JPH10164865A - Piezoelectric conversion power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small piezoelectric conversion power supply having a long service life in which energy loss and breakdown of a piezoelectric element can be prevented by contriving an arrangement for converting mechanical oscillation energy into electric energy through a piezoelectric element utilizing the inertial energy of an inertial rotator. SOLUTION: When an automobile oscillates, a casing 20 is subjected to mechanical vibration of the automobile through a spring 40 and vibrated alternately up and down. Consequently, the rotary blade member 60 of an interlink mechanism M is turned in one direction or multiple directions through interlinkage with the up/down vibration of the casing 20. On the other hand, a large diameter gear 54 rotates as the rotary blade member 60 turns in one direction to transmit a rotating force to a rotator 74 and a shaking member 85. When the rotary blade member 60 turns in another direction, the large diameter gear 54 rotates relatively to the rotary blade member and sustains the rotating force of the shaking member 85 while releasing transmission of rotating force to the rotator 74.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric conversion power supply using a piezoelectric element.

[0002]

2. Description of the Related Art Conventionally, power is supplied to various devices mounted on an automobile or the like from a power generator such as a generator via a power supply line or by using a battery.

[0003]

However, the power generator usually has a large external shape and is fixed to a stationary member.
Moreover, the power line is long. For this reason, when the power supply location is a movable part of a device in a narrow space, it is difficult to dispose the power generation device near the movable part, and it is difficult to perform wiring, poor connection, power loss, and the like. Is easy to invite.

Therefore, it is difficult to easily and satisfactorily supply power to a movable portion of a device via a power supply line. Further, even if the battery can be charged, there is a problem in the life thereof. Therefore, there is a demand for the development of a small-sized power supply device having a semi-permanent life and capable of supplying power to a movable portion of an apparatus satisfactorily and easily without using a long power supply line.

[0005] On the other hand, Japanese Patent Application Laid-Open No. 59-19467 discloses this.
As disclosed in Japanese Patent Application Laid-Open No. 7-49873 and Japanese Patent Application Laid-Open No. 7-49388, a power supply device that converts mechanical vibration energy into electric energy using a piezoelectric element has been proposed.
However, when an external force such as high acceleration is applied to the piezoelectric element near the resonance frequency of the piezoelectric element, the piezoelectric element is easily broken. In consideration of this, the power supply device has a structure for controlling the amplitude of the piezoelectric element in order to prevent the piezoelectric element from being broken. And such a structure is a factor which causes the loss of energy of a piezoelectric element.

Accordingly, the present invention utilizes the inertial energy of the inertial rotating body to cope with the above-mentioned problems.
It is an object of the present invention to provide a small-sized piezoelectric conversion power supply having a long life and capable of preventing energy loss and breakage of the piezoelectric element by devising a configuration for converting mechanical vibration energy into electric energy by the piezoelectric element.

[0007]

According to the first and second aspects of the present invention, a vibration sensing member receives a mechanical vibration of a mechanical vibration generator and moves upward and downward. When vibrated, the interlocking mechanism transmits a rotational force to the inertial rotating body and the vibrating body in conjunction with one of the upward and downward vibrations of the vibration sensing member, and the vibration is transmitted to the other of the vibration sensing member. Accordingly, the transmission of the torque to the vibrating body is maintained while the transmission of the torque to the inertial rotating body is released. Further, the inertial rotating body rotates while accumulating inertial energy, and the vibrating body vibrates the piezoelectric element by the rotation. Therefore, the piezoelectric element converts the energy into electric energy by mechanical vibration.

Thus, by utilizing the inertial energy of the inertial rotating body as described above, it is possible to satisfactorily convert the mechanical vibration energy of the piezoelectric element into electric energy.
In this case, there is no need to use an extra member to limit the vibration width of the piezoelectric element, so that the piezoelectric element does not break. Further, as long as the mechanical vibration generator vibrates, electric energy can be generated from the piezoelectric element, so that it is possible to provide a long life piezoelectric conversion power supply device. In addition, since only an inertial rotating body, a vibration sensing member, a vibrating body, and an interlocking mechanism need be employed in addition to the piezoelectric element, this kind of piezoelectric conversion power supply device can be downsized.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show an example of a piezoelectric conversion power supply device S according to the present invention provided in a door body 10a of a driver's seat door 10 of an automobile. As shown in FIG. 1, the piezoelectric conversion power supply device S includes an outer plate 1 of a door body 10a.
1 is attached to the inner wall of the outer plate 11 between the inner plate 1 and the inner plate 12.

The piezoelectric conversion power supply device S has a rectangular parallelepiped casing 20, and the casing 20 is supported on the inner wall of the outer plate 11 via an L-shaped rack member 30 described later. The rack member 30 is shown in FIGS.
As shown in FIG. 6, the rack member 30 is located in the casing 20, and as shown in FIG.
The support portion 32 is configured to extend in an L-shape from the upper end of the support member 1.

The support portion 32 is provided on the left side wall 2 of the casing 20.
1 (the side wall of the driver's seat door 10) extends through a slit-shaped opening 21a formed in the upper and lower direction in the upper half thereof, and a screw 32b is screwed into the outer plate 11 of the door body 10a at the flange 32a.
It is attached by tightening. Thus, the rack portion 31 is located in the casing 20 in parallel with the upper half of the left side wall 21.

As shown in FIGS. 1, 3 and 5, a coil spring 40 is provided between the support portion 32 and the projection 21b projecting from the left side wall 21 immediately below the support portion 32 in the casing 20. It is assembled. Thus, the casing 20 is supported by the outer plate 11 via the support portion 32 by the coil spring 40 so as to be able to vertically vibrate.

However, the casing 20 is located at the center in the vertical direction of the opening 21a when not receiving vibration. Further, the vertical opening length of the opening 21a is set to be longer than the vertical vibration range of the casing 20, so that when the casing 20 vibrates, the support portion 32
It does not hit the upper and lower ends of the inner wall of the opening 21a. As shown in FIG. 1 and FIGS. 3 to 5, an interlocking mechanism M, an inertia mechanism I, and a vibration mechanism A are assembled in the casing 20.

As shown in FIG. 5, the interlocking mechanism M is provided with a rotating shaft 50. The rotating shaft 50 is provided at both ends thereof at the front and rear side walls 23 and 24 of the casing 20 (in the front and rear direction of the vehicle). Are supported rotatably at both intermediate portions in the up-down direction via both bearings 51 and 52. Further, the interlocking mechanism M includes a small-diameter gear 53, which is coaxially supported by the rotating shaft 50 near the inner surface of the rear wall 24 so as to rotate integrally therewith.

A large-diameter gear 54 having a substantially U-shaped cross section is rotatably supported by a rear wall 54a coaxially with a rotary shaft 50 via a bearing 55 at the front side of the small-diameter gear 53.
As shown in FIGS. 1, 3, 4, and 7, a pair of projections 5 are formed on the inner peripheral wall 54b of the recess of the large-diameter gear 54.
6 are formed so as to project inward at equal angular intervals.

As shown in FIGS. 1 and 3, each of the projections 56 has a locking end surface 56a located on a normal line to the inner wall 54b of the recess. Rotating wing member 6 to rotate 54
It plays a role of locking to the leading end of the zero. Also, each protrusion 56
Has a relief end surface 56b perpendicular to the locking end surface 56a, and the relief end surface 56b plays a role of relatively rotating the large-diameter gear 54 with respect to the rotary wing member 60 in the direction opposite to the locking direction. . Note that the rack member 30 may be a concept included in the interlocking mechanism M.

As shown in FIGS. 1, 3 and 4, the rotary wing member 60 is coaxially coaxially rotatable with the rotary shaft 50 in the recess of the large-diameter gear 54, as shown in FIGS. Supported. This rotating wing member 60 is similar to that shown in FIGS.
8, a pair of strip-shaped wings 62 are provided, and both wings 62 are curvedly extended from the boss 61 so as to form an S-shape.

In this case, the two wings 62 are positioned point-symmetrically with respect to the rotating shaft 50 so that the respective tip portions 62a of the two wings 62 are simultaneously locked on the respective locking end surfaces 56a of the both projections 56. The two wings 62 have a shape that is convex in the direction opposite to the locking direction with respect to the locking end surfaces 56a. Inertial mechanism I
As shown in FIGS. 1 and 3 to 5, the interlocking mechanism M
It is located above. This inertia mechanism I has a rotating shaft 70
The rotary shaft 70 has two bearings 71 on both sides 23 and 24 of the casing 20 at both ends.
It is rotatably supported via 72.

The inertia mechanism I includes a small-diameter gear 73, which is coaxially supported on a rotating shaft 70 so as to be integrally rotatable therewith.
Is engaged. The disk-shaped rotator 74 is coaxially supported on the rotary shaft 70 at the front side of the small-diameter gear 73 so as to be integrally rotatable therewith. The rotator 74 has a predetermined moment of inertia, and the rotator 74 plays a role of storing inertial energy by its rotation. The rotating body 74 may be integrated with the small diameter gear 73.

The vibrating mechanism A is located below the interlocking mechanism M, as shown in FIGS. The vibration mechanism A has a rotating shaft 80, and the rotating shaft 80
Are the front and rear side walls 2 of the casing 20 at both ends thereof.
3 and 24 are rotatably supported via both bearings 81 and 82. The vibration mechanism A includes a small-diameter gear 83, which is supported by the rotating shaft 80 so as to be integrally rotatable therewith and meshes with the large-diameter gear 54 from below.

The vibrating member 85 is of a flat shape. The vibrating member 85 has a small-diameter gear 83 at its central shaft hole 85a.
Is supported on a rotating shaft 80 so as to be integrally rotatable therewith. Note that the vibration member 85 may be integrated with the small-diameter gear 83. Further, in addition to the casing 20, the vibration sensing member may include the rotating shafts 50, 70, and 80.

As shown in FIGS. 1, 3 and 4, the vibration member 90 is fixed to the inner surface of the right side wall 22 of the casing 20 below the vibration mechanism A on its pedestal 91. The vibrating member 90 includes a strip-shaped piezoelectric element 92. The piezoelectric element 92 is connected to an end surface 91 of a pedestal 91.
a, and extends at right angles to the left side wall 21 of the casing 20.

Here, the front end 92a of the piezoelectric element 92 is located at a predetermined distance below the center of the vibration member 85, and both surfaces of the piezoelectric element 92 are in a horizontal plane. However, the above-mentioned predetermined interval is slightly shorter than half of the entire length of the vibrating member 85 so as not to cause breakage due to the bending of the piezoelectric element 92. As a result, with the rotation of the vibration member 85, the piezoelectric element 92 is beaten by the tip of the vibration member 85 at the front end portion 92a and vibrates in the vertical direction. Occurs.

However, the piezoelectric element 92 is formed of a crystal having piezoelectricity, a piezoelectric ferroelectric, a polymer or semiconductor having piezoelectricity, or the like. Ni inside the casing 20
As shown in FIG. 1, a secondary battery 100 such as a Cd battery is
It is fixed on the bottom wall 25 of the casing 20 and this 2
Immediately above the secondary battery 100, a diode bridge circuit 11
0 is supported on the right side wall 22 of the casing 20 by appropriate means.

Thus, as shown in FIG. 9, the secondary battery 100 is charged by the piezoelectric element 92 via the diode bridge circuit 110. The secondary battery 100 is used, for example, as a power supply for the sensor circuit 120 of the side collision type occupant protection device. In addition, the secondary battery 10
Numeral 0 is connected to both terminals of the sensor circuit 120 through the right side wall 22 of the casing 20 at both terminals 101 (see FIG. 1).

In this embodiment constructed as described above, the casing 20
Receives the force in the direction indicated by the arrow F1 in FIG. 1 (that is, the rack member 30
1), the rack member 3
0 is pushed down in that direction by the force F1, and the rack portion 31 moves down.

Accordingly, the small-diameter gear 53 of the interlocking mechanism M
Are rotated in the direction of arrow a as shown in FIG. 3 and FIG.
0 also rotates in the same direction, and is locked at its both end portions 62a on the locking end surfaces 56a of both projections 56 of the large-diameter gear 54.
For this reason, the large-diameter gear 54 is connected to both the end portions 6 of the rotary wing member 60.
2a, and rotates in the same direction as the rotary wing member 60.

Next, the small-diameter gear 73 of the inertia mechanism I rotates in a direction opposite to the large-diameter gear 54 (in a direction indicated by a solid arrow in FIGS. 3 and 5) under engagement with the large-diameter gear 54. At the same time, the rotating body 74 also rotates in the same direction as the small diameter gear 73. Here, the rotator 74 stores inertial energy by its rotation. For this reason, the rotating body 74 continues to inertia rotate smoothly in the rotating direction.

On the other hand, when the large-diameter gear 54 rotates as described above, the small-diameter gear 83 of the vibrating mechanism A engages with the large-diameter gear 54 and rotates in a direction opposite to that of the large-diameter gear 54 ( FIG.
5 and a solid line in FIG. Therefore, the vibration member 85 also rotates in the same direction as the small-diameter gear 83, and strikes the top end portion 92a of the upper surface of the piezoelectric element 92 at its tip.

Along with this, the piezoelectric element 92 is temporarily bent downward to cause distortion. Hereinafter, under the vibrating action accompanying the rotation of the vibrating member 85, the piezoelectric element 92 repeatedly bends temporarily downward and vibrates up and down mechanically. In this case, each time the vibrating member 85 is hit, the piezoelectric element 92 attenuates and vibrates at the natural frequency. With such vibration, the piezoelectric element 92 converts mechanical vibration into voltage by its piezoelectric conversion action.

Further, as described above, since the rotating body 74 stores the inertial energy, the vibration member 85 continues to rotate smoothly in the direction of the arrow b shown by the solid line. Therefore, the piezoelectric element 9
2 is continued as long as the vibration of the vehicle continues. Further, since the vibrating member 85 rotates in the direction of the arrow b as described above, the distal end of the vibrating member 85 comes into contact with the piezoelectric element 92 from the base end side toward the distal end side. In addition, the tip 92a of the piezoelectric element 92 and the vibrating member 8
The distance between the center of the piezoelectric element 92 and the center of the piezoelectric element 92 is as described above.
Is set not to cause destruction.

Therefore, even if the vibration member 85 repeatedly hits the piezoelectric element 92, the piezoelectric element 92 is not broken. On the other hand, when the casing 20 receives the force in the direction of the arrow indicated by the two-dot chain line at F2 in FIG. 1 (that is, the rack member 30 moves in the direction of the arrow indicated by F2 in FIGS. 3 and 5). When a force is applied), the rack member 30 is pushed up in that direction by the force F2, and the rack portion 31 moves upward.

Accordingly, the small-diameter gear 53 of the interlocking mechanism M
3 and 5 rotate in the direction of the arrow b indicated by the two-dot chain line, and the rotating wing member 60 also rotates in the same direction, as shown in FIGS. At this time, the rotating body 74 maintains the rotation in the direction of the arrow b shown by the solid line due to its inertial energy. For this reason, both end portions 62 a of the rotary wing member 60 are dissociated from both projections 56 of the large-diameter gear 54. Then, the rotary wing member 60 is provided with both front end portions 62.
a is relatively rotated in the opposite direction to the large-diameter gear 54, while following a along the inner peripheral wall 54 b of the recess of the large-diameter gear 54 and the relief end faces 56 b of the two projections 56.

Accordingly, even if the above-described force F2 acts on the casing 20, the vibrating action of the vibrating member 85 on the piezoelectric element 92 is continued as it is.
The piezoelectric conversion effect of the piezoelectric element 92 is maintained as long as the vibration of the vehicle continues. Therefore, the secondary battery 100 is constantly charged by the piezoelectric element 92 via the diode bridge circuit 110, so that the supply of power to the sensor circuit 120 can be properly secured. Also, such power supply is
According to the present embodiment, a semi-permanent power supply for the sensor circuit 120 can be provided since the vehicle can be maintained if it vibrates.

Further, according to the present embodiment, the vibration member 90
Is housed in the casing 20 together with the rack member 30, the interlocking mechanism M, the vibration mechanism A, the inertia mechanism I, and the vibration member 90, so that a small power supply can be provided. At this time,
The secondary battery 100 and the diode bridge circuit 110 also
Since the secondary battery 10 is housed in the casing 20,
The wiring between 0 and the piezoelectric element 92 is also very short. Further, the secondary battery 100 and the diode bridge circuit 11
0 and no vibration between the vibration member 90 and the piezoelectric element 9
No connection failure occurs between the diode bridge circuit 2 and the diode bridge circuit 110.

In implementing the present invention, the piezoelectric element 9
2 may extend obliquely from the right side wall 22 to the bottom wall 25 without being limited to the position perpendicular to the left side wall 21 of the casing 20. Further, the piezoelectric element 92 may be arranged so as to extend from the bottom wall 25 toward the tip of the vibration member 85. In implementing the present invention, the vibration member 85
Is rotated in the direction opposite to the direction of the arrow b shown by the solid line,
The interlocking mechanism M and the inertia mechanism I may be configured to extend the piezoelectric element 92 from the left side wall 21 to the right side wall 22 of the casing 20.

In practicing the present invention, the casing 20 is not limited to the inside of the door body 10a, but may be attached to an appropriate place on the body of the automobile. Further, in the above-described embodiment, an example in which the piezoelectric conversion power supply device S is mounted on an automobile has been described. However, the present invention is not limited to this. The present invention may be applied to the present invention.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing a state in which an embodiment of a piezoelectric conversion power supply device according to the present invention is installed in a door body of an automobile.

FIG. 2 is a side view of the automobile.

FIG. 3 is a partially broken front view of the piezoelectric conversion power supply device.

FIG. 4 is a sectional view taken along line 4-4 in FIG.

FIG. 5 is a partially broken rear view of the piezoelectric conversion power supply device.

FIG. 6 is a front view of the rack member of FIG. 1;

7A is a front view of the large-diameter gear shown in FIG. 1, and FIG. 7B is a view showing a cross-section of the large-diameter gear.

8A is a front view of the rotary wing member of FIG. 1; FIG.
FIG. 4 is a view showing a side surface of the rotary wing member.

FIG. 9 is a connection circuit diagram of a piezoelectric element, a diode bridge circuit, a secondary battery, and a sensor circuit.

[Explanation of symbols]

M: interlocking mechanism, 20: casing, 40: spring, 54 ...
Large-diameter gear, 55: bearing, 60: rotary wing member, 73, 8
3 small gear, 74 rotating body, 92 piezoelectric element, 85
Exciting member.

Claims (2)

[Claims] 1. A vibration sensing member (20) vibrating upward and downward in response to a mechanical vibration of a mechanical vibration generator, and inertial rotating bodies (73, 74) rotating by a rotational force to accumulate inertial energy. A piezoelectric element (92) that converts its energy into electric energy by mechanical vibration; and a vibrating body (83, 85) that rotates by the rotational force and vibrates so as to cause the piezoelectric element to vibrate mechanically. The rotational force is transmitted to the inertial rotating body and the vibrating body in conjunction with one of the upward and downward vibrations of the vibration sensing member, and the vibration is applied to the other of the vibration sensing member. A piezoelectric conversion power supply device comprising: an interlocking mechanism (M) for maintaining transmission of rotational force to the vibrating body while releasing transmission of rotational force to the inertial rotating body. 2. The vehicle according to claim 1, wherein the mechanical vibration generator is an automobile, and the vibration sensing member includes a spring (4
(2) a casing (20) supported through the above (0) and vibrating upward and downward by receiving the mechanical vibration of the vehicle, wherein the interlocking mechanism interlocks in one direction with the upward and downward vibration of the casing. A rotary wing member (60) that rotates in multiple directions, and transmits the rotational force to the inertial rotator and the vibrator while rotating with the rotation of the rotary wing member in one direction, and in the other direction of the rotary wing member. Rotating members (54, 55) that maintain the transmission of the rotational force to the vibrating body while releasing the transmission of the rotational force to the inertial rotating body while rotating relative to the rotary wing member with the rotation of the rotating blade member. The piezoelectric conversion power supply device according to claim 1, further comprising: