JP2018182941A - Vibration power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration power generator arranged to be able to generate a power to vibrations in a wide frequency band without largely increasing the mass and size of the whole.SOLUTION: A vibration power generator 10 is arranged so that a magnet-side unit 30 vibrates through a coil spring 31, and a coil-side unit 40 vibrates through a coil spring 41, whereby a conductive coil 42 crosses a magnetic flux produced by a magnet 32, and an induced electromotive force (output voltage Vout) is generated from the conductive coil 42. In addition, a specific angular frequency ωwhen the magnet-side unit 30 vibrates, and a specific angular frequency ωwhen the coil-side unit 40 vibrates are set to different values.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration power generation apparatus configured to generate an induced electromotive force by utilizing mechanical vibration present in the environment.

FIG. 7A is a conceptual view of a vibration power generation apparatus (one degree of freedom type) disclosed in Patent Document 1. As shown in FIG. The vibration power generation device 80 includes a housing 81, a coil spring 82, a magnet 83 supported by the housing 81 via the coil spring 82, and a conductive coil 84 fixed to the housing 81. The magnet 83 gives the coil spring 82 the vibration of the natural angular frequency ω ₁ = √ (k ₁ / m ₁ ) determined by the spring constant k ₁ of the coil spring 82 and the weight m ₁ of the magnet 83. Since the vibration occurs, the conductive coil 84 generates an induced electromotive force. According to the vibration power generation device 80, it is possible to realize, for example, a beacon transmission device or the like which does not require maintenance such as battery replacement by converting dynamic vibration energy existing in the environment into electric energy.

The vibration power generation apparatus 80 can be called a single degree of freedom type, and the amount of power generation is maximum when the natural angular frequency ω ₁ is vibrated, and the amount of power generation is significantly reduced when the angular frequency is other than that. That is, since the natural angular frequency ω ₁ is one, there is a problem that the frequency band that can be generated is narrow. Patent Document 2 discloses a technology for solving this problem.

  FIG. 7 [B] is a conceptual view of a vibration power generation device (series two degrees of freedom type) disclosed in Patent Document 2. FIG. The vibration power generating apparatus 90 includes a housing 91, coil springs 92 and 94, a weight 93 supported by the housing 91 via the coil spring 92, a magnet 95 supported by the weight 93 via a coil spring 94, and a weight 93. And a conductive coil 96 fixed to the The magnet 95 vibrates via the coil spring 92, the weight 93 and the coil spring 94, and the conductive coil 96 vibrates via the coil spring 92 and weight 93, whereby an induced electromotive force is generated from the conductive coil 96. The vibration power generation apparatus 90 can be called a series two degree of freedom type, and has two natural angular frequencies, so the power generation available frequency band is broadened.

JP, 2015-33266, A Patent No. 6036143

  However, in the vibration power generation device 90, there is a problem that the mass ratio (small mass / large mass) of the two weights (the magnet 95 and the weight 93) becomes extremely small as the two natural angular frequencies are brought closer. For example, if it is desired to convert the middle and the difference of the two natural angular frequencies to 50 Hz and 5 Hz, respectively, the mass ratio of the two weights should be set to about 1/100. In general, the power obtained is proportional to the total mass of the weight (when the efficiency is the same). If the mass of the small side omori is made about 1 degree of freedom, and the mass of the large side omori is made 100 times, although large power can be obtained, the total weight becomes about 100 times the 1 degree of freedom type . Conversely, if the mass of the large side omori is made about 1 degree of freedom type and the mass of the small side omori is made 1/100 times, the small side omori becomes too small, and the power generation portion consisting of the magnet 95 and the conductive coil 96 Making it difficult. The problem is described in more detail below.

As shown in paragraph 0059 of Patent Document 2, each natural angular frequency of one degree of freedom type Ω ₁ = √ (k ₁ / m ₁ ), Ω ₂ = √ (k ₂ / m ₂ )
The equation for obtaining the natural angular frequencies ω ₁ and ω ₂ of the series two degrees of freedom from is as follows.
ω ₁ ² = (1/2) {Ω ₁ ² + (1 + μ) Ω ₂ ² }-(1/2) [[{Ω ₁ ² + (1 + μ) Ω ₂ ² } ² −4 Ω ₁ ² Ω ₂ ² ] (1)
ω ₂ ² = (1/2) {Ω ₁ ² + (1 + μ) Ω ₂ ² } + (1/2) √ {{Ω ₁ ² + (1 + μ) Ω ₂ ² } ² −4Ω ₁ ² Ω ₂ ² ] (2)
Here, μ = m ₂ / m ₁ , m ₁ and m ₂ are mass of mass (m ₁ is mass of mass 93 and m ₂ is mass of magnet 95), and k ₁ and k ₂ are spring constants (mass ratio) k ₁ is a spring constant of the coil spring 92, k ₂ is a spring constant of the coil spring 94). The mass of the weight 93 also includes the mass of the conductive coil 96.

However, in an actual design, ω ₁ and ω ₂ will be given first according to the acceleration requirements of the installation site, and Ω ₁ , Ω ₂ and μ will be found to be appropriate. Then, when equations (1) and (2) are solved for Ω ₁ and Ω ₂ in reverse,
^{_{Ω 1 4 - (ω 1 2}} + ω 2 2) Ω 1 2 + (1 + μ) ω 1 2 ω 2 2 = 0 (3)
^{_{(1 + μ) Ω 2 4}} - (ω 1 2 + ω 2 2) Ω 2 2 + ω 1 2 ω 2 2 = 0 (4)
The quadratic equation is obtained.

When ω ₁ and ω ₂ are given, the condition that Ω ₁ and Ω ₂ exist (have a real solution) is that the discriminant D of equations (3) and (4) becomes positive. The discriminants of equations (3) and (4) are the same as follows.
D = (ω ₁ ² + ω ₂ ² ) ^2-4 (1 + μ) ω ₁ ² ω ₂ ² ≧ 0 (5)

If equation (5) is rearranged for μ, the following equation is obtained.
μ ≦ {(ω ₂ ² −ω ₁ ² ) / ( ² ω ₁ ω ₂ )} ² (6)
That is, "mass ratio μ has an upper limit value".

Also, when ω ₀ >> Δω, the following equation holds approximately.
μ ≦ (Δω / ω ₀ ) ² (7)
Here, ω ₀ = (ω ₁ + ω ₂ ) / 2 and Δω = ω ₂ −ω ₁ . Therefore, μ is proportional to the square of the angular frequency difference ratio (Δω / ω ₀ ). Thus, in the series two degrees of freedom type vibration power generator 90, the mass ratio μ (small mass / small mass / two mass) of the two weights (the magnet 95 and the weight 93) increases as the two natural angular frequencies ω ₁ and ω ₂ get closer. The mass is very small.

  Therefore, an object of the present invention is to provide a vibration power generator capable of generating power against vibrations in a wide frequency band without significantly increasing the overall mass and size.

The vibration power generation device according to the present invention is
A housing, a magnet side spring member, and a coil side spring member;
A magnet side unit supported by the housing via the magnet side spring member and having a magnet;
A coil side unit supported by the case via the coil side spring member and having a conductive coil;
When the magnet side unit vibrates via the magnet side spring member and the coil side unit vibrates via the coil side spring member, the conductive coil crosses the magnetic flux generated from the magnet and the conductive state Configured to generate an induced electromotive force from the coil,
The natural angular frequency when the magnet side unit vibrates and the natural angular frequency when the coil side unit vibrates are set to different values.
It is a thing.

  According to the vibration power generation apparatus of the present invention, the magnet side unit vibrates via the magnet side spring member and the coil side unit vibrates via the coil side spring member so that an induced electromotive force is generated from the conductive coil. And two independent single one-degree-of-freedom units placed in parallel by having the natural angular frequency of the magnet side unit and the natural angular frequency of the coil side unit set to different values. It can operate as a two degree of freedom type. Therefore, it is not necessary to reduce the mass ratio (mass small / mass large) between the magnet side unit and the coil side unit according to the difference between the natural angular frequency of the magnet side unit and the natural angular frequency of the coil side unit. Power can be generated for vibrations in a wide frequency band without significantly increasing the overall mass and size.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view which shows the vibration electric power generating apparatus of embodiment, FIG. 1 [A] shows an external appearance, FIG. 2 [B] shows a magnet and a conductive coil with a broken line in external appearance. 2A is an enlarged view of a cross section taken along line IIa-IIa in FIG. 2B, and FIG. 2B is an enlarged view of a cross section taken along line IIb-IIb in FIG. 2B. The magnet side unit in FIG. 1 is shown, FIG. 3 [A] is a perspective view which notches and shows one part, FIG. 3 [B] is the IIIb-IIIb sectional view taken on the line in FIG. 3 [A]. The coil side unit in FIG. 1 is shown, FIG. 4 [A] is a perspective view, FIG. 4 [B] is the IVb-IVb sectional view taken on the line in FIG. 4 [A]. 5A is a plan view showing the operation of the vibration power generating apparatus of FIG. 1, and FIG. 5A is a case where the magnet side unit moves in the reverse direction and the coil side unit moves in the forward direction. FIG. In this case, the unit moves in the forward direction, and the coil unit moves in the reverse direction. It is a graph which shows the frequency characteristic of the output electric power in the vibration electric power generating apparatus of an Example, FIG. 6 [A] is before adjustment and FIG. 6 [B] is after adjustment. FIG. 7 [A] is a conceptual view showing the vibration power generation device (one degree of freedom type) of Patent Document 1, FIG. 7 [B] is a conceptual view showing the vibration power generation device (series two degree of freedom type) of Patent Document 2. 7 [C] is a conceptual diagram showing a vibration power generation device (parallel 2 DOF type) according to the embodiment.

  The term "comprising" in the present specification and claims also includes the case of including components other than the explicitly stated components. The same applies to "having" and "including". The "upper, lower, left, and right" in the present specification refer to the upper, lower, left, and right when viewed in the drawings, and does not mean that the upper, lower, left, or right is fixed. Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "embodiment") will be described with reference to the attached drawings. In each of the drawings, the same reference numerals are used for substantially the same components, and the redundant description will be omitted.

  First, the configuration of the vibration power generation device of the present embodiment will be described based on FIGS. 1 to 4. The reference numerals described below are described in any of FIGS. 1 to 4.

The vibration power generation device 10 according to the present embodiment is supported by a housing 20, a coil spring 31 as a magnet side spring member, a coil spring 41 as a coil side spring member, and the housing 20 via the coil spring 31. And a coil-side unit 40 supported by the housing 20 via a coil spring 41 and having a conductive coil 42. Then, in the vibration power generating apparatus 10, the magnet coil unit 30 vibrates via the coil spring 31, and the coil coil unit 40 vibrates via the coil spring 41, so that the conductive coil 42 crosses the magnetic flux generated from the magnet 32. The conductive coil 42 is configured to generate an induced electromotive force (output voltage Vout). Additionally, the natural angular frequency omega ₂ when natural angular frequency omega ₁ and the coil-side unit 40 when the magnet side unit 30 is vibrated to vibrate is set to different values.

  The mass ratio of the magnet side unit 30 to the coil side unit 40 (the mass of the coil side unit 40 / the mass of the magnet side unit 30) is, for example, in the range of 0.5 to 1.5.

  The magnet side spring member and the coil side spring member consist of four coil springs 31 and 41 respectively, and the expansion and contraction direction of the coil springs 31 and 41 is the vibration direction 11 of the magnet side unit 30 and the coil side unit 40. As shown in FIG. 3, the magnet-side unit 30 includes a square plate-like magnet holder 33 holding at least a pair of magnets 32 in which different magnetic poles face each other via an air gap, and an air gap in the magnet holder 33. It further has an insertion hole 34 through which the side unit 40 is inserted with a gap, and a unit-side spring fixing portion 35 which is provided at the four corners of the magnet holder 33 and fixes one end of four coil springs 31 respectively. As shown in FIG. 4, the coil side unit 40 is provided with a square plate-like coil holder 43 in which the conductive coil 42 is fitted at the center, and one end of four coil springs 41 provided at four corners of the coil holder 43. And a unit side spring fixing portion 45.

  As shown in FIG. 1, the housing 20 includes four housing-side spring fixing portions 21 for fixing the other end of the coil spring 31 fixed to the magnet holder 33 and the other end of the coil spring 41 fixed to the coil holder 43. And four housing-side spring fixing portions 22 for fixing the With the coil side unit 40 inserted through the insertion hole 34, both ends of the eight coil springs 31, 41 are fixed to the unit side spring fixing portions 35, 45 and the housing side spring fixing portions 21, 22, respectively.

  At least two coil springs 41 fixed to the coil holder 43 have conductivity, and electrically connect the conductive coil 42 and the output terminal 44 (FIG. 1 [B]).

  Next, each component of the vibration power generation device 10 will be described in detail.

  As shown in FIG. 1, the housing 20 is a base made of, for example, a synthetic resin, and a cap (not shown) is fitted as necessary, and the magnet side unit 30, the coil side unit 40, and the coil springs 31 and 41. Etc. and has a rectangular parallelepiped shape as a whole. Inside the housing 20, in addition to the housing-side spring fixing portions 21 and 22, a spring housing recess 23 for housing the coil spring 31, a spring housing recess 24 for housing the coil spring 41, and the like are formed. The housing-side spring fixing portions 21 and 22 are locking pins embedded in the thickness direction of the housing 20, and the other ends of the coil springs 31 and 41 are locked.

  In addition, a circuit board (not shown) connected to the output terminal 44 of the coil side unit 40 may be incorporated in the housing 20. The circuit board has a function of transmitting information such as an individual identification signal by using, for example, electrical energy obtained from an induced electromotive force generated by the coil side unit 40, and the function is by using a commercially available power circuit module or BLE module. It is feasible.

  As shown in FIG. 3, the magnet side unit 30 has a yoke 36 in addition to the magnet 32, the magnet holder 33, the insertion hole 34 and the unit side spring fixing portion 35. The magnet holder 33 holds four magnets 32 and two yokes 36. The magnet 32 may be of any type, but it is suitable for rare earth magnets such as neodymium magnets and samarium cobalt magnets having a small but strong magnetic force. ing. The yoke 36 is, for example, a soft iron plate.

  The magnet holder 33 is, for example, a horizontally long square plate in which a cap side frame 37 made of a synthetic resin or the like and a base side frame 38 are attached to each other. Insertion holes 34 for inserting and inserting the coil holder 43 are formed between the cap side frame 37 and the base side frame 38 so as to penetrate the left and right ends. Two magnets 32 and one yoke 36 are fitted in the cap side frame 37 and the base side frame 38, respectively. Therefore, a magnetic circuit composed of four magnets 32 and two yokes 36 is formed by facing each other two sets of magnets 32 with the coil holder 43 in the insertion hole 34 interposed therebetween. Unit-side spring fixing portions 35 provided at the four corners of the magnet holder 33 are locking pins that penetrate the magnet holder 33 in the thickness direction, and one end of the coil spring 31 is locked.

  As shown in FIG. 4, the coil holder 43 is made of a square plate-like synthetic resin, the conductive coil 42 is fitted in the center, and the output terminal 44 (FIG. 1 [B]) is electrically connected to the conductive coil 42. ing. The conductive coil 42 has a conducting wire wound to exhibit a horizontally long cylindrical shape, and an air core is formed at the center. Unit-side spring fixing portions 45 provided at the four corners of the coil holder 43 are locking pins that penetrate the coil holder 43 in the thickness direction, and one end of the coil spring 41 is locked.

  As shown in FIG. 1, in the state where the coil side unit 40 is inserted into the insertion hole 34 of the magnet side unit 30, the coil side unit 40 or the magnet side unit 30 vibrates up and down via the coil springs 31 and 41, respectively. . At this time, the magnetic flux of the magnet 32 passing through the conductive coil 42 changes in accordance with the relative position of the conductive coil 42 and the magnet 32, whereby an induced electromotive force is generated from the conductive coil 42.

  A total of eight coil springs 31 and 41 are tension springs, and are arranged one by one so as to be symmetrical. In the coil spring, the length in a state where no load is applied is called a natural length (or free length), and the length in a slightly extended state when assembled to a machine structure is called a set length. That is, in the initial state, the coil springs 31 and 41 are applied with tension according to the difference between the natural length and the set length. The magnet side spring member and the coil side spring member are not limited to the tension coil spring, and for example, a compression coil spring, a plate spring described in Patent Document 2, or the like may be used.

  Next, the operation of the vibration power generation system 10 will be described with reference to FIGS. 5 and 7 [C].

  The vibration power generation apparatus 10 may be called a parallel two-degree-of-freedom shown in FIG. 7C, as opposed to the one-degree-of-freedom shown in FIG. it can. In FIG. 5, the vibration direction 11 of the magnet side unit 30 and the coil side unit 40 (that is, the expansion and contraction directions of the coil springs 31 and 41) is divided into the forward direction 12 and the reverse direction 13 to vibrate the magnet side unit 30 and the coil side unit 40. The center position in the initial state in the direction 11 is taken as the balance position 14. The positive direction 12 is a direction in which the upper coil springs 31 and 41 are contracted and a direction in which the lower coil springs 31 and 41 are extended. Conversely, the reverse direction 13 is a direction in which the upper coil springs 31 and 41 extend and a direction in which the lower coil springs 31 and 41 contract.

The magnet side unit 30 and the coil side unit 40 vibrate independently (parallel two degree of freedom type). Therefore, the mass, spring constant and natural angular frequency of the magnet side unit 30 are k ₁ , m ₁ and ω _1, and the mass of the coil side unit 40, spring constant and natural angular frequency are k ₂ , m ₂ and ω ₂ Then, natural angular frequencies ω ₁ and ω ₂ are given by the following equations.
ω ₁ = √ (k ₁ / m ₁ ), ω ₂ = √ (k ₂ / m ₂ ) (11)

However, each value is set so that, for example, ω ₁ <ω ₂ in equation (11). m ₁ and m ₂ are adjusted by changing the material and size of each unit or adding a weight. Generally, the coil side unit 40 is lighter than the magnet side unit 30, so in the example shown in FIG. 7C, a weight 46 is added to the coil side unit 40.

Here, vibration of the angular frequency ω is applied to the vibration power generation device 10 to gradually increase the angular frequency ω from near zero. In this case, the magnet-side unit 30 and the coil-side unit 40 each satisfy the relationship between the amplitude and the phase in the one degree of freedom forced vibration. In other words, the amplitude of the magnet side unit 30, omega increases rapidly toward the omega _1, the maximum resonates when ω = ω _1, ω decreases significantly with increasing distance from omega _1. The phase difference of the response displacement of the magnet-side unit 30 is approximately 0 when ω <ω ₁ , −π / 2 when ω = ω ₁ and approximately −π when ω> ω ₁ . Similarly, the amplitude of the coil-side unit 40, omega increases rapidly toward the omega _2, a maximum resonates when ω = ω _2, ω is greatly reduced with increasing distance from omega _2. The phase difference of the response displacement of the coil side unit 40 is approximately 0 when ω <ω ₂ , −π / 2 when ω = ω ₂ and approximately −π when ω> ω ₂ .

Therefore, resonance magnet side unit 30 is at the _{ω = ω 1, ω = ω} 2 when resonating coil side unit 40 to, omega <omega ₁ or omega ₂ <omega magnet side unit 30 and the coil when the The side unit 40 vibrates in the same phase, and when ω ₁ <ω <ω ₂ , the magnet side unit 30 and the coil side unit 40 vibrate in the opposite phase. When the magnet side unit 30 and the coil side unit 40 vibrate in phase, when the magnet side unit 30 moves in the reverse direction 13, the coil side unit 40 also moves in the reverse direction 13 and the magnet side unit 30 moves in the forward direction 12 Means that the coil side unit 40 also moves in the forward direction 12. When the magnet side unit 30 and the coil side unit 40 vibrate in the reverse phase, the coil side unit 40 moves in the forward direction 12 when the magnet side unit 30 moves in the reverse direction 13 (FIG. 5 [A]). It means that the coil side unit 40 moves in the reverse direction 13 (FIG. 5 [B]) when 30 moves in the forward direction 12. When at least one of the magnet-side unit 30 and the coil-side unit 40 vibrates, the conductive coil 42 traverses the magnetic flux generated from the magnet 32, and an induced electromotive force (output voltage Vout) is generated from the conductive coil 42.

  Next, the operation and effects of the vibration power generation device 10 will be described.

<1>. According to the vibration power generation device 10, the magnet side unit 30 vibrates via the coil spring 31 and the coil side unit 40 vibrates via the coil spring 41 so that an induced electromotive force is generated from the conductive coil 42 It is configured, and by the natural angular frequency omega ₂ of the natural angular frequency omega ₁ and the coil-side unit 40 of the magnet side unit 30 is set to a different value, in parallel two 1 degree-of-freedom independent It becomes possible to operate as a parallel two degree of freedom type. Therefore, the mass ratio of the magnet-side unit 30 and the coil-side unit 40 in accordance with the difference between the natural angular frequency omega ₂ of the natural angular frequency omega ₁ and the coil-side unit 40 of the magnet side unit 30 (mass Small / Weight Large Since it is not necessary to reduce the), power can be generated for vibrations in a wide frequency band without significantly increasing the overall mass and size.

<2>. According to the vibration generator device 10, ω <ω ₁ or omega ₂ <magnet side unit 30 and a coil side unit 40 vibrates in the same phase when the omega, the magnet when omega ₁ <omega <omega ₂ By oscillating side unit 30 and coil side unit 40 in reverse phase, the amplitude of magnet side unit 30 and coil side unit 40 is subtracted when ω <ω ₁ or ω ₂ <ω, and ω ₁ <ω <ω _Since the amplitude of the magnet side unit 30 and the coil side unit 40 is added in the case of 2, the frequency characteristic of output electric power tends to become a rectangle. That is, the amount of power generation can be made approximately constant in the band of ω ₁ <ω <ω ₂ .

<3> When the mass ratio of the magnet side unit 30 to the coil side unit 40 (mass m ₂ of the coil side unit 40 / mass m ₁ of the magnet side unit 30) is in the range of 0.5 to 1.5 Since it is easy to make the two peaks of the output power (the amount of power generation) the same level, it is possible to make the frequency characteristic of the output power more rectangular. Because the output power is proportional to mass, the two peaks of the output power become equal as the mass ratio of the two becomes closer to one.

  <4>. When at least two coil springs 41 fixed to the coil holder 43 have conductivity and electrically connect the conductive coil 42 and the output terminal 44, the conductive coil 42 and the output terminal 44 Can be simplified because the wiring for electrically connecting them is not necessary.

<5> It demonstrates with the specific example compared with the serial 2 freedom degree type | mold. When it is desired to convert the middle and the difference of two natural angular frequencies ω ₁ and ω ₂ to 50 Hz and 5 Hz respectively in the series 2 degrees of freedom shown in FIG. 7B, ω ₀ = 50 Hz, Δω = 5 Hz From equation (7), Δω / ω ₀ = 0.1 and μ = 0.01. The output power is proportional to the total mass of the weight (when the efficiency is the same). Therefore, when the mass m ₁ and m ₂ of each omori are 10 g and the total mass is 20 g in the parallel 2 DOF type of the present embodiment shown in FIG. Since the weight of must have a mass ratio of μ = 0.01 or less, m ₁ = 19.8 g or more and m ₂ = 0.2 g or less. However, at 0.2 g, it is difficult to configure a power generation unit including a magnet and a conductive coil. Therefore, in the in-line two-degree-of-freedom type, m _{2 has} to be increased, and m ₁ is also increased accordingly, so that the overall mass and size are greatly increased.

  Next, an example in which the vibration power generation device of the present embodiment is further embodied will be described.

  FIG. 6 is a graph showing the frequency characteristic of the output power in the vibration power generation apparatus of the present embodiment. FIG. 6 [A] is before adjustment, and FIG. 6 [B] is after adjustment. 6A and 6B, the horizontal axis represents frequency [Hz], the vertical axis represents output power (average value) [mW], x represents an actual measurement value, and a solid line represents an analysis value.

  In the present embodiment, a parallel two-degree-of-freedom vibration power generator was made as an experiment, and frequency characteristics of output power were measured. The obtained measured value and the analysis value fitted to this are shown in FIG. 6 [A]. The measured values can be reproduced by analysis, and it has been confirmed that the theoretical operation is performed.

  The constant of the prototype is slightly deviated from the target value (due to manufacturing and assembly error). As a result, the amount of power generation at the two peaks is different and unbalanced. Therefore, the constants (mass, damping coefficient, etc.) related to the balance were adjusted on the theoretical formula, and the originally obtained characteristics were analyzed. The results are shown in FIG. 6 [B]. The main constant values used in the analysis of FIG. 6 [A] [B] are shown in Table 1.

[Table 1]
Item Fig. 6 [A] Fig. 6 [B]
Low frequency side weight [g] 33 31
High frequency side weight mass [g] 32 32
Low frequency side mechanical Q value [-] 55 130
High frequency mechanical Q value [-] 130 130
Load resistance [kΩ] 8.2 4.2

  As can be seen from FIG. 6 [B] and Table 1, in the vibration power generation device of this example, the masses of the two weights are almost equal and small, and the frequency characteristics of the output voltage are shaped like a rectangle.

  Next, the present invention will be supplementarily described. The present invention has a configuration of two weights connected in parallel from the input end. The weight includes a magnet on one side and a coil on the other side. The mass ratio of these two weights is set to about 1. The two natural frequencies are set to desired values close to the upper and lower limits of the input acceleration frequency to be responded. As a result, since the natural frequency is two, it is possible to generate power for vibration in a wide band. In addition, the amount of power generation at the two natural frequencies is approximately the same, and the balanced (close to rectangular) frequency characteristics are obtained.

  As mentioned above, although the present invention was explained with reference to the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention.

  The present invention is a vibration power generator capable of generating power in response to vibrations in a constant frequency band, for example, machines with minute vibrations, indoor / outdoor facilities such as pumps and air conditioning ducts, buildings such as bridge piers, electric poles, buildings, trains, The present invention can be used as a power source for vehicles such as automobiles, abnormality detection devices using sensors in these devices, and devices for transmitting information thereof.

DESCRIPTION OF SYMBOLS 10 Vibration power generator 11 Vibration direction 12 Positive direction 13 Reverse direction 14 Balance position 20 Housing | casing 21, 22 Case side spring fixing | fixed part 23, 24 Spring accommodation recessed part 30 Magnet side unit 31 Coil spring (magnet side spring member)
32 magnet 33 magnet holder 34 insertion hole 35 unit side spring fixing portion 36 yoke 37 cap side frame 38 base side frame 40 coil side unit 41 coil spring (coil side spring member)
42 conductive coil 43 coil holder 44 output terminal 45 unit side spring fixing portion 46 weight 80 vibration power generator 81 housing 82 coil spring 83 magnet 84 conductive coil 90 vibration power generator 91 housing 92, 94 coil spring 93 weight 95 magnet 96 conductive coil

Claims (4)

A housing, a magnet side spring member, and a coil side spring member;
A magnet side unit supported by the housing via the magnet side spring member and having a magnet;
A coil side unit supported by the case via the coil side spring member and having a conductive coil;
When the magnet side unit vibrates via the magnet side spring member and the coil side unit vibrates via the coil side spring member, the conductive coil crosses the magnetic flux generated from the magnet and the conductive state Configured to generate an induced electromotive force from the coil,
The natural angular frequency when the magnet side unit vibrates and the natural angular frequency when the coil side unit vibrates are set to different values.
Vibration generator. The mass ratio of the magnet-side unit to the coil-side unit (mass of the coil-side unit / mass of the magnet-side unit) is in the range of 0.5 to 1.5.
The vibration power generation device according to claim 1. Each of the magnet side spring member and the coil side spring member comprises four coil springs,
The expansion and contraction direction of these coil springs is the vibration direction of the magnet side unit and the coil side unit,
The magnet-side unit comprises a square plate-like magnet holder for holding at least a pair of magnets in which different magnetic poles face each other via a gap, and the gap in the magnet holder, and the coil-side unit is inserted with a gap And a unit-side spring fixing portion provided at four corners of the magnet holder for fixing one end of each of the four coil springs.
The coil side unit further includes a square plate-like coil holder in which the conductive coil is fitted at the center, and a unit side spring fixing portion provided at four corners of the coil holder and fixing one end of four coil springs. Have
The housing includes four housing-side spring fixing portions for fixing the other end of the coil spring fixed to the magnet holder, and four housing sides for fixing the other end of the coil spring fixed to the coil holder. And a spring fixing portion,
In a state where the coil side unit is inserted into the insertion hole, both ends of eight coil springs are respectively fixed to the unit side spring fixing portion and the housing side spring fixing portion.
The vibration power generator according to claim 1 or 2. At least two of the coil springs fixed to the coil holder have conductivity and electrically connect the conductive coil and the output terminal.
The vibration power generation device according to claim 3.

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