JPH02175360A - Water droplet removing device for automotive rear view mirror - Google Patents

Abstract

PURPOSE:To reduce power consumption by varying the setting time of a timer means for water droplet removing device containing a vibrator sticked on a mirror in accordance with the setting of a selection means selecting the operation speed of a wiper device for wiping off a frontshield. CONSTITUTION:A piezoelectric vibrator 20 is sticked and fixed on a part of the rear view mirror of a motor car, and alternating current power is applied on the piezoelectric vibrator from an oscillating circuit 40 to telescope the piezoelectric vibrator 20. At the same time, the reflecting surface of the mirror is moved at high speed to remove water droplet sticked on the reflected surface. The oscillating circuit 40 is composed of a choppin wave generating circuit 41, voltage / oscillating circuit 42, and a vibrator driving circuit 43. The vibrator driving circuit 43 varies the rest time of oscillation according to an electric signal from a wiper switch 50 by a microcomputer 63 in which a timer is incorporated, i.e., an oscillating time is increased and decreased according to which portion the wiper switch 50 is selected : off mode, intermittent operation mode, low speed operation mode, high speed operation mode, etc.

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 an automobile rearview mirror.

(Prior Art) As a conventional device of this kind, the one disclosed in Japanese Patent Application Laid-open No. 854.8/1983 is known (see Fig. 11). The vibrator 2 is fixed, and an oscillation circuit 3 causes the vibrator 2 to vibrate in the thickness direction. This oscillation circuit 3 repeatedly oscillates and stops at regular intervals in conjunction with the wiper operation.

When the mirror 1 vibrates, if water droplets adhere to the reflective surface of the mirror 1, the water droplets are excited by the vibration of the mirror 1 and removed.

(Problems to be Solved by the Invention) Incidentally, the amount of water droplets that adhere to the rearview mirror within a unit time varies greatly depending on the amount of rainfall, vehicle speed, and the like. in general,
As the amount of rainfall increases, the amount of water droplets that adhere to the rearview mirror within a unit time tends to increase.Similarly, as the vehicle speed increases, the amount of water droplets that adhere to the rearview mirror within a unit time tends to increase. shows.

However, in conventional water droplet removal devices, the oscillation circuit oscillated at regular intervals, so even if only a small amount of water droplets were attached to the mirror, the mirror would not move even though sufficient rearward visibility was obtained. There were problems in which the mirror would not vibrate even though the rear view was obstructed by large amounts of water droplets adhering to the mirror.

If the mirror vibrates even though sufficient rearward visibility is obtained, this is undesirable because it increases wasteful power consumption. Furthermore, if the mirror does not vibrate even though the rear visibility is obstructed, safe driving will be hindered, which is undesirable.

The present invention has been made to solve the problems of such conventional devices, and a technical problem is to change the time interval for vibrating the mirror according to the amount of water droplets that adhere to the rearview mirror within a unit time. shall be.

[Structure of the invention]

(Means for solving the problem) The technical means taken to achieve the above-mentioned technical problem is to provide a change means to the water droplet removal device that vibrates the mirror at every set time by a timer means, and to set the timer means to The set time is shortened as the operating speed of the wiper device increases.

(Function) The operating speed of the wiper device is switched by the driver of the vehicle, and is set to increase as the amount of rainfall increases or the vehicle speed increases. Therefore, it is considered that the amount of water droplets that adhere to the rearview mirror within a unit time is approximately proportional to the operating speed of the wiper device.

According to the above-mentioned technical means, the setting time of the timer means becomes shorter as the operating speed of the wiper device increases, that is, as the amount of water droplets deposited on the rearview mirror within a unit time increases, by the operation of the changing means. Be changed. Therefore, the time interval for vibrating the mirror is changed depending on the amount of water droplets that adhere to the rearview mirror within a unit time, and the intended technical problem is achieved.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described based on the drawings.

FIG. 1 is a plan view of an automobile side mirror using the water droplet removing device of this embodiment. Also, Fig. 2 shows A- in Fig. 1.
It is an A sectional view.

A disk-shaped piezoelectric vibrator 20 is fixed to a part of the mirror 11 with an adhesive. The piezoelectric vibrator 20 is a flat plate type [21 and 22] integrally formed on both end surfaces of an electrostrictive element 24 parallel to each other.

An extraction electrode 23 is bonded to the electrode 22 on the mirror 11 side using a conductive adhesive. Glue-F to electrode 2I
Ns31 and a lead wire 32 are soldered to the electrode 23, respectively. When power is input to the lead wires 31 and 32, the pressure 118 mover 20 expands or contracts in the thickness direction (vertical direction in the second figure) and radial direction (horizontal direction in the second figure).

An oscillation circuit 40 is connected to the piezoelectric vibrator 20, and the piezoelectric vibrator 2
When AC power is applied to the mirror 11, the mirror 11 is repeatedly bent mainly due to the expansion and contraction of the piezoelectric vibrator 20 in the radial direction.

If the frequency of the alternating current power is selected at an appropriate frequency, the mirror 11 resonates, and a standing wave that is uniform and large in amplitude is generated throughout the mirror 11. This standing wave causes the reflective surface 11b of the mirror 11 to move at high speed. At this time, the reflective surface 11
The water droplets adhering to the mirror 11 are given high kinetic energy by the mirror 11, and drop or atomize due to gravity, so that the water droplets adhere to the reflective surface 1.b of the mirror 11. lb is removed.

Oscillator lR40 of six embodiments explained with reference to FIG.
is a sweep oscillation circuit. The oscillation circuit 4° includes four triangular wave generation circuits, a voltage controlled oscillation circuit 42, and a vibrator drive circuit 43. The oscillation frequency of the voltage controlled oscillation circuit 42 repeatedly sweeps within a predetermined frequency range due to voltage changes in the electrical signal output from the triangular wave generation circuit 41.

The electric signal outputted from the voltage controlled oscillation circuit 42 is boosted by the vibrator drive circuit 43 and causes the piezoelectric vibrator 20 to vibrate.

When the oscillation frequency of the oscillation circuit 40 changes, the wavelength of the standing wave generated on the mirror 11 changes, so the positions of the antinode and node of the standing wave generated on the mirror 11 change. Therefore,
Kinetic energy can be distributed almost uniformly on the mirror 11, and water droplets attached to the entire surface of the mirror 11 can be removed almost simultaneously and evenly.

This will be explained with reference to FIGS. 3 and 10. The wiper switch 50 is a switch disposed near a steering wheel (not shown) of an automobile.

By changing the position of the wiper switch 50 according to the amount of rainfall and the vehicle speed, the driver of the car can select (off mode in which the wiper device 70 is not operated, middle) intermittent operation mode in which the wiper device 70 is operated intermittently. , (a low-speed operation mode in which the Cl wiper device 70 is operated at a low speed, (d) a high-speed operation mode in which the wiper device 70 is operated at a high speed, and (e) a mist mode in which the wiper device 70 is moved back and forth once) can be selected. Yes, when the driver of the vehicle moves the wiper switch 50 to a position other than the off mode, the wiper device 70 wipes the windshield 71 of the vehicle.

This will be explained with reference to FIG. 4 again. The wiper switch 50 has five electrical contacts 51, 52, 53, 54, 55.

The electrical contact 51 is a contact that turns off only when the wiper device 70 is set to (al off mode) and fat miss 1-mode, and the wiper device 70 is operated from the electrical contact 51. An electrical signal is output indicating whether or not the vehicle is present.

The electrical contact 52 is a contact that turns on only when the (g) intermittent operation mode is set, and the electrical contact 52 outputs an electrical signal indicating whether or not the wiper device 70 is operating intermittently. be done. The electrical contact 53 is a contact that is turned on only when the low speed operation mode (C) is set, and an electrical signal indicating whether the wiper device 70 is operating at low speed is output from the electrical contact 53. The electrical contact 54 is (d)
This contact is turned on only when the low speed operation mode is set, and the electric contact 54 outputs an electric signal indicating whether or not the wiper device 70 is operating at high speed. Electrical contact 5
5 is a contact that turns on only when the (e) mist mode is set, and the wiper device 1t70 is connected from the electrical contact 55.
An electrical signal indicating whether or not the misting operation is performed is output.

The electrical signal generated by the wiper switch 50 is sent to the control circuit 60.
is input. The control circuit 60 is a circuit that causes the oscillation circuit 40 to oscillate intermittently in response to the electrical signal generated by the wiper switch 50. The control circuit 60 includes a power supply circuit 61. It includes an input circuit 62 and a microcomputer 63.

The power supply circuit 61 is connected to the battery BTT and supplies constant voltage power to the control port Ia60 and the oscillation circuit 40.

The input circuit 62 connects each contact 51 to 55 of the wiper switch 50.
This is a buffer for manually inputting the on/off status of the microcomputer 63.

The microcomputer 63 has an internal timer, and changes the time during which the oscillation circuit 40 stops oscillating in response to an electrical signal from the wiper switch 50. Further, the microcomputer 63 outputs a strobe signal 64. When the strobe signal 64 is set to ON, AC power is supplied from the vibrator drive circuit 43 to the piezoelectric vibrator 20,
Mirror 11 vibrates. Conversely, when the strobe signal 64 is set to OFF, the vibrator drive circuit 43 has a pressure of 1! The AC power supplied to the vibrator 20 is cut off, and the mirror 11 stops vibrating.

The operation of the microcomputer 63 is achieved by the programs shown in FIGS. 5 to 9. The program executed by the microcomputer 63 will be described in detail below.

FIG. 5 shows the main routine of the program executed by the microcomputer 63. When power is supplied from the tfi circuit 61 to the microcomputer 63, the microcomputer 63 starts executing the process from step S1.

First, initialization necessary for subsequent processing is performed, and the wait flag WAIT is set to zero (step Sl).

After that, if the wiper switch 50 is set to the mist mode (step S2), that is, the wiper switch 50
If the electrical contact 55 is on, the subroutine of step S3 is executed and the mirror 11 vibrates for about 5 seconds. The subroutine of step S3 will be explained later with reference to FIG.

If the wiper switch 50 is set to off mode (
In step S4), that is, if the electrical contact 51 is off, the process returns to step S2 and repeats the process without doing anything.

If the wiper switch 50 is set to the intermittent operation mode (step S5), that is, if the electric contact 52 is on, the subroutine of step S6 is executed, and the mirror 11 vibrates for about 5 seconds every about 60 seconds. . The process of step S6 will be explained later with reference to FIG.

If the wiper switch 50 is set to the low-speed operation mode (step S7), that is, if the electric contact 53 is on, the subroutine of step S8 is executed, and the mirror 11 vibrates for about 5 seconds every about 30 seconds. The subroutine of step S8 will be explained later with reference to FIG.

If the wiper switch 50 is set to the high-speed operation mode (step S9), that is, if the electric contact 54 is on, the subroutine of step SlO is executed, and the mirror 11 vibrates for about 5 seconds every about 10 seconds. do. Step SI
The O subroutine will be explained later with reference to FIG.

As described above, in the main routine, an appropriate subroutine is selected based on the setting of the wiper switch 50, and the time interval at which the mirror 11 vibrates is shortened as the operating speed of the wiper switch 70 becomes higher. .

Next, referring to FIG. 6, the subroutine of step S3,
That is, mist mode processing will be explained. The mist mode process includes steps 3301 to 5305.

In the mist mode process, first, the strobe signal 64 is turned on to vibrate the mirror 11 (step 3).
301). Next, the timer is reset and restarted (step 5302). After the timer is restarted, the strobe signal is held on for 5 seconds (step 5303), and the mirror 11 vibrates for about 5 seconds. continue. Thereafter, the strobe signal 64 is turned off to stop the vibration of the mirror 11 (step 5304), and the process returns to the main routine (step 5305).

Through the process described above, when the wiper switch 50 is set to the mist mode, the mirror 11 vibrates for about 5 seconds.

Next, the intermittent operation mode processing corresponding to the subroutine of step S6 will be explained with reference to FIG. The intermittent mode process includes steps 5601-3611.

In the intermittent mode processing, first the wait flag WAIT is set to “l”.
” (step 56).
01), when the standby flag WAIT is set to "1", step 86 is performed without vibrating the mirror 1.
Proceed to 08. Conversely, when the standby flag WAIT is set to "zero", the strobe signal 64 is turned on to vibrate the mirror 11 (step 5602).
.

Next, the timer is reset and restarted (step 3603). Thereafter, the stove signal 64 is kept on for about 5 seconds, and the mirror 11 continues to vibrate (
Steps 5604, 5605), but if the wiper switch 50 is returned to off mode during this 5 seconds (
Step 5605) includes turning off the strobe signal 64 to stop the vibration of the mirror 11 (step 5605).
606), return to the main routine (step 561)
1).

After approximately 5 seconds have elapsed after the mirror 11 begins to vibrate, the strobe signal 64 is turned off in order to stop the vibration of the mirror 11 (step 5607).
It is determined whether 60 seconds have elapsed since the start of vibration (step 8608), and the standby flag WAIT is set to "1" until 60 seconds have elapsed (step 56).
10) After the wait flag WAIT is set, a process of returning to the main routine is performed (step S6l 1
).

During the 55 seconds during which the standby flag WAIT is set to 1'', the strobe signal 64 is not turned on even if the intermittent mode process is executed again (step 5601), so the mirror 11 continues to stop vibrating.

When 60 seconds have passed since the mirror 11 started vibrating, the standby flag WAIT is set to "zero 1" (step 5).
609). After the standby flag WAIT is set to "0", the strobe signal 64 is turned on when the listening mode process is executed again (steps 5601 and 36).
02), the mirror 11 begins to vibrate again.

Through the process described above, while the wiper switch 50 is set to the intermittent mode, the mirror 11 vibrates for about 5 seconds every about 60 seconds.

Next, the process of step S8, that is, the low-speed operation mode process will be explained with reference to FIG. The process of step S6 includes the processes of steps 8801 to 5811.

The program for the low-speed operation mode process is exactly the same as the program for the intermittent mode process shown in FIG. 7, except for the time set in step 3808.

Therefore, a description of the low-speed operation mode processing will be omitted by showing the correspondence between each step of the intermittent mode processing program and the low-speed operation mode processing program in Table 1.

By this low-speed operation mode processing, while the wiper switch 50 is set to the low-speed operation mode, the mirror 11 is
It vibrates for about 5 seconds every 0 seconds.

Next, high-speed operation mode processing corresponding to the processing in step $10 will be explained with reference to FIG.

The process of step S10 includes steps 5100I to 310
It has 11 processes.

The program for high-speed operation mode processing is step 51008.
This program is exactly the same as the intermittent mode processing program shown in FIG. 7, except for the time set in . Therefore, the correspondence between the steps of the intermittent mode processing program and the high speed operation mode processing program is shown in Table 2, thereby omitting the explanation of the high speed operation mode processing.

By this high-speed operation mode processing, while the wiper switch 50 is set to the high-speed operation mode, the mirror 11 is approximately 1
It vibrates for about 5 seconds every 0 seconds.

In this way, in the device of this embodiment, the wiper device 270
The time interval during which the mirror 11 stops vibrating is set shorter as the operating speed of the mirror 11 becomes higher.

That is, as water droplets tend to adhere to the mirror 11, the mirror 11 vibrates more frequently. Therefore,
Good rearward visibility is always available regardless of rainfall or vehicle speed.

Furthermore, in the device of this embodiment, the time interval during which the mirror 11 stops vibrating is set to be longer as the operating speed of the wiper device 70 becomes lower. That is, as the situation becomes such that water droplets are less likely to adhere to the mirror 11, the mirror 11 rarely vibrates. Therefore, the mirror 11 is less likely to vibrate unnecessarily, and the power consumption of the water droplet removing device is reduced.

Furthermore, in the device of this embodiment, the operation of the water droplet removal device is automatically switched according to the operating speed of the wiper device 70, so that the driver of the car does not have to perform troublesome operations to adjust the water droplet removal device. There's no need to.

In the device of this embodiment, a device for wiping the windshield 7e of a car is used as the wiper device 70, but the wiper device 70 does not need to be a device for wiping the windshield 71, for example. It may also be a wiper device that wipes the window.

Furthermore, in the device of this embodiment, the time during which the mirror 11 stops vibrating is changed depending on the operating speed of the wiper device 70, but it is not necessary to change only the time during which the mirror 11 is stopped vibrating, for example. The oscillation time may be varied, or both the oscillation stop time and the oscillation time may be varied.

〔Effect of the invention〕

According to the present invention, the mirror can be vibrated at appropriate time intervals depending on the amount of water droplets that adhere to the rearview mirror within a unit time. Therefore, the power consumption of the water droplet removal device can be reduced while ensuring good rearward visibility.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an automobile side mirror depicting a preferred embodiment of the present invention. FIG. 2 is a sectional view taken along the line AA in FIG. 1. FIG. 3 is a perspective view of a wiper switch depicting a preferred embodiment of the present invention. FIG. 4 is a block diagram of a control circuit depicting a preferred embodiment of the invention. 5, 6, 7, 8, and 9 are flowcharts depicting programs executed by the microcomputer. FIG. 10 is a front view of a wiper device depicting a preferred embodiment of the present invention. FIG. 11 is a block diagram depicting a conventional water droplet removal device. DESCRIPTION OF SYMBOLS 11...Mirror 11a...Back surface, llb...Reflecting surface, 20...Piezoelectric vibrator (vibrator), 21.22...Plant electrode, 23...Extraction electrode,
24... Electrostrictive element, 31.32... Lead wire, 40
...Oscillation circuit, 41...Triangular wave oscillation circuit, 42...
・Voltage controlled oscillation circuit, 43... Vibrator drive circuit, 50
...wiper switch (switching means), 51, 52, 53
, 54.55... Electric contact, 60... Control circuit, 6
DESCRIPTION OF SYMBOLS 1... Power supply circuit, 62... Input circuit, 63... Microcomputer, 70... Wiper device, 71... Windshield (automobile glass), Step S6. S8. SIO...timer means, step S4
．． S5. S7. S9...Switching means.

Claims (1)

[Scope of Claims] A wiper device for wiping the glass of an automobile, a switching means for switching the operating speed of the wiper device, a vibrator attached to a mirror, an oscillation circuit for vibrating the vibrator, and the oscillation. a timer means for causing the circuit to oscillate at each set time; and a changing means for changing the set time set in the timer means to be shorter as the operating speed of the wiper device increases, based on the setting of the switching means. Water droplet removal device for automobile rearview mirrors.