WO2014180571A1

WO2014180571A1 - Device for producing electric power

Info

Publication number: WO2014180571A1
Application number: PCT/EP2014/001241
Authority: WO
Inventors: Olaf Schulz; Zbigniew Ianelli
Original assignee: Intransid Gmbh
Priority date: 2013-05-08
Filing date: 2014-05-08
Publication date: 2014-11-13
Also published as: DE102013009715A1

Abstract

A device (1) and an apparatus for producing electric power are proposed, having a support (2), which has at least two piezoelectric elements (3) that are designed to generate an electrical voltage (U1, U2) when the support (2) is deformed, and having a seismic mass (4) that is arranged and designed such that acceleration of the device (1) prompts the seismic mass (4) to act on the support (2), as a result of which at least sections of the support (2) can be deformed in an S shape, so that a turning point (W) is formed in the bending line of said support, and wherein the S-shaped deformation of the support (2) deforms the piezo electric elements (3), as a result of which the electrical voltage (U1, U2) is generated.

Description

Device for obtaining electrical energy

The present invention relates to a device for obtaining electrical energy from energy forms that are available in the environment of the device, for example from heat, movement, solar radiation, wind or the like. In particular, the present invention relates to a device for obtaining electrical energy from an acceleration.

In the mobile use of energy-saving sensor systems, it may be possible and advantageous to reduce the energy consumption of the system, u. a. to gain occasional transmission of data directly from the environment. This makes it possible to avoid the maintenance by renewing the respective power source. Corresponding principles of converting and harnessing available energy in the environment are also called "energy harvesting". Well-known examples are solar-powered parking meters or machines in the outdoor area, which use the incident sunlight for energy supply. The present application relates primarily to the production of electrical energy from acceleration processes, in particular from movements such as vibrations during transport operations. This offers the advantage over solar systems that electrical energy can be obtained independently of a direct light effect.

In this context, it is known to use a piezo-active material to obtain electrical energy. If a force acts on such a piezoactive material or on a corresponding body made of such a material, surface charges are formed by dielectric displacement. This creates an eclectic field. On applied electrodes, this field can be tapped as a voltage. If the electrodes are connected to each other, the surface charges are equalized and a compensating current flows. The electrodes can be connected to one another via a consumer in order to use the electrical energy gained.

A consumer in the sense of the present invention is preferably a device that can receive electrical energy, in particular regardless of whether this energy is also used or only stored. Alternatively or additionally, it is thus possible to temporarily store the electrical energy obtained, in order to use it at a later time and / or to accumulate enough energy over time to allow a short-term operation of a supply to be supplied

BESTÄTiGUIMGSKOPiE Facility to enable. Also, an energy storage device such as a capacitor or accumulator may be a consumer in the sense of the present invention.

To generate energy, piezoelectrically active materials can be brought into a form in which an available force can act in a suitable manner. It is thus preferably provided that the piezoelectrically active material can be clamped in such a way that mechanical energy can be converted into electrical energy. With different piezoelectrically active materials, the piezoelectric effect can come to light with different mechanical loads. For example, there are materials in which torsion or shear results in the dielectric shift of the surface charges. In most cases, however, materials are used in which tensile or compressive stresses of the material lead to the dielectric shift of the surface charges and thus to voltage generation. In this case, the material can either be pulled apart or pulled together directly or it is loaded by a bending with tensile and / or compressive stress. The present invention particularly relates to the use of such by bending a carrier or the like. caused tensile or compressive stress, which is used to convert mechanical into electrical energy.

From US 8,174,167 B2, a system is already known that is designed as a bending beam, wherein one side of the beam is clamped and the other side is acted upon by a seismic mass. Upon acceleration of the system, the piezoceramic bending beam is deflected due to the inertia of the seismic mass, whereby the piezoelectric material is strained and an electrical voltage is generated. The known concept with a bending beam has in particular disadvantages with respect to the relatively large volume required per amount of energy, which can be converted by appropriate systems. So it is a relatively large volume accommodate, in order to convert enough energy from the environment can. However, it is regularly desired to subsequently integrate energy harvesting systems, for which a more compact design is advantageous. Furthermore, in the concrete known systems with bending beams, the aging of the respective ceramic can occur if too great an acceleration acts on the respective system. Therefore, it is an object of the present invention to provide a means for obtaining electrical energy, with a more compact, mechanically stable means for obtaining electrical energy with a greater power density, ie deliverable power per unit volume, can be achieved.

The above object is achieved by a device for obtaining electrical energy according to claim 1. Advantageous developments are the subject of the dependent claims.

The proposed device for obtaining electrical energy preferably has a flat, bendable carrier.

According to a first aspect of the present invention, an electrical energy source comprises a support having at least two piezoelectric elements adapted to generate an electrical voltage upon deformation of the support. Furthermore, the device has a seismic mass, which is arranged and formed in such a way that the seismic mass acts on the carrier by accelerating the device, whereby the carrier is S-shaped deformable at least in sections, so that a turning point forms in its bending line and wherein the S-shaped deformation of the carrier deforms the piezoelectric elements, thereby causing the electrical voltage. According to a further aspect of the present invention it can be provided that the carrier is clamped at at least one end, whereby the S-shaped deformation of the carrier is made possible.

According to a further aspect of the present invention, it can be provided that the at least two piezoelectric elements are arranged on the same side of the carrier adjacent and / or at least substantially on different sides of the inflection point, preferably by contrasting them by the S-shaped deformation of the carrier Be mechanically deformed way.

According to a further aspect of the present invention, it can be provided that the at least two piezoelectric elements are formed and arranged such that they are in the S-shaped deformation of the carrier in opposite additionally deformed and generate electrical voltages with the same sign, hereinafter called pair of piezoelectric elements.

According to another aspect of the present invention, it can be provided that the carrier has at least two pairs of piezoelectric elements which are arranged on different sides, in particular flat sides, of the carrier.

According to a further aspect of the present invention, it can be provided that the pairs of piezoelectric elements are arranged and configured such that electrical voltages with the same sign can be generated by the S-shaped deformation of the carrier.

According to a further aspect of the present invention can be provided that the carrier is double-S-shaped deformable, so that two inflection points form in its bending line, preferably wherein at least two pairs of piezoelectric elements arranged on the same flat side of the carrier and in particular arranged and formed are that by the double-S-shaped deformation of the carrier voltages are generated with the same sign.

According to a further aspect of the present invention it can be provided that in each case a pair of piezoelectric elements are arranged on different sides of the seismic mass, and / or that in each case two pairs of piezoelectric elements are arranged on different sides of the carrier, preferably so that at double S-shaped deformation of the carrier to the piezoelectric elements electrical voltages are generated with the same sign. According to a further aspect of the present invention it can be provided that the seismic mass forms with the carrier and the piezoelectric elements a spring-mass system, which preferably has a resonance frequency which is more than 10 Hz, preferably more than 25 Hz, in particular more than 35 Hz and / or less than 150 Hz, preferably less than 100 Hz, in particular less than 75 Hz.

A further, independently realizable aspect of the present invention relates to a device with at least two devices according to one of the preceding henden aspects whose carriers are coupled together so that they form a common spring-mass system, which preferably has a resonant frequency which is more than 10 Hz, preferably more than 25 Hz, in particular more than 35 Hz and / or less than 150 Hz, preferably less than 100 Hz, in particular less than 75 Hz.

A carrier in the sense of the present invention may be a flat, strip-shaped, physical structure that is at least as elastic that it can be deformed non-destructively to a certain extent. Preferably, the carrier is at least deformable such that a piezoelectric element can be clamped by the carrier deformation, so that electrical voltage is generated. By deformation, for example, due to the action of a seismic mass, the support material can be bent, forming a bending line w (x). The carrier material is standard board material such as FR4 in question. However, spring steel is preferred because of its significantly greater mechanical stability and durability. Alternatively or additionally, other preferably elastic or flexible materials may be used. In particular, the carrier may also be formed of piezoelectric material or have such.

The carrier preferably has at least two independent piezoelectric elements. Piezoelectric elements in the context of the present invention are preferably body or physical arrangements which comprise or are formed from piezoelectric material. In particular, it may be a pin-shaped or quarter-shaped, particularly preferably plate-shaped, in particular oblong, plate-shaped piezoelectrically active material. Again, the possible geometries are not limited. However, it is preferred that the piezoelectric material has at least one flat side and / or that the piezoelectric material, preferably on the flat side, for introducing a mechanical stress, in particular by the carrier, is designed for generating electrical energy.

Piezoelectric elements in the sense of the present invention preferably have at least two electrodes in order to be able to dissipate surface charges caused by deformation. Such electrically conductive electrodes may be arranged on or opposite to different flat sides of the piezoelectric element. For example, metallic materials are evaporated, tracked! or otherwise in immediate Rem contact with the piezoelectric material and thereby form one or more electrodes. It is also possible that three or more electrodes are arranged on, applied to or formed by the piezoelectric element.

In the following, a differentiation is made between the polarity of a piezoelectric element and its electrodes or also poles. The polarity of a piezoelectric element in the sense of the present invention is a property of the element formed of piezoelectric material, to generate an electrical potential difference or voltage in a certain direction between the electrodes by a certain deformation. For the purposes of the present invention, piezoelectric elements of opposite polarity are preferably those piezoelectric elements which, when deformed uniformly at their electrodes, generate voltages of different signs, preferably opposing voltages. It is possible that piezoelectric elements of opposite polarity in the context of the present invention merely rotated, preferably rotated or turned by 180 degrees, with different orientation of the material structure or the crystal lattice or the like. are executed. In the simplest case, therefore, different polarities of piezoelectric elements can be achieved by turning the arrangement. It is alternatively or additionally also possible that different materials and / or shapes or geometries are used.

The piezoelectric elements are preferably connected to the carrier in such a way that a bending of the carrier leads to a mechanical strain of the piezoelectric elements, whereby electrical voltages are caused on the piezoelectric elements. It may therefore be provided in particular that the piezoelectric elements are applied to the carrier, glued thereto or otherwise connected to it so that a bending of the carrier is transferable to the piezoelectric elements. As a result, the piezoelectric elements can be compressed or pulled apart or otherwise clamped to generate voltage, but in particular on a side facing the carrier less than on a side facing away from the carrier of the piezoelectric element. In this way, the tensile or compressive stresses of the piezoelectric material can be generated, which leads via dielectric displacement of the surface charge to generate the electrical voltage. In a variant, the piezoelectric elements could at least partially or completely form the carrier. The carrier may therefore consist of piezoelectrically active material or have such. The surface charges can be tapped with the at least two electrodes arranged on the piezoelectric material, preferably in direct electrical contact therewith, and thus the electrical energy can be utilized. For this purpose, the electrodes can be connected to a consumer.

According to the proposal, the carrier has a seismic mass which is arranged such that its inertia leads to a preferably reversible, bending or deformation of the carrier when the device is accelerated. Here, the seismic mass may be formed as any mass and / or as a weight that is attached to the carrier or formed by the carrier and / or the piezoelectric elements. But there are also alternative ways conceivable to realize a seismic mass. In particular, the seismic mass is characterized in that when accelerating the system, so the device, its inertia acts or is used. It is preferred that the seismic mass has sufficient inertia to permit significant flexing of the beam upon acceleration of the device, for example when the device is subject to movement of a motor vehicle. For example, the carrier and / or the piezoelectric elements themselves may at least partially form or have the seismic mass. In the following, the term "seismic mass" is used not only for a weight, but preferably also for its center of gravity or point of application with respect to the carrier. A weight forming a "seismic mass" can therefore also have a relatively large extent in the sense of the present invention. As far as a position of a seismic mass is concerned, therefore, the center of mass of the weight or the point of application for a weight on the carrier may be meant. If a seismic mass is provided at a certain location, then preferably no punctiform weight is meant, but an action at that location, be it in the form of an attack point or a center of gravity.

The device is preferably designed in such a way that, by clamping the carrier on at least one edge, a deformation of the carrier by the seismic mass is possible, which in cross section to the carrier surface and transversely to the clamped edge at least in a section of the carrier to an S shaped course of the carrier leads. An S-shaped course of the carrier in the context of the present invention is preferably a bending line having a turning point. The clamped carrier is thus first bent in a certain direction and in the further course, the bending direction changes, preferably in the opposite direction. As a result, a profile of the carrier can form, which has adjoining, oppositely curved sections, similar to an "S". Here, the S-shape is preferably not set to an exact order of the curvatures. The shape can thus also correspond to a rotated and / or mirrored "S". An S-shaped course of the carrier does not always have to be present. Particularly preferably, the seismic mass leads to the fact that the course of an S-shape over a straight line or elongated shape in a mirrored or inverted S-shape can be converted, and vice versa. The same applies to a double S-shape. A double S-shape preferably has at least three adjoining arc lines of different bending direction, preferably whereby at least two inflection points are formed. It is thus preferably two mirror-image juxtaposed S-forms. The term "clamping" in the sense of the present invention is preferably to be understood that an attachment of the carrier takes place such that it is secured at the attachment point at least substantially against rotation and tilting. The clamping in the sense of the present invention is therefore not limited in particular to the fact that the carrier is clamped or clamped between clamping jaws or the like, even if this constitutes a possible embodiment of the present invention. The carrier may for example also be glued, welded or formed together with a carrier spanning element, wherein the clamping is not necessarily associated with a clamping operation o. The like. It is thus preferably a clamping in the mechanical or static sense. Preferably, at the chuck, the boundary condition for the beamline W (x) of the beam, which may vary, for example, by deformation with the seismic mass, W = 0 and W = 0 (the bendline and its first derivative are zero), in the preferred case an immovable clamping additionally U '= 0 (the clamping is thus immovable, which does not necessarily have to be the case).

According to the proposed system of clamped carrier and seismic mass is designed such that upon acceleration of the device by the inertia of the mass, a force acts on the carrier and this is thereby deformed. Contrary to simple cantilever beams, according to the present invention, however, this does not result in a continuous, continuous bending line, but in an S-shaped profile in cross-section, in particular perpendicularly, for clamping the carrier. In a particularly preferred embodiment, in the As will be discussed in more detail below, the carrier is clamped on opposite sides to form the S-shaped profile, wherein the seismic mass or its center of gravity or point of application may be at least substantially midway between the clamps on the carrier. But there are also other forms of implementation possible, for example, a simple support on the side facing away from the clamping side of the seismic mass o. The like.

It is further provided that the piezoelectric elements are arranged on the same flat side of the carrier spaced from each other. The at least two different piezoelectric elements are therefore preferably non-contact or spaced apart from each other. The piezoelectric elements may be arranged and connected to the carrier in such a way that different, preferably opposing, mechanical stresses on the piezoelectric elements can be produced by the S-shaped deformation.

Furthermore, it is preferred that at least one of the piezoelectric elements is arranged on the carrier between the clamping and the seismic mass. In particular, at least two piezoelectric elements are arranged behind one another between the clamping and the seismic mass. It is further preferred that this is a point of inflection between the restraint and the seismic mass. The S-shape is thus preferably formed between clamping and seismic mass by the carrier, in particular when the seismic mass exerts force on the carrier.

If the carrier is deformed in an S-shape by the force of the seismic mass, a point of inflection results in the course of the carrier, and consequently in a preferred strip-shaped carrier a turning line or plane transverse to the longitudinal extent of the carrier. Consequently, the carrier is convexly deformed on the same side of the flat side between the restraint and the inflection point concave and on the side facing away from the instep of the inflection point, or vice versa. This can be used to exert different, preferably opposite, mechanical stresses on the two different piezoelectric elements, as soon as the carrier is deformed by the seismic mass S-shaped. It can be provided that the first piezoelectric element between the clamping and the inflection point and / or on the side facing away from the seismic mass of the inflection point is arranged. The second piezoelectric element may be on the side facing away from the clamping and / or the seismic be arranged mixing mass zugwandten side of the inflection point. Hereby it can be achieved that one of the piezoelectric elements is compressed by the concave deformation of the carrier and at the same time the other piezoelectric element is stretched by convex deformation of the carrier. It should again be emphasized that it is possible and intended that the S-shape may change and also invert by the action of the seismic mass. It is therefore possible that, in particular in a rest position, the carrier has no curvature. The position of the turning points is then the one where a turning point would result with infinitesimal effect of the seismic mass.

The carrier is preferred, but not necessarily provided as a flat strip. However, the invention may be practiced with a carrier having a round, square, rectangular, triangular, part-circular, or otherwise shaped cross-section. However, preference is given to a strip-shaped carrier material or a plate-shaped material, in particular in thin sheet metal or a thin plate having a rectangular base area and / or cross-sectional area, since such has proved to be advantageous for reliable and inexpensive production. For example, the ratio of length and / or cross section to thickness or thickness of the carrier is not more than 1:10, preferably less than 1:20 or 1:30, in particular 1/50 or less. For example, the ratio of length to cross section is more than 2: 1, preferably more than 3: 1, in particular more than 4: 1.

According to one aspect of the present invention, provision can be made for voltages with different signs to be produced on the piezoelectric elements during an imaginary continuous bending of the carrier, referred to below as different polarity of the piezoelectric elements. In this case, it is fictitiously assumed that the carrier is deformed continuously as in the case of a bending beam, ie the two piezoelectric elements are uniformly pressurized either both in tension or both. The different polarity of the piezoelectric elements in this case means that with the same or similar deformations between corresponding electrodes or poles of the piezoelectric elements voltages of different signs are generated. Due to the fact that different or at least opposite mechanical stresses on the piezoelectric elements can be caused by the S-shaped deformation of the carrier during operation of the device, electrical voltages with the same sign can be generated on the piezoelectric elements. This is particularly advantageous since the piezoelectric electrical elements or their electrodes can be connected to each other on the same side for operating a consumer in such a case directly with each other. According to a further aspect of the present invention it can be provided that in each case a pair with at least two spaced apart piezoelectric elements are arranged on different flat sides of the carrier so that in the S-shaped deformation of the carrier opposite mechanical stresses on the piezoelectric elements of the respective pairs can be generated.

It is thus possible that piezoelectric elements are provided between the clamping and the point of inflection or the turning line or turning plane of the carrier on both flat sides of the carrier. In a deformation, at least partially or essentially directly opposite piezoelectric elements are strained in opposite directions or ways. The same applies if piezoelectric elements are arranged on both sides of the carrier on the side facing away from the clamping point of the inflection point or the inflection line or turning plane. In particular, therefore, at least four piezoelectric elements can be arranged on the carrier, two each on one of the two flat sides and two in front of and two behind the turning point or the turning line or turning plane. Also in this case, it is particularly preferable that the piezoelectric elements located on one side have opposite polarities. As a result, at least the electrodes or poles of the piezoelectric elements can each be connected to one another on one of the flat sides of the carrier.

According to a first very particularly preferred embodiment, the piezoelectric elements adjacent to the respective flat side of the carrier are of different or opposite polarity, but the opposite polarity with respect to the carrier surface or carrier plane. In this case, with S-shaped deformation of the carrier by all the piezoelectric elements of the respective side, a voltage of the same sign is generated. Thus, it is possible to use the poles or electrodes of the piezoelectric elements electrically connected to each other. As a result, an uncomplicated, robust and cost-effective design are made possible in an advantageous manner. According to a second very particularly preferred embodiment, the piezoelectric elements adjacent to the respective flat side of the carrier are of different or opposite polarity, and which are at least substantially opposite with respect to the carrier surface or carrier plane are also of different or opposite polarity. In this case, with S-shaped deformation of the carrier by all the piezoelectric elements, a voltage of the same sign is generated. Thus, it is possible to use the poles or electrodes of the piezoelectric elements electrically connected to each other. As a result, an uncomplicated, robust and cost-effective design are made possible in an advantageous manner.

In general, it can be provided that the carrier is coated in an electrically conductive or electrically conductive manner, so that the carrier in each case connects one of the poles or an electrode of each individual one of the piezoelectric elements to one another. Alternatively or additionally, however, it is also possible for the carrier to electrically connect only the piezoelectric elements on one of the two flat sides to one another. Further, it is possible that the carrier of each of the piezoelectric elements which are arranged on this, in each case a pole or an electrode connects to each other, but not itself serves for connection. Instead, it may be possible that the carrier electrically connects the piezoelectric elements on one of the flat sides of the carrier with those on the opposite flat side of the carrier to a series circuit. In this case it is preferred that in each case with respect to the carrier plane at least substantially opposite elements have the same polarity. As a result, adjacent piezoelectric elements on the same flat side still generate voltages with the same sign due to different polarities, but the signs of the voltages generated on the different flat sides are contradictory. This makes it possible to generate a double voltage between the respectively not connected to the electrical carrier poles or electrodes of the piezoelectric elements on the different flat sides due to the series connection. The piezoelectric elements of the respective flat sides are thus connected to one another by a pole or an electrode through the carrier, and the voltage can be removed between the respective other poles or electrodes of the piezoelectric elements of the different flat sides. The piezoelectric elements of the respective flat sides can also be electrically connected to one another here per flat side. The voltage can then be between a first pole formed by connected piezoelectric elements of a first flat side and a second th, are tapped by connected piezoelectric elements of an opposite, second flat side formed pole.

According to a further aspect of the present invention, provision can be made for a pair each having at least two piezoelectric elements arranged at a distance from one another to be arranged on different sides of the seismic mass or the center of gravity or point of application of the seismic mass. Furthermore, the carrier can be deformable by the seismic mass on different sides of these seismic dimensions or the center of gravity of the seismic mass in each case in an S-shape or in a double-S-shape overall. As a result, it is possible to mechanically clamp the piezoelectric elements of the respective pair in opposite directions. It is optionally possible that two pairs of piezoelectric elements have a common piezoelectric element, that is, two pairs are composed of a total of three piezoelectric elements.

For example, the carrier can be clamped on both sides and the seismic mass between the restraints, in particular in the center. This results in that between the restraint and the seismic mass an S-shaped course of the carrier can be achieved by deformation by means of the seismic mass. According to the proposal, it is then possible to arrange two piezoelectric elements separately between a first one of the clampings and the seismic mass on the same flat side and likewise between the further clamping and the seismic mass or the center of gravity thereof. Furthermore, it can be provided that the piezoelectric elements of the respective pair have different polarities. As already explained above, it can thereby be achieved that, despite the respectively different mechanical stresses, electrical voltages with the same sign can be generated.

In the event that the device is designed so that the carrier in each case takes an S-shaped course under the effect of the seismic mass on both sides of the seismic mass, the same sign of the voltages can thus also be achieved. For this purpose, it is particularly preferred that each of the seismic mass or the center of gravity of the seismic mass facing elements on the same flat side have the same polarities. Alternatively or additionally, it is preferred that each of the seismic mass or Focusing the seismic mass facing away from piezoelectric elements on the same flat side also have the same polarities.

In addition, it is preferred that piezoelectric elements with opposite polarities are respectively arranged on opposite flat sides. In this way, it can be achieved that the poles or electrodes, which are not connected to the carrier, of the piezoelectric elements generate voltages in the same direction or with the same sign. In a further alternative, it is possible that the piezoelectric elements respectively facing the seismic mass and the piezoelectric elements facing away from the seismic mass have different polarities on the same flat side. This may apply to the piezoelectric elements of both flat sides, each of which may have the same polarity with respect to the carrier's opposite positions of the flat sides. This leads to voltages of opposite sign being generated on the different flat sides. In such a case, a double voltage between the non-connected to the carrier poles or electrodes of the piezoelectric elements of the different flat sides can be removed. Therefore, at least the free, so not connected to the carrier, electrodes of the piezoelectric elements of the respective flat sides are electrically connected to each other. This significantly facilitates the design, construction and durability or reliability of the device. According to another aspect of the present invention, the seismic mass may form a spring-mass system with the carrier and the piezoelectric element. This is particularly preferred because upon excitation at the resonant frequency, more preferably the first mode, a relatively strong vibration can be achieved. This allows for strong accelerations or changes in the tensile and compressive loading of the piezoelectric elements in a continuous or recurring manner. It is particularly preferred that a resonance frequency of the spring-mass system is achieved which is higher than 10 Hz, preferably higher than 25 Hz, in particular higher than 35 Hz and / or lower than 150 Hz, preferably lower than 100 Hz, in particular lower than 75 Hz. At these frequencies, especially in the frequency range between 50 and 55 Hz, vibrations and noises in the movement of land vehicles such as plows, trucks, cars, etc. are preferred. If the spring-mass system thus resonant frequencies of the first mode in this frequency range ranges, optimal energy conversion can be ensured in the most common application areas.

According to another aspect of the present invention, it can be provided that the carrier is designed to be electrically conductive, for example by an electrically conductive coating or the like, and that the piezoelectric elements each have a pole facing the carrier or an electrode facing the carrier the carrier are electrically connected to each other. It is also possible that the poles or electrodes facing away from the carrier of such piezoelectric elements are electrically connected to one another, which are clamped uniformly in a deformation of the carrier by the seismic mass. This general rule allows operation of the device even when the piezoelectric elements are not polarized in the manner previously described or all have the same polarization. However, the above-described configurations are preferred because in such cases, the overhead of wiring can be minimized, the wiring complexity can be reduced and thus the efficiency, cost-efficiency and reliability can be improved.

According to another aspect of the present invention, it may be provided that a piezoelectric element of pairs of piezoelectric elements arranged on opposite flat sides of the carrier is arranged and arranged such that it faces both piezoelectric elements of the pair of piezoelectric elements arranged on the opposite flat side of the carrier. In this case, it is preferred that this is provided only in a region which, in the case of an S-shaped deformation of the carrier, represents a point of inflection of the S-shaped curvature.

For the efficiency of energy generation, it is advantageous if the carrier has an at least substantially continuous or uniform rigidity. Between two adjacent to one side of the carrier, forming a pair of piezoelectric elements, due to the fact that they should not be connected to each other, a portion of the carrier is not covered with piezoelectric material on this flat side. The same applies preferably to the opposite flat side, if there are also arranged piezoelectric elements. For the efficiency disadvantageous, therefore, has shown a configuration in which in the region of the inflection point of the S-shaped deformation on any of the flat sides piezoelectric material is present. This also and especially against the background that in the area of the inflection point hardly to no mechanical tension of the is expected at first glance, then the continuation of a piezoelectric element in the region of the inflection point or the inflection line of the carrier makes little sense. Surprisingly, however, it has been found that if a piezoelectric element is further developed on a first flat side, in particular on the side of the inflection point or the inflection line facing the clamping, into the region and / or past the inflection point, and / or If, on the side of the inflection point or the inflection line facing away from the clamping, in particular on an opposite, second flat side of the carrier, the piezoelectric element continues into the region of the inflection point or the inflection line and / or continues beyond this, the rigidity the entire carrier is much more homogeneous and thereby the efficiency of energy production can be significantly improved. Since in the region of the point of inflection hardly a voltage generation of mechanical and electrical nature is to be expected or is expected at exceeding the point of inflection even with an opposite mechanical and electrical voltage, it is preferred that the one electrode on the side facing away from the carrier of the respective piezoelectric Elements in this region of the inflection point (s) are not metallized or at least only metallized in isolation from the other electrodes and / or not connected and / or short-circuited to the carrier. It can thereby be achieved that the efficiency of the generation of electrical energy due to the homogenized stiffness of the carrier is improved and this improvement is not at least partially reversed by a possible reduction in stress by contacting a region around the respective inflection point of the S-shape. Because this area beyond the inflection point can be opposite to the rest of the respective piezoelectric element clamped and thus at least partially compensate for the effect or voltage.

A further aspect of the present invention, which can also be implemented independently, relates to a device with two proposed devices for obtaining electrical energy, in which the carriers are arranged at least substantially parallel to one another. For the facilities, a common seismic mass may be provided. The common seismic mass can interconnect or couple the devices. It goes without saying that three, four, five or more means for obtaining electrical energy according to the above description, at least substantially parallel to each other and can be operated with one or more common seismic masses. According to another aspect of the present invention, the seismic mass or masses may be used to form a stop for limiting the deflection of the carrier or carriers. It can be provided that a seismic mass, in particular between two or more means for obtaining electrical energy or between two or more carriers, is arranged such that they protrude beyond the respective carrier and in this preferably laterally beyond the carrier protruding area further stops are provided to limit the deflection of the carrier.

Further aspects, details, features, properties and advantages of the present invention will become apparent from the claims and from the drawings and the following description of preferred embodiments of the inventive device for obtaining electrical energy. In the drawing shows:

Fig. 1 is a schematic plan view of a proposed device for

Obtaining electrical energy according to a first embodiment;

FIG. 2 shows a schematic cross-section of a device according to the invention for obtaining electrical energy at rest according to the first embodiment; FIG.

3 shows a schematic cross-section of a proposed device for obtaining electrical energy in the state deflected by the seismic mass according to the first embodiment;

4 shows a section of the device for obtaining electrical energy in the deflected state according to FIG. 3; FIG. and

Fig. 5 shows a schematic cross section of a device with two means for obtaining electrical energy.

In the following description, the same reference numerals are used for the same or similar elements, the same or corresponding advantages and Properties can be achieved, even if a repeated description has been omitted.

1 shows a plan view of a proposed device for obtaining electrical energy 1 with a carrier 2.

Fig. 2 shows a section along section line II-II of the proposed device for obtaining electrical energy 1 of Fig. 1. The carrier 2 has at least two piezoelectric elements 3A to 3H, which are adapted to mechanical stresses on voltages U1, U2 cause. Further, a seismic mass 4 is provided, which is arranged and designed such that upon acceleration of the device 1, the seismic mass 4 acts on the carrier 2. As illustrated in FIG. 3, the carrier 2 can be deformed S-shaped at least in sections by the seismic mass 4, whereby the piezoelectric elements 3A to 3H can be clamped in opposite directions. Fig. 3 shows in this connection the proposed device for obtaining electrical energy 1, in which the carrier 2 is deflected by the seismic mass 4. As a result, at least in a section 5A and / or 5B of the carrier 2, an S-shaped course, preferably a double-S-shaped course over the entire area, which comprises the sections 5A and 5B.

In the illustrated example, the carrier 2 is clamped on at least one side. For this purpose, one or more restraints 6 may be provided which prevent a rotational and / or tilting movement on the clamping 6. This makes it possible that the first and preferably also the second derivative of the bending line of the carrier 2 at the clamping 6 is zero. Preferably, the carrier 2 is also also mounted on a preferably opposite edge, particularly preferably also clamped, for which a clamping 6 may be provided. As will be shown in more detail later, it is thereby possible to achieve a double-S-shaped deformation of the carrier 2 by the action of the seismic mass 4. However, it is also possible to use another bearing such as another counter-bearing, support o. The like. For the carrier 2 to the seismic mass 4, the at least partially S-shaped course of the carrier 2 when deflected by the seismic mass 4 to reach. In the illustrated example, the carrier 2 is clamped on two, preferably opposite, sides, and the seismic mass 4 is located at least substantially centrally between the clamps 6 on the carrier 2. In this way, a symmetrical arrangement can be produced in which a common seismic mass 4 in the direction of each of the at least two restraints 6 can each lead to an S-shaped course of the carrier 2.

An S-shaped course in the sense of the present invention is preferably any course or bend line having a point of inflection W. A turning point W in the sense of the present invention may be a turning line or turning plane with respect to the three-dimensional design of the carrier 2 without mention to the contrary in the present description. For the sake of simplicity, however, only the term inflection point W is used below, even if it can correspond to a turning line or turning plane.

The carrier 2 has at least two piezoelectric elements 3A to 3H, which are designed to cause an electrical voltage during clamping, in particular mechanical clamping, compression and / or expansion. This electrical voltage, which can be generated by dielectric displacement of the surface charges, can be conducted from the respective piezoelectric element 3A to 3H via at least two electrodes or 7A1, 7A2, 7A3, 7B1, 7B2, 7C1, 7D2, 7E1, 7E2, 7E3, 7F1, 7F2, 7G1, 7G2, 7G3, 7H1 and 7H2, hereinafter also referred to as electrodes 7 or 7A1 to 7H2, are removed or derived.

Piezoelectric elements 3A to 3H are preferably arranged, fixed and / or form part of carrier 2 in such a way that an S-shaped deformation of the carrier 2 by the seismic mass 4, the at least two piezoelectric elements 3A to 3H different, more preferably in in opposite directions, be tightened. Contrary bracing of two piezoelectric elements 3A to 3H in the sense of the present invention is in particular a mechanical stress with opposite sign, a tensile stress against a compressive stress, a torsion in different directions or any other mechanical stress on two piezoelectric elements 3A to 3H to such different Way that with identical material properties and identical orientation electrical voltages are generated in different directions or with different signs. According to one aspect of the present invention, the carrier 2 is clamped on at least one side or edge, with reference to the previous definition. In the illustrated example, the carrier 2 is clamped on two, preferably opposite, sides or edges. A two-sided clamping is particularly preferred, since this allows a double-S-shaped course. As indicated in FIG. 3 with different dashed center lines S1, S2, a two-sided clamping enables the generation of a double-S-shaped bend line of the carrier 2 from two oppositely extending S-shaped bend lines S1, S2.

Another aspect of the present invention relates to the arrangement of the piezoelectric elements 3A to 3H. A fundamental principle of formation is that two each are arranged on piezoelectric elements on the same flat side of the carrier 2 adjacent and / or on the same side of the carrier 2 at least substantially on different sides of the respective inflection point W of the S-shaped curve S1, S2 , These piezoelectric elements 3A to 3H are preferably formed and arranged so as to generate electric voltage of the same sign in opposition to the stress of the piezoelectric elements 3A to 3H. This property is called different polarity of the piezoelectric elements 3A to 3H. This can be made possible in particular by the choice of different materials. For example, for a first one of the piezoelectric elements 3A to H, a material which generates a voltage of the same sign under tensile stress as another material in another one of the piezoelectric elements 3A to H due to compressive loads may be used. This allows voltages with the same sign to be generated by two differently mechanically strained piezoelectric elements 3A to H. In the illustrated example, by the deformation shown in Fig. 3, for example, the piezoelectric element 3A is compressed / pressure-stressed and the piezoelectric element 3B is pulled apart. The mechanical stress acting on the piezoelectric elements 3A and 3B as a result of the illustrated deformation of the carrier 2 is therefore opposite. The same applies to all piezoelectric elements 3A and 3B (first pair), 3C and 3D (second pair), 3E and 3F (third pair), and 3G and 3H (adjacent to each other in the region of a point of inflection W on the same side or flat side of the carrier 2). fourth pair). Further, it is preferable that the piezoelectric elements 3A and 3B or the respective piezoelectric elements of the other pairs are so differently constructed or arranged, have different materials or are otherwise differently arranged such that, in the present mechanical stress, electrical voltages are applied in opposite ways by the piezoelectric elements 3A and 3B or the piezoelectric elements Elements of the other pairs can be generated that have the same sign. This advantageously makes it possible to connect the electrodes 7A1 and 7B1 of the piezoelectric elements 3A and 3B directly to each other. The same applies to the electrodes 7C1 and 7D1 of the second pair, 7E1 and 7F1 of the third pair, and / or 7G1 and 7H1 of the fourth pair of the piezoelectric elements 3A to 3H. Thus, they can provide a consumer 10 in a simple and cost-effective manner together with electrical energy.

Piezoelectric elements 3A to 3H of different polarity, which are arranged adjacent to one another, are referred to below as pairs. In particular, a pair is arranged adjacent to one another in the region of a point of inflection W and / or on the same side or flat side of the carrier 2 and / or between the seismic mass 4 and the clamping 6. Such a pair of piezoelectric elements 3A to 3H is preferably characterized in that the piezoelectric elements 3A to 3H of the pair have different polarities and thus can generate electrical voltages with the same sign under different mechanical stress.

In a variant, at least one pair of piezoelectric elements 3A to H is arranged on both sides or flat sides of the carrier 2. These pairs may be arranged on opposite sides with respect to the carrier 2, such as the piezoelectric elements 3A, 3B, 3E and 3F in the illustrated example. This makes it possible to more effectively convert the mechanical energy introduced via the seismic mass 4 into the spring-mass system into electrical energy. Particularly preferred is a symmetrical structure, as shown in the representation example. Here, the carrier 2 has four pairs of piezoelectric elements 3A to H. In this case, it is preferable for two pairs of piezoelectric elements to be arranged on different sides of the carrier 2. Alternatively or additionally, it is possible that in each case one pair, preferably two pairs, of piezoelectric elements 3A to H are arranged on different sides of the seismic mass 4. In addition, it can be provided that in each case the piezoelectric elements 3A to H of the respective pairs are arranged on different sides of the inflection points W. It is further preferred that the at a Deformation of the carrier 2 by the seismic mass 4 compressed piezoelectric elements 3A, 3D, 3F, 3G have the same piezoelectric properties and / or the same orientation and the oppositely strained piezoelectric elements 3B, 3C, 3E and 3H of the compressed piezoelectric see elements 3A, 3D, 3F, 3G have properties that are so different that, on the whole, piezoelectric elements can be tapped off voltages that have the same sign. In the consideration of signs of electrical voltages in the context of the present invention, it is assumed that the piezoelectric elements 3A to H have at least two electrodes 7, one of which is connected to the conductive carrier 2 or a conductive surfaces of the carrier 2. The potential of the carrier 2 is assumed to be ground without loss of generality. Therefore, the described electrical voltages result in each case on the electrodes 7A1 to 7H1 of the piezoelectric elements 3A to H facing away from the carrier 2. If optional auxiliary electrodes 7A3, 7D3, 7F3, 7G3 are provided in the area of the inflection points on the piezoelectric elements 3A to HH , These remain preferably for the tapping of electrical voltages out of consideration or are not contacted. In the embodiment described above, at least substantially opposite piezoelectric elements 3 have different polarities with respect to the carrier 2. These are then automatically loaded in different, in particular opposing, manner when the support 2 is deformed, which leads to the described electrical voltage with the same sign. In this way it can be made possible for the power supply of a load 10, wherein an energy storage device can also represent a consumer 10 in the sense of the present invention, to have in each case one electrode 7A1, 7B1, 7C1, 7D1, 7E1, 7F1, 7G1. 7H1 of the piezoelectric elements 3A to H can be used electrically connected to each other. These can form a common node K1, K2.

In an alternative embodiment, at least substantially opposite piezoelectric elements 3A to H may have the same polarity with respect to the carrier 2. As a result, although the signs of the electric voltages generated by the piezoelectric elements 3A to H on the respective side have the same sign, the signs of the electric voltages generated by the piezoelectric elements 3A to H on the different sides of the carrier 2 are opposite Sign. This makes it possible to connect the electrodes 7 of the piezoelectric elements 3A to H on the respective side facing away from the carrier 2, but not to connect the electrodes 7 of the piezoelectric elements 3A to H of the different sides of the carrier 2 facing away from the carrier 2. Instead, a voltage between the interconnected piezoelectric elements 3A to H of the different sides can be tapped, which is greater than that of the last presented example.

A corresponding interconnection is shown in Fig. 2, wherein electrodes of the respective piezoelectric elements 3A to H are electrically connected to each other on the respective sides of the carrier 2. By connecting the electrodes 7A1, 7B1, 7C1, 7D1 facing away from the carrier of the piezoelectric elements 3A, 3B, 3C, 3D on one of the sides of the carrier 2, a node K1 can be formed. On another side of the carrier 2, the electrodes 7E1, 7F1, 7G1, 7H1 facing away from the carrier 2 can be electrically connected to each other, whereby a node K2 can be formed. The electrodes 7A2, 7B2, 7C2, 7D2, 7E2, 7F2, 7G2, 7H2 facing the carrier 2 can likewise be electrically connected to one another, in particular via the carrier 2 or a conductive layer of the carrier 2, and / or form a reference node K0.

As indicated in FIG. 2, a first voltage U1 can then be tapped between nodes K1 and K0. Furthermore, it is possible to tap another voltage U2 between nodes K2 and K0. If it is provided that piezoelectric elements 3A to 3H, which are at least essentially opposite one another with respect to the carrier 2, each have different polarities, U1 and U2 result with the same sign. Thus, the nodes K1 and K2 for supplying a load 10 can be connected to each other and a voltage supply can be formed by the common node of node K1 and node K2 opposite node K0.

In an alternative, it can be provided that the piezoelectric elements 3A to H, which are at least essentially opposite one another with respect to the support 2, have the same polarities. This results in the described S-shaped deformation voltages of different signs on the respective opposite sides. In this case, a voltage between the nodes K1 and K2 may be used, alternatively or additionally with reference node K0, whereby a symmetrical voltage with respect to node K0 can be generated. For this purpose, it is preferred that the electrodes 2 facing the carrier 2 7A2, 7B2, 7C2, 7D2, 7E2, 7F2, 7G2, 7H2 are electrically connected to each other, preferably by the carrier 2 or a coating 9 of the carrier 2. It can also galvanically isolated coatings 9 are provided on different sides of the carrier 2. It is also possible to use the voltage U 1 between node K1 and node K0 as well as the voltage U2 between node K2 and node K0 separately. A tap of the voltage between the nodes K1 and K2, however, allows to avoid the effort to contact the node K0 separately. FIG. 4 shows a section of the device according to the invention from FIG. 3. It is preferably provided that piezoelectric elements 3A to 3H are arranged on at least two opposite sides of the carrier 2. In the embodiment according to FIG. 4, the electrodes 7A1, 7B1, 7E1 and 7F1 are electrically interconnected. This can be realized by electrical connections 8, preferably by cables, bonds and / or by soldering, welding, more preferably by gluing with a conductive adhesive. Also, the electrodes facing the carrier 7A2, 7B2, 7C2, 7D2, 7E2, 7F2, 7G2, 7H2 are preferably fixedly connected to the carrier 2 with a conductive adhesive, there are alternatively or additionally also soldering, welding or other connections possible.

As already explained above, it is preferable that the piezoelectric elements 3A to 3H are arranged in pairs so that piezoelectric elements 3A to 3H are respectively disposed on different sides of the inflection points W of (respective) S-shaped deformation on one side of the carrier 2 , At the same time, however, it is preferable to achieve the most homogeneous possible rigidity of the combination of carrier 2 and piezoelectric elements 3A to 3H. If the carrier 2 has no piezoelectric element 3A to 3H in the region of the respective inflection point W, it has been found that this can lead to reduced rigidity at this point or in this region. A partial reduced stiffness has been found to be disadvantageous because such areas with less rigidity stronger and thus the areas with piezoelectric elements 3A to 3H can be deformed weaker. As a result, less mechanical energy is converted, which reduces the efficiency. However, the piezoelectric elements 3A to H are preferably spaced apart to avoid short circuits and to allow different materials, particularly orientations of the adjacent piezoelectric elements 3A to 3H, to be made possible. For this reason, a distance between two adjacent piezoelectric elements 3A to 3H is preferably on the same Side of the carrier 2 is provided. This distance or gap can therefore lead to the described, reduced rigidity.

According to a further, also independent realizable aspect of the present invention, such disadvantages are avoided in that a piezoelectric element 3A to 3H is arranged or continued on a gap of the opposite side of the carrier 2, so that the gap between two on one side of the carrier 2 adjacent piezoelectric elements 3A to H on the opposite side relative to the carrier 2 is preferably covered by a piezoe- lectric element 3A to 3H. This way, I can guarantee rigidity even in the gap area in a simple and effective way.

In the illustrated embodiment, a piezoelectric element 3A, 3D, 3F, 3G of each pair of piezoelectric elements 3A to 3H is guided over the inflection point W in each case. Thus, a piezoelectric element 3A to 3H is respectively provided on a side opposite a gap associated with a pair of piezoelectric elements 3A to 3H with respect to the carrier 2, which extends into the region of the gap on an opposite side of the gap, preferably over the entire gap , in particular surmounted.

However, it is not necessary or even intended to electrically contact the region of the respective piezoelectric element 3A, 3D, 3F, 3G, which is disposed opposite to the point of inflection W or the gap, since at the point of inflection W there is no substantial distortion of the piezoelectric material neck is to be expected. In the region of the point of inflection W, it may be provided that piezoelectric elements 3A, 3D, 3F, 3G lying opposite each other at least substantially diagonally with respect to the carrier 2 also lie opposite or overlap with respect to the carrier plane directly or perpendicularly to the carrier plane. However, this overlapping area particularly preferably forms only a small portion of the respective piezoelectric element 3A, 3D, 3F, 3G, preferably less than 40%, in particular less than 30 or 15%, in the display area 20% or less. By means of such overlapping or overlapping, an at least substantially homogeneous rigidity can be ensured in the case of pairs of piezoelectric elements 3A to 3H opposite the carrier 2.

As far as in the context of the present invention of opposite piezoelectric elements 3A to 3H is mentioned, such a small overlap remains unless explicitly stated. It is also possible that the invention is carried out without this overlapping area. Thus, a differentiation is made between an overlapping area which involves an overlap with respect to the support 2 of opposite piezoelectric elements 3A to 3H and an "at least substantially opposite" of the piezoelectric elements, by which it is to be understood that the piezoelectric elements 3A to 3H are transverse or are perpendicular to the surface of the support 2 more than 50% of the voltage applied to the carrier 2 surface of the piezoelectric elements 3A to 3H opposite. Opposing piezoelectric elements 3A to 3H are preferably those which overlap with respect to the carrier 2 at least 60%, preferably at least 70%, in the embodiment 75% or more.

The seismic mass 4 may be at least partially formed by the carrier 2 and / or the piezoelectric elements 3A to 3H or integrally therewith. However, the seismic mass 4 is preferably arranged here on the carrier 2, in particular adhesively bonded, welded, riveted or otherwise fastened to the carrier 2. The seismic mass 4 is designed in relation to the elasticity and rigidity of the carrier 2 so that the seismic mass 4 forms a spring-mass system with the carrier 2. For the rigidity and the other mechanical properties of the carrier 2, the influences of the piezoelectric elements 3A to 3H arranged on or on this carrier are preferably taken into account. Thus, it is possible to form a spring-mass system whose properties differ from the seismic mass 4, from the carrier 2 and the piezoelectric elements 3A to 3H and possibly also from the way in which the carrier 2 is fastened, that is to say in particular from FIG the one or the restraints 6 depends. The described spring-mass system preferably has a resonant frequency in the range between 1 Hz and 1000 Hz, preferably with the proviso that the resonant frequency is as close as possible to oscillation maxima of the respective application in order to ensure particularly efficient energy production. In particular, it is preferred that the spring-mass system has a resonant frequency which is more than 10 Hz, preferably more than 25 Hz, in particular more than 35 Hz and / or less than 150 Hz, preferably less than 100 Hz, in particular less than 75 Hz, is. With a resonant frequency in the range around 50 Hz or 55 Hz, for example between 40 and 65 Hz, particularly preferably between 52 and 62 Hz, the scope of the proposed device 1 has been found to be particularly universal and therefore advantageous, since such frequencies in many machine and vehicle systems occur and thus an energy production and universal use can be significantly facilitated.

5 shows a device according to another aspect of the present invention, which can also be implemented independently, in which two carriers 2 or devices 1 are arranged at least substantially parallel to one another. The carriers 2 can be clamped on at least one edge, particularly preferably on respectively opposite edges. In the illustrated example, two or more carriers 2 are respectively clamped on the same edges. For this purpose, clamping means 6 can be provided, which are designed to clamp a plurality of carriers 2. In this way, in the exemplary embodiment according to FIG. 5, it can be assumed that a plurality of proposed devices 1 are arranged in parallel. This makes it possible to use a common seismic mass 4 as shown in FIG. The devices 1 are thus connected to each other in the illustration of FIG. 5 by a common seismic mass 4. Consequently, a common spring-mass system is formed from a plurality of devices 1, preferably by coupling, in particular by means of a common seismic mass 4. In this way, the power density can be improved, so that a more compact design can be achieved by the one with smaller volume of construction the same amount of energy can be converted.

A stop may be provided to limit the deflection of the carrier 2. According to one aspect of the present invention, a stop may be provided which limits the deflection or movement of the seismic mass 4. As indicated in FIG. 1, the seismic mass 4 can protrude laterally beyond the carrier 2. The parts of the seismic mass 4 projecting beyond the carrier 2 can be used to guide the seismic mass 4, for example in a scenery. Furthermore, the parts of the seismic mass 4 projecting beyond the carrier 2, in particular by stops at the end of the guide, can be used to limit the deflection of the seismic mass 4 and thus the deformation of the carrier 2 and of the piezoelectric elements 3A to 3H and thus to prevent damage if the acceleration is too high. However, alternative stops for limiting the deflection are also possible, in particular by means of a stop which is attached to or formed with the carrier, for example a section projecting laterally from the carrier strip, which in turn can run in a slot with end stops. Particular preference is given to a device according to FIG. 5, in which a common seismic see mass 4 of several facilities 1 for this together forms a stop.

The device 1 can be designed to store energy. For example, it is possible to connect the nodes K1 and / or K2 with an energy store such as a rechargeable battery, capacitor or the like in order to accumulate enough energy to be able to carry out occasional measurement operations or the like. The device therefore preferably has electrical connections 8, which connect electrodes 7 with a possible consumer 10 in such a way that the energy which is obtained from the acceleration can be dissipated and utilized. This is indicated in Fig. 4.

An independently realizable aspect of the present invention relates to a device for obtaining electrical energy 1, in which the carrier 2 is clamped on two sides. Between the restraints, preferably centrally between this, the seismic mass 4 may be provided, in particular fixed. This results between the seismic mass 4 and the clamping 6 leg or sections 5A, 5B, on each side piezoelectric elements 3A to 3H may be arranged.

It can be provided that the piezoelectric elements 3B, 3C, 3F, 3G facing the seismic mass 4 have different, in particular opposing, polarities compared to the outer piezoelectric elements 3A, 3D, 3E, 3H facing the restraints 6.

It is further preferred that the piezoelectric elements 3A to 3H are arranged on the carrier 2, in particular fixed.

As a result of the described arrangement of the piezoelectric elements of different polarity, an equally polarized voltage can be generated at all piezoelectric elements 3A to 3H when the carrier 2 is bent or deflected by the seismic mass 4. Here, it can be provided that the carrier side of the piezoelectric elements 3A to 3H or a carrier-side electrode of the respective piezoelectric elements 3A to 3H form a common reference point or node K0. For this purpose, the piezoelectric elements may be electrically connected by the wearer, in particular by the support 2 or by a layer 9 or the like applied thereto. Further, it is preferable that the piezoelectric elements 3A to 3H overlap each leg 5A, 5B, particularly in an area midway between the respective restraint 6 and the seismic mass 4. As a result, joints between piezoelectric elements 3A to 3H can be stabilized. This allows a uniform or homogeneous rigidity of the system.

The piezoelectric elements 3A to 3H can form the carrier 2 completely or at least partially. For example, it is possible to laminate piezoelectric elements 3A to 3H in plastic or otherwise introduce them into a carrier material. For example, the use of standard board material such as FR4 as carrier 2 is an option, since board material is very cost-effective and can have sufficient flexibility. It is also possible to use other printed circuit board material or other elastic materials. However, particularly preferred is the use of metal, in particular of spring steel, beryllium bronze as the material for the carrier 2. A carrier 2 made of spring steel is much more resistant, both against corrosion and against aging. The piezoelectric elements 3A to 3H are preferably fastened to the carrier 2 made of spring steel with an adhesive, in particular an electrically conductive adhesive, for example a two-component adhesive.

In one embodiment, provision may be made for the carrier 2 to be fixed or firmly clamped at different, in particular opposite, ends.

The carrier 2 can be compressed or pulled apart when deflected by the seismic mass 4 in order to generate and reverse the S-shaped deformation of the carrier 2. The device 1 may for example have a rest position, in which the carrier 2 is at least substantially straight or flat. Once the device 1 is accelerated, the inertia of the seismic mass acts on the carrier 2 and deforms it. In this case, the S-shaped or double-S-shaped form of the carrier 2 is particularly preferably formed. In particularly preferred multiple, alternating and / or continuous accelerations of the device 1, which is the rule when mounted on machines or vehicles, the seismic mass 4 is accelerated regularly in different directions preferably transversely to the support surface. In this case, the carrier 2 can leave the rest position in different directions. The S-shape or double-S-shape is then preferably inverted in its course. If the seismic mass 4 is thus accelerated in a first direction, that is to say in that the position of the device 1 or the clampings 6 changes, an S Shape or double-S-shape of the carrier generates and accelerates the seismic mass 4 in a second, preferably opposite direction, ie the fact that changes the position of the device 1 and the clamping 6 in a different or opposite direction exercises the seismic mass 4 force such that the S-shape or double S-shape is inverted. In the course of the repeated inversion of the S-shape, the rest position of the carrier 2 can be traversed in each case.

As a result, an alternating voltage can be generated, which can preferably be rectified and / or stored. The regular inversions of the S-shape or double-S-shape preferably correspond to vibration of the spring-mass system formed by the carrier 2, the piezoelectric elements 3A to 3H and the seismic mass 4. The inversion of the S-shape can be used to alternately tension and compress the respective piezoelectric elements and thus to generate different, preferably alternating voltages.

The generated voltage U1, U2 can have the properties of the spring-mass system described above or the properties can be transferred to the generated voltage U1, U2. Thus, the voltage U1, U2 may have a frequency between 1 and 1000 Hz, more than 10 Hz, preferably more than 25 Hz, in particular more than 35 Hz and / or less than 150 Hz, preferably less than 100 Hz, in particular less than 75 Hz. With a frequency in the range of 50 Hz or 55 Hz, for example between 40 and 65 Hz, particularly preferably between 52 and 62 Hz, therefore, a particularly high efficiency can be achieved, as described above.

It is preferred that the restraints 6 are immovable relative to each other. For this purpose, it may be provided that the restraints 6 are fastened or anchored in a mechanical construction, in particular a common frame. Although the grips 6 can not move relative to each other, the device 1 is overall designed to be set in motion or vibration. The seismic mass 4 can then lead by its inertia that the carrier 2 is deformed in the manner described. In particular, it is provided that the seismic mass 4 acts on the carrier 2 in such a way that it is deformed in an S-shape, in particular double-S-shaped. With reference to FIG. 3, therefore, the seismic mass 4 can exert force on the carrier 2 by movement of the entire system in such a way that, in the event of alternating deflection, it can exert its force on the carrier 2. Different directions can also assume S-forms or double S-forms with opposite course. With reference to the sectional views of FIGS. 2 and 3, starting from a linear or straight course, as shown in FIG. 2, the carrier 2 can be deflected by the seismic mass 4 in different or opposite directions. This results in different S-shaped or double S-shaped deflections of the carrier. 2

According to one aspect of the present invention, the piezoelectric elements 3A to 3H are bonded to the carrier 2 by sticking or soldering.

According to another aspect of the present invention, the device is configured to non-uniformly, preferably in opposite directions, bend the piezoelectric elements 3A to 3H in a deflected position. Different piezoelectric elements 3A to 3H of the proposed device 1 can thus form opposite arches or curved lines.

At the joint of the arches, a neutral, undeformed point is formed, which is also called inflection point W. The opposite arcs forming the described S-shape are responsible for some of the piezoelectric elements 3A, 3D, 3F, 3G being compressed when deflected by the seismic mass 4 and others of the piezoelectric elements 3B, 3C, 3E, 3H being stretched become. When the carrier 2 is deflected by the seismic mass 4 in the opposite direction, the previously stretched piezoelectric elements 3B, 3C, 3E, 3H are compressed and the previously compressed piezoelectric elements 3A, 3D, 3F, 3G are stretched.

There may be a neutral fiber in which neither stretching nor compression occurs. This is particularly preferably in the middle of the center in the material of the carrier 2. Thus, over the thickness of the material of the carrier 2, a certain degree of stretching or compression of the piezoelectric elements 3A to 3H can be ensured or adjusted.

Adjacent piezoelectric elements 3A to 3H are preferably oppositely polarized, which can be done by different orientation and / or different material terialwahl.

In the region of the points of inflection W of the bending line of the carrier 2 in the deflected state, the carrier 2 or the piecing respectively arranged in this region is subject to zoelektrische element 3A to 3H hardly a deformation. Thus, this area hardly contributes to the generation of electrical energy. According to one aspect of the present invention, it is provided that in the region of the inflection points W at least on the side facing away from the carrier 2 of the piezoelectric elements 3A to 3H no electrode is arranged or indeed an electrode 7A3, 7D3, 7F3, 7G3 arranged, but not contacted , In this way, it can be advantageously prevented that charge carriers are conducted into the region of the point of inflection W, ie a piezoelectric element 3A to 3H is connected to a voltage in the region of the point of inflection W, and that is that one electrode of the respective piezoelectric element 3A until 3H into the area of the inflection point W protrudes. It has surprisingly been found that the piezoelectric element 3A to 3H stiffen in the region of the inflection point W by the piezoelectric effect and the efficiency of the proposed device 1 can be reduced thereby. It is advantageous if non-contacted electrodes 7A3, 7D3, 7F3, 7G3 are arranged in the region of the inflection points W isolated from the remaining electrodes on the same side of the piezoelectric element 3A to 3D on the piezoelectric element 3A to 3H, since this is possible homogeneous mechanical properties of the carrier 2 can be ensured. In addition, it is advantageous for the production if the electrode coating in the region of the inflection points W is not completely omitted. However, this is also possible as an alternative.

In the following, alternative or additional aspects of the present invention are explained:

The described piezoelectric generator is preferably based on clamping a carrier on two sides. The restraints can be fixed points, between which, typically in the middle, a seismic mass can be attached. On different sides of the seismic mass legs of the carrier may result, wherein on the two legs per side two piezo elements can be arranged. These piezoelectric elements are preferably mounted inside with opposite polarity as outside. This results in the type of bending of the system, an equal polarized stress on all elements, if the side of the carrier is considered a common reference point. The piezoelectric elements per leg preferably overlap in the middle and thus stabilize the joints, so that as uniform a rigidity of the system results. According to one aspect of the present invention, both ends are fixed and a force is applied between these fixed points. This results in a mechanically very stable construction. However, the conditions of the bend are significantly different from those of a simple bending beam.

A proposed system for generating energy by means of piezoelectric elements can be based on using a carrier which is electrically conductive at least at the surface for facilitating the contact. The two ends of the carrier are in particular fixed. According to another aspect of the present invention, the points are anchored in the mechanical construction and do not move relative to the other elements and to each other. A mass may be secured between the fixed ends. With this mass, the resonance frequency can be influenced in connection with the parameters of the carrier. Piezo elements are attached to the surface of the carrier. This is in contrast to the normal bending beam constructions not an element on one side of the carrier, but preferably by two. This may be a peculiarity of this construction. The piezoelectric elements can be connected to the carrier, for example by gluing or soldering on. If the system described is in a deflected position, the piezo elements are preferably not uniformly bent. Rather, two opposite arcs are preferably formed which, depending on the geometry of the construction, may or may not have the same conditions. At the junction of the two arches always a neutral undeformed place arises. The opposite arches are responsible for stretching one part of the piezo elements while upsetting the other. The construction is very effective in that a neutral fiber or the area in the material, which is neither pulled nor compressed, lies in the carrier material. This effectively loads the elements on both sides of the carrier. However, when an element is stretched, the charge separation occurs exactly opposite to the ratios as when it is compressed. The resulting voltage is therefore opposite. This explains the separation of the piezoelectric elements into two partial elements per side. These are polarized opposite, in particular polarized opposite polarity. This again results in a same polarization in the voltage in the type of bending and the individual elements can be electrically connected very easily. The electrical interconnection of the elements is preferably such that, at the point of bending, a region results which does not or hardly undergoes deformation. This does not contribute to the generation of energy. However, if this is due to the electrical contact is possible, charge carriers are directed into this area. Due to the reverse piezoelectric effect, this area then stiffens and reduces the energy that can be tapped off. Therefore, these non-energy generating areas are preferably electrically separated. It is possible that there are areas on the piezoceramic in which the free electrode is contacted and there are areas that are separated from it and in which the electrode is not contacted. This ensures that the mechanical conditions in the bending of the system remain simple and predictable. A complete removal of the ceramic in these areas would have the consequence that these areas have a lower rigidity than the areas with piezoceramic. These areas without Piezokeramik could thus be less force, so easier to deform. As a result, the whole construction would bend mainly at the places where no piezoceramic is applied. Against this background, it is preferable to achieve a uniform or at least essentially unchangeable rigidity over the entire bending beam. It is thus preferably ensured that as far as possible all areas have the same rigidity. This can be achieved by reinforcing the entire surface with piezoceramic. However, it is contrary to the fact that according to the description two ceramics should be applied per side, since the polarity of the two parts is opposite. In terms of design, it is therefore preferable to ensure that parts or sections of the carrier without ceramic are kept as small as possible. In the middle part of the stiffness is improved by the fact that the ceramics on the upper side and the lower side do not meet in the same place, but offset. So at least at the weakened spot is always a ceramic throughout. In addition, the structure can be chosen so that the gap between the ceramics is as small as possible.

In principle, a proposed sheet metal or support with piezoceramic elements can be used by itself, but to improve the overall stability, it is good to arrange two sheets or supports in parallel with piezoceramic elements and to concentrate the mass between the two sheets. This embodiment has some advantages in terms of mechanical stability. By the leadership of the mass within the two support plates, the possibility of tilting sideways and thus to perform a 3D movement is reduced. As a result, the formation of the oscillation perpendicular to the carrier plates is so strongly preferred that the oscillation forms in this plane and there also attacks the total mechanical energy. This is a very effective and stable system for converting the mechanical energy of motion or vibration possible. For mechanical limitation of the deflection, the mass may be provided with two pins, which preferably engage in a guide in the lateral support. There is thus a mechanical stop which mechanically protects the system from excessive deflection. This also ensures that the yield strength of the piezoelectric elements is not exceeded and they are always operated within their mechanical working range.

Further aspects of the present invention relate to a system for obtaining electrical energy from kinetic energy using the piezoelectric effect and a corresponding material, wherein the piezoceramics are applied to a piezoelectrically passive carrier. This carrier is fixed at both ends. The seismic mass is located between these fixed points. The ceramic is divided on each resulting page. In this case, the ceramic, which adjoins the fixed points, polarized exactly negative to the ceramic, which are facing the seismic mass. The ceramics are formed and arranged such that the ceramics located on both sides of the support overlap. The system may be characterized in that certain parts of the ceramics are electrically separated from the other regions around the inflection point of the forming bend. The system may be characterized in that the carrier material is a spring steel whose coefficient of expansion corresponds approximately to that of the ceramic. The system may be characterized in that the seismic mass is located midway between the fixed ends for ease of relationships. The system may be characterized in that, in a special embodiment, two carriers arranged with piezo elements are arranged parallel to one another and the seismic mass is located between these two carriers. The system may be characterized in that the seismic mass has on each side two pins, which engage in a respective guide in the lateral mounting wall and has a mechanical stop for the deflection of the mass. LIST OF REFERENCE NUMBERS

1 device 7D3 electrode

2 carriers 7E1 electrode

3A piezoelectric element 7E2 electrode

3B piezoelectric element 7E3 electrode

3C piezoelectric element 30 7F1 electrode

3D piezoelectric element 7F2 electrode

3E piezoelectric element 7G1 electrode

3G piezoelectric element 7G2 electrode

3F piezoelectric element 7H1 electrode

3H piezoelectric element 35 7H2 electrode

4 seismic mass 7H3 electrode

5A Section 8 Electrical Connection 5B Section 9 Coating

6 clamping 10 consumers

7A1 electrode 40

7A2 electrode K0 node

7A3 electrode K1 node

7B1 electrode K2 node

7B2 electrode

7C1 electrode 45 U1 voltage

7C2 electrode U2 voltage

7D1 electrode

7D2 electrode W inflection point

Claims

claims:

A device (1) for obtaining electrical energy with a carrier (2), which has at least two piezoelectric elements (3), which are adapted to cause an electrical voltage (U1, U2) upon deformation of the carrier (2), and with a seismic mass (4) which is arranged and formed in such a way that the seismic mass (4) acts on the carrier (2) by acceleration of the device (1), whereby the carrier (2) is at least partially S-shaped deformable such that a turning point (W) forms in its bending line, and the piezoelectric elements (3) are deformed by the S-shaped deformation of the carrier (2), thereby causing the electric voltage (U1, U2).

2. Device according to claim 1, characterized in that the carrier (2) is clamped on at least one end, whereby the S-shaped deformation of the carrier (2) is made possible.

3. Device according to one of the preceding claims, characterized in that the at least two piezoelectric elements (3) on the same side of the carrier (2) adjacent and / or at least substantially on different sides of the inflection point (W) are arranged, preferably so that they are mechanically deformed by the S-shaped deformation of the carrier (2) in a contrary manner.

4. Device according to one of the preceding claims, characterized in that the at least two piezoelectric elements (3) are formed and arranged such that they are deformed in the S-shaped deformation of the carrier (2) in opposite directions and electrical Generate voltages (U1, U2) with the same sign, hereinafter called pair of piezoelectric elements (3).

5. Device according to claim 4, characterized in that the carrier (2) has at least two pairs of piezoelectric elements (3) which are arranged on different sides, in particular flat sides, of the carrier (2).

6. Device according to claim 5, characterized in that the pairs of piezoelectric elements (3) are arranged and designed such that through the S-shaped deformation of the carrier (2) electrical voltages can be generated with the same sign.

7. Device according to one of claims 4 to 6, characterized in that the carrier (2) is double-S-shaped deformable, so that two inflection points (W) form in its bending line, preferably wherein at least two pairs of piezoelectric elements (3) arranged on the same flat side of the carrier (2) and in particular arranged and designed such that by the double-S-shaped deformation of the carrier (2) electrical voltages (U1, U2) are generated with the same sign.

8. Device according to claim 7, characterized in that in each case a pair of piezoelectric elements (3) on different sides of the seismic mass (4) are arranged, and / or that in each case two pairs of piezoelectric elements (3) on different sides of the carrier (2) are arranged

Preferably, so that in double-S-shaped deformation of the carrier (2) on the piezoelectric elements (3) electrical voltages (U1, U2) are generated with the same sign.

9. Device according to one of the preceding claims, characterized in that the seismic mass (4) with the carrier (2) and the piezoelectric elements (3) forms a spring-mass system, which preferably has a resonant frequency exceeding 10 Hz, preferably more than 25 Hz, in particular more than 35 Hz and / or less than 150 Hz, preferably less than 100 Hz, in particular less than 75 Hz.

10. A device having at least two devices (1) according to one of the preceding claims, whose carrier (2) are coupled together such that they form a common spring-mass system, which preferably has a resonant frequency, which is more than 10 Hz , preferably more than 25 Hz, in particular more than 35 Hz and / or less than 150 Hz, preferably less than 100 Hz, in particular less than 75 Hz.