DE102013009715A1 - Device for obtaining electrical energy - Google Patents

Abstract

The invention relates to a device (1) and a device for generating electrical energy, comprising a carrier (2) which has at least two piezoelectric elements (3) which are designed to generate an electrical voltage (2) when the carrier (2) is deformed. U1, U2), and with a seismic mass (4), which is arranged and designed in such a way that the seismic mass (4) acts on the carrier (2) by accelerating the device (1), whereby the carrier (2) can be deformed at least in sections in an S-shape, so that a turning point (W) is formed in its bending line, and the S-shaped deformation of the carrier (2) deforms the piezoelectric elements (3), as a result of which the electrical voltage (U1, U2 ) is caused.

Description

The present invention relates to a device for obtaining electrical energy from forms of energy 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 power-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 direct exposure to light.

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 each other via a consumer in order to use the electrical energy obtained.

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 enable a short-term operation of a device to be supplied. Also, an energy storage device such as a capacitor or accumulator may be a consumer in the sense of the present invention.

For energy generation, piezoelectrically active materials can be brought into a form in which an available force can attack 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. In particular, the present invention relates to the use of such tensile or compressive stress caused by bending a beam or the like, which is used to convert mechanical energy into electrical energy.

From the US 8,174,167 B2 already a system is 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 integrate energy harvesting systems later, 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. Further, the device has a seismic mass, which is arranged and formed such that by accelerating the device, the seismic mass acts on the carrier, whereby the carrier is at least partially S-shaped deformable, so that a turning point forms in its bending line, and wherein the S-shaped deformation of the carrier, the piezoelectric elements are deformed, whereby the electrical voltage is caused.

According to another aspect of the present invention, it may be provided that the carrier is clamped at at least one end, thereby enabling the S-shaped deformation of the carrier.

According to a further aspect of the present invention, it may 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 designed and arranged such that they are deformed in opposite directions during the S-shaped deformation of the carrier and generate electrical voltages with the same sign, hereinafter pair called 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 electrical voltages are generated with the same sign.

According to a further aspect of the present invention, provision can be made for a pair of piezoelectric elements to be arranged on different sides of the seismic mass, and / or for two pairs of piezoelectric elements to be arranged on different sides of the carrier, preferably so that at double-S In the case of deformable deformation of the carrier on the piezoelectric elements, electrical voltages with the same sign can be generated.

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.

Another, independently realizable aspect of the present invention relates to a device having at least two devices according to one of the preceding aspects, whose carriers are coupled together so that they form a common spring-mass system, which preferably has a resonant frequency which 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 pin-shaped or quared-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 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 vapor-deposited, sputtered, or otherwise in direct contact with the piezoelectric material, thereby forming 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 sense of the present invention merely rotated, preferably rotated by 180 degrees or turned, with different orientation of the material structure or the crystal lattice o. 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 for generating 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 support has a seismic mass arranged such that its inertia, upon acceleration of the device, leads to a preferably reversible, bending or deformation of the support. 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 be sufficiently inert in order to allow a significant bending of the carrier during acceleration of the device, for example when the device is subjected to movements of a motor vehicle. For example, the carrier and / or the piezoelectric elements themselves may at least partially form or comprise 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 "seismic mass" forming weight can therefore also have a relatively large extent in the context 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 such that, by clamping the carrier on at least one edge, a deformation of the carrier by the seismic mass is made possible, which in cross section to the carrier surface and transversely to the clamped edge at least in a portion 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 juxtaposed 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. At the clamping is preferably the boundary condition for the bending line W (x) of the carrier, the z. B. by deformation with the seismic mass, W = 0 and W '= 0 (the bending line and its first derivative are zero), in the preferred case of an immovable clamping in addition U' = 0 (the clamping is thus immovable, which is not mandatory must 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. Unlike in the case of simple, cantilevered bending 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, which will be discussed in more detail below, the carrier is clamped on opposite sides to form the S-shaped profile, the seismic mass or its center of gravity or point of application being at least substantially midway between the clamps on the carrier can. 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 such that different, preferably opposite, 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 arranged one behind the other 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 arranged on the side facing away from the clamping and / or the seismic mass sent 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 at most 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 because the piezoelectric elements or their electrodes on the same side in each case for operating a consumer in such a case can be directly connected to 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. Upon deformation, at least partially or substantially directly opposed piezoelectric elements are strained in opposite directions or modes. 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, in each case two on one of the two flat sides and two in front and two behind the turning point or of 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 same 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 each other. 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 tapped between a first pole formed by connected piezoelectric elements of a first flat side and a second pole formed by connected piezoelectric elements of an opposite, second flat side.

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 may 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 as a whole being double-S-shaped. 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 profile of the carrier can be achieved by deformation by means of the seismic mass. According to the proposal, it is then possible between a first of the restraints and the seismic mass on the same flat side to arrange two piezoelectric elements separated from each other and between the further restraint and the seismic mass or the center of gravity of these also. 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 in each case the piezoelectric elements facing away from the seismic mass or the center of gravity of the seismic mass also have the same polarities on the same flat side.

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, which may each have the same polarity with respect to the carrier 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. Thus, if the spring-mass system achieves resonant frequencies of the first mode in this frequency range, optimal energy conversion in the most common applications can be ensured.

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. Furthermore, it is possible for the poles or electrodes facing away from the carrier to be electrically connected to one another, which are braced uniformly during 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 wiring overhead can be minimized, the wiring complexity can be reduced, and thus the efficiency, cost-efficiency and reliability can be improved.

According to a further 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. It is preferred that this is provided only in a region which represents a turning point of the S-shaped curvature in S-shaped deformation of the carrier.

For the efficiency of energy production, it is advantageous if the carrier has an at least substantially continuous or uniform Having stiffness. 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 in light of the fact that in the region of the inflection point hardly to no mechanical strain of the piezoelectric element is to be expected, so at first glance, 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 when continued on the side facing away from the clamping of the inflection point or the inflection line, in particular on an opposite, second flat side of the carrier arranged piezoelectric element continues into the region of the inflection point or the inflection line and / or beyond this, the rigidity of the entire Beam 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 when exceeding the inflection point 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. In this way it can be achieved that the efficiency of the production of electrical energy due to the homogenized stiffness of the carrier is improved and this improvement is not at least partially nullified by a possible reduction in stress by contacting a region around the respective turning 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:

1 a schematic plan view of a proposed device for obtaining electrical energy according to a first embodiment;

2 a schematic cross section of a proposed device for recovering electrical energy at rest according to the first embodiment;

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

4 a section of the means for obtaining electrical energy in the deflected state according to 3 ; and

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

In the following description, the same reference numerals will be used for the same or similar elements, and the same or equivalent advantages and characteristics may be obtained even though a repeated description has been omitted.

1 shows a plan view of a proposed device for the production of electrical energy 1 with a carrier 2 ,

2 shows a section along section line II-II of the proposed device for obtaining electrical energy 1 out 1 , The carrier 2 has at least two piezoelectric elements 3A to 3H on, which are adapted to cause electrical stresses U1, U2 in mechanical stress. Further, a seismic mass 4 provided, which is arranged and designed such that when accelerating the device 1 the seismic mass 4 on the carrier 2 acts.

As in 3 illustrates, the carrier may 2 through the seismic mass 4 be deformed S-shaped at least in sections, whereby the piezoelectric elements 3A to 3H can be clamped in opposite directions. 3 shows in this context the proposed device for the production of electrical energy 1 in which the carrier 2 through the seismic mass 4 is distracted. This results in at least one section 5A and or 5B of the carrier 2 an S-shaped course, preferably a double-S-shaped course over the entire area of the sections 5A and 5B includes.

In the illustration example is the carrier 2 clamped on at least one side. For this purpose, one or more restraints 6 be provided, the rotational and / or tilting movement of the clamping 6 prevent. 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 additionally also mounted on a preferably opposite edge, particularly preferably also clamped, for which a clamping 6 can be provided. As will be shown later in more detail, this makes it possible to have a double S-shaped deformation of the carrier 2 by the action of the seismic mass 4 to reach. However, it is also possible, other storage as another abutment, support o. The like. For the wearer 2 to use with 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 illustration example is the carrier 2 clamped on two, preferably opposite, sides and the seismic mass 4 is located at least substantially midway between the restraints 6 on the carrier 2 , As a result, a symmetrical arrangement can be generated in an advantageous manner, in which a common seismic mass 4 towards each of the at least two restraints 6 each to an S-shaped course of the carrier 2 can lead.

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, without mention to the contrary in the present description with regard to the three-dimensional design of the carrier 2 be a turning line or turning plane. 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 on, which are adapted to cause tension in particular mechanical stress, compression and / or expansion, an electrical voltage. This electrical voltage, which can be generated by dielectric displacement of the surface charges, can be generated by 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 electrodes 7 or 7A1 to 7H2 called, removed or derived.

Piezoelectric elements 3A to 3H are preferably so on the carrier 2 arranged, fastened and / or form part of carrier 2 in that an S-shaped deformation of the carrier 2 through the seismic mass 4 the at least two piezoelectric elements 3A to 3H different, more preferably in opposite ways, be braced. An opposite tension between two piezoelectric elements 3A to 3H For the purposes of the present invention, 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 in such a different way that with identical material properties and identical orientation electrical voltages are generated in different directions or with different signs.

In one aspect of the present invention, the carrier is 2 clamped on at least one side or edge, with reference to the previous definition. In the illustration example, the carrier 2 clamped on two, preferably opposite, sides or edges. A two-sided clamping is particularly preferred because this allows a double-S-shaped course. As in 3 with different dashed center lines S1, S2 indicated, a two-sided clamping allows the generation of a double-S-shaped bending line of the carrier 2 from two oppositely extending S-shaped bending lines S1, S2.

Another aspect of the present invention relates to the arrangement of the piezoelectric elements 3A to 3H , A basic principle of education is that each two 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 are arranged. These piezoelectric elements 3A to 3H are preferably designed and arranged such that they are in the tension of the piezoelectric elements 3A to 3H generate in opposite manner electrical voltage with the same sign. This property is different polarity of the piezoelectric elements 3A to 3H called. This can be made possible in particular by the choice of different materials. For example, for a first of the piezoelectric elements 3A until H, a material is used which under tensile load generates a voltage with the same sign as another material in another of the piezoelectric elements 3A to H due to pressure loads. This allows voltages with the same sign by two differently mechanically strained piezoelectric elements 3A to produce H.

In the illustration example, the in 3 shown deformation, for example, the piezoelectric elements 3A compressed / pressure-locked and the piezoelectric elements 3B pulled apart. The illustrated by the deformation of the carrier 2 on the piezoelectric elements 3A and 3B acting mechanical stress is therefore opposite. The same applies to all in each case in the region of a point of inflection W on the same side or flat side of the carrier 2 adjacent piezoelectric elements 3A and 3B (first pair), 3C and 3D (second pair), 3E and 3F (third pair) as well 3G and 3H (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 configured differently such that in the present mechanical strain in opposite ways electrical voltages through the piezoelectric elements 3A and 3B or the piezoelectric elements of the other pairs can be generated, which have the same sign. This advantageously allows the electrodes 7A1 and 7B1 the piezoelectric elements 3A and 3B to connect directly with each other. The same applies to the electrodes 7C1 and 7D1 the second pair, 7E1 and 7F1 of the third pair and / or 7G1 and 7H1 of the fourth pair of piezoelectric elements 3A to 3H , This can be a consumer 10 Supply electrical energy in a simple and cost-effective way.

Piezoelectric elements 3A to 3H different polarity, which are arranged adjacent to each other, are hereinafter referred to as pairs. In particular, a pair is 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 restraint 6 arranged adjacent to each other. 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 at different mechanical strain.

In a variant is on both sides or flat sides of the carrier 2 in each case at least one pair of piezoelectric elements 3A arranged to H. These pairs may be in relation to the wearer 2 be arranged on opposite sides, as the piezoelectric elements 3A . 3B . 3E and 3F in the representation example. This allows it to pass over the seismic mass 4 to more effectively convert mechanical energy introduced into the spring-mass system into electrical energy. Particularly preferred is a symmetrical structure, as shown in the representation example. Here the carrier points 2 four pairs of piezoelectric elements 3A up to H. In this case, it is preferable that in each case two pairs of piezoelectric elements on different sides of the carrier 2 are arranged. Alternatively or additionally, it is possible that in each case one pair, preferably two pairs, of piezoelectric elements 3A to H on different sides of the seismic mass 4 are arranged. In addition, it can be provided that in each case the piezoelectric elements 3A to H of the respective pairs on different sides of the inflection points W are arranged. It is further preferred that the deformation of the carrier 2 through the seismic mass 4 compressed piezoelectric elements 3A . 3D . 3F . 3G have the same piezoelectric properties and / or the same orientation and the opposite strained piezoelectric elements 3B . 3C . 3E and 3H from the compressed piezoelectric elements 3A . 3D . 3F . 3G have such different properties that in total voltages can be tapped at all piezoelectric elements having the same sign. In the considerations of signs of electrical voltages in the context of the present invention, it is assumed that the piezoelectric elements 3A to H at least two electrodes 7 each having one with the conductive support 2 or a conductive surface of the carrier 2 connected is. The potential of the carrier 2 is assumed to be mass without restriction of generality. Therefore, the electrical voltages described each result in the carrier 2 remote electrodes 7A1 to 7H1 the piezoelectric elements 3A to H. If in the area of inflection points on the piezoelectric elements 3A to H optional auxiliary electrodes 7A3 . 7D3 . 7F3 . 7G3 are provided, these are preferably for the tapping of electrical voltages out of consideration or are not contacted.

In the embodiment described above, with respect to the carrier 2 at least substantially opposite piezoelectric elements 3 different polarities. These are at deformation of the carrier 2 then automatically loaded in different, in particular opposing way, resulting in the described electrical voltage with the same sign. This can be made possible for the power supply of a consumer 10 , Wherein also an energy store is a consumer 10 in the sense of the present invention, in each case one electrode 7A1 . 7B1 . 7C1 . 7D1 . 7E1 . 7F1 . 7G1 . 7H1 the piezoelectric elements 3A until H can be used electrically connected to each other. These can form a common node K1, K2.

In an alternative embodiment, with respect to the carrier 2 at least substantially opposite piezoelectric elements 3A to H have the same polarity. This causes, although the signs of the piezoelectric elements 3A to H generated electrical voltages on the respective side have the same sign, the sign of the piezoelectric elements 3A to H on the different sides of the vehicle 2 generated electrical voltages, however, have opposite signs.

This enables the wearer 2 remote electrodes 7 the piezoelectric elements 3A to connect H to each other on the respective side, which is the carrier 2 remote electrodes 7 the piezoelectric elements 3A to H of the different sides of the vehicle 2 but not to connect with each other. Instead, a voltage between the interconnected piezoelectric elements 3A to H of the different pages are tapped, which is greater than that from the last presented example.

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

As in 2 indicated, then a first voltage U1 can be tapped between node K1 and K0. Furthermore, it is possible to tap another voltage U2 between nodes K2 and K0. If provided is that piezoelectric elements 3A to 3H that relate to the wearer 2 at least substantially opposite each other, each having different polarities, U1 and U2 arise with the same sign. Thus, the nodes K1 and K2 can supply a consumer 10 be connected to each other and it can be a voltage supply through the common node of node K1 and node K2 opposite node K0 formed.

In an alternative, it may be provided that the piezoelectric elements 3A to H, referring to the support 2 at least substantially opposite, 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 carrier 2 facing electrodes 7A2 . 7B2 . 7C2 . 7D2 . 7E2 . 7F2 . 7G2 . 7H2 electrically connected to each other, preferably by the carrier 2 or a coating 9 of the carrier 2 , It can also be galvanically isolated coatings 9 on different sides of the vehicle 2 be provided. It is also possible, the voltage U1 between node K1 and node K0 and the voltage U2 between node K2 and node K0 to use separately. A tap of the voltage between the nodes K1 and K2, however, allows to avoid the effort to contact the node K0 separately.

4 shows a section of the proposed device 3 , It is preferably provided that on at least two opposite sides of the carrier 2 piezoelectric elements 3A to 3H are arranged. In the embodiment according to 4 are the electrodes 7A1 . 7B1 . 7E1 and 7F1 electrically connected with each other. This can be done by electrical connections 8th be realized, preferably by cables, bonds and / or by soldering, welding, more preferably by gluing with a conductive adhesive. Also the electrodes facing the wearer 7A2 . 7B2 . 7C2 . 7D2 . 7E2 . 7F2 . 7G2 . 7H2 are preferably fixed to the carrier with a conductive adhesive 2 connected, it is alternatively or additionally also soldering, welding or other connections possible.

As already explained above, it is preferred that the piezoelectric elements 3A to 3H are arranged in pairs such that in each case on one side of the carrier 2 piezoelectric elements 3A to 3H are arranged on different sides of the inflection points W of the (respective) S-shaped deformation. At the same time, however, it is preferable to have as homogeneous a rigidity as possible of the combination of carriers 2 and piezoelectric elements 3A to 3H to reach. If the carrier 2 in the region of the respective inflection point W no piezoelectric element 3A to 3H has shown that this can lead to a reduced rigidity at this point or in this area. A partial reduced stiffness has been found to be disadvantageous because such areas with lower stiffness 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. The piezoelectric elements 3A However, H to H are preferably spaced apart to avoid short circuits and to allow different materials or configurations, particularly orientations of the adjacent piezoelectric elements 3A to 3H , is enabled. For this reason, a distance between two adjacent piezoelectric elements is preferred 3A to 3H on the same side of the carrier 2 intended. This distance or gap can therefore lead to the described, reduced rigidity.

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

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

However, it is not necessary and not intended to cover the range of the respective piezoelectric element 3A . 3D . 3F . 3G , which is arranged in the region of the inflection point W or the gap opposite, also to contact electrically, since in the inflection point W no significant tension of the piezoelectric material is to be expected. In the region of the point of inflection W it can be provided that at least substantially diagonally with respect to the carrier 2 opposite piezoelectric elements 3A . 3D . 3F . 3G also in relation to the carrier plane directly or perpendicular to the carrier plane opposite or overlap. 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 presentation range 20% or less. Such overlap or overlap may occur with respect to the wearer 2 opposite pairs of piezoelectric elements 3A to 3H ensuring an at least substantially homogeneous rigidity.

As far as in the context of the present invention of opposite piezoelectric elements 3A to 3H it is not considered that such a small overlap area is considered, unless it is explicitly based on such. It is also possible that the invention is carried out without this overlapping area. It is thus differentiated between an overlap area, the overlap with respect to the support 2 opposite piezoelectric elements 3A to 3H and an "at least substantially opposite" of the piezoelectric elements, which is to be understood that the piezoelectric elements 3A to 3H transverse or perpendicular to the surface of the carrier 2 more than 50% of the carrier 2 adjacent surface of the piezoelectric elements 3A to 3H are opposite. Opposite piezoelectric elements 3A to 3H are preferably those with respect to the carrier 2 at least 60%, preferably at least 70%, overlap 75% or more in the illustrative example.

The seismic mass 4 can be at least partially by the wearer 2 and / or the piezoelectric elements 3A to 3H or be formed integrally with these. The seismic mass is preferred 4 but here on the carrier 2 arranged, in particular glued, welded, riveted or otherwise on the carrier 2 attached. The seismic mass 4 is in proportion to the elasticity and rigidity of the wearer 2 designed so that the seismic mass 4 with the carrier 2 forms a spring-mass system. For the stiffness and other mechanical properties of the wearer 2 are preferably the influences of arranged on or on this support piezoelectric elements 3A to 3H considered. So it can be formed a spring-mass system whose properties of the seismic mass 4 , from the carrier 2 and the piezoelectric elements 3A to 3H and possibly also of the type of attachment of the carrier 2 , ie in particular of the one or more 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 maximum vibration 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 has 1 shown as particularly universal and therefore advantageous because such frequencies occur in many machine and vehicle systems and thus energy production and universal use can be significantly facilitated.

5 shows a device according to another, also independently realizable aspect of the present invention, in which two carriers 2 or facilities 1 are arranged at least substantially parallel to each other. The carriers 2 can be clamped on at least one edge, particularly preferably on opposite edges. In the illustration example, there are two or more carriers 2 each clamped on the same edges. These can be clamped 6 be provided for clamping several carriers 2 are formed. In this way, in the embodiment according to 5 be accepted that several proposed facilities 1 be arranged in parallel. This allows a common seismic mass 4 to use as in 5 shown. The facilities 1 are in the representation example according to 5 So by a common seismic mass 4 interconnected. It thus becomes a common spring-mass system of several devices 1 formed, preferably by coupling, in particular by means of a common seismic mass 4 , As a result, the power density can be improved, so it can be a more compact design can be achieved by the same amount of energy can be converted with a smaller volume.

A stop may be provided to the deflection of the carrier 2 to limit. According to one aspect of the present invention, a stop may be provided which controls the deflection or movement of the seismic mass 4 limited. As in 1 implied, the seismic mass can 4 laterally over the carrier 2 protrude. The over the carrier 2 protruding parts of the seismic mass 4 can be used to seismic mass 4 for example, to lead in a backdrop. Furthermore, the over the carrier 2 protruding parts of the seismic mass 4 , in particular by stops at the end of the scenery, used to deflect the seismic mass 4 and thus the deformation of the carrier 2 and the piezoelectric elements 3A to 3H to limit and thus prevent damage in case of excessive acceleration. But there are also alternative stops to limit the deflection possible, in particular by a stop which is attached to the carrier or formed therewith, for example, a laterally projecting from the carrier strip section, which in turn can run in a backdrop with end stops. Particularly preferred is a device according to 5 in which a common seismic mass 4 several facilities 1 for this collectively 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 to 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 8th on, the electrodes 7 so with a possible consumer 10 connect, that the energy that is gained from the acceleration, can be dissipated and used. This is in 4 indicated.

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 clamps, preferably in the middle between this, the seismic mass 4 provided, in particular fixed. This results in between the seismic mass 4 and the restraints 6 Thighs or sections 5A . 5B , on each of which side piezoelectric elements 3A to 3H can be arranged.

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

Further, it is preferable that the piezoelectric elements 3A to 3H on the carrier 2 arranged, in particular fixed.

Due to the described arrangement of the piezoelectric elements of different polarity can at bending or deflection of the carrier 2 through the seismic mass 4 an equal polarized voltage across all piezoelectric elements 3A to 3H be generated. 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 on the part of the carrier, in particular by the carrier 2 or by a layer applied thereto 9 o. The like. Be electrically connected.

Further, it is preferable that the piezoelectric elements 3A to 3H per leg 5A . 5B overlap, especially in a region in the middle between the respective clamping 6 and the seismic mass 4 , As a result, joints between piezoelectric elements 3A to 3H be stabilized. This allows a uniform or homogeneous rigidity of the system.

The piezoelectric elements 3A to 3H can the carrier 2 form wholly or at least partially. For example, it is possible to use piezoelectric elements 3A to 3H to be laminated in plastic or otherwise incorporated in a carrier material. For example, there is the use of standard board material such as FR4 as a carrier 2 because board material is very inexpensive 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 are preferred 3A to 3H on the carrier 2 made of spring steel with a, in particular electrically conductive, adhesive, for example a two-component adhesive attached.

In an embodiment it can be provided that the carrier 2 is fixed at different, in particular opposite, ends or firmly clamped.

The carrier 2 can be deflected by the seismic mass 4 compressed or pulled apart to the S-shaped deformation of the wearer 2 to create and undo. The device 1 may for example have a rest position, in which the carrier 2 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 is particularly preferably formed 2 out. In particularly preferred multiple, alternating and / or continuous accelerations of the device 1 What is the rule when attached to machinery or vehicles, the seismic mass 4 regularly accelerated in different directions preferably transversely to the support surface. Here, the carrier 2 leave the rest position in different directions. The S-shape or double-S-shape is then preferably inverted in its course. Will the seismic mass 4 So accelerates in a first direction, that is, that the position of the device 1 or the restraints 6 changes, an S-shape or double S-shape of the carrier is generated and becomes the seismic mass 4 accelerated in a second, preferably opposite direction, that is, characterized in that the position of the device 1 or the restraints 6 changes in another or opposite direction, the seismic mass exercises 4 Force such that the S-shape or double-S-shape is inverted. In the course of repeated inversion of the S-shape, the rest position of the wearer 2 to be run through each.

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 a vibration of the carrier 2 , the piezoelectric elements 3A to 3H and the seismic mass 4 formed spring-mass system. 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 may have the properties of the spring-mass system described above or the properties may 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 immovable to each other. For this purpose, it can be provided that the clamping 6 are fastened or anchored in a mechanical construction, in particular a common frame. The clamping 6 Although they can not move relative to each other, the whole thing is the device 1 however, adapted to be set in motion or vibration. The seismic mass 4 then, by its inertia can cause the wearer 2 is deformed in the manner described. In particular, it is provided that the seismic mass 4 so on the carrier 2 acts that this S-shaped, in particular double-S-shaped deformed. With regard 3 Thus, by moving the entire system, the seismic mass can 4 Force on the wearer 2 exercise in such a way that this can take on alternate deflection in different directions and S-shapes or double-S shapes with opposite course. With regard to the sectional views of the 2 and 3 is based on a linear or straight course, as in 2 is shown, the carrier 2 through the seismic mass 4 deflected 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 are 3A to 3H by sticking or soldering with the carrier 2 connected.

According to a further aspect of the present invention, the device is designed, in a deflected position, the piezoelectric elements 3A to 3H inconsistent, preferably to bend in opposite directions. Different piezoelectric elements 3A to 3H the proposed facility 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 piezoelectric elements 3A . 3D . 3F . 3G when deflected by the seismic mass 4 upset and other of the piezoelectric elements 3B . 3C . 3E . 3H be stretched. With deflection of the carrier 2 through the seismic mass 4 in the opposite direction become the previously stretched piezoelectric elements 3B . 3C . 3E . 3H upset 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 section in the material of the wearer 2 , About the thickness of the material of the wearer 2 So can a certain degree of stretching or compression of the piezoelectric elements 3A to 3H be secured or set.

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

In the area of the inflection points W of the bending line of the carrier 2 in the deflected state is subject to the carrier 2 or the respectively arranged in this area piezoelectric 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 carrier 2 opposite side of the piezoelectric elements 3A to 3H no electrode is arranged or an electrode 7A3 . 7D3 . 7F3 . 7G3 arranged but not contacted. This can be prevented in an advantageous manner that charge carriers are conducted into the region of the inflection point W, a piezoelectric element 3A to 3H Thus, in the region of the inflection point W is connected to a voltage, and be it by that one electrode of the respective piezoelectric element 3A to 3H extends to the area of the inflection point W. 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 this can be reduced. It is advantageous if non-contacted electrodes 7A3 . 7D3 . 7F3 . 7G3 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 is arranged, since this possible homogeneous mechanical properties of the support 2 can be guaranteed. 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 piezoelectric generator described 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 may be based on using a carrier which is electrically conductive at least at the surface for facilitating the contacting. 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 piezo elements can z. B. by gluing or soldering to be connected to the carrier. 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 interconnected 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 possible by the electrical contact, charge carriers are conducted 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 is the Stiffness improved by 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. Thus, a very effective and stable system for converting the mechanical energy of the movement or vibration is 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 specific 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

Facility

2

carrier

3A

piezoelectric element

3B

piezoelectric element

3C

piezoelectric element

3D

piezoelectric element

3E

piezoelectric element

3G

piezoelectric element

3F

piezoelectric element

3H

piezoelectric element

4

seismic mass

5A

section

5B

section

6

clamping

7A1

electrode

7A2

electrode

7A3

electrode

7B1

electrode

7B2

electrode

7C1

electrode

7C2

electrode

7D1

electrode

7D2

electrode

7D3

electrode

7E1

electrode

7E2

electrode

7E3

electrode

7F1

electrode

7F2

electrode

7G1

electrode

7G2

electrode

7H1

electrode

7H2

electrode

7H3

electrode

8th

Electrical connection

9

coating

10

consumer

K0

node

K1

node

K2

node

U1

tension

U2

tension

W

turning point

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 8174167 B2 [0007]

Claims (10)

Facility ( 1 ) for obtaining electrical energy with a carrier ( 2 ) comprising at least two piezoelectric elements ( 3 ), which are adapted to deformation of the carrier ( 2 ) cause an electrical voltage (U1, U2), and with a seismic mass ( 4 ) arranged and formed such that by accelerating the device ( 1 ) the seismic mass ( 4 ) on the carrier ( 2 ), whereby the carrier ( 2 ) is at least partially S-shaped deformable, so that a turning point (W) forms in its bending line, and wherein by the S-shaped deformation of the carrier ( 2 ) the piezoelectric elements ( 3 ) are deformed, whereby the electrical voltage (U1, U2) is caused. Device according to claim 1, characterized in that the carrier ( 2 ) is clamped at at least one end, whereby the S-shaped deformation of the carrier ( 2 ). 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 ) are arranged adjacent and / or at least substantially on different sides of the inflection point (W), preferably by the S-shaped deformation of the carrier ( 2 ) are mechanically deformed in a contrary manner. Device according to one of the preceding claims, characterized in that the at least two piezoelectric elements ( 3 ) are arranged and arranged such that they are in the S-shaped deformation of the carrier ( 2 ) are deformed in opposite directions and generate electrical voltages (U1, U2) with the same sign, in the following pair of piezoelectric elements ( 3 ) called. Device according to claim 4, characterized in that the carrier ( 2 ) at least two pairs of piezoelectric elements ( 3 ), which on different sides, in particular flat sides, of the carrier ( 2 ) are arranged. Device according to claim 5, characterized in that the pairs of piezoelectric elements ( 3 ) are arranged and formed such that by the S-shaped deformation of the carrier ( 2 ) electrical voltages can be generated with the same sign. 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 ) on the same flat side of the carrier ( 2 ) are arranged and in particular arranged and formed such that by the double-S-shaped deformation of the carrier ( 2 ) electrical voltages (U1, U2) are generated with the same sign. 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. 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 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. Device with 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, the 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.

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