vehicle. Further, FIG. 2 is a plan view of the vehicle side mirror 10 viewed from above in FIG. 1.

The vehicle side mirror 10 is disposed near the side window 50 so that the mirror 30 can be viewed from inside the vehicle through the side window 50.

The vehicle side mirror 10 includes a frame 20 and a mirror 30. The frame 20 includes a mirror housing 21 and a housing base 22.

The housing base 22 is fixed to the vehicle body 40. Further, the mirror housing 21 is rotatably supported on a housing base 22, and as shown in FIG.
Approximately 18 mm between the folding position and the storage position centered on the use position
It can be rotated within a range of 0 degrees.

Note that the vehicle side mirror 10 is disposed not only on the left side of the vehicle but also on the right side. However, since the side mirror disposed on the right side of the vehicle has the same structure and function as the side mirror 10, a detailed explanation of the right side mirror will be omitted hereinafter.

FIG. 3 is a plan view of a mirror 30 using the water droplet removing device of this embodiment. Further, FIG. 4 is a sectional view taken along the line AA in FIG. 3.

A disk-shaped piezoelectric vibrator 31 is located approximately at the center of the mirror 30.
is fixed with adhesive. The piezoelectric vibrator 31 is
Electrodes 33 and 34 are integrally formed on both end surfaces of an electrostrictive element 32. A lead wire 34 is soldered to the electrode 33, and a lead wire 35 is soldered to the electrode 34, respectively. When power is input to the lead wires 34 and 35, the piezoelectric vibrator 31 expands or contracts in the thickness direction (vertical direction in the fourth figure) and radial direction (horizontal direction in the fourth figure).

This will be explained with reference to FIG. 5a. Connect the power supply to the lead wire 34 (
When the (+) terminal and the (-) terminal of the power source are connected to the lead wire 35, the piezoelectric vibrator 31 contracts in the radial direction. At this time,
A strong contraction force acts on the back surface 30a of the mirror 30, causing the mirror 30 to bend.

This will be explained with reference to FIG. 5b. Contrary to the case of FIG. 5a, when the (-) terminal of the power source is connected to the lead wire 34 and the (+) terminal of the power source to the lead wire 35, the piezoelectric vibrator 31 expands in the radial direction. At this time, a strong stretching force acts on the back surface 30a of the mirror 30, causing the mirror 30 to bend in the opposite direction to that shown in FIG. 5a.

This will be explained with reference to FIG. 5c. When the oscillation circuit 60 is connected to the piezoelectric vibrator 31 and AC power is supplied to the piezoelectric vibrator 31, the mirror 20 is repeatedly bent. If the frequency of the AC power is selected to be around an integral multiple of the lowest resonant frequency of the mirror 30, the mirror 30 will resonate, and a standing wave that is uniform and large in amplitude will be generated over the entire surface of the mirror 30. This standing wave causes the reflecting surface 30b of the mirror 30 to move at high speed. At this time, the water droplets adhering to the reflective surface 30b are given high kinetic energy by the mirror 30, are dropped or atomized by gravity, and are removed from the reflective surface 30b of the mirror 300.

Since the apparatus of this embodiment removes water droplets using the standing waves generated in the mirror 30, water droplets can be removed efficiently with little power consumption.

In this example, the frequency range is 70 (kHz) to 80 (kHz).
The resonant frequency of the mirror 30 existing in a frequency range of about However, since there are many natural vibrations of the mirror 11 ranging from low frequencies to high frequencies, it may be oscillated at other frequencies.

The oscillation circuit 60 of the device of this embodiment will be explained below with reference to FIG. The oscillation circuit 60 of the device of this embodiment has a special configuration to further reduce power consumption.

The oscillation circuit 60 includes a microcomputer 61, a power supply circuit 62, an input circuit 63, a left mirror drive circuit 64, and a right mirror drive circuit 65.

The power supply circuit 62 is connected to a battery 66 and supplies power to each circuit of the oscillation circuit 60.

The input circuit 63 also includes various eight switches 71 to 7.
7 is connected. The switch 71 is an ignition switch, and is turned on when the engine is started. Further, the switch 72 is a start switch, and is turned on when the vehicle driver manually operates the water droplet removing device to operate the water droplet removing device.

Switch 73 is a changeover switch. The changeover switch 73 has a left drive button 73a and a right drive button 7.
3b. When the left drive button 73a is operated by the driver of the vehicle, only the water droplets on the left side mirror 30 are removed. Further, when the right drive button 73b is operated by the driver of the vehicle, only the water droplets on the right side mirror are removed.

Furthermore, the left drive button 73a and the right drive button 73b
When the mirrors are not being operated, water droplets are removed from the left and right mirrors in turn.

Note that, as shown in FIG. 7, the ignition switch 71, start switch 72, and changeover switch 73 are fixed at positions in the vehicle interior where the driver can easily operate them.

Switch 74 is a left mirror position detection switch. The left mirror position detection switch 74 is turned on when the side mirror 10 is in the use position (see FIG. 2). Similarly, switch 75 is a right mirror position detection switch that is turned on when the vehicle's right side mirror (not shown) is in the use position.

The switch 76 is a left side window opening/closing detection switch. The left side window opening/closing detection switch 76 detects whether the side window 50 is open or closed.

The left side window opening/closing detection switch 76 is turned on when the side window 50 is closed beyond the position Po5 (see FIG. 1) where the side window 50 sufficiently covers the mirror 30 (eg, position Pct). Here, the position Pos may be between the fully closed position and the fully open position of the side window 50. Therefore, the position Po
s is determined by an experiment in which the vehicle is actually driven, and is set at a position where water droplets removed from the mirror 30 do not jump into the vehicle interior. Similarly, switch 77 is a right side window opening/closing detection switch, which is turned on when the right side window (not shown) of the vehicle is closed beyond a position that fully covers the mirror.

The states of the left mirror position detection switch 74 and the left side window open/close detection switch 76 are determined by the microcomputer 61.
This is confirmed by the subprogram (see FIG. 9) stored in . In the left mirror state determination subroutine, flag L is set. The flag is left mirror position detection switch 7.
5 is on (step 521) and the left side window opening/closing detection switch 76 is on (step 522).
.

Set to 1°°. Conversely, when the left mirror position detection switch 74 is off (step 521) or the left side window opening/closing detection switch 76 is off (step 522), the flag L is set to "0".

That is, the flag is set to "1" when no unfavorable situation occurs even if the left mirror is driven;
It is set to "0" when it is inappropriate for the left mirror to be driven.

In exactly the same way, the states of the right mirror position detection switch 75 and the right side window opening/closing detection switch 77 are confirmed by a subprogram (see FIG. 19) stored in the microcomputer 61. In the right mirror state determination subroutine, the state of the right mirror position detection switch 75 (step 5
31) and the state of the right side window open/close detection switch 77 (step 532), and flag R is set (steps 334, 335). Flag R is set when no unfavorable situation occurs even if the right mirror is driven.
It is set to "1", and conversely, it is set to "0" when it is inappropriate for the right mirror to be driven.

Next, the left mirror drive circuit 64 and the right mirror drive circuit 65 will be explained. Since the left mirror drive circuit 64 and the right mirror drive circuit 65 are exactly the same circuit, the left mirror drive circuit 64
A detailed explanation of the right mirror drive circuit 65 will be omitted.

The frequency of the AC power supplied to the piezoelectric vibrator 31 is determined by the voltage controlled oscillation circuit 82.

The voltage controlled oscillation circuit 82 is controlled by the microcomputer 61 via eight D/A converters.

A vibrator drive circuit 83 is connected between the voltage controlled oscillation circuit 82 and the piezoelectric vibrator 31. The vibrator drive circuit 83 receives a strobe signal 84 from the microcomputer 61.
is input. The vibrator drive circuit 83 receives the strobe signal 8
AC power is supplied to the piezoelectric vibrator 31 only when 4 is on.

The oscillation frequencies of the left mirror drive circuit 64 and the right mirror drive circuit 65 are controlled by a subprogram (see FIG. 12) stored in the microcomputer 61.

Steps 341 to S of the mirror vibration subroutine
At 42, the oscillation frequency of the voltage controlled oscillation circuit 82 is set. That is, each time step S41 is executed, the flag f
The value of is updated. The value of flag f is then output to the D/A converter 81 in step S42, and the voltage controlled oscillation circuit 82 starts oscillating at a frequency corresponding to the value of flag f.

The value of the flag f continuously fluctuates between "75" and "96". The value of the flag f corresponds to the oscillation frequency of the voltage controlled oscillation circuit 45. Table 1 shows the relationship between the value of the flag f and the oscillation frequency of the voltage controlled oscillation circuit 45. Since the resonant frequency of the mirror 30 of this embodiment device is approximately 74 (kHz), according to the program shown in FIG. 9, the voltage controlled oscillation circuit 45
The oscillation frequency of the mirror 30 changes continuously within a predetermined frequency range that includes one resonance frequency of the mirror 30 every time step S41 is executed.

Step S43. In step S44, the strobe signal 84 for the left mirror drive circuit 64 is set. When the left mirror drive circuit 64 is permitted to operate, that is, when the flag L is set to "1" (step 543).
The strobe signal 8 for the left mirror drive circuit 64 is
4 is set on (step 544). this moment,
AC power is supplied from the vibrator drive circuit 83 to the piezoelectric vibrator 31 .

Similarly, step S45. In step 346, strobe signal 85 for right mirror drive circuit 65 is set. When the right mirror drive circuit 65 is allowed to operate,
That is, when flag R is set to 1 (step 5
45), the strobe signal 85 for the right mirror drive circuit 64 is set on (step 546).

In step S47, execution of the process is suspended for approximately 50 (msec). That is, for about 50 (msec),
AC power having the frequency set in step S42 continues to be supplied from the vibrator drive circuit 83 to the piezoelectric vibrator 31.

In step S48, strobe signals 84 and 85 for the left and right mirror drive circuits 64 and 65 are both set to OFF.

In step S49, it is determined whether one second has elapsed after the mirror vibration subroutine was called. After the mirror vibration subroutine is called, the processes of steps 341 to 348 are repeatedly executed until approximately one second has elapsed.

By the mirror excitation routine described above, the oscillation circuit 60 outputs one resonant frequency 74 of the mirror 30 [
64 (kHz) ~ 84 (kHz) including [kHz]
A frequency that sequentially and continuously fluctuates within the range of is output for about 1 second.

According to the subprogram shown in FIG.
Since the oscillation frequency of the mirror 30 fluctuates sequentially and continuously,
The wavelength of the vibrations generated above changes. Therefore, mirror 3
It is possible to move the antinode and node of the vibration that occurs above 0,
The kinetic energy can be distributed substantially uniformly on the mirror 30.

As a result, it becomes possible to atomize the water droplets adhering to the entire surface of the mirror 12 almost simultaneously.

Furthermore, according to the subprogram shown in FIG. 11, the oscillation frequency of the piezoelectric vibrator 31 is set outside the audible frequency range. Therefore, no unpleasant audible sound is generated from the mirror 30.

Furthermore, according to the subprogram shown in FIG.
The oscillation frequency of the oscillation circuit 60 varies within a predetermined frequency range that includes one of the resonance frequencies of the mirror 30. Therefore, even if the resonant frequency of the mirror 30 changes due to various causes, the mirror 30 can be reliably resonated.

Now, the three subprograms described above are called from the main program stored in the microcomputer 61 and executed. FIG. 8 shows an example of the main program executed by the microcomputer 61.

When the power supply circuit 62 is connected to the battery 66, the process of step S1 is executed. In step S1, initial settings necessary for subsequent processing are performed, and strobe signals 84 and 8
5 are both set to off.

Further, in step S1, flags °L" and "R" are both set to zero.

In steps 32 to S4, it is determined whether or not to execute the processes after step S5. The processes after step S5 are executed only when the ignition switch 71 is on (step S2) and the start switch 72 is on (step 34). Furthermore, when the ignition switch 71 is off, the microcomputer 6
1 enters the standby state (step S3). here,
The standby state is a low power consumption mode that the microcomputer 61 has.

In step S5, the state of the changeover switch 73 is determined. Then, when the left drive button 73a of the changeover switch 73 is operated, the processes of steps 86 to S8 are executed. Further, when the right drive button 73b of the changeover switch 73 is operated, step 3
Processing from 9 to Sll is executed. Further, if neither the left drive button 73a nor the right drive button 73b is operated, the processes of steps 312 to S17 are executed.

When the processes in steps S6 to S8 are executed, water droplets are removed from the left mirror. Also, steps 39 to S
When processing ll is executed, water droplets are removed from the right mirror. Furthermore, when the processes of steps 312 to S17 are executed, water droplets are alternately removed from the left and right mirrors.

In steps 35 to S8, the left mirror drive circuit 6
4 is to be permitted to operate (step 36).
. The left mirror drive circuit 64 is driven only if vibrating the left mirror does not cause undesirable conditions (step 37).

After that, flag L is set to "0" (step S8).
, the operation of the left mirror drive circuit 64 is prohibited.

Similarly, in steps 39 to S12, it is determined whether or not to permit operation of the right mirror drive circuit 65 (step S9). The right mirror drive circuit 65 is activated only if vibrating the right mirror does not cause undesirable conditions (step 510). After that, flag R is “
0'' (step 5ll), and the operation of the right mirror drive circuit 65 is prohibited.

Further, in steps 312 to S17, the left mirror drive circuit 64 is first driven (steps 312 to 31).
4) After that, the right mirror drive circuit 65 is driven (steps 315 to 517). That is, the left mirror drive circuit 64
and the right mirror drive circuit 65 are sequentially driven.

After the water droplets are removed from the left or right mirror, step 318 is performed. Approximately 10 in step S18
Program execution is paused for a period of seconds. When the pause time of about 10 seconds has elapsed, the process returns to step S2 and the program is executed again.

As mentioned above, according to the program shown in FIG. 8, when the start switch 72 is operated while the engine is running, water droplets will appear from the left or right mirror at regular intervals (approximately 10 seconds). removed. Further, at this time, if the side windows are not fully closed or the side mirrors are not in the use position, the removal of water droplets is prohibited.

〔Effect of the invention〕

According to the present invention, since either one of the vibration means is selectively driven, power consumption per unit time is reduced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a vehicle side mirror to which an embodiment of the present invention is applied, as viewed from the front left seat of the vehicle. FIG. 2 is a plan view of a vehicle side mirror to which an embodiment of the present invention is applied, viewed from above FIG. 1. FIG. 3 is a plan view of a mirror to which an embodiment of the present invention is applied. FIG. 4 is a sectional view taken along the line AA in FIG. 3. FIGS. 5a, 5b, and 5c are explanatory diagrams showing the operation of an embodiment of the present invention. FIG. 6 is a block diagram depicting an oscillation circuit according to an embodiment of the present invention. FIG. 7 is a perspective view depicting the interior of a vehicle to which an embodiment of the present invention is applied. 8, 9, 10, and 11 are flowcharts depicting programs used in one embodiment of the present invention. FIG. 12 is an explanatory diagram depicting a conventional water droplet removing device. 10...Side mirror (rearview mirror), 20...
Frame, 21...Mirror housing, 22...Housing base, 30...Mirror, 31...Piezoelectric vibrator (excitation means), 32...Electrostrictive element, 33.34.
...Electrode, 34.35... Lead wire, 40... Vehicle body, 50-... Side window, 60... Oscillation circuit (drive means), 61... Microcomputer, 62... Power supply circuit , 63... input circuit, 64...
Left mirror drive circuit (drive means), 65... Right mirror drive circuit (drive means), 66... Battery 71... Ignition switch (vehicle state detection means), 72... Start switch, 73... - Changeover switch, 74...Left mirror position detection switch (vehicle state detection means), 75...Right mirror position detection switch (vehicle state detection means), 76...Left side window opening/closing detection switch (vehicle state detection means) 77... Right side window opening/closing detection switch (vehicle state detection means), 81... D/A converter, 82... Voltage controlled oscillation circuit, 83... Vibrator drive circuit, 84.85 . . . strobe signal, step S6, 512. S15. S19... Drive inhibiting means Steps 312 to S17... Control means 2 Step 81
8...Timer means.

Claims (1)

[Claims] (1) A vehicle rearview mirror disposed on both left and right sides of the vehicle body; a vibrating means attached to each of the vehicle rearview mirrors for vibrating the mirror to remove water droplets attached to the mirror; A water droplet removal device for a vehicle rearview mirror, comprising: a drive means for selectively driving either one of the shaking means; and a timer means for operating the drive means at predetermined time intervals.