Title:
Piezoelectric power generator
Kind Code:
A1


Abstract:
In order to provide a piezoelectric generating apparatus which ensures by one-time beating an electricity generation of more than dozens of times an output current that a piezoelectric generating apparatus with a conventional steel ball produces, a piezoelectric generating apparatus 1 comprises a piezoelectric ceramic boy 10; a cushion member 3 which supports the piezoelectric ceramic body 10 in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic body 10 to other structure; and a beating means 20 which has an impact on the piezoelectric ceramic body 10, the beating means 20 further comprising a hammer body 21, an elastic body 24 boosting the hammer body 21 in a direction of separating from the piezoelectric ceramic body 10 in the ordinary state and a switch member 27 changing a boosting direction of the elastic body 24.



Inventors:
Sakai, Yasuhiro (Tokyo, JP)
Application Number:
10/546957
Publication Date:
10/12/2006
Filing Date:
12/22/2003
Assignee:
USC CORPORATION (Tokyo, JP)
Primary Class:
International Classes:
H01L41/113; E05B45/06; F03G7/06; F03G7/08; G08B13/16; H02N2/18; E05B47/00; E05C3/04
View Patent Images:
Related US Applications:
20080252180Electricity Generating Playground Equipment and MethodOctober, 2008Markham
20050082942Combined power sourceApril, 2005Shirley
20070040466Electric machine with an induction rotorFebruary, 2007Vollmer
20060261700Method of making armature and power tool; electric motor and armature thereforNovember, 2006Du et al.
20090256440Actuator with electrical equipment enclosed in a separate enclosure made of a fire resistantOctober, 2009Kragh et al.
20060071561Electromagnetic power deviceApril, 2006Chiu et al.
20020084710Line start permanent magnet motorJuly, 2002Worley et al.
20100090561PROJECTING POLE ROTOR COMPRISING COIL END SUPPORT PLATES AND ROTARY ELECTRIC MACHINE COMPRISING ONE SUCH ROTORApril, 2010Leroy et al.
20100059056BRUSHLESS DC MOTOR WITH BEARINGSMarch, 2010Sears et al.
20100033053BRUSH DEVICE FOR MOTORFebruary, 2010Kimura et al.
20020101128Electric motor comprising a rotor mounted on one sideAugust, 2002Christian Weihrauch



Primary Examiner:
BUDD, MARK OSBORNE
Attorney, Agent or Firm:
KRATZ, QUINTOS & HANSON, LLP (WASHINGTON, DC, US)
Claims:
1. (canceled)

2. (canceled)

3. (canceled)

4. A piezoelectric generating apparatus, which applies a distortion or deformation on the plate-shaped piezoelectric ceramic body to generate electricity, comprising: a pair of piezoelectric ceramic bodies; a cushion member which supports the piezoelectric ceramic bodies in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic bodies to other structure; a pendulum body which swings via a vertical elastic body by beating; a pair of horizontal elastic bodies which is fixed to the both ends of the vertical elastic body and elongated in a direction where the horizontal elastic body orthogonally crosses the vertical elastic body; and a hard beating means which is fixed to each distal end of the pair of horizontal elastic bodies respectively, alternately beating the pair of piezoelectric ceramic bodies and having an impact on the piezoelectric ceramic bodies, wherein, when the pendulum body swings, a beating action that one of the pair of beating bodies beats one of the pair of piezoelectric ceramic bodies and a separating action that other of the pair of beating bodies separates from other of the pair of piezoelectric ceramic bodies are alternately repeated in straight succession.

5. A piezoelectric generating apparatus according to claim 4, wherein the vertical elastic body is made of a rectangle-shaped plate spring and the pair of horizontal elastic bodies is made of a column-shaped bar spring.

6. A piezoelectric generating apparatus according to claim 4, wherein, when the pendulum body swings, an intermittent mechanism is constituted that alternately repeats in straight succession a beating action and a separating action in which the pair of horizontal elastic bodies actuates each beating body to beat on or separate from each piezoelectric ceramic body.

7. A piezoelectric generating apparatus according to claim 4, wherein the piezoelectric generating apparatus is connected with the resonance vibrator.

8. A piezoelectric generating apparatus, which applies a distortion or deformation on the plate-shaped piezoelectric ceramic body to generate electricity, comprising: at least a piezoelectric ceramic body; a cushion member which supports the piezoelectric ceramic body in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic body to other structure; a base member which is formed of a spring member; a horizontal elastic body which is fixed to the vertical portion of the base member; and a hard beating body which is fixed to the both ends of the horizontal elastic body and beats the piezoelectric ceramic body to have an impact on the piezoelectric ceramic body, wherein the piezoelectric generating apparatus is constituted so that, if an external force is given to the beating bodies, other of the beating bodies continuously repeats a vertical vibration by resonance.

9. A piezoelectric apparatus according to claim 8, wherein the horizontal elastic bodies are fixed to the base member at a position of same distance from the base member and the beating bodies to be fixed to the both ends of the base member are of almost same shape and weight.

10. A piezoelectric generating apparatus according to claim 8, wherein a connection of the horizontal elastic body with the base member is integrated by either means of screw cramp, caulking, adhesive material or welding.

11. A piezoelectric generating apparatus according to claim 5, wherein the piezoelectric generating apparatus is connected with the resonance vibrator.

12. A piezoelectric generating apparatus according to claim 6, wherein the piezoelectric generating apparatus is connected with the resonance vibrator.

13. A piezoelectric generating apparatus according to claim 9, wherein a connection of the horizontal elastic body with the base member is integrated by either means of screw cramp, caulking, adhesive material or welding.

Description:

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a piezoelectric generating apparatus which can generate an output current more than dozens of times a volume with using a conventional piezoelectric ceramic element.

2. Background Art

A piezoelectric material has a variety of applications as a transducer between a mechanical energy and an electric energy. A large number of materials of both inorganic material and organic material are known as a material, which represents a piezoelectric effect, and a piezoelectric ceramic such as PZT (piezoelectric ceramic) is a material currently available in practical use.

The piezoelectric ceramic element is a device having a piezoelectric property caused by applying a direct current high voltage to a polycrystal so as to produce a residual polarization. Since the piezoelectric ceramic element can vary a basic piezoelectric constant depending on composition, the piezoelectric ceramic element has a wide application. The piezoelectric ceramic element of zinc zirconium titanate ceramic, especially, has a wide choice range of a composition ratio and an adhesive material and has a variety of applications.

By the way, the conventional piezoelectric generating apparatus is formed by a substrate of an acrylic, material or the like connected with a piezoelectric ceramic element plate, and fixing both ends of the substrate with a holder made of a hard material such as a metal. Then, a ball made of steel is dropped from the ceramic element plate so as to apply a mechanical impact energy by collision onto the piezoelectric ceramic plate, and a flexural vibration is energized on the piezoelectric ceramic element plate including the substrate, thereby picking up an electric energy.

Here, we explain a piezoelectric ceramic element of the PZT which has been used since long and is applied to the invention of Japanese Patent Disclosure No.2001-145375 and others.

Although the piezoelectric ceramic element of the PZT above described is expected for a practical use, since an amount of electric energy is little, it is a problem that the piezoelectric ceramic element lacks a practical use. Key reasons for the problem are that (1) for a piezoelectric generating apparatus using a piezoelectric ceramic element of this kind it is essential to maintain a characteristic vibration of the piezoelectric ceramic element plate so long as it can and (2) what strong and effective impact can be given on the piezoelectric ceramic element.

However, in the conventional piezoelectric generating apparatus, the characteristic vibration of the piezoelectric ceramic element plate has not a supporting structure without accompanying a mechanical resistance and in many cases, for example, as shown in the patent reference 1, the piezoelectric generating apparatus is structured so that a steel ball has an impact on the piezoelectric ceramic element. In order to generate a sufficient electric energy, there is currently no way other than colliding as many as possible of the steel balls on the piezoelectric ceramic element.

The present invention has been attained and an object thereof is to provide a piezoelectric generating apparatus which is capable of assuring by one-time beating a generation of an output current of more than dozens of times a volume by using a piezoelectric generating apparatus using a conventional steel ball.

Another object of the present invention is to provide a piezoelectric generating apparatus which is capable of assuring an electric power generation at practical level by parallelly using a means which allows automatic repeat of the beat, for example, such as electricity for cellular phone or an electric source for life buoy or the like.

SUMMARY OF THE INVENTION

In view of the above object, a first aspect of the present invention provides a piezoelectric generating apparatus which applies a distortion or deformation on a plate-shaped piezoelectric ceramic body to generate electricity, comprising: the piezoelectric ceramic body; a cushion member which supports the piezoelectric ceramic body in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic body to other structure; and a beating means which has an impact on the piezoelectric ceramic body, the beating means comprising a hammer body and a switch member actuating the hammer body in a beating direction, wherein, when the hammer body beats the piezoelectric ceramic body, the switch member is structured so as to transmit a boosted power of an elastic body on the hammer body.

A second aspect of the present invention provides a piezoelectric generating apparatus that, in order to continuously obtain the beating, the switch member is connected with a pendulum body and constructed so that a performance of the switch member controls an on- and off-actuation by swing energy of the pendulum body, or a third aspect of the present invention provides a piezoelectric generating apparatus which is connected with a resonance vibrator formed of a spring member and the like.

Further, a fourth aspect of the present invention provides an piezoelectric generating apparatus which applies a distortion or deformation on the plate-shaped piezoelectric ceramic body to generate electricity, comprising: a pair of piezoelectric ceramic bodies; a cushion member which supports the piezoelectric ceramic bodies in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic bodies to other structure; a pendulum body which swings via a vertical elastic body by beating; a pair of horizontal elastic bodies which are fixed on the both ends of the vertical elastic body and elongated in a direction where the horizontal elastic body orthogonallly crosses the vertical elastic body; and a hard beating means which is fixed to each distal end of the pair of horizontal elastic bodies respectively, alternately beating the pair of piezoelectric ceramic bodies and having an impact on the piezoelectric ceramic bodies, wherein, when the pendulum body swings, a beating action that one of the pair of beating bodies beats one of the pair of piezoelectric ceramic bodies and a separating action that other of the pair of beating bodies separates from other of the pair of piezoelectric ceramic bodies are alternately repeated in straight succession.

Further, a fifth aspect of the present invention provides a piezoelectric generating apparatus, wherein, in order to continuously obtain a beating of the pendulum body the vertical elastic body is, for example, made of a rectangle-shaped plate spring and the pair of horizontal elastic bodies is made of a column-shaped bar spring. Moreover, a sixth aspect of the present invention provides a piezoelectric generating apparatus, wherein, when the pendulum body swings, an intermittent mechanism is produced that alternately repeats in straight succession a beating action and a separating action in which the pair of horizontal elastic bodies actuates each beating body to beat or separate from each piezoelectric ceramic body.

Moreover, any one of aspects fourth to sixth of the present invention provides a piezoelectric generating apparatus which is formed so as to obtain a continuous beating, in a manner that a seventh aspect of the present invention provides a piezoelectric generating apparatus which is connected with the resonance vibrator.

An eighth aspect of the present invention provides a piezoelectric generating apparatus which applies a distortion or deformation on the plate-shaped piezoelectric ceramic body to generate electricity, comprising as other means for continuously obtaining an beat on the beating body: at least a piezoelectric ceramic bodies; a cushion member which supports the piezoelectric ceramic body in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic body to other structure; a base member which is formed of a spring member; a horizontal elastic body which is fixed to the vertical portion of the base member; and a hard beating body which is fixed to the both ends of the horizontal elastic body and beats the piezoelectric ceramic body to have an impact on the piezoelectric ceramic body, wherein the piezoelectric generating apparatus is constituted so that, if one of the beating bodies is received an external force, other of the beating bodies continuously repeats a vertical vibration by resonance.

In this case, a ninth aspect of the present invention provides a piezoelectric generating apparatus, wherein the horizontal elastic bodies are fixed to the base member so as to keep a same distance from the base member and the beating body being fixed to the both ends of the base member are formed in approximately same shape and weight. Furthermore, a tenth aspect of the present invention provides a piezoelectric generating apparatus, wherein a joint between the horizontal elastic body and the basic member is integrated by one of screw cramp, caulking, adhesive material or welding.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective illustration showing the schematic structure of a piezoelectric generating apparatus according to the embodiment 1 of the present intention.

FIG. 2 is a side view of the piezoelectric generating apparatus.

FIG. 3 is a schematic diagram showing a beating means of the piezoelectric generating apparatus according to the embodiment 2.

FIG. 4 is a schematic diagram showing the piezoelectric generating apparatus connected with a resonance vibrator according to the embodiment 3.

FIG. 5 is a circuit diagram showing an example of a battery charger of the piezoelectric generating apparatus.

FIG. 6 is a schematic, block diagram showing a piezoelectric generating apparatus according to the embodiment 4 of the invention.

FIG. 7A is a waveform chart showing a pendulum body and a displacement magnitude of a pair of beating bodies of the piezoelectric generating apparatus according to the embodiment 4.

FIG. 7B is a waveform chart showing a pendulum of the piezoelectric generating apparatus of the embodiment 4 and a speed of a pair of beating bodies.

FIG. 8 is a circuit diagram of a piezoelectric generating apparatus measuring electric power generation according to the embodiment 4.

FIG. 9 is a graph showing the electricity generated by the measuring circuit of piezoelectric generating apparatus of the embodiment 4.

FIG. 10 is a schematic diagram showing a schematic structure of a piezoelectric generating apparatus according to the embodiment 5 of the invention.

FIG. 11 is a graph showing an electric power generation of a piezoelectric generating apparatus according to the embodiment 3 which is measured by using a same measuring circuit as the measuring circuit shown in FIG. 8.

BEST MODE FOR CARRYING OUT THE INVENTION

This invention will be described hereinafter in detail based on embodiments as shown in attached figures.

FIG. 1 and FIG. 2 show a piezoelectric generating apparatus 1 according to the embodiment 1 of the present invention. The piezoelectric generating apparatus 1 is comprised of: a container 8; a piezoelectric ceramic body 10 being set on a vertical wall upper part 8a of the container 8; a cushion member which supports the piezoelectric ceramic body 10 in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic body 10 to other structure; and a beating means 20 having an impact on the piezoelectric ceramic body 10.

Not shown in the figure, but on the center of the beating face of the piezoelectric ceramic body 10 a protector plate (not shown) may be fixed.

The piezoelectric ceramic body 10 having coincident form (same material, same shape and same thickness) is composed of two plate-shaped piezoelectric ceramic elements 10a and 10b and a metal electrode 11. Polarity of the polarization of the piezoelectric ceramic elements 10a and 10b are in the same direction. The metal electrode 11 which is made of a conductive metal such as phosphorous bronze, brass or the like and has an ultrathin thickness of 10A m to 50 μm is placed between the piezoelectric ceramic elements 10a and 10b. These piezoelectric ceramic elements 10a and 10b are joined with the metal electrode 11.

Since the thickness of the metal electrode 11 is set to the ultrathin thickness, a mechanical resistance generated by the metal electrode 11 can be minimized to a very small quantity. Even if a flexural vibration is occurred centering on (a non-expandable and non-contractionable site) of the joint surface between the two piezoelectric ceramic elements 10a and 10b and the metal electrode 11, a reduction of the flexural vibration by the metal electrode can be minimized as quickly as possible. According to the structure of the embodiment, if the piezoelectric ceramic element 10a as one part expands, the piezoelectric ceramic elements 10b as other part contracts and the electrode of an output current becomes inverse. Then, the piezoelectric ceramic elements 10a and 10b are connected in parallel for generating electricity.

Further, in this embodiment, if the flexural vibration is performed, both actions of expansion and contraction are carried out in one of the piezoelectric ceramic elements 10a and 10b, and an electric power generation is efficiently performed without negating the polarity. The current generated as an electric energy is picked up by lead wires 9A, 9B and 9C conductively connected to the both piezoelectric ceramic elements 10a and 10b and the metal electrode 11.

Here, a case is explained that the metal electrode 11 is placed in layered manner between the two piezoelectric ceramic elements 10a and 10b. Each piezoelectric ceramic element 10a (or 10b) itself can be formed in a layered structure. In this layered structure, a plurality of piezoelectric ceramic elements is joined (in this case, polarities of the polarization are same directions), thereby one piezoelectric ceramic element 10a (or 10b) being formed.

Thus, if the piezoelectric ceramic elements 10a (or 10b) itself is formed in the layered structure and, for example, jointed with an adhesive material having an elastic property, due to the elastic effect the piezoelectric ceramic body 10 lack of material strength becomes more flexible and maintains a bending strength. According to the present invention, an external shape of piezoelectric ceramic body 10 is not particularly limited. Appropriate shapes including a circular shape, an elliptic shape, a triangular shape, a quadrilateral shape, a polygonal shape or the like may be selected according to a practical application.

The cushion member 3 according to the embodiment is made of synthetic resins, rubbers, or soft sponge-like material thereof. The reason why such cushion member 3 is used and the piezoelectric ceramic body 10 is fixed only at the center or at the both ends of the cushion member 3 by using the adhesive material, is for preventing from decrease of the vibration of the piezoelectric ceramic body 10. When the piezoelectric ceramic body 10 vibrates, a member supporting the piezoelectric ceramic body 10 becomes a factor of decreasing the vibration of the piezoelectric ceramic body 10. To remove the factor of the decrease, the piezoelectric ceramic 10 is kept in condition as much as free by using the cushion member 3.

According to the invention, a distortion of the piezoelectric ceramic body is transformed into a characteristic vibration of the ceramic body itself, and then maintained for some time. In order to keep the characteristic vibration for some time, it is a key point not to transmit the characteristic vibration to a structure other than the piezoelectric ceramic body 10. The characteristic vibration of the piezoelectric ceramic body is transformed into an electric energy, but a vibration of other structure is all trasformed into a mechanical resistance to absorb a characteristic vibration energy and cannot be picked out. Therefore, in this embodiment, since the cushion member 3 is used as a means for realizing a soft contact of preventing the piezoelectric ceramic body 10 from transmitting the characteristics vibration into other structure, the characteristic vibration of the piezoelectric ceramic body 10 can be maintained for some time and the generation efficiency is improved. The cushion member 3 has also a function of absorbing an impact which is applied on the piezoelectric ceramic body 10. The protector plate is made of metal, synthetic resin or the like, and protects the piezoelectric ceramic body 10 from a beating by the hammer 21.

In the embodiment 1, a case is explained that the piezoelectric ceramic body 10 is arranged in parallel. But in this invention, the arrangement is not limited. An arrangement in a straight line according to the patent reference 1 which the applicant has proposed before or a piezoelectric ceramic body of a conventional known structure may be applied. The structure with the best generation efficiency is the piezoelectric ceramic body 10 according to the embodiment 1.

The impacting means 20 is comprised of: a hammer body 21 at whose upper portion a right rectangular shape with a beating protrusion 22 is formed in a V-shape; a hammer body supporting member 23 which supports the bottom portion of the hammer body 21; a coil spring (elastic body) 24 which encourages to a direction away from the piezoelectric ceramic body 10 with an upper portion thereof joined with the hammer body 21 to; a slide member 25 which slides freely with a bottom edge thereof connected with the coil spring 24; a coil spring (elastic body) 26 which, in an ordinary state, encourages to a direction of colliding with a spring body 28 to be mentioned later; and a switch member 27 which is encouraged in an ordinary state to an off direction by encouraging the spring body 28. Other end portion of the coil spring 26 is fixed to a vertical wall concave 8b of the container 8. An upper portion of the spring body (elastic body) 28 is fixed to the container 8. Code 29 shows a magnet which absorbs and supports the hammer body 21 when the body 21 is set in an ordinary state.

According to the beating means 20 of such structure, if the switch member 27 is pressed, the spring body 28 resists the pressing energy and a resistance against the energy presses the slide member 25 in the right direction as shown in FIG. 2.

Through this action, the slide member 25 resists the pressing energy of the coil spring 26 and slides to the right direction as shown in FIG. 2. If a movement position of the slide member 25 moves to the right direction from a contact point P where the bottom portion of the hammer body 21 and the hammer supporting member 23 contact each other, the encouragement of the coil spring 24 actuates the hammer body 21 to beat the piezoelectric ceramic body 10. Thus, since the encouragement gives the piezoelectric ceramic body 10 more than dozens of times a beating energy in comparison with a piezoelectric generating apparatus using the conventional steel ball, one-time beating enables to generate a large amount of piezoelectric generation quantity.

After having hammer body 21 completed beating, if the pressing energy of the switch member 27 is cancelled, positions of the hammer body 21, the slide body 25 and the switch member 27 automatically return to original positions by encouragement of each coil springs 24, 26 and 28, respectively, then the conditions are reset to a standby state for a next beating.

FIG. 3 shows an application of a piezoelectric generating apparatus 1 according to the present invention. In the application, the coil spring 26 and the spring body 28 of the embodiment shown in FIG. 1 and FIG. 2 are not used and the switch member 27 is arranged so as to slide freely. A free end portion of the switch member 27 is connected with a bottom portion of a spring member 31 on which upper portion a plummet (pendulum body) 30 is fixed. The switch part 27 is arranged so that the vibration energy of the plummet 30 actuates the pressing and a release of the pressing. For example, as a means for acquiring electricity for life buoy requiring unmanned electric power generation, the piezoelectric generating apparatus is structured so as to apply in practical use. Other structures of the piezoelectric generating apparatus 1 are as same as those in the embodiment as shown in FIG. 1 and FIG. 2. In both figures, same codes are used. Detailed explanation is omitted here.

FIG. 4 shows an embodiment in the same manner. The coil spring 26 and the spring body 28 which are shown in the embodiment 1 of FIG. 1 and FIG. 2 are not used and the switch member 27 is set so as to slide according to a vibration of a resonance vibrator 40 formed of a spring body or the like. FIG. 4 also shows an example which a continuous beat by the piezoelectric generating apparatus 1 of the structure is enabled. In the embodiment 3, the piezoelectric generating apparatus 1 is connected with vibrators 41 and 42 of the resonance vibrator 40, and the switch member 27 is turned on or off by a resonance vibration by the vibrators 41 and vibrator 42. Besides, the piezoelectric ceramic body 10 of the piezoelectric generating apparatus 1 is arranged on the both sides of the hammer 21 so as to further improve the electric generation efficiency by continuous beating. Since other basic structure is as same as the piezoelectric generating apparatus 1 as shown in FIG. 1 and FIG. 2, detailed explanation is omitted here. A structure of the resonance vibrator 40 is as same as a known resonance or electromagnetic resonance, the detailed explanation is also omitted.

FIG. 5 shows a circuit of a battery charger of charging electricity that a piezoelectric ceramic body 10 of the piezoelectric generating apparatus 1 generates. In the embodiment 3 as shown in FIG. 4, since a pair or a plurality of pairs of piezoelectric ceramic body 10 are arranged across the hammer body, the charging circuits are conductively connected in parallel or in series. Further, number of the parallel circuit as shown in the figure may be increased according to the application purpose if necessary.

The charging circuit is comprised of: two piezoelectric ceramic elements 10a and 10b as two piezoelectric ceramic bodies 10; a metal electrode 11; rectifying diodes D1 to D6; a condenser C which stores electricity; switch SW; and light-emitting diodes L1 to L3. Electricity which the piezoelectric ceramic element 10a generates is full-wave rectified by the rectifying diodes D1 to D3, and electricity which the piezoelectric ceramic element 10b generates is full-wave rectified by the rectifying diodes D4 to D6. The full-wave rectified electricity is charged in the condenser C. In the condenser C, only one parallel circuit can be provided. Further, switch SW allows the condenser C to discharge to turn on the light-emitting diodes L1 to L3.

Since the piezoelectric generating apparatus 1 is constituted of such battery charger, a generation efficiency of more than dozens of times an efficiency with the conventional art can be obtained, for example, it is, for example, effective to use as a battery charger for a device such as cellular phone or the like requiring a comparative more electricity or as an electric source for a light-emitting device. Furthermore, the piezoelectric generating apparatus 1 has a simple structure, being economical because of an ability to output a larger current, and practical.

FIG. 6 shows a piezoelectric generating apparatus 1′ according to an embodiment 4 of the present invention. The piezoelectric generating apparatus 1′ is comprised of a frame 9; a pair of piezoelectric ceramic bodies 10A and 10B which are arranged on the both left and right sides of an upper face 9a of the frame 9; a cushion member 3 which supports a pair of piezoelectric ceramic bodies 10A and 10B in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic bodies 10A and 10B to other structure; a spherical plummet (pendulum body) 50 which swings via a rectangle-shaped plate spring (vertical elastic body) 51 by vibration; a pair of column-shaped bar springs (horizontal elastic body) 52 and 52′ which is fixed to the both left and right sides of the plate spring 51 and orthogonally crosses the plate spring 51; and steel balls (hard beating body) 53 and 53′ which are fixed to each distal end 52a of the pair of bar springs 52 and 52′ and take a role as a plummet of alternately beating the pair of piezoelectric ceramic bodies 10A and 10B to have an impact on the piezoelectric ceramic bodies 10A and 10B.

A shown in FIG. 6, a pair of piezoelectric ceramic bodies 10A and 10B are comprised of two plate-shaped piezoelectric ceramic elements 10a and 10b of coincident form (same material, same shape and same thickness) and an ultrathin metal electrode 11. The piezoelectric ceramic elements 10a and 10b are arranged so as to maintain the polarity of the polarization of the piezoelectric ceramic elements 10a and 10b in a same direction, respectively, and have the metal electrode 11 which is made of a conductive metal such as phosphorous bronze, brass or the like and has a thickness of 10 μm to 50 μm, and arranged between the piezoelectric ceramic elements 10a and 10b. These piezoelectric ceramic elements 10a and 10b are connected with the ultrathin metal electrode 11.

For example, if one side of the piezoelectric ceramic element 10a expands, other side of the piezoelectric ceramic elements 10b contracts and an electrode of output current becomes inverse. Then, the piezoelectric ceramic elements 10a and 10b are connected in parallel for generating electricity. In other expression, if the flexural vibration is occurred, both actions of expansion and contraction are carried out in one of the piezoelectric ceramic elements 10a and 10b, and an electric power is efficiently generated without negating the polarity. The current generated as an electric energy is picked up by lead wires 9A, 9B and 9C which are conductively connected to the both piezoelectric ceramic elements 10a and 10b and the metal electrode 11.

The cushion member 3 is made of synthetic resins, rubbers, or soft sponge-like material thereof. Only the center or the both ends of such cushion member 3 are fixed to the piezoelectric ceramic bodies 10A and 10B by using an adhesive material as well as fixed to the upper face 9a of the frame 9 by using an adhesive material. This arrangement helps a vibration of the piezoelectric ceramic bodies 10A and 10B be not damped as quickly as possible. In other words, if the piezoelectric ceramic bodies 10A and 10B vibrate respectively, a member supporting the piezoelectric ceramic bodies 10A and 10B becomes a factor for damping vibration by the piezoelectric ceramic bodies 10A and 10B. In order to remove the damping factor, the piezoelectric ceramic bodies 10A and 10B are put in as free condition as possible by using the cushion member 3.

Distortion of the piezoelectric ceramic bodies 10A and 10B becomes a characteristic vibration caused by the piezoelectric ceramic itself and is maintained for some time. In order to maintain this characteristic vibration for a long time, it is a key point not to transmit the characteristic vibration to a structure other than the piezoelectric ceramic bodies 10A and 10B. Since the characteristic vibration of each piezoelectric ceramic body 10A and 10B is transformed as an electric energy and all vibration of other structure becomes mechanical resistance and absorbs the characteristic vibration energy, and cannot be picked up as an electric energy. Therefore, in the same manner of the embodiment 1, if the cushion member 3 is used as a means for performing such a soft contact that the characteristic vibration is not transmitted between the piezoelectric ceramic body 10 and other structure, the characteristic vibration of the piezoelectric ceramic bodies 10A and 10B can be maintained as long as possible and the generation efficiency becomes better. The cushion member 3 has an effect of absorbing an impact which is to be put on the piezoelectric ceramic bodies 10A and 10B. A protector plate may be stuck on the center of the beating face of the piezoelectric ceramic bodies 10A and 10B (not shown). The protector plate is made of metals, synthetic resins or the like and protects the piezoelectric ceramic bodies 10A and 10B from being beaten by the steel balls 53 and 53′.

A rectangle-shaped plate spring 51 vertically stands against the frame 9 with a bottom portion 51c thereof fixed to the frame 9. A spherical plummet 50 is fixed to a distal end 51a of the plate spring 51. Further, at the center of a middle portion 51b of the bottom portion of the plate spring 51, each end portion 52b of a pair of left and right bar springs 52 and 52′ is fixed, respectively. Through this arrangement, the pair of left and right bar springs 52 and 52′ orthogonally crosses the plate spring 51 each other and has a same distance to both left and right horizontal directions. At each distal end 52a of the pair of bar springs 52 and 52′, steel balls 53 and 53′ co-functioning as a plummet are fixed respectively.

As an arrow shows in FIG. 6, if the plummet 50 or the plate spring 51 is beaten left and right and the plummet 50 vibrates left and right, two kinds of actions are repeatedly alternated in series succession. One action is a beating action where the steel ball 53 (one beating body), one of the pair of steel balls 53 and 53′ as a beating body beats a piezoelectric ceramic body 10A, one (the left side of FIG. 6) of the piezoelectric ceramic bodies 10A and 10B as a beating body. Other action is a separating action where other of steel balls (other beating body) 53′ of the pair of steel balls 53 and 53′ separates other (the right side of FIG. 6) piezoelectric ceramic body 10B of the pair of piezoelectric ceramic bodies 10A and 10B. In other words, at a vibration time of the plummet 50, an intermittent mechanism is constructed of a beating action and a separating action, where the bar springs 52 and 52′ alternately beat the piezoelectric ceramic bodies 10A and 10B of steel balls 53 and 53′ in straight succession.

In this embodiment 4, if the piezoelectric generating apparatus 1′ and 1′ are joined with vibrators 41 and 42 of the resonance vibration body 40 shown in the FIG. 4 respectively and a continuous beating produced by the pair of bar springs 52 and 52′ and 52 and 52′ is produced by resonance vibration produced by the vibrators 41 and 42, it is possible to further improve an electric power generation. As shown in FIG. 6, if a vibrator is consisted of a pair, since a vibration to be transmitted from the bottom portion 51c of the plate spring 51 to the frame 9 is big, a steel property of the frame 9 is to be strengthened and the bottom portion 51C of the plate spring 51 is to be fixed solid. If two sets of the piezoelectric generating apparatus 1′ and 1′ are assembled with the resonance vibrator 40, since vibrations by two sets of the piezoelectric generating apparatus 1′ and 1′ negate each other and then a vibration to be transmitted to the frame 9 becomes slight, a strengthening of the frame 9 is not required and a cost on parts can be reduced. Further, a quantity of kinetic energy of escaping from the frame 9 and the like to an external portion can be drastically reduced and a generation efficiency can be much improved, as in the embodiment 1.

In the piezoelectric generating apparatus 1′ of vibration type which has the structure and repeatedly beats, a power generation is performed by providing a distortion or deformation produced at a time that a pair of steel balls 53 and 53′ beats a pair of plate-shaped piezoelectric ceramic bodies 10A and 10B. In other words, a kinetic energy is stored by beating the plummet 50 or the plate spring 51 with a predetermined means for one time to vibrate the plummet 50 in horizontal direction. If the kinetic energy stored is given to one of the pair of left and right bar springs 52 and 52′ to alternately beat, and then the steel balls 53 and 53′ alternately beat the piezoelectric ceramic bodies 10A and 10B in straight succession. Thus, an electric power is generated.

In this case, FIG. 7A shows a phase relation between a displacement magnitude (vibration volume) of the plummet 50 and the displacement magnitude of the steel balls 53 and 53′. FIG. 7B shows a phase relation between a speed (angular speed) of the plummet 50 and a speed (beating speed) of the steel balls 53 and 53′. In a waveform diagram in FIG. 7A, a displacement of the plummet 50 is shown by solid line A. A displacement of either steel ball 53 is shown by chain line B. A displacement of other steel ball 53′ is shown by chain double-dashed line C. Further, in the waveform diagram of FIG. 7B, a speed of the plummet 50 is shown by solid line E. A displacement of either steel ball 53 is shown by chain line F. A displacement of other steel ball 53′ is shown by chain double-dashed line G.

As known from the waveforms in FIGS. 7A and 7B, in the piezoelectric generating apparatus 1′ of vibration type which repeatedly beats, a storage of vibration power (kinetic energy) by the plummet 50 is separated from a consumption which a pair of steel balls 53 and 53′ beats the piezoelectric ceramic bodies 10A and 10B, and a movement of the plummet 50 and a movement of steel balls 53 and 53′ are arranged to perform a first-order lag (a lag of about 90 degrees in terms of phase is optimal). If the speed of the plummet 50 in the arrangement is zero or small, the speed of one of the steel balls 53 and 53′ can be set to a best data. The arrangement also maximizes the beating speed of the steel balls 53 and 53′ on the piezoelectric ceramic bodies 10A and 10B, and keeps vibrating the plummet 50 (vibration) repeatedly.

Further, when the plummet 50 vibrates, an intermittent mechanism (first-order lag) repeats a beating action and a separating action in a row on alternate side. The beating action is that a pair of bar sprigs 52 and 52′ being fixed to the both sides of the plate spring 51 having the plummet 50 fixed actuates the steel balls 53 and 53′ to beat a pair of piezoelectric ceramic bodies 10A and 10B. The separating acting is that a pair of bar sprigs 52 and 52′ being fixed to the both sides of the plate spring 51 having the plummet 50 fixed actuates the steel balls 53 and 53′ to separate from a pair of piezoelectric ceramic bodies 10A and 10B. Therefore, if the arrangement is compared with a beating without the intermittent mechanism (namely, in a case that a steel ball is fixed to only one side of the plate spring 51), one time beating by the plummet 50 allows an alternate beating of the steel balls 53 and 53′ in straight succession.

If a beating is performed without the intermittent mechanism, since a speed caused by an acute impact decreases to zero when the plummet 50 keeps speed, a kinetic energy by a beat is big but cannot be repeated to make a movement. In the embodiment 2, as shown in FIG. 7B, a pair of bar spring 52 and 5a′ delays the position of the steel balls 53 and 53′ at a maximum speed behind the position of the plummet 50 at a maximum speed. When a speed of the plummet 50 is small or zero, if the speed of either steel ball 53 or other steel ball 53′ is set to a maximum, the piezoelectric ceramic bodies 10A and 10B can be beaten at the maximum beating rate. In this manner, a generation efficiency more than dozens of times an efficiency with the conventional arrangement can be obtained. For example, it is effective to use as an electric source for battery charger such as cellular phone or the like requiring a comparative more electricity or for light-emitting device. The piezoelectric generating apparatus 1′ of the vibration type is more simply structured and is economical because of an ability of outputting a larger current, and is expected for practical use.

As above, the piezoelectric generating apparatus provides a beating action and a separating action, both of which are repeated in a row on alternate side. The beating action is that the steel ball 53, one of the pair of steel balls 53 and 53′ beats the piezoelectric ceramic body 10A, one of the pair of piezoelectric ceramic bodies 10A and 10B. The separating action is that other steel ball 53′, one of the pair of steel balls 53 and 53′ separates from other piezoelectric ceramic body 10B, one of the pair of piezoelectric ceramic bodies 10A and 10B. These actions assure a generation quantity of more than dozens of times an output current with the piezoelectric generating apparatus using a conventional steel ball, by beating the steel balls 53 and 53′ which are alternately repeated by one-time beating of the plummet 50 in a straight succession. Further, a parallel use of a means which automatically repeats beating the plummet 50 enables, for example to use as an electricity for cellular phone or an electric source for life buoy or the like to secure a generation quantity of a practical level.

Here, FIG. 6 provides a plummet 50 being made of a steel ball having a weight of 6.3 g, a plate spring 51 being made of spring steel having a width of 5 mm, a thickness of 0.4 mm and a length of 28 mm, a pair of bar springs 52 and 52′ being made of piano wire of 0.5 mm in diameter and 20 mm in length, and a pair of steel balls 53 and 53′ being made of steel balls having a weight of 0.65 g, and further providing a pair of piezoelectric ceramic bodies 10A and 10B (the same structure of the embodiment 1) of 5.8 mm×17.5 mm×2 mm. The cushion member 3 is made of urethane foam of having a thickness of 2 mm. A voltage is measured by the measuring device as shown in FIG. 8. The result is shown in FIG. 9.

As is clear from the data shown in FIG. 9, if the plummet 50 is beaten once, a pair of the steel balls 53 and 53′ continuously repeats a beating action in alternate shifts left and right without damping. Thus, it demonstrates that an electric generation of more than dozens of times an electric power generation with the conventional art at one-time beating is obtained.

The piezoelectric generating apparatus uses a rectangle-shaped plate spring 51 as a vertical elastic body of vibrating the plummet 50 as a pendulum. The piezoelectric generating apparatus also uses column-shaped bar springs 52 and 52′ as a pair of horizontal elastic bodies having steel balls 53 and 53′ as a beating body fixed to the distal end 52a. The pair of bar springs 52 and 52′ provides an intermittent mechanism which repeats a beating action and a separating action in a row on alternate side. These actions are that, when the plummet 50 vibrates, the pair of bar springs 52 and 52′ actuates the steel balls 53 and 53′ to continuously beat on or separate from the pair of piezoelectric ceramic bodies 10 and 10 in alternate shifts left and right. Thus, a simple and low price structure enables a continuous beating of the pair of steel balls 53 and 53′ on the pair of piezoelectric ceramic bodies 10 and 10 in alternate shifts left and right, and produces an electric power generation of practical level for applying as an electric source requiring comparative more electricity such like cellular phone or the like, or as an electric source for life buoy or the like.

FIG. 10 shows a piezoelectric generating apparatus 1A according to the embodiment 5 of the present invention. The piezoelectric generating apparatus 1A is comprised of: a frame 9; a piezoelectric ceramic body 10 which is arranged on the left side of an upper face 9a of the frame 9; a cushion member 3 which supports the piezoelectric ceramic body 10 in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic bodies 10 to other structure; a base member 51A which is made of L-shaped spring member and is fixed on an upper face of the frame 9; horizontal elastic bodies 52A and 52B which are fixed to a vertical portion 51A1 of the base member 51A; and steel balls 53A and 53B which are made of hard beating body and are respectively fixed to the both ends of the horizontal elastic bodies 52A and 52B. The piezoelectric generating apparatus 1A is further constructed in a manner that, if an external force F is given to the steel ball 53B, other steel ball 53A continuously repeats a vertical vibration by resonance and then the piezoelectric ceramic body 10 is beaten to have an impact on the piezoelectric body 10 to generate. In this embodiment 5, component parts which are as same as those in the embodiment 4 are given the same codes in the figure as those of the embodiment 4. The detailed explanation is omitted here.

The horizontal elastic bodies 52A and 52B which are made of metal member such as bar-shaped stainless or the like have same lengths l1 and l2 from a point of 10 height from the bottom portion of the vertical portion 51A1 of the base member 51A and are fixed by welding.

According to FIG. 10, if the steel balls 53A and 53B are made of steel ball having a weight of 0.6 g, horizontal elastic bodies 52A and 52B being made of stainless bar member (sus304-WPB) having a diameter of 0.6 and having a distance between the l1 and the l2 of 70 mm, and a base member 51A being made of stainless member (sus 301: t=0.4) and having a length of l0 of 15 mm, a vertical vibration stroke of the steel balls 53A and 53B had a width of 14 to 15 mm. An electric power generation by the piezoelectric generating apparatus 1A of such structure was measured by a same measuring device as the measuring device as shown in the FIG. 8. The result is shown in FIG. 11.

As apparent from the data of FIG. 11, if an external force F is once given to the steel ball 53B, the steel ball 53A continuously repeats a vertical vibration to generate an electric power generation of more than dozens of times an electricity by one-time beating of the conventional art. In the embodiment 3, if symmetric l1=l2 and 53A=53B are arranged and the number of characteristic vibration on the left side and the number of characteristic vibration on the right side of FIG. 10 are equalized, the left and the right resonate each other. Such structure can raise the characteristic frequency (n·fo) on the left side by integral multiple more than the characteristic frequency on the right side (fo) . Consequently, if a stored energy on the right side is increased (or an inertial moment is raised), the characteristic frequency decreased and the continuous vibration time can be prolonged.

Further, in the piezoelectric generating apparatus according to the embodiment 5, in comparison with a device according to the embodiment 4, the number of parts is drastically reduced so that the production cost is reduced and the device is downsized very much. Accordingly, a practical use is highly expected in an electric source for device such as cellular phone as a small electronic device or the like requiring a comparative more electricity.

In the embodiment 5, it is explained of a weld link of the horizontal elastic bodies 52A and 52B with the base member 51A, but the invention does not limit to it, but also known means such as screw cramp, caulking, strong adhesive material or soldering can join parts integrally.

INDUSTRIAL APPLICABILITY

According to the first aspect of the invention, there is provided a piezoelectric generating apparatus which applies a distortion or deformation on the plate-shaped piezoelectric ceramic body to generate electricity, comprising: the piezoelectric ceramic body; a cushion member which supports the piezoelectric ceramic body in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic body to other structure; and a beating means, the beating means comprising a hammer body and a switch member actuating the hammer body in a beating direction. When at beating the piezoelectric ceramic body by the hammer body, since the switch member actuates a boosted power of an elastic body on the hammer body, an electric power generation of more than dozens of times an output current with a piezoelectric generating apparatus using the conventional steel ball can be secured by one-time beating. Together with using a means which automatically repeats beating, it provides an effect: it enables to secure a generation quantity of practical level, for example, as an electricity for cellular phone or an electric source for life buoy or the like.

According to the second or third aspect of the present invention, since a beating can be obtained continuously, effects such as an electric source for a device such like cellular phone or the like requiring a comparative more electricity or an electric generation of practical level as an electric source for buoy or the like may be obtained.

Further, according to the fourth aspect of the invention, a piezoelectric generating apparatus which applies a distortion or deformation on plate-shaped piezoelectric ceramic to generate electricity, the piezoelectric generating apparatus is comprised of: a pair of piezoelectric ceramic body; a cushion member which supports the piezoelectric ceramic body in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic body to other structure; a pendulum which swings via a vertical elastic body by beating; a pair of horizontal elastic bodies which is fixed on the both sides of the vertical elastic body and elongated in a direction where the horizontal elastic body orthogonally crosses a vertical elastic body; and a hard beating body which is fixed to each distal end of the pair of horizontal elastic bodies and has an impact on the piezoelectric ceramic bodies by alternately beating the pair of piezoelectric ceramic bodies, wherein, a beating action and a separating action are alternately repeated in straight succession. The beating action is that, when the pendulum swings, one of the pair of beating bodies beats one of the pair of piezoelectric ceramic bodies. The separating action is that, when the pendulum swings, other of the pair of beating bodies separates from other of the pair of piezoelectric ceramic bodies. These actions ensure an electricity generation of more than dozens of times an output current with a piezoelectric generating apparatus using a conventional steel ball when beating each beating body which is produced by one-time beating on the plummet and repeated continuously in an alternate order. Further, a parallel use of a means which automatically repeats beating the plummet may generate, for example, an electric power of a practical level as an electricity for cellular phone or as an electric source for life buoy or the like.

According to any one of the aspects fifth to seventh of the present invention, there is provided a piezoelectric generating apparatus with a simple and low price structure which encourages each beating body to continue beating alternately and assures a generation quantity of a practical level as an electricity for cellular phone or the like requiring a comparative more electricity, or as an electric source for buoy or the like.

According to the eighth aspect of the present invention, there is provided a piezoelectric generating apparatus as other means for continuously obtaining a beating of a beating body, the piezoelectric generating apparatus which applies a distortion or deformation on the plate-shaped piezoelectric ceramic body to generate electricity, comprising: at least a piezoelectric ceramic body; a cushion member which supports the piezoelectric ceramic body in a soft condition of hardly transmitting a characteristic vibration of the piezoelectric ceramic body to other structure; a base member which is made of spring member; a horizontal elastic body which is fixed to a vertical portion of the base material; and a hard beating body which is fixed to the both ends of the horizontal elastic body and has an impact on the piezoelectric ceramic body by beating the piezoelectric ceramic body. It is further constructed in a manner that, if an external force is given to one of the heating bodies, other beating body continuously repeats a vertical vibration by resonance. Thus, an electricity generation of more than dozens of times an output current with a piezoelectric generating apparatus using the conventional steel ball can be secured by resonance via one-time beating by an external force. It provides an effect that a generation quantity of practical level enables a compact size and a lower price, for example, as an electricity for cellular phone or as an electric source for life buoy or the like.

Further, according to the ninth or tenth aspect of the present invention, a simple and compact device with a simple and low price structure enables a continuous repeat of beating by each beating body and achieves a generation quantity of practical level, for example, as an electric source for a compact, comparatively more electricity requiring device such as cellular phone or the like, or as an electric source for life buoy or the like.