DE102009020371A1 - Piezoelectric drive device for moving e.g. cleaning device on surface of glass pane of aquarium, has support elements comprising different geometric shapes such that elements are excited with frequencies to natural oscillation - Google Patents

Abstract

The device (1) has a supporting body (2) comprising two elongate support elements (4a, 4b) made of a resilient material. The elements are connected rigidly with the body with an end for introduction of the mechanical vibrations in the elements, and another end of the elements is supported on a surface (8) of a glass pane. The elements comprise different geometric shapes, length and/or material characteristics such that the elements are excited with frequencies to a natural oscillation. The latter end of the elements is moved away from the surface. Independent claims are also included for the following: (1) a cleaning device comprising a mechanical holding element (2) an inspection device comprising a detector (3) a toy comprising a housing.

Description

The The invention relates to a piezoelectric drive device and the use of such according to the preamble of claim 1.

piezoelectric Drive devices are known in the art and are used to mechanically usually smaller objects move and position. Here are the piezoelectric used Crystals in one or more spatial directions by applying a corresponding electrical voltage periodically expands and contracts, the resulting microscopic length expansions the crystals in the different spatial directions frictionally be transferred to the surface, relative to which the crystal or the crystal driven Object should move.

That's how it describes DE 196 36 827 C1 a piezoelectric driving device having a base from which a first and a second rod-shaped piezoelectric crystal extend at an angle of about 45 ° to each other and converge in an isosceles triangle manner at a common tip. At the top of a spherical cap is attached, on which the surface of a moving drive body is supported. The two rod-shaped crystals are laterally occupied with layer electrodes which extend along the outer surfaces of the crystals and which are alternately energized so that the spherical cap moves on a circular path with a diameter of 5 microns, resulting in a feed of the drive body of approx. 3 microns per oscillation period leads. Since a total of two rod-shaped piezoelectric crystals are needed to produce the circular movement of the cap, the electrical control of the same is relatively expensive. In addition, the manufacturing cost of the device is comparatively high due to the two inclined rod-shaped crystals, and the device allows, despite the use of two crystals only a movement of the drive body along a straight line.

Accordingly It is an object of the present invention, a piezoelectric To provide drive device, which with a low device cost a movement in at least two different directions of movement a level allows. Another object of the invention is to find new uses for the To provide drive device according to the invention.

These The object is achieved by the features from claim 1, 12, 15 and 17 solved.

Further Features of the invention are contained in the subclaims.

To The invention relates to a piezoelectric drive device for Moving small objects such as inspection equipment, cleaning equipment and toys on a preferably hard and smooth surface a support body on which a piezoelectric Crystal is attached, which preferably takes the form of a hollow cylinder or a solid cylinder owns. The piezoelectric crystal is via electrical leads with an electrical Frequency generator connected to the crystal to mechanical vibrations stimulated with at least a first and a second frequency, which be transferred to the support body. Of the Support body has a first and a second elongated Support element made of a springy material with good acoustic properties, with the speed of sound within the Material is preferably greater than 1000 m / s. The material may in particular spring steel wire with a diameter from 0.5 to 2.5 mm, one adapted to the weight of the device generates sufficient support force, and each with a first end to initiate the mechanical vibrations in the Support element rigid with the support body connected is.

The second end of the support elements is supported in contrast on the surface, with the two support elements a slightly different geometric shape and / or have length and / or material property, such that the first support member at the first frequency and the second support element at the second frequency to a mechanical self-oscillation is excited, in which the second End of the respective support element from the surface gone and moved towards this.

By The invention has the advantage that only one piezoelectric Crystal is required to move the support body opposite the surface into a first and a to enable the second direction. Here, the propulsion of the Device according to the invention achieved in that the free ends of the resilient support elements, over which is the support body together with the crystal and the other components on the surface supports, perform an up and down movement, due to the weight-related deflection of the angle from the support body laterally extending support elements in connection with the mass-conditioned persistence of the support body acting in a lateral direction Frictional force generated by the support elements is introduced into the support body when the corresponding support element for mechanical self-oscillation is stimulated.

in this connection It has surprisingly been shown that the at Operating the crystal with certain natural frequencies on the support body exerted driving force depending on condition and material the surface even exceed the frictional force can be that between the contact points of the support elements and the surface is created when the piezoelectric Crystal rests, d. H. from the frequency generator not with an AC voltage is charged. This is due to, that the material of the surface moved by the up and down free ends of the support elements themselves to wavy Surface vibrations is excited at the wave crests the free ends of the support elements upon impact repelled figuratively speaking on the surface.

at the preferred embodiment of the invention is on the support body attached yet another third support element, which opposite to the other two support elements one slightly different geometric shape or length or material property, so that this at least a further mechanical natural frequency can be excited differing from the natural frequencies of the other two supporting elements in the respective frequency range slightly, z. B. order 10 Hz to 50 Hz, different.

in this connection have the three almost identical trained support elements preferably all at an inclination angle of z. B. 45 ° in different spatial directions of the support body away towards the surface, leaving the support body vividly spoken standing on a tripod. Because of the engagement of a total of three elongated rod-shaped or leg-shaped Support elements that over the crystal and the Frequency generator each separate from each other mechanical self-oscillation can be excited, whose Frequencies are only slightly separated by a few 10 Hz differ, the opportunity opens up an appropriate choice of the frequency of the frequency generator three generate mutually acting propulsive forces, which one forward, backward and also Sideways movement as well as rotation of the support body enable.

The two or three support elements have in the previously described Embodiments of the invention preferably spatially curved, in side view S-shaped cross-sectional shape on and are slightly opposite to the perpendicular to the surface twisted, z. B. by 10 to 20 °, so that due to its own weight of the support body and arranged on this Components a certain torque on the support elements is exercised. This results in conjunction with the torsional elasticity of the support elements of Advantage that the support elements in the case of resonance, a torsional vibration run, which causes the free ends of the Support elements on a substantially circular or elliptical trajectory. These opposite the perpendicular to the surface at an angle of z. B. 10 to 20 ° inclined, convex portions, within those preferred also the support points for the support elements are arranged, are also below referred to as cranked sections.

To Another embodiment of the invention comprises Support body one with the piezoelectric crystal directly connected plate or a ring, preferably made of Metal, e.g. B. sheet iron, steel or copper sheet or a similar, preferably solderable metal is made. Here are the first Ends of the support elements in particular by soldering or pressing or a positive connection in the way rigidly connected to the support body, that the second free ends of the support elements in different Show spatial directions. The piezoelectric crystal, in particular has a cylindrical or hollow cylindrical shape is there with one of its two faces z. B. by gluing attached directly to the support body, which latter can also be provided with a slot to an enlarged Stimulate number of vibration modes of the support body to be able to. The embodiment described above The invention has the advantage that both the support elements, also the support body in cheaper Made of a tough and high-strength material can be, which has a relatively high Tragfühigkeit allows the inventive arrangement, wherein the weight of a housing carried by the assembly or any other large-scale facility in the piezoelectric crystal is introduced.

Although the drive device according to the invention in principle can also be operated by hardwired electronics, this preferably has an electronic control device, which the frequency generator corresponding default values for the first, second and further frequency feeds, which in one electronic memory are stored. The electronic control device comprises In this case, preferably a microcontroller, the frequency generator on the basis of stored in the memory default values for controls the respective frequencies at which the respective support elements be put into natural oscillations.

In the preferred embodiment of the invention, a sensor is arranged on the support body, preferably on the board of the electronic control device, which determines the position of the base body on the surface and / or the movement of the base body relative to the surface and / or the Be detected acceleration of the body in a first and a second direction and feeds the electronic control device. The sensor can z. B. as an imaging sensor, for. B. a CCD area sensor, be configured which detects the surface and determines the relative position, or the position change on the basis of the movement of the drive device relative to the surface changing pixels.

Of the However, sensor may also be another known from the prior art Position sensor or an acceleration sensor, which is the electronic control device via the corresponding signals the direction of movement, movement speed and acceleration supplies.

By opens the use of a previously described sensor not only the possibility of the movement of the invention Drive device according to a predetermined movement scheme to control, but the device of the invention can also be used in a very simple way for the first time be initialized. For this purpose, the electronic control device is right the frequency generator over a given frequency range away - in the range of the natural frequencies of the two, or three support elements is - as long as, until the electronic control device via the sensor detects a movement of the drive device in a first direction. The associated frequency value is then combined in the memory with a first directional value for the movement of the support body stored, and the frequency generator then continue tuned until the sensor detects a movement of the support body, or the drive device detected in a second direction. The associated frequency value then becomes together with the associated directional value of the sensor for the second direction of movement also in memory filed and the whole for further directions of movement until repeated in the frequency range of the fundamental and preferably also the 1st and second harmonics of the support elements the resulting directions of movement are detected by the sensor and together stored in memory with the associated directional values are. The direction values can be in the form of directional vectors or acceleration vectors in the memory of the electronic control device be filed.

Around after this initialization process described above, a movement along the drive device according to the invention to get a desired trajectory through one or more directional default values is defined, the z. B. may also be stored in the form of vectors, the electronic control device acts on the frequency generator with the stored frequency value, the directional value closest to the current direction of movement comes. By alternating switching for one each different length of time between a first frequency value for a first direction value and a second frequency value for a second directional value can be the straight desired direction of movement in the manner of a vectorial Addition received.

To Another idea underlying the invention are to the free ends of the first and second support members as well preferably also arranged third support element permanent magnets, around the support body at a particular inclined or even vertically extending surface of magnetizable To hold material. This opens up the possibility the drive device according to the invention z. B. for driving an inspection device arranged thereon on vertical Metal walls, such. B. ship walls or hall walls use, it has been shown that the inventive Drive device due to the resonant oscillation of the support elements, or the excited by these to surface vibrations magnetizable surface even a movement in the upward direction allows.

To another idea underlying the invention can at the free ends of the first and second support members as well as the third support element float body be arranged over which the supporting body supported on a liquid surface. As the Applicant has found this, it comes with some of the Variety of natural frequencies with which the support elements to stimulate resonant oscillations even on the surface a liquid, for. As water, to a propulsive force. This is due to the fact that the resonantly swinging support body vividly spoken at the antinodes of simultaneously generated secondary Repel surface waves on the liquid. This embodiment of the invention Drive device opens up the possibility, in particular smaller floating objects on liquid surfaces without the use of known propellers and control towers flexible to move in any direction.

After a further application possibility of the drive device according to the invention, this has a cleaning element, for. As a cleaning cloth or a sponge or the like, which is arranged on the underside of the support body, and contacted the surface to remove adhering dirt therefrom. It has been found to be advantageous that the surface through the support elements to Eigenschwin tions in kHz, or in the ultrasonic range is excited when the cleaning element is moved by the drive device over this time, whereby the cleaning effect can be improved in an advantageous manner.

According to one Another embodiment of the invention may be hereby be provided that for cleaning the surface of a thin-walled sheet-like element, in particular a windowpane of a building or the glass pane an aquarium, on the support body, a first magnetic holding element be arranged, which is generating a by the plane Element by acting magnetic attraction with a arranged on the opposite surface of the element second magnetic holding element cooperates. In this embodiment the invention, the cleaning element is preferably on a contact surface attached to the first magnetic holding element, which is to be cleaned Contacted surface and which in turn turn supported on the support body.

With opened the previously described cleaning device the possibility of outside windows on large buildings, in particular skyscrapers, in an efficient way without from outside the building to clean attached cargo elevators, as only the cleaning element according to the invention on the Outside of the window to be cleaned placed and Z. B. by a Perlonschnur against accidental dropping must be secured. On the inside of the building on the other hand, only the second magnetic element with a appropriate cleaning coating set, the magnetic Attractions in connection with the cleaning elements that are preferably mounted on both magnetic holding elements, generate the required frictional force, which the device against a slide down secures, and that allows that the drive device according to the invention the support body with the cleaning element on the outside of the building moved against gravity in the upward direction.

In Connection with a motion sensor described above continue the possibility that the inventive Drive device with the attached cleaning element at the cleaning goes through a given trajectory, z. B. a meandering trajectory in the horizontal direction from top to bottom. To make a change of direction in the area of the edges of a pane to be cleaned, can the piezoelectric crystal upon reaching a disc edge due to the accompanying signal of the motion sensor of the electronic control device with a previously stored Frequency value are applied, resulting in a rotation of the support body leads. Of course you can too be passed through other predetermined paths of movement, the in the electronic memory preferably in the form of sequences of frequency values for the different natural oscillations of the piezoelectric Crystals are stored. The frequency value sequences can z. B. preferably determined empirically and stored in memory.

To Another idea underlying the invention is the Drive device according to the invention an inspection device with which the surface z. B. can be examined in terms of their nature. For this purpose, on the drive device, in particular on the support body or a carrier elastically coupled thereto Detector taken, which according to the to be performed Inspection task z. B. an electrical measuring head, a mechanical Probe, an ultrasonic probe or one on the Surface-facing camera or the like can.

in this connection It can be especially useful when inspecting certain surfaces be advantageous to material error when the frequency generator the piezoelectric crystal during the actual measurement process with a frequency applied to the surface to be inspected itself stimulates to mechanical surface vibrations, the from the detector, in turn, to determine the properties recorded the surface and then z. B. from an electronic evaluation unit are evaluated, the z. B. is part of the electronic control device.

After all can the drive device according to the invention according to another application for driving a Toys, in particular a children's toy, why attached to the support body a housing is that at least partially surrounds the support body and in particular the shape of a beetle or a Insect possesses. The drive device has in this application preferably three supporting elements that are the legs of the beetle or insect.

In order to move the drive device according to the invention in particular in the aforementioned applications along a freely selectable or fixed predetermined path of movement, it may be provided that the electronic control device has a radio reception module, which with the help of a radio transmitter from the outside a selection of stored frequency values possible when z. B. an electrical switch on the radio transmitter is actuated. When pressing the switch -. B. the switch for the movement to right side - selected frequency value is then supplied to the frequency generator and from this as electrical voltage at the appropriate frequency of the piezoelectric crystal, which generates a mechanical vibration of the support body, which moves it to the right side. In a corresponding manner, further frequency values for the movement of the support body in other directions can likewise be stored in the memory, which can be activated via corresponding further electrical switches on the radio transmitter, so that the support body by pressing the respective switch on the radio transmitter similar to a remote-controlled Move and steer the vehicle.

The The invention will be described below with reference to the drawings of preferred embodiments.

In show the drawings:

1 a schematic plan view of the support body with the piezoelectric crystal and the arranged thereon three leg-shaped support elements according to the preferred embodiment of the invention,

2 a schematic side view of the drive device according to the invention with the in 1 shown support body on an indicated surface,

3 a schematic representation of the piezoelectric crystal and the associated electronic control device for operating a drive device according to the invention,

4 a schematic cross-sectional view through a glass pane with a cleaning device arranged thereon, which is held by a magnet on the outside of the disc and driven by a drive device according to the invention,

5 a schematic side view of an inspection device with a drive device according to the invention, on the support elements permanent magnets are arranged to hold the inspection device on a likewise indicated surface of a magnetizable material and to move along this,

6 a remote-controlled toy with a housing in the shape of a beetle, which is driven by a drive device according to the invention,

7a a schematic plan view of the support body with piezoelectric crystal and electronic control device according to another embodiment of the invention, and

7b a schematic side view of the drive device according to the invention according to the in 7a shown embodiment.

As in 1 is shown comprises a piezoelectric drive device according to the invention 1 a support body 2 which is preferred as one in the illustration of 1 shown sheet metal ring or metal ring with a thickness of z. B. 0.2 to 1.0 mm and a diameter of z. B. 1 to 5 cm is designed.

On the underside of the support body are a first support element 4a , a second support element 4b and preferably still another third support element 4c rigid with its first end, ie non-rotatable in the region of the attachment point, z. B. by soldering or gluing, attached. The free end of the support elements 4a . 4b . 4c are curved according to the invention or configured S-shaped and have a bent portion 6 within, within which preferably the support point is defined, over which the corresponding support element 4a . 4b . 4c on a preferably flat and hard surface 8th , such as B. a metal or glass surface supported.

The support elements 4a . 4b and 4c have a length of for example 2.5 cm to 5 cm and consist in the preferred embodiment of the invention of steel wire with a diameter of z. B. 0.8 mm to 1.5 mm.

Like the presentation of 1 and also from 2 can still be found on the top of the support body 2 a piezoelectric crystal 10 attached, the z. B. is designed as a solid cylindrical crystal shown in the drawings hollow cylindrical crystal.

The piezoelectric crystal 10 is here from above on the annular support body 2 glued on, which downwards in the manner of a tripod on the surface 8th supported.

As shown by 3 is the piezoelectric crystal 10 in a known manner via non-illustrated electrodes, for. B. layer electrodes connected to the two end faces of the crystal with the poles of a known frequency generator, which acts on the piezoelectric crystal with an electrical voltage, such as a sine wave voltage whose frequency the frequency generator 12 from an electronic control device 14 is supplied as a frequency value. As a result of the applied alternating electrical voltage, the piezoelectric crystal expands at the predetermined frequency of the alternating voltage ter periodically in the longitudinal direction and then pulls together again. Accordingly, the piezoelectric crystal 10 via the frequency generator 12 to be excited to mechanical longitudinal vibrations, via the mechanically rigid coupling between the piezoelectric crystal 10 and the support body 2 to a mechanical vibration of the support body 2 leads, which in turn due to the rigid mechanical coupling of the first, second and further support member 4a . 4b . 4c with the support body 2 to a mechanical vibration of the respective support element 4 leads in the manner of a cantilevered oscillating rod. The frequency generator 12 it draws its electrical energy in the same way as the electronic control device 14 from a power source 13 that z. B. is a battery or a rechargeable battery.

According to the invention, the first support element 4a and the second support element 4b as well as preferably also provided, but not necessarily for generating a movement of the drive device 1 required third support element 4c with respect to their geometric shape and / or their length or their material properties designed slightly different, which leads to that upon excitation of the piezoelectric crystal 10 with a first frequency F1, only the first support element 4a is excited to a resonant mechanical natural vibration, in which the free end of the first support element 4a relative to the surface 8th moved in the upward and downward direction. This upward and downward movement is over the preferably also provided, side-facing cranked portion 6 in a circular movement of the support point in the region of the free end of the support element 4a convicted, which causes the free end of the first support element 4a generates a feed force, via the support element in the support body 2 is introduced and in the case of a circular movement to a rotation or a lateral movement of the support body 2 Leads.

In the same way, the second support element 4b with a second frequency F2 to resonant mechanical natural vibrations excitable, for example, only a few heart of the first resonant natural frequency of the first support element 4a different.

By a corresponding adjustment of the length and the geometric shape, or the material properties such as in particular the modulus of elasticity of the material from which the first and second support element 4a . 4b are made, the associated natural frequencies are selected so that they are sufficiently far apart to ensure that when operating the frequency generator 12 with the first natural frequency F1, only the first support element 4a and in operating the same with the second frequency F2, only the second support member 4b is set in a resonant mechanical up and down movement, which causes the support body 2 is moved either in one direction or in the other direction. This does not exclude that there are other matching natural frequencies where both support bodies 4a and 4b be stimulated together to resonant natural oscillations, through which the support body 2 due to the overlapping driving forces z. B. performs a straightforward forward movement or movement on a slightly curved circular path. This can be done by introducing a gap or slot 16 in the in 1 and 2 shown annular configured supporting body 2 the number of possible vibration modes of the support body 2 be increased in an advantageous manner. The above-described piezoelectric crystal and annular support body 2 For example, as drives for electric watches are freely available in the trade and are characterized by a low cost and very low energy consumption.

By using a further support element shown in the figures 4c with a respect to the other support elements also slightly different length or geometric shape or material property of the resilient material from which the support member is made, can be further surprisingly alone by selecting a corresponding frequency with which the piezoelectric crystal 10 is operated, both linear and rotational movements of the support body 2 on the surface 8th generate that in 2 through the two arrows 18 and 19 are indicated.

To the frequencies required for such a movement of the frequency generator 12 To determine the generated AC voltage, the frequency generator 12 over a frequency range of z. B. 10 kHz to 80 kHz tuned away, which, for example, by the electronic control device 14 can be done. The one with an incipient movement of the support body 2 Connected frequency value is doing together with an associated directional default value, which is the direction of movement of the support body 2 for example as a vector, in an electronic memory 20 the electronic control device 14 filed in the form of value pairs.

The drive device according to the invention furthermore preferably has a sensor 23 on that with the electronic control device 14 is coupled and detects the direction of movement in connection with the occurring acceleration, which of the electronic control device 14 as ent supplied electrical signal and stored by this in the memory.

To the drive device according to the invention 1 In a simple way to initialize, in this embodiment of the invention, the frequency generator 12 starting from the lowest frequency, z. B. 10 kHz tuned and the occurrence of a sensor 23 detected movement of the associated frequency value F _i together with the associated acceleration value and the acceleration direction in the form of an acceleration vector a _i in the memory 20 stored. After passing through the frequency spectrum, which in a support body 2 and support elements 4 with the size described above in the range of approximately 10 kHz to 100 kHz, the drive device according to the invention can subsequently be moved, for example, with the aid of directional default values along a desired direction of movement or a trajectory to be traversed, which preferably takes the form of a parameterized curve In the storage room 20 are stored.

In this case, it may furthermore be provided that the movement path which the drive device according to the invention 1 to go through, with the help of a radio transmitter 22 is given, which with one with the electronic control device 14 coupled radio receiver 24 on the support body 1 interacts. By pressing a corresponding electrical switch 26 can be by radio previously in the memory 20 stored direction default value for the movement of the device according to the invention in the direction of the arrow 18 , and in a corresponding manner by actuation of the electrical switch 28 in the direction of the arrow 19 in 2 by an appropriate selection of the respective directional default values and supplying the frequency values associated therewith to the frequency generator 12 cause so that the supporting body 2 once to the right / left and to the other times moved forward / backward.

Thus, the drive device according to the invention can be 1 with the help of the radio transmitter 22 by retrieving the respective frequency values F _i from the memory 20 in the manner of a remote-controlled vehicle alone on the surface 8th in the desired direction 18 . 19 control that frequency generator 12 with the corresponding frequency value F _{i is} applied.

According to another, not shown in the drawings embodiment of the invention may be attached to the free ends of the support elements floating body over which the support body 2 on a liquid surface, such. B. a water surface supported. In this case, the floats can in particular also have a flattened, paddle-like shape, in order in conjunction with the previously described circular movement of the free ends of the support elements 4 to create a propulsive motion in the liquid. Although the buoyancy force generated by the floats is preferably greater than the weight generated by the drive device according to the invention, it is also possible for the floats smaller and z. B. only as a flattened paddle to create a propulsive force by repeated immersion in the liquid. The buoyancy of the support body is preferably generated in this case via a central float, the z. B. is arranged below the support body.

As continues the presentation of 5 can be removed, in a further embodiment of the drive device according to the invention 1 at the free ends of the support elements 4a . 4b and 4c permanent magnets 30 be attached. The permanent magnets 30 are designed by an appropriate choice of size, or of the permanent magnetic material in such a way that of them on a surface 8th made of magnetizable material, such. B. an iron plate or a steel wall generated magnetic attraction has such a size that the support body 2 with the components disposed thereon adheres to the surface, especially when the surface 8th inclined or even vertical, as in 5 is indicated in the drawing. The drive device according to the invention 1 serves here preferably for use in a in 5 schematically indicated inspection device 101 , at the support body 2 a detector 32 is included, for. As a camera or the like, with which the surface 8th for cracks, bumps or other surface defects.

According to another idea underlying the invention, the drive device according to the invention is used 1 for use in an in 4 schematically shown cleaning device 201 , which is used to the surface 8th from adhering dirt and impurities to clean. This is on the support body 2 a cleaning element 34 arranged, which z. B. unrolled from a supply roll not shown in detail includes cleaning cloth that is then wound onto a likewise not shown in detail role for the used cleaning cloth.

For the use of the drive device according to the invention 1 in a cleaning device 201 , with which advantageously a surface in the form of a thin-walled sheet-like element 208 , as in particular a glass pane, clean, is on the support body 2 a first magnetic holding element 36 arranged. This first magneti cal holding element 36 is preferably a permanent magnet, which generates a through the planar element 208 acting through magnetic attraction with a second magnetic holding element 38 interacts that on the first magnetic Haleelemente 36 opposite side 40 of the planar element 208 , z. B. on the outside of a building, located.

Like the presentation of 4 this can still be taken, is the cleaning element 34 on one's surface 8th contacting contact surface 42 of the first magnetic holding element 26 attached, which in turn is supported on the support body. The second magnetic holding element 38 is also preferably also with a cleaning element 44 provided, which is the planar element 208 in the area of the page 40 contacted to both surfaces 8th - ie in particular both sides of a glass pane - to clean.

Finally, the drive device according to the invention 1 in a toy 301 be used, including according to the representation of 6 on the support body 2 a housing 46 attached, which is the support body 2 at least partially surrounds. The housing consists in particular of plastic and has, for example, the shape of a beetle or an insect, wherein the support elements 4a . 4b and 4c forming the legs of the insect.

According to another, in 7a and 7b shown embodiment of the invention, which can be manufactured particularly cost, consists of the support body 2 from a preferably triangular sheet metal, for example steel sheet, with a thickness of z. B. 0.5 mm, which in particular has the shape of an equiangular triangle with a height of 5 cm. Alternatively, the sheet may be made of another material having good acoustic properties, the speed of sound within the material being at least 1000 m / s.

In this embodiment of the invention, the support elements 4a . 4b and 4c through angled areas 404a . 404b and 404c formed, for example, extend down at an angle of 10 to 30 degrees, so that the support body 2 forms an integral component with the support elements, which has the form of a tripod or tripod, as in 7a and 7b is indicated.

Also in this embodiment of the invention is preferably the length or the geometric shape, or the physical and / or mechanical material property of the three angled regions 404a . 404b and 404c slightly different in accordance with the invention, so that the regions can be excited to natural oscillations with different frequencies F1, F2 and F3, as has been described in detail in connection with the previously described embodiments of the invention.

On the flat area of the one-piece designed supporting body 2 with the support elements integrally formed thereon 4a . 4b . 4c in the form of angled areas 404a . 404b and 404c is the piezoelectric crystal 10 preferably at a small distance - z. B. 1 to 15 mm - arranged from the geometric center of the support body and attached to this, for example by gluing. On the support points on the angled areas opposite the top of the support body 2 are preferably rubber-elastic damping elements 402 attached, which is a slightly greater height than the piezoelectric crystal 10 own, and on which the board of the electronic control device 14 , or the electronic components, and preferably also a housing or a cleaning element, etc. are resiliently mounted.

This embodiment of the invention has the advantage that the sheet can be produced with high precision by a simple punching and stamping process in a very cost-effective manner, resulting in the cost of the drive device according to the invention 1 Reduce significantly in mass production.

1

driving device

2

support body

4a

first support element

4b

second support element

4c

additional support element

6

cranked section

8th

surface

10

piezoelectric crystal

12

frequency generator

13

power source

14

electronic control device

16

gap

18

arrow for lateral movement direction

19

arrow for forward-backward movement

20

Storage

22

Radio transmitter

23

sensor

24

Radio receiver

26

electrical Switch for right and left movement

28

electrical Switch for forward-backward movement

30

permanent magnet

32

detector

34

cleaning element

36

first magnetic holding element

38

second magnetic holding element

40

of the the drive device opposite side of the flat Elements

42

contact surface

44

cleaning element

46

casing

101

inspection device

201

cleaning device

208

flat for cleaning element / glass pane

301

toy

402

elastomeric damping element

404a

first angled area

404b

second angled area

404c

third angled area

F1

first frequency

F2

second frequency

F3

third frequency

F _i

frequency values in memory

a _i

acceleration vector in memory

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19636827 C1 [0003]

Claims (19)

Piezoelectric drive device ( 1 ) for moving small objects such as in particular inspection devices, cleaning devices and toys on a surface ( 8th ), with a supporting body ( 2 ), one on the support body ( 2 ), in particular cylindrical piezoelectric crystal ( 10 ) and one with the piezoelectric crystal ( 10 ) electrically connected frequency generator ( 12 ), which excites it to mechanical vibrations with a first and a second frequency (F1, F2), which on the support body ( 2 ), characterized in that the supporting body ( 2 ) a first and a second elongated support element ( 4a . 4b ) comprises a resilient material, each having a first end for introducing the mechanical vibrations in the support element ( 4a . 4b ) rigidly with the support body ( 2 ) and its second free end is on the surface ( 8th ) is supported, wherein the two support elements ( 4a . 4b ) have a slightly different geometric shape and / or length and / or material property, such that the first support element ( 4a ) is excited at the first frequency (F1) and the second support element at the second frequency (F2) to a self-oscillation, in which the second end of the respective support element ( 4a . 4b ) from the surface ( 8th ) and move towards it. Drive device according to claim 1, characterized in that the piezoelectric crystal ( 10 ) by the frequency generator ( 12 ) is excitable to mechanical vibrations with a different frequency of the first and second frequency (F1, F2) F3), and that on the support body ( 2 ) at least one further support element ( 4c ), each having a first end for introducing the mechanical vibrations into the support element ( 4c ) rigidly with the support body ( 2 ) and its second free end is on the surface ( 8th ) is supported, wherein the geometric shape and / or length and / or material property of the further support element ( 4c ) of that of the first and second support element ( 4a . 4b ) slightly deviates, such that only the further support elements ( 4c ) is excited at the further frequency (F3) to a natural oscillation, in which the second end of the further support element ( 4c ) from the surface ( 8th ) and move towards it. Drive device according to one of the preceding claims, characterized in that the support elements ( 4a . 4b . 4c ) a spatially curved, in cross-section S-shaped form with a bent portion ( 6 ) over which they lie on the surface ( 8th ), such that the free end of a respective support element ( 4a . 4b . 4c ) is excitable to a substantially circular motion. Drive device according to one of the preceding claims, characterized in that the supporting body ( 2 ) one with the piezoelectric crystal ( 10 ) directly connected plate, in particular of metal, with which the first ends of the support elements ( 4a . 4b . 4c ) are rigidly connected in particular by soldering or pressing or a positive connection in such a way that the second ends of the support elements ( 4a . 4b . 4c ) in different directions. Drive device according to one of the preceding claims, characterized in that it comprises an electronic control device ( 14 ) which includes the frequency generator ( 12 ) and supplies to it corresponding default values (F _i ) for the first, second and further frequency which are stored in an electronic memory ( 20 ) are stored. Drive device according to one of the preceding claims, characterized in that on the supporting body ( 2 ) a sensor ( 23 ) is arranged, which determines the position of the support body ( 2 ) on the surface ( 8th ) and / or the movement of the support body ( 2 ) relative to the surface ( 8th ) and / or the acceleration of the support body ( 2 ) in a first and a second direction ( 18 . 19 ) and that of the electronic control device ( 14 ) feeds. Drive device according to one of the preceding claims, characterized in that the electronic control device ( 14 ) the frequency generator ( 12 ) is tuned over a predetermined frequency range, and that the electronic control device ( 14 ) those frequency values (F _i ) at which the sensor ( 23 ) a movement of the support body ( 2 ) in a first and a second direction of movement ( 18 . 19 ), in memory ( 20 ) of the electronic control device ( 14 ) stores. Drive device according to claim 7, characterized in that the electronic control device ( 14 ) with a radio receiver ( 24 ), which is used for reading in memory ( 10 ) stored frequency values (F _i ) and supply them to the frequency generator ( 12 ) via a radio transmitter ( 22 ) is operable. Drive device according to claim 6, characterized in that the electronic control device a directional default value for the movement of the support body ( 2 ), and that the electronic control device ( 14 ) the frequency generator ( 14 ) alternately with the stored frequency values (F _i ) for the first and second direction of movement ( 18 . 19 ) acted in such a way that the supporting body ( 2 ) is moved in the direction of the directional default value. Drive device according to one of the preceding claims, characterized in that at the free ends of the first and second support element ( 4a . 4b ) Permanent magnets ( 30 ) are provided to the support body ( 2 ) on a particular inclined or vertical surface ( 8th ) of magnetizable material. Drive device according to one of claims 1 to 9, characterized in that at the free ends of the first and second support member ( 4a . 4b ) Floating bodies are provided, over which the support body ( 2 ) is supported on a liquid surface. Cleaning device for cleaning a surface ( 8th ), characterized by a drive device ( 1 ) according to any one of claims 1 to 11 and a surface ( 8th ) contacting cleaning element ( 34 ). Cleaning device according to claim 12, characterized in that for cleaning the surface ( 8th ) of a thin-walled sheet-like element ( 201 ), in particular a glass pane, on the support body a first magnetic holding element ( 36 ), which is generated by the planar element (FIG. 208 ) acting through magnetic attraction with one on the opposite surface ( 40 ) of the element ( 201 ) arranged second magnetic holding element ( 38 ) cooperates. Cleaning device according to claim 13, characterized in that the cleaning element ( 36 ) on one's surface ( 8th ) contacting contact surface ( 42 ) of the first magnetic holding element ( 36 ), which in turn on the support body ( 2 ) is supported. Inspection device for inspecting a surface, characterized by a drive device ( 1 ) according to one of Claims 1 to 11 and a detector which inspects the nature of the surface ( 32 ). Inspection device according to claim 15, characterized in that the frequency generator ( 12 ) the piezoelectric crystal ( 10 ) with a frequency (F1, F2, F3) which determines the surface to be inspected ( 8th ) excites to surface vibrations emitted by the detector ( 32 ) for determining the properties of the surface ( 8th ). Toy, in particular for children, characterized by a drive device ( 1 ) according to one of claims 1 to 11 and one on the supporting body ( 2 ) fixed housing ( 46 ), which supports the supporting body ( 2 ) at least partially surrounds and which in particular has the shape of a beetle or an insect, wherein the support elements ( 4a . 4b . 4c ) the legs of the turn ( 301 ) form. Drive device according to one of claims 1 to 11, characterized in that the supporting body ( 2 ) a particular triangular metal sheet or other material with angled towards one side areas ( 404a . 404b . 404c ), which supports the support elements ( 4a . 4b . 4c ) and which have a slightly different geometric shape and / or material property, and that the piezoelectric crystal ( 10 ) is preferably attached directly to the support body. Drive device according to claim 18, characterized in that the piezoelectric crystal ( 10 ) on a central portion of the support body ( 2 ), and in particular that the frequency generator ( 12 ) and / or further electronic components of the device and / or a housing ( 46 ) via rubber-elastic damping elements ( 402 ) on the support body ( 2 ).