JP2850978B2 - Mirror cleaning equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mirror cleaning device for maintaining visibility of a mirror surface such as a fender mirror and a door mirror, and more particularly, to water droplets and ice adhered to the mirror surface. The present invention relates to a mirror cleaning device for removing frost, fogging and the like.

[Prior Art] As a conventional example of this type of mirror cleaning apparatus, there is a technique described in Japanese Utility Model Laid-Open Publication No. 30552/1986.

FIG. 7 is a cross-sectional view of a mirror cleaning device provided outside the vehicle disclosed in the above publication.

In the figure, a rearview mirror disposed outside the vehicle is a rearview mirror body 32 to which a glass mirror 31 is attached.
Is supported by a stay 33, and the rearview mirror body 32
An ultrasonic vibrator made of, for example, ceramics is provided between the stay and the stay 33. This ultrasonic vibrator 34 includes
An operation switch 35 is connected to the interior of the vehicle so that the operation switch 35 can be operated from inside the vehicle. A drive circuit 36 and a power supply 37 are connected in series between the ultrasonic transducer 34 and the operation switch 35.

The drive circuit 36 amplifies the signal generated by the oscillator with an amplifier, sends the amplified signal to the ultrasonic vibrator 34, and appropriately vibrates the ultrasonic vibrator 34.

The mirror cleaning device using the conventional ultrasonic transducer configured as described above can operate as follows.

When water droplets or the like adhere to the mirror surface of the rearview mirror, the operation switch 35 in the vehicle compartment is operated to vibrate the ultrasonic transducer 34. The vibration of the ultrasonic vibrator 34 can remove water droplets and the like attached to the mirror surface by vibrating the entire rearview mirror main body 32.

[Problems to be Solved by the Invention] However, in order to completely remove water droplets and the like adhering to the surface of the mirror 31 with the ultrasonic vibrator 34, the ultrasonic vibrator 34
Needs to be driven for about 10 minutes or more.
In addition, the temperature rise of the mirror 31 is increased, and the durability is reduced.

As a means for solving this problem, it is possible to deal with this problem by disposing a number of ultrasonic transducers 34 and driving them simultaneously. However, this solution has a high cost and has a problem in its installation space.

On the other hand, examples of the prior art include Japanese Utility Model Application Laid-Open No. 62-82850, Japanese Utility Model Application Laid-Open No. 63-6968, and Japanese Patent Application Laid-Open No. 57-70754.

The technology disclosed in Japanese Utility Model Application Laid-Open No. 62-82850 discloses that, when water droplets or the like adhere to the mirror surface of a rearview mirror, this is detected by a sensor and the ultrasonic vibrator is vibrated to remove the water droplets or the like adhering to the mirror surface. However, in this type of rearview mirror, by increasing the detection sensitivity of the sensor, the ultrasonic vibrator frequently operates, the temperature rise becomes high, and the durability thereof becomes a problem. Conversely, when the sensitivity is lowered, the mirror surface becomes difficult to see.

In the technique disclosed in Japanese Utility Model Laid-Open No. 63-6968, an electrode on which a dielectric film is formed is provided as a sensor, and a heater of a mirror is energized when the resistance value decreases due to water drops or the like. Therefore, the mirror repeatedly undergoes rapid expansion and contraction due to the heater and water droplets depending on the temperature of the heater, and may be broken by fatigue.

Japanese Patent Application Laid-Open No. Sho 57-70754 discloses a technique in which two ultrasonic vibrators are arranged on the rear surface of a mirror of a rearview mirror to remove water droplets on the surface of the mirror. When vibration is applied by the vibrator, a resonance point is generated at a specific position of the mirror, and fatigue failure may occur at the resonance point position of the mirror.

Therefore, the present invention has been made to solve the above-described problem, and an object of the present invention is to provide a mirror cleaning device in which the efficiency of removing water droplets on the mirror surface is increased without reducing the durability of the ultrasonic transducer and the mirror. Is what you do.

Means for Solving the Problems A mirror cleaning device according to the present invention forms a silicon-fluorine-based coating film having a large surface tension on the entire surface of a mirror having a predetermined curvature, and forms one or more coating films. Are disposed on the back surface of the mirror.

[Operation] In the present invention, a coating film having a large surface tension of silicon-fluorine is formed on the entire surface of a predetermined mirror such as a fender mirror or a door mirror, and water such as water droplets adhered to the coating film is formed. Particles have a small surface area and a small contact area with the coating film. Therefore, water particles of water droplets adhering to the coating film having a large surface tension of the silicon-fluorine system can be removed from the coating film surface with a small ultrasonic vibration energy, and the removal efficiency of the water droplets on the mirror surface can be increased. At this time, since the load on the ultrasonic vibrator is not increased, the durability of the ultrasonic vibrator and the mirror is not reduced.

[Example] Here, an example of the present invention will be described.

FIG. 1 is a sectional view of the entire structure of a mirror cleaning device according to an embodiment of the present invention, and FIG. 2 is an explanatory view showing the arrangement of the ultrasonic vibrators of the embodiment of FIG. 1 as viewed from the front.

In the figure, a metal frame 2 is fixed by a tapping screw 3 in a synthetic resin mirror case 1 fixed to a vehicle body (not shown). A mirror base 4 made of a synthetic resin is fixed to the frame 2 using a free ball (not shown) so as to be tiltable up, down, left and right. A mirror position driving device 5 is fixed to the frame 2 with screws. The mirror position drive device 5 has two output rods (not shown) that can be driven independently. One ends of the two output rods are respectively connected to different positions on one surface of the mirror base 4. The mirror base 4 tilts up and down or left and right when one or two output rods are driven by the operation of the vehicle occupant. The two output rods of the mirror position driving device 5 are respectively covered with a cover 6 or a cover 7 made of synthetic rubber. One end of the cover 6 or the cover 7 is joined to the housing of the mirror position driving device 5, respectively, and the other end of the cover 6 or the cover 7 is joined to the mirror base 4. The cover 6 or the cover 7 uses bellows of bellows so as not to hinder the tilting of the mirror base 4.

A mirror frame 8 made of synthetic resin is joined to the mirror base 4. A locking portion 11 is provided on the outer periphery of the mirror frame 8.
The locking portion 11 clamps the entire periphery of the plate-like mirror 12 and fixes the mirror 12. Further, the mirror frame 8 is provided with a plurality of protrusions 8a, 8b, 8c,
The mirror frame 8 and the mirror 12 are partially in contact with each other. As shown in FIG. 2, there are six ultrasonic transducers 10a, 10b, 10c, 10 between the mirror frame 8 and the mirror 12.
d, 10e, and 10f are respectively joined.

The ultrasonic transducers 10a to 10f of this embodiment are arranged so as to form a matrix of 2 rows and 3 columns. In particular, in this embodiment, a piezoelectric element using a piezo effect element is used as the ultrasonic transducers 10a to 10f.

A thermistor 13 is joined between the back side of the mirror 12 and the mirror frame 8 as a temperature sensor so that the temperature of the mirror 12 can be detected.

A vibrator control device 14 is provided between the mirror base 1 and the mirror case 1 on the mirror case 1 side. The transducer control device 14 has a built-in control circuit for a mirror cleaning device such as an oscillation circuit for driving each of the ultrasonic transducers 10a to 10f and a power supply circuit. The drive of the vibrator control device 14 is controlled by a switch, which will be described later, provided in the vehicle.

Next, the relationship between the mirror 12 and the ultrasonic transducers 10a to 10f will be described in detail with reference to FIGS.

FIG. 3 is a sectional view showing the state of adhesion between the mirror and the ultrasonic transducer used in the mirror cleaning device of the present embodiment. FIG. 4 is a side view (a) and a front view (b) of an ultrasonic transducer used in the mirror cleaning device of the present embodiment.
It is.

In the figure, a mirror 12 has a reflection member 12b formed on the back surface of a transparent member 12a, and the surface of the transparent member 12a, that is, the entire surface on the front side of the mirror 12, is made of, for example, silicon-fluorine. A coating film 12c having a large surface tension such as oil is formed. The coating film 12c having a large surface tension at this time is the coating film 12c.
Means that a material that can reduce the contact surface with the film surface of the coating film 12c when water droplets are adhered to the coating film 12c. The end faces of the ultrasonic transducers 10a to 10f are adhered to the inner diameter side of the reflection member 12b with an adhesive 15. The ultrasonic transducers 10a to 10f (hereinafter, simply referred to as “10” when not pointing to a specific ultrasonic transducer) are obtained by sticking the ultrasonic transducer 10 formed in the same form. As shown in the side view (a) of FIG. 4, the end face of the ultrasonic vibrator 10 is bonded to the back surface of the reflecting member 12b of the mirror 12, and the mirror 12 A spherical portion 10A equal to or substantially equal to the curvature of the inner diameter of the back surface of the member 12b is formed.

Therefore, the spherical portion 10A that is equal to or substantially equal to the curvature of the inner diameter of the back surface of the reflecting member 12b of the ultrasonic vibrator 10 can be adhered to the back surface of the reflecting member 12b of the mirror 12 with a thin layer of the adhesive 15, so that the ultrasonic vibration The vibration of the child 10 is less likely to be buffered by the layer of the adhesive 15, and the transparent member 12a of the mirror 12 can be vibrated with high efficiency.

Further, it can be configured as shown in the rear view (a) and the cross-sectional view (b) showing the bonding state between the mirror and the ultrasonic transducer used in the mirror cleaning device of another embodiment shown in FIG. .

That is, the ultrasonic transducers 20a, 20 used in this embodiment
b, 20c, 20d, and 20e (hereinafter, simply referred to as “20” when not pointing to a specific ultrasonic vibrator) are formed by further reducing the diameter of the cylindrical portion 10B of the ultrasonic vibrator 10 of the above embodiment. Formed in
Thereby, even if one end of the cylindrical portion of the ultrasonic transducer 20 of the present embodiment is not formed to have the same curvature as the inner diameter of the back surface of the reflecting member 12b of the mirror 12, a thin adhesive is applied to the back surface of the reflecting member 12b of the mirror 12. Since the fifteen layers can be closely adhered to the back surface of the reflecting member 12b of the ultrasonic vibrator 20, the vibration of the ultrasonic vibrator 20
The transparent member 12a and the coating film 12c of the mirror 12 can be vibrated with high efficiency because there is little buffering by the layer of the adhesive 15.

Next, a circuit built in the transducer control device 14 will be described with reference to FIG. FIG. 6 is an overall configuration circuit diagram showing a mirror cleaning device according to one embodiment of the present invention.

In the figure, an oscillation circuit 24 including a known Colpitts oscillation circuit and the like includes ultrasonic vibrators 10a to 10f (20a
20e) corresponding to the number of oscillation circuits 24a to 24f. Since these oscillation circuits 24a to 24f use the same circuit connected in parallel, their illustration is omitted here. If the capacitor C1 and the capacitor C2 in FIG. 6 are set to C = C1 · C2 / (C1 + C2), the oscillation frequency f0 will be roughly described. Becomes Incidentally, the oscillation frequency f0 of this embodiment is set to 1.7 MHz. At this time, the transistor Q0 is for amplification, and the resistors R1, R
2, R3 is for setting a DC bias, and capacitors C3, C4 are for bypass.

The temperature detection circuit 21 is a circuit in which a thermistor 13 as a temperature sensor is incorporated in one side of a resistance bridge including resistors R4, R5, R6, and R7. Further, the comparison circuit 22 is provided with the temperature detection circuit 21.
Is compared with a predetermined threshold value Vth obtained as a divided voltage of the series resistor R20 and the resistor R21.
The output voltage is set to “H (high level)” and a predetermined threshold
When the output voltage is lower than Vth, the output voltage is set to “L (low level)”.
It is assumed that. In the present embodiment, the threshold value Vth is set to a threshold voltage corresponding to about 60 ° C. or less as the temperature of the mirror 12 detected by the thermistor 13. When the output of the comparison circuit 22 is "H", the transistor Q1 is turned on via the resistor R22 and the diode D1, and the output of the comparison circuit 22 is "L".
At this time, the transistor Q1 is turned off. Transistor Q1
When the transistor Q1 is turned on, the potential on the collector side is set to the ground potential, and when the transistor Q1 is turned off, the potential on the collector side is made dependent on the applied voltage.

The transistor Q2 is turned on / off by the output “L” / “H” of the timer circuit 23, and the transistor Q3 is turned on / off by the transistor Q2 being turned on / off when the transistor Q1 is off. Then, when the transistor Q1 is on, the transistor Q2 is off regardless of the on / off state of the transistor Q2. By turning on / off the transistor Q3, the relay RY turns on / off the contact ry, and the oscillation circuit 24 (24a to 24f) enters the oscillation state or the stop state.

The timer circuit 23 outputs the "H" pulse width set for three predetermined time periods. These three
The type of pulse width output is output when the first switch SW1, the second switch SW2, and the third switch SW3 are pressed and "H" is input. That is, the first switch SW1, the second switch SW2, and the third switch SW3 have the resistance R11 and the resistance R
Series circuit with 12, series circuit with resistors R13 and 14, resistor R
“H” is input when each switch is turned on by a series circuit of 15 and the resistor R16. These first switches SW1,
The second switch SW2 and the third switch SW3 are installed in the vehicle so that the driver can operate freely.

In the figure, R1 to R9, R11 to R16, R20 to R26 are resistors, C1 to
C5 is a capacitor, and D1 to D4 are diodes.

The mirror cleaning device of the present embodiment configured as described above operates as follows.

First, when the first switch SW1, the second switch SW2, or the third switch SW3 is turned on, the timer circuit 23 outputs a predetermined pulse width corresponding to the switch.
When a predetermined pulse width length is output, the transistor Q2 turns on, thereby turning on the transistor Q3,
Energize the relay RY and close its contact ry. As a result, the oscillation circuit 24 (24a to 24f) has an oscillation frequency f0 = 1.7 MHz.
The ultrasonic vibrator 10 (20) vibrates the mirror 12 at that frequency, and instantaneously atomizes and removes water droplets attached to the surface of the mirror 12, that is, the coating film 12c.
In addition, a part of the water droplet drops downward due to gravity when the mirror 12 is vibrated, and is removed from the coating film 12c of the mirror 12.

At this time, since the coating film 12c having a large surface tension is formed on the surface of the predetermined mirror 12, water particles such as water droplets adhered to the coating film 12c act to reduce the area of the surface. And its coating film 12c
And the area of contact with it is also reduced. Therefore, water particles attached to the coating film 12c can be removed from the surface of the coating film 12c with a small ultrasonic vibration energy,
The efficiency of removing water droplets on the surface of the mirror 12 can be increased.

Further, the heat generated from the ultrasonic vibrator 10 (20) evaporates water droplets, fogging and the like attached to the mirror 12, or thaws water and frost stubbornly attached to the surface of the mirror 12, With the vibration of the mirror 12, the thawed water droplets attached to the coating film 12c on the surface of the mirror 12 are instantaneously atomized and removed, and the ice and frost during the thawing, and the thawed water droplets are dropped downward, from the mirror 12. Removed. In particular, in the heating by the ultrasonic vibrator 10 (20) according to the present embodiment, the responsiveness to the temperature rise is higher than the heating by Joule heat, so that the ice and frost attached to the surface of the mirror 12 are rapidly thawed. be able to.

During this time, the thermistor 13 of the temperature detection circuit 21
When the detected temperature of 12 rises to about 60 ° C. or higher, the output of the temperature detecting circuit 21 becomes equal to or higher than the predetermined threshold Vth, the output of the comparing circuit 22 becomes “H”, and the transistor Q1 is turned on. When the transistor Q1 is turned on, the base voltage of the transistor Q3 is suppressed to the ground potential, so that power is not supplied to the oscillation circuit 24 regardless of the pulse width of the output from the timer circuit 23. Do not do. Therefore, the detected temperature of the mirror 12 does not rise to about 60 ° C. or more, and the temperature rise of the ultrasonic transducer 10 (20) can be suppressed.

As described above, the mirror cleaning device according to the present embodiment includes a mirror having a predetermined curvature, a coating film having a large surface tension formed on the surface of the mirror, and one or a plurality of adhesive films adhered to the back surface of the mirror. And an ultrasonic vibrator.

Therefore, a coating film having a large surface tension formed on the surface of a mirror having a predetermined curvature causes water particles such as water droplets attached to the coating film to change the surface area of the water particles such as water droplets by the surface tension. It acts to make it smaller, and the contact area with the coating film also becomes smaller. Therefore, water particles adhering to the coating film can be removed with less ultrasonic vibration energy, and as a result, the efficiency of removing water particles such as water droplets on the mirror surface can be increased. At this time, before removing water particles such as water droplets from the mirror surface, the load on the ultrasonic vibrator is reduced and an excessive rise in temperature does not occur, so that the durability of the ultrasonic vibrator and the mirror is reduced. There is no.

In addition, one or a plurality of ultrasonic transducers having an end portion having a curvature equal to or substantially equal to the curvature of the back surface of the mirror are bonded to the back surface of the mirror having a predetermined curvature. With a thin layer of adhesive on the back surface of the reflecting member, a spherical portion equal to or substantially equal to the curvature of the inner diameter of the back surface of the reflecting member of the ultrasonic transducer can be bonded, so that the vibration of the ultrasonic transducer is caused by the adhesive layer. Less buffered,
The transparent member of the mirror can be vibrated with high efficiency.
Further, since the diameter of the ultrasonic vibrator can be reduced, the vibration frequency can be increased. In addition, the surface of a conventionally used mirror becomes spherical, and the mirror can be configured without impairing its original basic function.

By the way, the coating film having a large surface tension formed on the surface of the mirror when practicing the present invention is coated with a material whose contact surface with the film surface of the coating film is reduced when water droplets are attached to the coating film. Anything should do.

Further, the plurality of ultrasonic transducers bonded to the back surface of the mirror in the above-described embodiment are obtained by bonding six or five ultrasonic transducers. The present invention is not limited to this, and any device provided with one or more ultrasonic transducers may be used. Also, the arrangement may be arbitrarily set. In particular, the ultrasonic transducer
By setting the vibration frequency to 1M Hz or higher, highly efficient atomization can be expected.

[Effects of the Invention] As described above, the mirror cleaning device of the present invention includes a mirror having a predetermined curvature, a silicon-fluorine-based coating film having a large surface tension provided on the entire surface of the mirror, One or more ultrasonic transducers adhered to the back surface of the mirror. Therefore, the coating film having a large surface tension of silicon-fluorine on the mirror surface is used to reduce the surface area of the water particles such as water droplets due to the surface tension of the water particles such as water droplets attached thereto. Acting, the contact area with the coating film can be reduced, and water particles such as water droplets can be removed with less ultrasonic vibration energy. Therefore, the water droplet removal efficiency can be increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the entire structure of a mirror cleaning device according to one embodiment of the present invention, FIG. 2 is an explanatory diagram showing the arrangement of the ultrasonic transducers of the embodiment of FIG. 1 as viewed from the front, and FIG. FIG. 4 is a cross-sectional view showing a bonding state between the mirror and the ultrasonic vibrator used in the mirror cleaning device of the present embodiment. FIG. 4 is a side view of the ultrasonic vibrator used in the mirror cleaning device of the embodiment of the present invention. FIG. 5 (a), front view (b), and FIG. 5 are rear views (a) showing a bonding state between a mirror and an ultrasonic transducer used in a mirror cleaning device according to another embodiment of the present invention.
FIG. 6 is an overall circuit diagram showing a mirror cleaning device according to an embodiment of the present invention, and FIG. 7 is a cross-sectional view of a conventional mirror cleaning device provided outside the vehicle. It is. In the figure, 10 (10a to 10f) and 20 (20a to 20e): ultrasonic vibrator, 12: mirror, 12a: transparent member, 12b: reflective member, 12c: coating film. In the drawings, the same reference numerals and symbols indicate the same or corresponding parts.

Continuation of the front page (56) References JP-A-57-70754 (JP, A) JP-A-60-45683 (JP, A) JP-A-60-82850 (JP, U) JP-A-63-6968 (JP) , U) Fully open 58-69802 (JP, U) Fully open 61-30552 (JP, U) (58) Fields investigated (Int.Cl. ⁶ , DB name) B60R 1/06 B60S 1/08 B60S 1/60

Claims (1)

(57) [Claims] A mirror having a predetermined curvature; a coating film having a large surface tension of silicon-fluorine provided on the entire surface of the mirror; and at least one ultrasonic wave provided on a back surface of the mirror. A mirror cleaning device, comprising: a vibrator;