CN1220782A - Power generator and portable device - Google Patents
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- H02N2/18—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
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Abstract
A power generator suitably used for small-sized portable devices which generates electric power by vibrating a vibrating piece carrying a piezoelectric layer. The energy transmitting efficieny from an exciter to the vibrating piece is improved and the generator can efficiently generate electric power by utilizing the movement of the arm, etc., of the user. The occurrence of a secondary collision between the vibrating piece (21) and an exciting lever (35) is prevented by making the equivalent mass of the exciting lever (35) - which causes the vibration of the vibrating piece (21) by giving a blow to the piece (21) - smaller than that of the piece (21). Since the energy loss of the vibrating piece (21) caused by the secondary collision is prevented, the energy transmitting efficieny from the exciting lever (35) to the vibration piece (21) is improved remarkably. Therefore, a power generator which has a high power generating ability and a small size and is suitable for portable devices is provided.
Description
Technical Field
The present invention relates to a power generation device for generating power by exciting a vibrating reed having a piezoelectric body, and a portable apparatus having the power generation device.
Background
There have been several proposals for small-sized devices for generating electricity using piezoelectric materials, and for example, in jp 6-76894 a, a technique of generating electricity by driving a hammer rod using a rotational motion of a weight and striking a piezoelectric material is described.
Furthermore, jp 63-72593 a describes a technique in which a piezoelectric element is incorporated in a timepiece case, a weight is caused to vibrate by inertia in the vertical direction, and electric energy is generated by the vibration.
By capturing the movement of the wrist and the like by the power generation method of the piezoelectric body, the power for operating the timepiece device and the like can be obtained by generating power by generating strain in the piezoelectric body. In order to obtain kinetic energy from the movement of the wrist or the like and then efficiently convert the kinetic energy into electric energy, it is important that the movement of the wrist or the like is first efficiently converted into kinetic energy such as the rotation of the rotary weight for actual power generation, and then the kinetic energy is applied to the piezoelectric body as strain with high efficiency, and then the strain applied to the piezoelectric body is efficiently converted into electric energy.
The kinetic energy (input energy) applied to the piezoelectric body can be mainly classified into: the strain energy of a support layer or the like supporting the piezoelectric body, the strain energy of the piezoelectric body itself, and the electric energy stored in an electric storage device such as a capacitor due to the power generation of the piezoelectric body. In these three parts, the most important electric energy as a power generator varies depending on the electromechanical coupling coefficient of the piezoelectric body, the output voltage and electrostatic capacity when the piezoelectric element is not charged, the voltage of the electric storage device, and the like, but it is only a few percent of the strain energy of the piezoelectric body. Therefore, electric power generation using a piezoelectric body, such as free vibration, as an elastic rod has been studied. This is because the strain can be repeatedly generated by vibrating the piezoelectric body, and the generated strain is gradually converted into electric energy by inputting energy. In this way, it is possible to improve the efficiency of the generated electric energy with respect to the input energy corresponding to the 3 rd factor. Further, in the wristwatch-type power generation device worn on the wrist of the user, the movement of the wrist of the user is analyzed to efficiently rotate the rotary weight, which is a factor related to the 1 st factor.
Accordingly, an object of the present invention is to provide a device corresponding to the above-mentioned 2 nd factor, which can efficiently transmit kinetic energy obtained as a rotational motion of a rotary weight or the like to a piezoelectric body as input energy, and to provide a power generating device having a sufficient power supply capability, which actually drives a portable instrument from a motion of a user's wrist or the like, by realizing such a device.
In particular, as described above, since the input energy can be efficiently converted into electric energy by vibrating the vibrating reed having the piezoelectric body, the present invention aims to provide a power generator capable of transmitting the kinetic energy of the rotary weight or the like to the vibrating reed with as little loss as possible. It is another object of the present invention to provide a power generation device that has high power generation efficiency by applying displacement to a piezoelectric body with high efficiency, and that can ensure a sufficient amount of power generation by movement of a wrist or the like.
Disclosure of the invention
The inventors of the present application found that: when the vibration piece is excited by the kinetic energy of the rotary weight, the loss of the input energy supplied to the vibration piece is large, which is caused by the secondary collision of the striking portion striking the vibration piece with the excited vibration piece.
In order to prevent such secondary collision, after the striking portion gives a strike to the vibrating piece, it is necessary to give a velocity opposite to the initial displacement direction of the vibrating piece to the striking portion.
Therefore, the power generating device comprises at least 1 vibrating piece having the piezoelectric layer of the present invention and an excitation device for exciting vibration by applying an impact to the vibrating piece, and the power generating device can output power generated in the vibrating piezoelectric layer, and in the power generating device, the vibrating piece is collided with the vibrating pieceOf the impact portion of the vibration excitation deviceeSet to be smaller than the equivalent mass M of the vibrating piecee. Thus, after the impact is provided to the vibration plate, the impact portion is provided with a velocity opposite to the initial displacement direction of the vibration plate.
Therefore, since energy retransmission and loss due to secondary collision of the striking portion with the vibrating piece can be prevented, more input energy can be applied to the vibrating piece, and the power generation capability can be improved.
For example, in the case of mounting the vibrating piece in a cantilever beam shape, the mass of the vibrating piece is assumed to be MHAnd a distance L from the fixed end to the other end (free end)HX is the distance from the fixed end to the excitation point where the impact is applied by the impact portionHStandard function of vibration mode of
Equivalent mass M at the excitation pointeCan be represented by the following formula (A). The striking section is a rotary excitation rod that provides a strike at the excitation point, and its moment of inertia is assumed to be IbX is the distance from the center of rotation to the point of impact providing the impact to the excitation pointbThen the equivalent mass of the impact portion can be represented by the following formula (B):
Me=MH/(Ξn(xH/1H))2 (A)
me=Ib/xb 2 (B)
in order to increase the equivalent mass of the vibrating plate, it is desirable to add a weight to the free end of the one-armed beam-like mount, the equivalent mass M beingeCan be represented by the following formula (D). Further, assume that the mass of the cantilever portion of the vibrating piece is MHThe weight of the weight is Ma.
Me=Ma+MH/(Ξn(xH/1H))2 (D)
Further, when the coefficient of collision between the striker and the vibrating reed is assumed to be e, the following expression (C) is satisfied, whereby a secondary collision between the striker and the vibrating reed can be prevented. Thus, there is no input energy loss caused by secondary collision; therefore, the power generation capability of the power generator using the vibrating reed including the piezoelectric layer can be further improved.
Me＞((2·e+3·π+2)/3·π·e)×me (C)
When a vibrating reed including a piezoelectric layer is vibrated to generate power, it is desirable to efficiently excite primary mode (モ - ド) vibration effectively used for power generation and reduce higher-order mode vibration of a secondary mode or more. Therefore, it is effective that the striking portion gives a strike in the vicinity of the node of the secondary mode of the vibrating piece which returns a certain distance from the free end to the fixed end side of the vibrating piece mounted in the single-arm beam shape. In the case where the vibrating piece is not cantilever-shaped, it is naturally desirable to excite the vibrating piece in the vicinity of the node of the secondary or more mode having a small power generation effect.
When a weight is added to the free end of the vibrating piece mounted in the shape of a one-armed beam to increase the equivalent mass, a heavy weight can be mounted on the tip of the vibrating piece by using a weight including a recess opening toward the free end side (i.e., toward the tip of the vibrating piece). Further, by providing the excitation lever so as to collide with the inside of the concave portion, the excitation lever can be provided compactly. Meanwhile, the shock is provided near the section of the secondary mode which returns for a certain distance from the free end side to the fixed end side through the shock excitation rod, so that the 1-time mode vibration can be efficiently excited, and the power generation capacity is improved.
The power generating device can be implemented as a portable device by incorporating the power generating device into a case of a device such as a wrist-worn device, and a portable device which does not require power supply from the outside and battery exchange can be provided by incorporating a processing device such as a clock device or a communication device which can operate by using the power output from the power generating device into the portable device.
Further, it is desirable to provide a rotary weight rotatably mounted on the housing, and a gear train for accelerating the motion of the rotary weight and transmitting the accelerated motion to the striking portion, and to use an excitation lever that is driven to rotate in conjunction with the gear train at the striking portion and collides with the vibration plate. By accelerating the movement of the rotary weight, the rotary weight can rotationally drive the vibration exciting rod at a period faster than the movement period, and therefore, the kinetic energy of the rotary weight can be divided by the vibration exciting rod and applied to the vibrating piece. Therefore, the input energy applied to the vibrating reed can be dispersed, and thus, the damage of the vibrating reed can be prevented, and the small-sized vibrating reed can be repeatedly applied with the vibration having a small amplitude. Therefore, a small-sized generator with small loss can be realized, and a sufficient amount of power generation can be ensured.
Further, by providing a drive lever rotationally driven by a gear train, and rotationally driving the exciting lever by bringing one end of the exciting lever into contact with one end of the drive lever, the exciting lever can be downsized. Therefore, the moment of inertia of the exciting lever can be reduced, so that the equivalent mass of the exciting lever can be reduced, and the secondary collision with the vibrating reed can be prevented to sufficiently follow the speed of the accelerated gear train. Further, it is desirable to mount such an excitation lever in the housing so that the center of rotation coincides with the center of gravity. Thus, the angle of the case is changed along with the movement of the wrist, and the exciting rod is stabilized without unnecessary movement, so that the secondary collision of the vibrating reed and the exciting rod can be prevented, and the power generating device with high power generating capability can be provided, which can effectively and fully utilize the movement of the wrist of the user.
By providing a plurality of vibrating pieces and applying vibrations to these vibrating pieces alternately by the exciting rod, the duration of the vibrations caused on each vibrating piece by 1 impact can be made long. Therefore, loss due to the next excitation applied to the vibration of the vibrating reed can be prevented, and efficiency can be improved.
Further, the vibration plate may be hit by at least 1 ball moving in a groove formed around the vibration plate without using the excitation lever.
Further, the vibrating plate may be combined into a tuning fork shape, and the shape other than the one-armed beam such as a rectangular plate may be adopted, and the support position may be a node of vibration, whereby the vibration loss is reduced, and a highly efficient power generation device can be configured.
Brief description of the drawings
Fig. 1 is a schematic configuration diagram showing a power generation device having a vibrating piece including a piezoelectric body layer relating to embodiment 1 of the present invention;
fig. 2 is a cross-sectional view showing the structures of a drive system and an excitation device of the power generation device shown in fig. 1;
fig. 3 is an enlarged view of the excitation device shown in fig. 1;
fig. 4 is a graph showing a case where a loss rate of mechanical energy of the vibrating piece is varied with an amplitude;
fig. 5 is a graph showing a case where energy transfer efficiency from the excitation rod to the vibration plate changes with a ratio of the vibration plate equivalent mass to the excitation rod equivalent mass;
fig. 6 is a diagram illustrating a case where the excitation lever collides with the vibrating reed, where fig. 6(a) shows a state before the collision and fig. 6(b) shows a state after the collision;
fig. 7 is a diagram showing conditions for calculating equivalent masses of the excitation rod and the vibrating piece;
fig. 8 is a graph showing a displacement after the excitation lever collides with the vibrating piece;
fig. 9 is a graph showing the ultimate equivalent mass of the re-collision of the excitation rod with the vibration plate based on several collision coefficients;
fig. 10 is a graph showing a case where amplitudes of 1-order mode and 2-order mode are changed according to a collision position where a collision is provided to the vibrating piece when the vibrating piece vibrates;
FIG. 11 is a graph of the magnitude of the 1 st and 2 nd modes shown in FIG. 10 as a function of open circuit voltage;
fig. 12 is a view showing a schematic configuration of a power generation device relating to embodiment 2 of the present invention;
fig. 13 is a view showing a schematic configuration of a power generation device relating to embodiment 3 of the present invention;
fig. 14 is a view showing a schematic configuration of a power generation device relating to embodiment 4 of the present invention;
fig. 15 is a view showing a schematic configuration of a power generation device relating to embodiment 5 of the present invention;
fig. 16 is a view showing a cross section of a groove portion of the power generation device shown in fig. 15;
fig. 17 is a view showing a schematic configuration of a power generation device relating to embodiment 6 of the present invention;
fig. 18 is a view showing the shape and vibration mode of the vibration plate of the power generation device shown in fig. 17.
Best mode for carrying out the invention
[ example 1]
The present invention will be described in more detail below with reference to the accompanying drawings. Fig. 1 shows the main aspects of a wrist-worn portable instrument comprising a power generation device in connection with an embodiment of the invention. The portable apparatus 10 of the present example includes: a power generating device 20 including a vibrating piece 21 including piezoelectric layers 22a and 22 b; a rectifying circuit 2 for rectifying an alternating current obtained by the vibration of the vibrating piece 21; an electricity storage circuit 4 that stores the rectified current; and a processing device 6 for performing a timing process using the generated current. The processing device 6 may include functions such as radio paging, a personal computer, and the like, in addition to the time counting process of driving the time counting unit 7 or performing the alarm process. In the present example, the capacitor 5 is used for the power storage circuit 4, but a device having power storage capability such as a battery may be used. The rectifier circuit 2 is not limited to full-wave rectification using the diode 3 as in this example, and may be a half-wave rectifier circuit, or may be a rectified current using an inverter or the like. Although the portable device of the present example is shown in a conceptual view in fig. 1, the rectifier circuit 2, the accumulator circuit 4, the processing device 6, and the like can be arranged in a planar overlapping state with the drive system 11 described below, and the entire device can be miniaturized.
The power generation device 20 of the present example includes an excitation device 30 that supplies vibration to a vibrating reed 21 having a piezoelectric layer, and the excitation device 30 is driven by an excitation system 40. The vibrating piece 21 includes: a support layer 26 made of metal and fixed to the base plate 12 in a cantilever shape; and piezoelectric layers 22a and 22b formed on both sides of the support layer 26. A weight 25 is attached to a tip (free end) 23 of the vibrating reed 21, which freely vibrates. The weight 25 is provided with a recess 25c opened at the free end 23 side at the center. Further, the active end 39 of the exciting lever 35 is provided so as to collide with the inside of the concave portion 25c to provide a collision to the vibrating piece 21. Therefore, when the excitation lever 35 of the excitation device 30 is rotated, the vibration plate 21 is excited, and the vibration plate 21 is vibrated freely with the tip 23 thereof being a free end and the side 24 fixed to the base plate 12 by the screw 27 being a fixed end. Accordingly, a displacement is repeatedly applied to the piezoelectric layers 22a and 22b of the vibrating reed 21, and an electromotive force is generated.
The driving system 40 of this example includes a rotary weight 13 rotating inside the case 1, and when worn as a wristwatch, the rotary weight 13 rotates in response to the movement of the user's wrist and body, etc., to provide vibration to the vibrating piece 21 with the force. In the driving system 40 of this example, a gear train 41 having a structure shown in fig. 2 is provided to accelerate the movement of the rotary weight 13 and supply the accelerated movement to the excitation device 30. The movement of the rotary weight 13 is transmitted to the 1 st intermediate gear 15a via the rotary weight gear 14 constituting the gear train 41, and accelerated. The 1 st intermediate gear 15a meshes with the 2 nd intermediate gear 15b having the same radius, and the 1 st and 2 nd intermediate gears 15a and 15b are rotated by the movement of the rotary weight 13. Further, since the respective motions of the intermediate gears 15a and 15b are transmitted to the driving lever gears 31a and 31b of the exciting device 30, the intermediate gears 15a and 15b have the same radius and rotate in opposite directions, and therefore, the driving lever gears 31a and 31b are rotationally driven in opposite directions at the same speed. By using such a gear train 41, for example, when the rotary weight 13 captures the movement of the user's wrist or the like and moves to the limit of 1Hz, the movement can be accelerated to the limit of 50Hz and transmitted to the excitation device 30. In the excitation device of this example, since the excitation lever 35 is driven by the two drive levers 32a and 32b, the vibration of 2KHz limit is excited in the vibration plate 21 by applying the impact to the vibration plate 21 in units of 100Hz limit. The above frequencies are described as examples, and the present invention is not limited to these frequencies. The intermediate gears 15a and 15b constituting the gear train 41, and gears and levers described below are combined so as to be disposed in a narrow space between the bottom plate 12 in the housing 1 and the rotary weight bearing 16 supporting the rotary weight 13.
When the drive lever gears 31a and 31b are rotationally driven by the drive system 40, the drive levers 32a and 32b that move in the same direction as the drive lever gears 31a and 31b rotate at the same speed in opposite directions, and thus the two driven ends 36a and 36b of the exciting lever 35 are driven, respectively. The exciting lever 35 is rotated left and right about the center 37 of the exciting lever by the drive levers 32a and 32b, and in response to this movement, the active end 39 on the side opposite to the passive end 36 of the exciting lever 35 is moved left and right. The active end 39 is used to apply an impact to the inner side of the front end weight 25 of the vibrating piece 21, thereby exciting vibration to the vibrating piece 21. Fig. 2 shows a combination of one intermediate gear 15a, the drive lever gear 31a, the drive lever 32a, and the driven end 36a, but the same applies to a combination of another intermediate gear 15b, the drive lever gear 31b, the drive lever 32b, and the driven end 36 b.
When the vibration plate 21 of the power generator 20 is directly excited by a device having a large kinetic energy such as the rotary weight 13, the vibration plate must be increased in size to prevent damage to the vibration plate. On the contrary, when the movement of the rotary weight 13 is accelerated by the gear train 41 as in this example, the kinetic energy of the rotary weight 13 can be divided and applied to the vibration plate 21, and the vibration plate 21 can be prevented from being damaged, and the size can be reduced.
Further, as shown in fig. 4, if the same resonator is used, since the rate of loss of mechanical energy when the resonator element vibrates increases with an increase in amplitude, the amplitude can be reduced by dividing the input energy and applying it again, and the loss of mechanical energy at the resonator element 21 can also be reduced.
Fig. 3 shows an enlarged view of the arrangement of the drive levers 32a and 32b and the exciting lever 35 constituting the exciting device 30. The drive levers 32a and 32b in this example are substantially spindle-shaped levers, and the respective levers 32a and 32b are rotationally driven at equal speeds in opposite directions with their centers 33a and 33b as the rotational center. The spindle-shaped levers 32a and 32b are set to be shifted in phase and rotated so that the opposite ends 34 of each lever alternately contact the exciting lever passive ends 36a and 36b to drive the passive lever 35.
In consideration of the arrangement of the intermediate gears 15a and 15b, the driven ends 36a and 36b are disposed at positions separated by an appropriate angle so that the driving end 39 is located on the side opposite to the center 37 of the exciting rod with respect to the driven ends 36a and 36 b. Further, in the excitation device 30 of the present embodiment, the center 33a of the driving lever 32a and both ends 34 thereof are arranged so that the position 38a in contact with the driven end 36a of the excitation lever and the center 37 of the excitation lever 35 are substantially aligned, and further, the center 33b of the driving lever 32b and both ends 34 thereof are arranged so that the position 38b in contact with the driven end 36b of the driven lever and the center 37 of the excitation lever 35 are substantially aligned, so that the kinetic energy of the driving levers 32a and 32b can be transmitted to the driven lever 35 with the highest efficiency.
The exciting lever 35 of the exciting apparatus of this example is arranged as described above, and can transmit energy from the drive system 40 to the exciting lever 35 with very small loss, and further, can be driven alternately by the two drive levers 32a and 32b, and therefore, input energy can be supplied to the vibrating reed 21 in a shorter time unit, and vibration can be excited with high efficiency. Since the exciting lever 35 is driven by the drive levers 32a and 32b, the moment of inertia of the exciting lever 35 can be reduced, and even when the exciting lever 35 moves at a high frequency, the high-frequency motion obtained by accelerating the motion can be sufficiently tracked. Further, as described below, since the equivalent mass of the exciting lever can be reduced by reducing the moment of inertia of the exciting lever, there is an effect of reducing energy loss caused by a secondary collision with the vibrating reed.
Since the exciting lever 35 of this example is attached to the inside of the housing 1 with its center of gravity as the rotation center 37, the exciting lever 35 does not rotate arbitrarily when the direction of the housing 1 is changed. Therefore, the exciting lever 35 is driven only by the drive levers 32a and 32b, and normally, it is appropriately maintained in a positional relationship with the drive levers. Further, the excitation rod 35 is prevented from being inadvertently moved in the direction of the case 1 to cause a secondary collision with the vibrating reed 21, which causes an energy loss.
Fig. 5 shows the input energy (vibration energy of the vibrating reed 21) Ei obtained by the vibrating reed 21 and the kinetic energy E of the excitation rod 35 in the generator 20 of this exampleoRatio of (energy transfer efficiency) ηt(= Ei/Eo) equivalent mass m with exciting rod 35eMass M equivalent to the vibrating reed 21eRatio of (equivalent mass ratio) MR = (m)e/Me) But the situation is changed. As can be seen from this figure, the equivalent mass ratio MRLess than 1, energy transfer efficiency etatAccording to equivalent mass ratio MRIs increased. In contrast, the equivalent mass ratio MRNear 1, energy transfer efficiency ηtSharply decreases; equivalent mass ratio MROver 1, the energy transfer efficiency etatAgain increased, but at a mass ratio M equivalent toRThe maximum value is small when the value is less than 1. Equivalent mass ratio MRWhen less than 1, the starting speed of vibration of the vibrating reed 21 is dependent on the equivalent mass ratio MRIs increased, and therefore, the energy transfer efficiency η is increasedtAnd (4) rising. In contrast, the equivalent mass ratio MRWhen the distance approaches 1, the kinetic energy Eo of the excitation rod 35 is substantially transmitted to the vibrating reed 21, and therefore, the excitation rod 35 stops at a position where the shock is applied to the vibrating reed 21, and the excitation piece 35 makes a secondary collision with the vibrating reed 21. Due to such secondary collisionThe input energy obtained by the vibrating reed 21 is reversely supplied to the exciting rod 35 side to cause energy loss, and therefore, the energy transfer efficiency ηtAnd sharply decreases. And when the equivalent mass ratio MRWhen the ratio exceeds 1, the energy loss due to the secondary collision is somewhat reduced on the side of the vibrating reed 21, and the energy transfer efficiency η is increased because of the occurrence of the tertiary collision or the liketAnd (4) rising.
Thus, when the mass ratio M is equivalentRAt 1, the energy transfer efficiency ηtIs very low. In order to improve the energy transfer efficiency etatThe equivalent mass ratio M must be madeRLess than 1 so as not to cause secondary collision; alternatively, it is necessary to determine the energy transfer efficiency η even if a secondary collision occurstNor too low conditions. Therefore, the inventors of the present application have found a condition for not causing the secondary collision between the excitation lever 35 and the vibration plate 21 as follows. In FIG. 6, the respective equivalent masses M are usedeAnd meAnd the equivalent elastic constant k of the vibration plate 21 represents a system in which the excitation rod 35 collides with the vibration plate 21. By using equivalent masses M, as described belowe、meAnd the vibration elastic constant K, the impact portion and the vibrating piece are not limited to the combination of the excitation lever and the cantilever, and the present invention can be applied to the case where a different structure such as a ball is used for the impact portion as described below and the case where a piezoelectric body having a different shape such as a rectangular plate is used for the vibrating piece.
For a mass M as shown in FIG. 7(a)HThe distance from the fixed end to the other end (free end) is IHThe distance from the fixed end to the excitation point X where the impact is applied by the impact part is XHStandard function of vibration mode of
Of the vibrating reed, equivalent mass M of the vibrating reed 21eCan be expressed as follows:
Me=Mh/(Ξn(xH/1H))2(1) wherein,assuming a density at the integration point of ρ, the standard function
As a function satisfying the following relationship:
SSSρ·Ξn 2·dV=MH(2) it is desirable to excite a vibration of 1 st mode in the vibrating piece 21 of this example, and the standard function of such a mode is as follows:
Ξ1=(cosα1y-coshα1y)
-(cosα1y+coshα1y)/(sinα1y+sinhα1y) wherein, x (sin α)1y-sinhα1y) …(3)
y=XH/lH
cosα1×coshα1=-1 (α1For the 1 st solution)
Also, for a moment of inertia of IbThe distance from the center of rotation to the point of impact providing the impact to the excitation point of the vibration plate is XbOf the excitation rod 35, the equivalent mass m of the excitation rod 35eCan be expressed as follows:
me=Ib/xb 2 (4)
further, as shown in fig. 7(b), when the weight 25 having the concave portion is attached to the tip of the vibration piece 21 and when the vibration piece is not a one-arm beam, the standard function is
(y) is different from the above, but can be obtained in the same manner as described above. Furthermore, the excitation point is very close to the front end, the distance L from the fixed end to the free endHA distance X from the fixed end to an excitation point X where the impact is applied by the impact partHSubstantially equal, the equivalent mass M of the beam-like vibrating piece obtained by the equation (1) is usedeAnd the mass Ma of the weight, which can approximate the equivalent mass of the vibrating piece shown in fig. 7(b) by the following equation:
Me=Ma+MH/(Ξn(xH/1H))2 (1’)
returning to FIG. 6, at an equivalent mass of meAt a speed V of the exciting rod 35bCollision to equivalent mass meAfter the vibration piece 21, in order not to cause a secondary collision with the vibration piece 21 that has started vibrating, the excitation rod 35 must obtain a velocity opposite to the displacement direction of the vibration piece 21 after the collision. Thus, the equivalent mass m at the excitation rod 35eMass m equivalent to the vibrating reed 21eThe following relationship must be established:
me＜Me (5)
when a more detailed analysis is performed, assuming that the collision coefficient between the excitation rod and the vibrating plate is e, the following equations are derived based on the principle of conservation of momentum: 0 XMe+Vb×me=VH’×Me+Vb’×me (6)
(Vb’-VH’)/VbHere, = -e (7) VH' and Vb' are the velocities of the vibration plate 21 and the excitation rod 35 immediately after the collision, respectively.
Next, when the movement of the vibrating reed 21 and the movement of the excitation lever 36 after the collision are examined, fig. 8 shows the result. First, the vibrating piece 21 starts vibrating from the moment of receiving the impact, and fig. 8 shows the displacement shown by the solid line. This displacement can be expressed by the following equation. For simplicity, the vibration of the 1 st mode is considered for the vibrating reed 21, and the attenuation of the vibration is not considered,
uHwhere ω denotes an angular velocity, a denotes an amplitude, and t denotes time, the following relationship is satisfied according to initial conditions:
(duH/dt)t=0=ω·A=VH’ (9)
on the other hand, the exciting rod 35 has a velocity V as indicated by the chain line 52b' moving from the point of impact to a distance, the displacement can be expressed as:
ub=Vb’·t (10)
according to the above, the displacement u is set so that the vibration plate 21 does not collide with the excitation rod 35 secondarilyHAnd ubExcept that the instant t is equal to 0, as long as there is a solution. That is, the following formula (11) may be used as long as a solution is obtained, except for t = 0:
A·sinωt=Vb'. t (11) to solve the formula (11), the formula (8) is approximated by a cubic equation. Displacement u of vibrating reed 21HPassing through points O, Q, S of fig. 8, therefore, can be approximated by the following cubic equation:
uH3(t) = B · t (t-7 pi/ω) (t-2 · pi/ω) (12) here, since the formula (12) passes through the point R (3 pi/2 ω, -a) of fig. 8, the constant B becomes the following formula according to the formula (9):
B=8·ω2/(3·π3)×VH' (13) thus, the following equation (14) can be used to approximate equation (11): b.t ((t-pi/omega) (t-2. pi/omega) -Vb'/B)) =0(14) therefore, a discriminant D of the following expression (15) is obtained from ω, e and meIf both of them are larger than 0, the condition of discriminant D < 0 is obtained, and the relationship among formula (13), formula (6), and formula (7) is used for sorting to obtain:
(t-π/ω)(t-2·π/ω)-Vb'/B =0 (15) so that the equivalent mass M at the vibrating pieceeMass m equivalent to the exciting rodeTo obtain the relationship shown in the formula (16):
Me＞((2·e+3·π+2)/3·π·e)×me(16) according to the above, by using the vibrating reed and the exciting rod having the equivalent mass satisfying the above expression (16), it is possible to provide the power generating apparatus free from energy loss due to the secondary collision between the vibrating reed and the exciting rod.
By the above-mentioned examination, the condition that the vibration piece and the excitation rod do not have the secondary collision can be replaced with the condition of each equivalent mass.
In fig. 9, the equivalent mass M of the vibrating piece satisfying the following ultimate equivalent mass relationship of re-collision is shown for different collision coefficients e based on the above-listed expression (16)eAnd equivalent mass m of the excitation rode：
Me=((2·e+3·π+2)/3·π·e)×me(17) As shown in fig. 5, the equivalent mass ratio M is within a range where secondary collision does not occurRNear 1, energy transfer efficiency ηtHigh. Therefore, it is desirable to use the equivalent mass M of the vibrating pieceeMass m equivalent to the exciting rodeA value of the relationship close to the ultimate equivalent mass of the re-collision.
Further, the inventors of the present application have found that the voltage generated from the vibration 21 fluctuates with the change in the excitation point X shown in fig. 7. When vibration is given to the vibrating reed 21, vibration contributing to power generation is 1 st-order mode vibration, and when high-order vibration of a secondary mode or more is generated, input energy to the 1 st-order mode effective in power generation is reduced in order to excite the vibrating mode. In order to measure such a change, the inventors measured that the amplitude of the 1 st mode and the amplitude of the 2 nd mode change depending on the excitation point X, and the results are shown in fig. 10. In the measurement, a piezoelectric body (i.e., a PZT layer laminated on a support material made of phosphor bronze, the entire length L) is usedH21mm single piezoelectric wafer type), the distance between the excitation point X and the tip (free end) of the vibrating piece [ collision position (L) shown in fig. 7 ] was changedH-XH)]After the collision is provided, the open circuit voltage V generated on the vibrating piece is measured. The open-circuit voltage V obtains a value substantially proportional to the amplitude of vibration of the vibrating piece, as shown in fig. 11, and a waveform in which a 2-th mode is superimposed on a 1-th mode of vibration is obtained. Thus, the amplitudes V of the 1 st and 2 nd modes are obtained from the obtained waveformαAnd VβFig. 10 shows the results.
As can be understood from fig. 10, when the impact is applied to a position returning from the free end to the fixed end by a certain distance, the amplitude of the 1 st mode can be made large and the amplitude of the 2 nd mode can be made small, compared to when the impact is applied to the free end of the vibrating piece. Moreover, the 1 st mode amplitude is maximum when the impact position is about 3.5mm from the front end; the amplitude of the 2 nd mode is minimal at substantially the same impact location. The vicinity of the position where the amplitude of the secondary mode is minimum can be regarded as a nodal portion where the secondary mode vibration exists. Therefore, it is known that by providing the impact to the vicinity of the node where the 2 nd mode of the vibrating piece vibrates, the generation of the 2 nd mode can be suppressed, and the amplitude of the 1 st mode contributing to the power generation can be increased. Therefore, by applying the impact not to the free end of the vibrating piece but to a position returned by a certain distance from the free end, the input energy can be supplied to the vibrating piece, and the input energy can be more effectively utilized for power generation, and a power generation device using a piezoelectric body having high power generation capability can be provided.
As described above, the inventors of the present application have found that, in a power generation device using a vibrating reed including a piezoelectric layer, in order to efficiently transmit energy to the vibrating reed, it is desirable to set the relationship between the equivalent mass of the vibrating reed and the equivalent mass of a striking portion such as an excitation rod that strikes the vibrating reed within a range in which 2 times of collisions do not occur. Further, it has been found that, in order to suppress the generation of 2-order mode vibration in the vibrating piece and to more effectively utilize the input energy for power generation, it is desirable to apply an impact to the vicinity of a node corresponding to the 2-order mode vibration, which is difficult to excite the 2-order mode vibration.
In the power generating device 20 of the present example shown in fig. 1, a concave weight 25 is added to the free end 23 side of the vibration plate 21, and the equivalent mass is adjusted in the small vibration plate 21, so that the structure is larger than the exciting rod 35 and is easier. Further, since the exciting lever 35 is provided with a cam portion or the like so as to be driven by the drive lever 32 without being directly driven from the gear train 41, the exciting lever 35 can be made compact and the equivalent mass can be small. Therefore, the power generator 20 of the present example can prevent the secondary collision between the vibrating reed 21 and the exciting rod 35, and is a power generator having high energy transfer efficiency with a configuration that can eliminate the energy loss due to the 2-time collision. Further, since the concave weight 25 is used, the weight can be extended on both sides of the free end of the vibrating piece, and therefore, the weight having a sufficient mass can be disposed in a small space.
Further, in the power generation device 20 of the present embodiment, the driving end 39 of the exciting lever 35 is provided inside the concave portion 25c of the concave weight 25. Therefore, the active end 39 excites the vibration returning a little distance from the free end 23 of the entire vibrating reed 21 including the weight 25 toward the fixed end 24. Therefore, the input energy is transmitted to the vibrating reed 21 so that the amplitude of the 2-th mode is small and the amplitude of the 1-th mode is large, and a power generating device with high power generating capability can be obtained.
As described above, the power generator 20 of the present embodiment accelerates the motion of the rotary weight 13 by the gear train 41 to apply the impact to the vibration plate 21, divides the kinetic energy of the rotary weight 13, applies the kinetic energy to the vibration plate 21, and the like, and can very efficiently transmit the kinetic energy of the rotary weight 13 to the small-sized vibration plate 21 including the piezoelectric layer, and is a small-sized power generator with high power generation capability.
The electric power supplied by the power generator of this example can operate not only the timer of this example but also a processing device such as a pager, a telephone, a radio station, a hearing aid, a desktop computer, or an information terminal. The shape of the portable device is not limited to wrist-worn portable devices such as vehicle-mounted type and pocket-sized type. In these portable devices, the power generation device according to the present invention can function as a processing device mounted on the portable device at any time and place without fear of battery replacement or the like.
[ example 2]
Fig. 12 shows a wrist-worn portable instrument 60 comprising a power generation means 20 in connection with the present invention. The power generator 20 of this example also includes a vibrating reed 21 having a piezoelectric layer, and the current generated by the vibrating reed 21 is provided by striking the vibrating reed 21 with the kinetic energy of the rotary weight 13 rotating in the case 1 of the portable device 60 to excite vibration. Therefore, the same reference numerals are attached to portions common to the above-described embodiments, and the description thereof is omitted. The same applies to other embodiments described below.
The power generation device 20 of this example rotates the excitation lever 35 by 1 drive lever 32 to supply kinetic energy to the vibrating reed 21. Thus, the gear set 41 of the driving system 40 also accelerates the movement of the rotary weight 13 by using 1 intermediate gear 15 so as to transmit to the driving rod 32. Therefore, the gear train 41 and the drive lever 32 of the drive system 40 can be simplified in structure, and therefore, the power generation device 20 and the portable device 60 can be further miniaturized. Further, since the concave weight 25 is provided at the free end 23 of the vibrating reed 21 and the active end 39 of the exciting lever 35 is provided inside the concave portion 25c, the secondary collision of the exciting lever 35 with the vibrating reed 21 can be prevented and the 1-order mode vibration can be easily excited, as in embodiment 1. Since the motion of the rotary weight 13 is accelerated and transmitted by the gear train 41, the kinetic energy of the rotary weight 13 is divided and supplied to the vibrating piece. As described above, the power generator and the wrist-worn instrument of the present example can improve the energy transfer efficiency as in example 1, and are a smaller power generator and a wrist-worn instrument with high power generation capability.
[ example 3]
Fig. 13 shows an example of the power generation device 20 different from the embodiment of the present invention. The power generating device 20 includes two vibrating pieces 21a and 21b, and the active end 39 of the excitation rod 35 is located between the two vibrating pieces 21a and 21 b. Further, the weights 25a and 25b provided on the free ends 23a and 23b of the two vibrating pieces 21a and 21b alternately give impacts to points returning a little distance from the free ends 23 to the fixed ends 24 of the weights 25a and 25b by the exciting rod 35, and excite vibrations in the respective vibrating pieces 21a and 21 b. In the power generation device 20 of the present example, since the impacts are alternately applied to the two vibration pieces 21a and 21b, the duration of the vibration caused by one impact on the two vibration pieces can be made long. Therefore, since the period in which the input energy caused by 1 impact is converted into the electric energy can be set long, when the energy transmitted through the excitation rod is large and the number of times of vibration of the vibration plate 21 is large, a sufficient margin can be secured until the next excitation. Therefore, a state in which the vibration is excited again by the next vibration can be prevented, and a loss of vibration energy due to such a state can be avoided.
In this example, the two vibration pieces 21a and 21b are alternately struck by the excitation rod, but 3 or more vibration pieces may be alternately struck by n vibration pieces by arranging 3 or more vibration pieces around the excitation rod that rotates, or by using a plurality of excitation rods, for example.
[ example 4]
Fig. 14 shows an example of a power generation device different from the embodiment of the present invention. In the power generating device 20 of this example, the supporting layers 26a and 26b of the two vibrating pieces 21a and 21b are formed in a tuning fork shape, and the bottom 26c connecting the two supporting layers 26a and 26b is mounted on the base plate 12. Further, currents are supplied from the vibrating pieces 21a and 21b to two different rectifier circuits, not shown, through the piezoelectric layers 22a and 22b provided on the vibrating pieces 21a and 21b, respectively. Therefore, when the tuning fork is excited from the outside, power can be extracted from two modes, i.e., an in-phase vibration mode and an anti-phase vibration mode, caused by the left and right beams. It is believed that the vibration loss of the in-phase mode is substantially the same as for the shoulder rest beam (shoulder-held ち beam); however, since no force is applied to the fixed portion, the vibration loss of the reverse mode is very small. Therefore, the input energy applied to the reverse mode can be efficiently converted into power, and therefore, a power generator using a piezoelectric body having higher efficiency than that of a single-arm beam can be provided.
Further, as in the above-described embodiment, the equivalent mass of the exciting rod 35 is set smaller than the vibrating pieces 21a and 21b, and further, the impact is given to the portion returning by a certain distance from the free end to the fixed end of the vibrating pieces 21a and 21 b. Therefore, by generating power using the tuning fork combined oscillator 29 of this example, it is possible to generate vibration with a small vibration loss rate by making full use of tuning fork characteristics, and therefore, it is possible to provide a power generator with high power generation efficiency while suppressing loss of mechanical energy.
[ example 5]
Fig. 15 and 16 show a schematic configuration of a power generation device 20 different from the embodiment of the present invention. In the power generation device 20 of this example, the ball 62 is used in the striking portion that excites the vibration reed 21. In the power generating device 20 of this example, a circular groove 61 is formed in the upper and lower cases 65a and 65b on which the vibrating piece 21 is mounted so that the ball 62 can move freely in the groove 61 by returning the position from the free end 23 to the fixed end 24 of the vibrating piece 21 by a certain distance. Thus, when the ball 62 is moved by providing a movement to the case 65, the ball 62 collides with the vibrating piece 21 at a position returning from the free end 23 of the vibrating piece 21 by a certain distance, and the vibration is provided to the vibrating piece 21. As a result, electromotive force is generated in the piezoelectric layers 22a and 22b of the vibrating reed 21, and power is generated.
Since the equivalent mass of the ball 62 provided to the vibrating piece 21 by the impact can be made smaller than that of the vibrating piece 21 in the power generating device 20 of this example, as described in detail in embodiment 1, the secondary impact can be prevented, and the energy transfer efficiency from the ball 62 to the vibrating piece 21 can be improved. Further, since the ball 62 provided to strike the vibrating piece 21 can move freely inside the groove 61, a complicated structure for mounting the rotary weight and the bearing of the gear train is not required. Therefore, a power generation device having high power generation capability can be provided at low cost with a simple configuration. Further, by sealing the plurality of balls 62 in the groove 61, the number of times of striking the vibrating piece 21 can be increased, and the energy for moving the case 65 can be transmitted to the vibrating piece 21 with higher efficiency.
[ example 6]
Fig. 17 and 18 show a schematic configuration of a power generation device 20 different from the embodiment of the present invention. In the power generation device 20 of this example, the ball 62 is used in the striking portion that excites the vibration reed 21. The power generator 20 of this example has a circular groove 61 formed in a case 65 having a rectangular plate-shaped vibrating piece 21 with two free ends, so that a ball 62 can move freely in the groove 61. Thus, when the ball 62 is moved by providing a motion to the case 65, the ball 62 collides with the vibrating piece 21 to provide a vibration to the vibrating piece 21. As a result, electromotive force is generated in the piezoelectric layers 22a and 22b of the vibrating reed 21, and power is generated.
In this embodiment, as shown in fig. 18(a), since the shape of the vibrating reed 21 is a rectangular plate with two free ends, the nodes 81a and 81b are formed in the 1-th mode. By supporting the nodes 81a and 81b by the supporting members 71a and 71b shown in fig. 18(b), the vibration loss due to the fixation of the vibrating piece can be prevented.
Further, as in the case of the cantilever, by applying the impact to the vicinity of the node of the vibration of the higher mode of the vibrating piece, the generation of the higher mode can be suppressed, and the 1 st mode width contributing to the power generation can be increased. Fig. 18(c) shows the 1 st mode, fig. 18(d) shows the 2 nd mode, and fig. 18(c) shows the 3 rd mode of a rectangular plate with both free ends. In the figure, a straight line indicates a position in the longitudinal direction of the rectangular plate, and a curved line indicates a shape at the time of deformation. In the figure, the number indicates the position of the vibration node when the longitudinal length of the rectangular plate is made 1. According to these figures, it is desirable to apply the impact to the sections of the 2 nd and 3 rd modes, that is, the vicinity of both sides of the center of 10% to 13% of the entire length from the free end or 36% to 50% of the entire length from the free end, instead of applying the impact to both ends of the entire mode, which become the antinodes.
Since the equivalent mass of the ball 62 provided to the vibrating piece 21 by the impact can be made smaller than that of the vibrating piece 21 in the power generating device 20 of this example, as described in detail in embodiment 1, the secondary impact can be prevented, and the energy transfer efficiency from the ball 62 to the vibrating piece 21 can be improved. Further, since the ball 62 provided to strike the vibrating piece 21 can move freely inside the groove 61, a complicated structure for mounting the rotary weight and the bearing of the gear train is not required. Therefore, a power generation device having high power generation capability can be provided with a simple configuration at low cost. Further, by sealing the plurality of balls 62 in the groove 61, the number of times of striking the vibrating piece 21 can be increased, and the energy for moving the case 65 can be transmitted to the vibrating piece 21 with higher efficiency.
Therefore, by generating power using the vibrator 21 of this example, it is possible to generate vibration with a small vibration loss by making full use of the characteristics of the rectangular plate having free both ends, and therefore, it is possible to provide a power generator with high power generation efficiency while suppressing the loss of mechanical energy.
Thus, in embodiments 1 to 5, the inventors of the present application established a mass relationship between the one-arm beam-like vibrating piece and the exciting portion (rod, ball, etc.) without secondary collision loss; in example 6, a case is described in which the rectangular plate-shaped vibrating reed having both free ends and the exciting portion can be set so as not to have the same loss. However, the present invention is not limited to these vibrating reed and exciting structure, and in a combination of any vibrating reed such as a circular plate, trapezoidal plate, rectangular plate, cylinder, or rectangular parallelepiped and any exciting portion such as a rod, ball, or plate spring, as shown in fig. 8, by setting such that the exciting portion receives a velocity opposite to the direction of the vibrating reed after striking the vibrating reed, the same effect as the loss without secondary collision can be obtained. This setting can be easily obtained by gradually reducing the mass of the excitation portion and observing the excitation portion by simultaneously colliding the same vibrating piece. That is, it is obvious that the power generation device in which the exciting portion receives a velocity opposite to the direction of the vibrating reed after the vibrating reed is struck is also within the scope of the present invention.
In the above-described embodiment, the description has been made based on the device for generating electricity using the bimorph-type vibrating reed in which two piezoelectric layers 22a and 22b are formed on both sides of the metal supporting layer 26, or the vibrating reed in which the piezoelectric layers 22a and 22b are laminated, but of course, a vibrating reed in which two or more piezoelectric layers are laminated, a single piezoelectric wafer-type vibrating reed, or the like may be used. Further, the material constituting the piezoelectric portion may be, of course, PZT (trademark), ceramic materials such as barium titanate series and lead titanate series, single crystals such as quartz and lithium niobate, and polymer materials such as PVDF.
The present invention is not limited to the wrist-worn portable device such as the timepiece described in the above embodiment. The present invention can provide a small-sized power generating device having high power generating capability, and therefore, the power generating device of the present invention is suitable for a power generating device incorporated in other small-sized portable electronic devices, and for example, the power generating device of the present invention can be applied to information terminals such as pagers, telephones, radio stations, hearing aids, pedometers, desktop computers, electronic notebooks, and the like, and IC cards, wireless receivers, and the like. In addition, by using the power generation device of the present invention in these portable devices, power generation can be efficiently performed while capturing the motion of a person, and battery consumption can be suppressed, or even a battery can be eliminated. Therefore, the user can use these portable devices without worrying about battery replacement, and can prevent trouble such as losing the contents stored in the memory due to battery replacement. Further, the function of the portable electronic device can be exhibited in an area or a place where the battery and the charging device are not easily handled, or in a case where the battery is difficult to be replenished due to a disaster or the like.
Industrial applicability
As described above, in the power generation device for generating power by vibrating the vibrating reed including the piezoelectric layer according to the present invention, the equivalent mass of the striking portion for applying a striking to the vibrating reed to excite vibration is made smaller than the equivalent mass of the vibrating reed, thereby preventing the secondary collision between the vibrating reed and the striking portion. Therefore, according to the present invention, since energy loss due to secondary collision can be prevented, a power generation device having extremely high energy transfer efficiency from the striking portion to the vibration piece can be provided. Therefore, the power generator according to the present invention can efficiently supply the kinetic energy generated by the rotary weight or the like to the vibrating piece as the input energy, and therefore, a large input energy can be supplied to the vibrating piece, and a power generator with high power generation capability can be realized. Therefore, it is possible to provide a power generation device suitable for supplying power to a small-sized portable device using a piezoelectric body.
Further, in the present invention, by making the position where the vibration piece is excited in the vicinity of the section of the 2 nd-order mode, the amplitude of the 1 st-order mode contributing to the power generation can be increased to efficiently use the input energy for the power generation. In the present invention, the rotational motion of the rotary weight mounted on the wrist-worn device is accelerated by the gear train, and the kinetic energy is divided and supplied to the vibrating piece, thereby reducing the mechanical loss during vibration and improving the conversion efficiency, and realizing a small-sized power generator with high power generation capability using a piezoelectric body. Further, by providing a plurality of vibrating pieces and applying vibrations to these vibrating pieces alternately by the exciting rod, the duration of the vibrations caused by 1 impact can be made longer on each vibrating piece. Therefore, loss due to the next excitation applied to the vibration of the vibrating reed can be prevented, and efficiency can be improved. Further, the vibrating reed is formed in a tuning fork and a rectangular plate shape with both free ends, and is supported on the section of the 1 st order mode, so that the fixing loss can be reduced, the conversion efficiency can be improved, and a power generation device using a piezoelectric body with high power generation capability can be realized.
Thus, the power generator of the present invention can efficiently transmit the kinetic energy obtained by capturing the movement of the user's wrist or the like to the vibrating piece, and therefore, can provide a power generator capable of supplying sufficient power to a small-sized and portable instrument.
Claims (15)
1. An electrical power generation device, comprising: at least one vibrating plate having a piezoelectric layer, and an excitation device for exciting vibration by applying an impact to the vibrating plate, and outputting power generated in the vibrating piezoelectric layer, characterized in that:
the vibration excitation device includes an impact portion for colliding the vibrating piece, and the mass m of the impact portion is equivalent to the mass meLess than the equivalent mass M of said vibrating piecee。
2. A power generating apparatus comprising at least one vibrating plate having a piezoelectric layer, and an excitation device for exciting vibration by applying an impact to the vibrating plate, and outputting power generated in the vibrating piezoelectric layer, characterized in that:
the vibration excitation device includes an impact portion that collides with the vibration plate, and the impact portion receives a speed opposite to a direction of the vibration plate immediately after the impact portion strikes the vibration plate.
3. The power generation apparatus of claim 1, wherein: the vibrating plate is mounted in a cantilever shape assuming that its mass is MHAnd a distance L from the fixed end to the other end (free end)HX is the distance from the fixed end to the excitation point where the impact is applied by the impact portionHStandard function of vibration mode of
The equivalent mass M at the excitation pointeCan be represented by the following formula (A):
Me=MH/(Ξn(xH/lH))2 (A)
the impact portion is a rotary excitation rod providing impact on the excitation point, assuming that its moment of inertia is IbThe distance from the center of rotation to the point of impact providing the impact to the excitation point is XbThen the equivalent mass meCan be represented by the following formula (B):
me=Ib/xb 2 (B)
4. the power generation apparatus of claim 1, wherein: assuming that a collision coefficient between the striking portion and the vibrating piece is e, the equivalent mass meAnd MeSatisfies the following formula (C):
Me＞((2·e+3·π+2)/3·π·e)×me (C)
5. the power generation apparatus of claim 1, wherein: the vibrating piece is mounted in a single-arm beam shape, and the striking portion gives a strike near a node of the secondary mode of the vibrating piece which returns by a certain distance from a free end to a fixed end side of the vibrating piece.
6. The power generation apparatus of claim 1, wherein: the vibrating plate is mounted in a single-arm beam shape, and a weight is attached to the free end of the vibrating plate.
7. The power generation apparatus of claim 6, wherein: assuming that the mass of the cantilever portion of the vibrating piece is MHThe distance from the fixed end to the other end (free end) is lHX is the distance from the fixed end to the excitation point where the impact is applied by the impact portionHStandard function of vibration mode of
When the mass of the heavy hammer is Ma, the equivalent mass M on the excitation pointeCan be represented by the following formula (D):
Me=Ma+MH/(Ξn(xH/lH))2 (D)
8. the power generation apparatus of claim 6, wherein: the weight includes a recess opening toward the free end side, and the striking portion is a shock excitation rod for providing a shock to an inner side of the recess.
9. The power generation apparatus of claim 1, wherein: the vibrating pieces are multiple.
10. The power generation apparatus of claim 1, wherein: the striking part is at least 1 ball moving in a groove formed around the vibrating piece.
11. A portable apparatus, characterized by: comprising a power plant as claimed in claim 1 and processing means operable with said power output from the power plant.
12. A portable apparatus, characterized by:
the method comprises the following steps: a housing for housing the power generating apparatus of claim 1, a rotary weight rotatably mounted in the housing, and a gear train for accelerating the movement of the rotary weight and transmitting the accelerated movement to the striking part;
the striking section is an excitation lever that is rotationally driven in conjunction with the gear group and collides with the vibration plate.
13. The portable apparatus of claim 12, wherein: the shell is wrist-worn.
14. The portable apparatus of claim 12, wherein: the excitation rod comprises a rod driven by the rotation of the gear set; one end of the driving rod is in contact with one end of the excitation rod to drive the excitation rod in a rotating mode.
15. The portable apparatus of claim 12, wherein: the rotation center of the excitation rod is basically consistent with the gravity center.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP66002/96 | 1996-03-22 | ||
| JP6600296 | 1996-03-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1220782A true CN1220782A (en) | 1999-06-23 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97190233A Pending CN1220782A (en) | 1996-03-22 | 1997-03-19 | Power generator and portable device |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP3711562B2 (en) |
| CN (1) | CN1220782A (en) |
| WO (1) | WO1997036364A1 (en) |
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| CN104617814A (en) * | 2015-01-20 | 2015-05-13 | 南京邮电大学 | Portable power generation device |
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| RU2150170C1 (en) * | 1997-10-30 | 2000-05-27 | Нунупаров Мартын Сергеевич | Method and device for feeding electronic system |
| JP3539187B2 (en) * | 1998-03-06 | 2004-07-07 | セイコーエプソン株式会社 | Power generation equipment and electronic equipment |
| DE10025561A1 (en) | 2000-05-24 | 2001-12-06 | Siemens Ag | Self-sufficient high-frequency transmitter |
| MXPA04000103A (en) | 2001-07-03 | 2005-01-07 | Davis Boyd Clark | Self-powered switch initiation system. |
| JP5245699B2 (en) * | 2008-09-30 | 2013-07-24 | 日立工機株式会社 | Electric tool |
| CN108150336B (en) * | 2017-12-06 | 2020-11-13 | 钟小二 | Portable generator utilizing water flow and vibration to generate electricity |
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| JPS5133373U (en) * | 1974-09-02 | 1976-03-11 | ||
| JPS529388A (en) * | 1975-07-11 | 1977-01-24 | Seiko Epson Corp | Electricity generator |
| JPS52127092A (en) * | 1976-04-16 | 1977-10-25 | Seiko Instr & Electronics Ltd | Portable generator |
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1997
- 1997-03-19 WO PCT/JP1997/000885 patent/WO1997036364A1/en active Application Filing
- 1997-03-19 CN CN97190233A patent/CN1220782A/en active Pending
- 1997-03-19 JP JP53423097A patent/JP3711562B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104617814A (en) * | 2015-01-20 | 2015-05-13 | 南京邮电大学 | Portable power generation device |
Also Published As
| Publication number | Publication date |
|---|---|
| WO1997036364A1 (en) | 1997-10-02 |
| JP3711562B2 (en) | 2005-11-02 |
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