JPH0328057A - Water drop removing device - Google Patents

Abstract

PURPOSE:To remove water drops certainly by installing a supporting plate, to which a piezo vibrator is fixed, on the rear side of an exposed plate at a certain spacing reserved between and interposing a space retaining member between the periphery of supporting plate and the exposed plate. CONSTITUTION:A supporting plate 5 is parallelly installed on the rear side of a mirror plate 4 with a certain spacing 6 reserved. This supporting plate 5 is formed in approximation so that a supported part 4a with a certain width remains at the periphery of the mirror plate 4 and coupled in the condition with said spacing 6 held while adhesives 7 are interposed between the periphery of supporting plate 5 and the mirror plate 4. The supported part 4a of the mirror plate 4 positioned outside the adhesives 7 is held at several points by a holding part 3 of a holder 1 through an elastic bushing 8. To the rear side of the supporting plate 5, a piezo vibrator 12 is fixed so as not to touch the mirror plate 4. Accordingly the vibration of the supporting plate 5 occurs in such a way that the part innermore than the supported part 4a of the mirror plate 4 is vibrated through the adhesives 7 in the form of a standing wave uniform in the whole and having a large amplitude.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a water droplet removing device used for outdoor equipment such as side mirrors for automobiles, and in particular, the present invention relates to a water droplet removing device used in equipment installed outdoors such as side mirrors for automobiles, and in particular, a device for removing water droplets by ultrasonic vibration of a piezoelectric vibrator. The present invention relates to a water droplet removing device configured to remove water droplets.

[Prior Art] As a conventional water droplet removing device of this type, the technology shown in FIGS. 5 and 6 is known.

Fig. 5 is a sectional view showing a water droplet removing device for an automobile side mirror according to the first conventional example disclosed in Japanese Utility Model Application No. 61-30552, and Fig. 6 is a sectional view showing a water droplet removing device for an automobile side mirror according to the second conventional example. FIG. 3 is a partial cross-sectional view showing the device.

In the first conventional example, as shown in FIG. 5, a holder 41 is supported by a vehicle body (not shown) via a stay 42,
A glass mirror plate 43 whose surface is exposed is attached to the holder 41.

A piezoelectric vibrator 44 that generates ultrasonic vibrations due to the piezoelectric effect is interposed between the holder 41 and the stay 42. A drive circuit 46 and an operation switch 47 in the vehicle interior are connected in series between the piezoelectric vibrator 44 and the power source 45.

In the water droplet removing device of this first conventional example, when water droplets adhere to the surface of the mirror plate 43, when the operation switch 47 in the passenger compartment is operated, the piezoelectric vibrator 44 generates ultrasonic vibration, and the vibration is It propagates to the mirror plate 43 via the housing member 41, and the mirror plate 43 resonates to generate a standing wave.

This standing wave imparts high kinetic energy to the water droplets adhering to the surface of the mirror plate 43, and as a result, the water droplets fall by gravity or become atomized, and the water droplets adhere to the surface of the mirror plate 43.
removed from the surface.

In the second conventional example, as shown in FIG. 6, a holder 51 is formed with an open part 52 and a holding part 53. A mirror plate 54 is held at the outermost edge of the holding portion 53 of the holder 51 via a spacer 55 . A piezoelectric vibrator 56 that generates ultrasonic vibration in a transverse vibration mode is directly bonded to a part of the back surface of the mirror plate 54.

In the second conventional water droplet removing device, when the piezoelectric vibrator 56 is driven, the piezoelectric vibrator 56 generates ultrasonic vibration in a transverse vibration mode, and the vibration is directly propagated to the mirror plate 54. As a result, a standing wave is generated on the mirror plate 54, thereby removing water droplets attached to the surface of the mirror plate 54.

[Problems to be Solved by the Invention] However, according to the water droplet removing device of the first conventional example, since the piezoelectric vibrator 44 is bonded to the back surface of the holder 41, the ultrasonic vibration of the piezoelectric vibrator 44 is not transmitted to the holder 41. As a result of the absorption, the amplitude of the standing wave on the mirror plate 43 becomes small, and the water droplet removal efficiency decreases.

Further, according to the second conventional water droplet removing device, the mirror plate 5
Since the piezoelectric vibrator 56 is directly bonded to the back surface of the piezoelectric vibrator 56, the ultrasonic vibration in the transverse vibration mode generated by the piezoelectric vibrator 56 is restrained by the bonded portion and weakened, and is transmitted to the mirror plate 54 at the bonded portion. A phenomenon occurred in which water droplets remained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a water droplet removing device that can efficiently remove water droplets over the entire surface of an exposed plate.

[Means for Solving the Problems] In order to solve the above problems, the water droplet removing device according to claim 1 includes an exposed plate whose surface is exposed and a held portion of a predetermined width left at the peripheral edge of the exposed plate. In this state, a support plate is arranged at a predetermined interval on the back side of the exposed plate, a piezoelectric vibrator is fixed to the support plate and imparts ultrasonic vibration to the support plate by piezoelectric effect, and An intervening member that is interposed between the peripheral edge and the exposed plate, maintains the distance between the supporting plate and the exposed plate, and propagates ultrasonic vibrations of the supporting plate to the exposed plate, and an intervening member that is outside the interposed member. and a holding means for holding the held portion of the exposed plate located at the exposed plate.

In the water droplet removing device according to a second aspect of the present invention, the exposed plate is a mirror plate.

Further, in the water droplet removing device according to claim 3, preferably, the holding means includes a holder having an opening for exposing the surface of the exposed plate and a holding part that abuts one side of the held part of the exposed plate; It consists of an elastic bush interposed between the holding part of the holder and the held part of the exposed plate.

[Function] In the water droplet removing device according to claim 1, the piezoelectric vibrator is fixed to the support plate, and a predetermined interval is secured between the support plate and the exposed plate by the intervening member. The ultrasonic vibration in the transverse vibration mode generated by the vibrator spreads and propagates throughout the exposed plate via the support plate and the intervening member. Therefore, unlike in the past, there is no fear that ultrasonic vibrations will be restrained at the bonded portion of the piezoelectric vibrator and water droplets will remain on the exposed plate at that portion. In addition, since the held portion of the exposed plate located on the outside of the intervening member is held by the holding means, propagation of vibration energy to the holder side is suppressed, and the ultrasonic vibration of the piezoelectric vibrator is transmitted more than the intervening member. It is efficiently propagated to the inner exposed plate. Therefore, water droplets can be efficiently removed over the entire surface of the exposed plate.

In the water droplet removing device according to the second aspect, since the exposed plate is a mirror plate, water droplets can be efficiently removed from side mirrors for automobiles, etc.

Further, in the water droplet removing device according to claim 3, since the held portion of the exposed plate is held by the holding portion of the holder via the elastic spacer, resonance of the holder is suppressed by the elastic action of the elastic spacer. minutes of vibration energy can be effectively used to remove water droplets.

[Example] An example in which the present invention is embodied in a side mirror for an automobile will be described based on the drawings.

FIG. 1 is a rear view of a side mirror for an automobile showing one embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1.

As shown in FIGS. 1 and 2, the holder 1 of the automobile side mirror of this embodiment is molded into a dish shape from a synthetic resin material, and the holder 1 has an opening 2 through which light rays enter and reflect. , and a holding portion 3 having a substantially C-shaped cross section and surrounding this opening 2 are formed. Inside holder 1,
A mirror plate 4 made of a glass plate or a transparent synthetic resin plate having a convex surface of a predetermined ratio exposed from the opening 2 is housed, and an opposite film (not shown) is attached to the back surface by metal vapor deposition or the like. ing.

On the back side of the mirror plate 4, support plates 5 made of a plate-shaped material such as glass or metal are arranged in parallel at a predetermined interval 6. The support plate 5 is formed into a similar shape with a smaller area than the mirror plate 4 so that a held portion 4a of a predetermined width remains at the peripheral edge of the mirror plate 4. An adhesive 7 is interposed between the peripheral edge of the support plate 5 and the mirror plate 4, and the adhesive 7 connects the support plate 5 and the mirror plate 4 to each other while maintaining the gap 6. There is.

The held portion 4a of the mirror plate 4 located on the outside of the adhesive 7 is held by the holding portion 3 of the holder 1 through elastic bushes 8 made of rubber at a plurality of locations (for example, 6 locations). has been done. The holding portion 3 includes a pin that locks the elastic bush 8 and a projection 10 that makes point or line contact with the outermost peripheral surface of the mirror plate 4.

The piezoelectric vibrator 12 is fixed to the back surface of the support plate 5 by suitable fixing means such as an adhesive 13 so as not to contact the mirror plate 4. This piezoelectric vibrator 12 has electrodes 15 made of a flexible printed circuit board attached to both the front and back surfaces of a flat piezoelectric element 14 made of piezoelectric ceramics using a conductive adhesive.
When a voltage from a power source (both not shown) is applied between the electrodes 15 via an oscillation circuit,
It is configured to generate ultrasonic vibration in a transverse vibration mode by the piezoelectric effect of the piezoelectric element 14.

The ultrasonic vibrations generated by the piezoelectric vibrator 12 spread throughout the support plate 5, starting from the outermost edge of the adhesive 7.
It is propagated to the mirror plate 4 via.

Next, the operation of the automobile side mirror of this embodiment configured as shown in -L will be explained.

When an AC voltage is applied between the electrodes 15 of the piezoelectric vibrator 12,
The piezoelectric element 14 generates ultrasonic vibration in a transverse vibration mode due to its piezoelectric effect, and the vibration spreads throughout the support plate 5. In this case, since the peripheral edge of the support plate 5 is fixed to the mirror plate 4 via the adhesive 7, the vibration of the support plate 9 is transmitted inward from the held portion 4a of the mirror plate 4 via the adhesive 7. Propagate throughout.

Therefore, if the frequency of the AC voltage is selected to an appropriate value, the mirror plate 4 resonates with the ultrasonic vibration of the piezoelectric vibrator 12, and the amplitude is uniform and large over the entire mirror plate 4 inside the held portion 4a. A standing wave is generated, and the mirror plate 4 moves at high speed due to the standing wave. At this time, water droplets, frost, dust, and other adhering matter adhering to the surface of the mirror plate 4 are given high kinetic energy by the mirror plate 4, and are removed from the mirror plate 4 by dripping or atomizing due to gravity. Ru.

As described above, the automobile side mirror of this embodiment includes the mirror plate 4 as an exposed plate whose surface is exposed, and the mirror plate 4 with a predetermined width of the held portion 4a remaining at the peripheral edge of the mirror plate 4. 4, and a piezoelectric vibrator 12 that is fixed to the support plate 5 and imparts ultrasonic vibration in a transverse vibration mode to the support plate 5 due to the piezoelectric effect. is interposed between the peripheral edge of the support plate 5 and the mirror plate 4, and maintains the distance 6 between the support plate 5 and the mirror plate 4, and propagates the ultrasonic vibration of the support plate 5 to the mirror plate 4. It is composed of an adhesive 7 as an intervening part shrine, and a holding means for holding the held part 4a of the mirror plate 4 located outside the adhesive 7. A holder 1 has an opening 2 to be exposed and a holding part 3 that comes into contact with one side of a held part 4a of a mirror plate 4, and an intermediary between the holding part 3 of the holder 1 and the held part 4a of the mirror plate 4. It is composed of an elastic bush 8 equipped with an elastic bush 8.

Therefore, according to the automobile side mirror of this embodiment, the piezoelectric vibrator 12 is fixed to the support plate 5, and a predetermined distance 6 is secured between the support plate 5 and the mirror plate 4 by the adhesive 7. Therefore, the ultrasonic vibration in the transverse vibration mode generated by the piezoelectric vibrator 12 spreads and propagates throughout the mirror plate 4 via the support plate 5 and the adhesive 7. Therefore, unlike the prior art, the vibration of the mirror plate 4 is restrained in the portion corresponding to the piezoelectric vibrator 12, and there is no fear that water droplets will remain in that portion. Also, holder 1
Since the held portion 4a of the mirror plate 4 located outside the adhesive 7 is held by the holding portion 3 and the elastic bush 8,
The propagation of vibration energy to the holder 1 side is suppressed,
The ultrasonic vibration of the piezoelectric vibrator 12 is efficiently propagated to the mirror plate 4 located inside the adhesive 7. Therefore, mirror plate 4
Water droplets can be efficiently removed over the entire surface area.

In addition, in this embodiment, the held portion 4a of the mirror plate 4
is held by the holding part 3 of the holder 1 via the elastic bush 8, so the resonance of the holder 1 is suppressed by the elastic action of the elastic bush 8, and the vibration energy is effectively used for removing water droplets. This can further improve water droplet removal efficiency. Moreover, since the holding part 3 is in point or line contact with the held part 4a of the mirror plate 4 only by the protrusion 10, the attenuation rate of vibration energy can be further reduced.

Here, the Sakukawa effect of the present example described above will be confirmed based on experimental results.

FIG. 3 is a perspective view showing the shape of the automobile side mirror shown in FIG. 1 analyzed by a computer, with (a) showing the shape when not vibrating, and (b) showing the shape when vibrating.

As is clear from FIG. 3(b), when the piezoelectric vibrator 12 is driven, a standing wave with a large amplitude is generated over the entire mirror plate 4. Note that in this experiment, a rectangular piezoelectric vibrator 12 was used.

On the other hand, Figure 4 shows a comparative example using an automobile side mirror with a different configuration from that in Figure 1, where (a) is a partial cross-sectional view showing the configuration, and (b) is the shape when not vibrating. (c) is a computer-analyzed perspective view showing the shape during vibration.

The automobile side mirror of this comparative example is shown in FIG. 4 (a).
As shown, an adhesive 7 is interposed between the outermost edges of the mirror plate 4 and the support plate 5. According to this structure, as shown in FIG. 4(c), the amplitude of the standing wave generated on the mirror plate 4 when the piezoelectric vibrator 12 is driven is greater than that in FIG. 3(b). Significantly reduced. This is because the mirror plate 4 and the support plate 5 are each held by the holder 1 at a common outermost peripheral position, so the vibration propagation rate toward the holder 1 side increases, and the vibration efficiency of the mee plate 4 decreases accordingly. Because it does. On the other hand, in this embodiment, the support plate 5 is connected via the adhesive 7 at a position inside the outermost edge of the mirror plate 4, so as described above,
A standing wave with a large amplitude can be excited over the entire area of the mirror plate 4.

Note that in the embodiment L, the intervening member is made of only the adhesive 7, but the present invention is not limited to this, and the intervening member may be made of glass, metal, or glass-based material. It may be made of engineering plastic such as epoxy and fixed between the mirror plate 4 and the support plate 5 using an adhesive.

Further, in the above embodiment, the piezoelectric vibrator 12 having a substantially rectangular parallelepiped shape is used, but its shape is not particularly limited. '' It is possible to obtain almost the same effects as in the second embodiment.

Furthermore, in the above embodiments, the present invention is embodied in a water droplet removing device for an automobile side mirror, but when implementing the present invention, the present invention is not limited to only this application.
It is also possible to embody the present invention by applying it to a water droplet removing device for various types of outdoor equipment such as outdoor advertising devices or outdoor display devices.

[Effects of the Invention] As detailed above, the water droplet removing device according to the fourth aspect of the present invention as set forth in claim 1 comprises an exposed plate whose surface is exposed and a predetermined interval provided on the back side of the exposed plate. a piezoelectric vibrator that is fixed to the support plate and generates ultrasonic vibrations; and a piezoelectric vibrator that is interposed between the peripheral edge of the support plate and the exposed plate to propagate the ultrasonic vibrations of the support plate to the exposed plate. Since the structure consists of an intervening member and a holding means for holding the held portion of the exposed plate located outside of the intervening part, the ultrasonic vibrations generated by the piezoelectric vibrator are transmitted to the exposed plate. The effect is that the vibration spreads over the entire area and is suppressed from propagating toward the holding means, and as a result, the water droplets can be efficiently removed over the entire surface of the exposed plate.

In the water droplet removing device of the present invention as set forth in claim 2,
Since the exposed plate is a mirror plate, water droplets can be efficiently removed over the entire surface of the mirror plate.

Furthermore, in the water droplet removing device of the present invention as set forth in claim 3, since the held portion of the exposed plate is held by the holding portion of the holder via the elastic bush, the resonance of the holder is suppressed by the elastic action of the elastic bush. This has the effect of suppressing the amount of vibration energy and making effective use of the vibration energy for removing water droplets.

[Brief explanation of drawings]

FIG. 1 is a rear view of a side mirror for an automobile showing an embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1, and FIG. 3 is an explanation explaining the vibration operation of the side mirror for an automobile shown in FIG. 1. figure,
Fig. 4 is a comparative example with a different configuration from Fig. 1 and an explanatory diagram for explaining its vibration operation, Fig. 5 is a sectional view showing the first conventional example of a water droplet removal device for an automobile side mirror, and Fig. 6 is FIG. 7 is a partial sectional view showing a second conventional example of a water droplet removing device for an automobile side mirror. In the figure, 1: Holder 2 = Opening 3: Holding part
4: Mirror plate 4a: Part to be held
5: Support plate 6: Spacing 7: Adhesive 8
: Elastic bush 12: Piezoelectric vibrator. Note that in the drawings, the same reference numerals and symbols indicate the same or equivalent parts.

Claims (3)

[Claims] (1) An exposed plate whose surface is exposed; a support plate disposed at a predetermined interval on the back side of the exposed plate, with a held portion of a predetermined width remaining at the periphery of the exposed plate; and the support plate. a piezoelectric vibrator fixed to the plate and imparting ultrasonic vibration to the support plate; and a piezoelectric vibrator interposed between the peripheral edge of the support plate and the exposed plate to maintain a distance between the support plate and the exposed plate. A water droplet removing device comprising: an intervening member that propagates ultrasonic vibrations of the support plate to the exposed plate; and a holding means that holds a held portion of the exposed plate located outside the intervening member. . (2) The water droplet removing device according to claim 1, wherein the exposed plate is a mirror plate made of glass with a reflective film formed on one surface. (3) The holding means includes a holder having an opening that exposes the surface of the exposed plate and a holding part that abuts one side of the held part of the exposed plate, and the holding part of the holder and the held part of the exposed plate. 3. The water droplet removing device according to claim 1, further comprising an elastic bush interposed between the water droplet removing device and the elastic bushing.