JP6183160B2 - Vibration power generator - Google Patents

Description

  The present invention relates to a vibration power generation apparatus that generates power by vibration capable of supplying power to sensors installed on, for example, an expressway or a bridge.

  As a power generation technique using vibration, a method using a piezoelectric element is well known. Many of the power generation methods using this piezoelectric element are to generate electric power by deforming the piezoelectric element by applying external force to the piezoelectric element by some method. As a vibration power generation apparatus using this piezoelectric element, for example, there is one described in Patent Document 1. The vibration power generation apparatus includes a piezoelectric element having a plurality of grooves formed on at least one surface of a piezoelectric material, a vibration plate that is bonded to the piezoelectric element and transmits vibration to the piezoelectric element, and an output of the piezoelectric element. Means for rectifying and means for storing the rectified power are provided.

However, in the vibration power generation apparatus using this piezoelectric element, the piezoelectric material constituting the piezoelectric element is a brittle material and is weak against bending and impact. Therefore, an excessive load cannot be applied, and there is a problem that it is difficult to apply a large bending or impact in order to increase the power generation amount.
In addition, the piezoelectric element has a high impedance at a low frequency, and when a load having a lower impedance than that of the piezoelectric element is connected, the voltage generated in the load is small, so the power obtained by power generation is small and the power generation efficiency is low. There is also a problem.

  In order to solve the problems of the vibration power generation apparatus using such a piezoelectric element, a vibration power generation apparatus using a magnetostrictive element described in Patent Document 2 has been proposed. This vibration power generation apparatus includes a power generation element 100 shown in FIGS. 9A and 9B. The power generating element 100 includes coupling yokes 100a and 100b, magnetostrictive rods 110a and 110b supported in parallel to the coupling yokes 100a and 100b, coils 120a and 120b wound around the magnetostrictive rods 110a and 110b, and coupling yokes. A back yoke 150 connected to 100a and 100b via permanent magnets 140a and 140b is provided.

  As shown in FIG. 10, the power generating element 100 has a connecting yoke 100 a fixed to a fixed portion to form a cantilever beam structure, and a bending stress P is applied to the connecting yoke 100 b in a direction perpendicular to the axial direction of the power generating element 100. Thus, the magnetostrictive rods 110a and 110b are bent and deformed. As a result, the magnetic flux passing through the coils 120a and 120b changes due to the inverse magnetostrictive effect generated in the magnetostrictive rods 110a and 110b, thereby generating an induced voltage (or induced power) in the coils 120a and 120b. As a result, power can be generated by applying vibration to the power generation element 100.

  The magnetostrictive material composing the magnetostrictive rods 110a and 110b is a ductile material, and is more resistant to bending deformation and impact than the piezoelectric material. Therefore, it is possible to increase the amount of power generation by applying large bending or impact. In addition, since the impedance of the power generation element is lower than that of the piezoelectric material, there is little reduction in power generation efficiency due to connection of a load with low impedance, and the above-described problems of the piezoelectric material can be solved.

JP 2006-166694 A Japanese Patent No. 4905820

However, in the conventional example described in Patent Document 2, since power generation is performed by resonance in a secondary mode involving bending and twisting, there is an unsolved problem that power generation efficiency decreases.
Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and an object thereof is to provide a vibration power generation apparatus capable of generating power that can increase power generation efficiency.

In order to achieve the above object, an aspect of the vibration power generator according to the present invention includes a support base to which vibration is transmitted, and a vibration power conversion unit supported by the support base, the vibration power conversion unit being And a pair of power generation beams supported so that the tip side intersects the support base, and weights fixed at the intersecting positions of the pair of power generation beams, each of the pair of power generation beams A mounting portion fixed to the support, a magnetic beam supported on the mounting portion so as to be rotatable in an amplitude direction of vibration, a magnetostrictive beam arranged in parallel with the magnetic beam, and the magnetostriction A magnetic coil wound around a body beam, wherein the magnetic beam is formed with a base portion pivotally attached to the support base at one end and an attachment portion for fixing the weight body at the other end, On one side of the end surface perpendicular to the longitudinal direction between the base and the mounting portion Said housing notch for accommodating the magnetostrictive body beam magnetic coil is wound to form the longitudinally flexible rods portion.

  According to the present invention, the pair of power generation beams are arranged so as to intersect at the front end side, and the weight body is fixed at the intersecting position of the pair of power generation beams, so that the primary mode without twisting is achieved. The displacement can be applied to the magnetostrictive beam, and the power generation efficiency can be improved.

It is a top view which shows one Embodiment of the vibration electric power generating apparatus which concerns on this invention. It is sectional drawing which abbreviate | omitted a part on the AA line of FIG. It is a perspective view which shows a vibration electric power conversion part. It is a top view which shows the beam for electric power generation. It is a side view which shows the magnetic body beam and magnetostrictive body beam of a power generation beam. It is a characteristic diagram which shows the relationship between the angle between the beam for electric power generation, and the resonant frequency of an apparatus. It is a characteristic diagram which shows the relationship between a weight mass and a vibration frequency. It is a side view which shows the modification of the magnetic body beam of a power generation beam, and a magnetostriction beam. It is a figure which shows the electric power generation element of the conventional vibration power generator, Comprising: (a) is a front view, (b) is a side view. It is a figure which shows the electric power generation principle of the electric power generation element of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing an embodiment of a vibration power generator according to the present invention, FIG. 2 is a cross-sectional view in which a part on the line AA in FIG. 1 is omitted, and FIG. 3 shows a vibration power converter. It is a perspective view.
As shown in FIGS. 1 and 2, the vibration power generation apparatus 10 according to the present invention includes a cylindrical support base 20 and a vibration power conversion unit 30 supported by the support base 20.

As shown in FIG. 2, the support base 20 is composed of a cylindrical body 23 attached by bolts 22 on a circular substrate 21. For example, 24 mounting female screws 24 are formed on the upper surface of the cylindrical body 23 at equal intervals. ing.
As is apparent with reference to FIG. 3, the vibration power converter 30 includes a pair of power generation beams 31 </ b> A and 31 </ b> B supported by the support base 20 so that the tip side intersects at a predetermined angle θ, and the pair of power generation beams And a weight 41 attached at the intersection of the beams 31A and 31B.

  Each of the pair of power generating beams 31A and 31B is configured to be rotatable by a base 34 as a mounting portion fixed to the cylindrical body 23 of the support base 20 formed at one end by a bolt 32 and a pin 34 on the base 33. A magnetic beam 35 serving as a magnetic yoke made of a supported magnetic material and a magnetostrictive beam 36 made of a magnetostrictive material supported by the magnetic beam 35 are provided.

  As shown in FIGS. 2 to 4, the base portion 33 is composed of a relatively thin mounting plate portion 33 a and a relatively thick support portion 33 b formed on the right end side of the mounting flat plate portion 33 a. Yes. A through hole 33c through which the bolt 32 is inserted is formed in the mounting flat plate portion 33a. An insertion recess 33d for inserting the magnetostrictive beam 36 from the right end side is formed in the support portion 33b so as to penetrate vertically. Further, as shown in FIG. 4, the support portion 33b is formed with an insertion hole 33e through which a pin is inserted perpendicularly to the insertion recess 33d.

  As shown in FIG. 5, the magnetic beam 35 is formed in an elongated plate shape, a base mounting portion 35 a that is attached to the base portion 33 is formed at one end, and a weight body mounting portion 35 b that attaches the weight body 41 is formed at the other end. Has been. An insertion hole 35d through which the pin 34 is inserted is formed in the base attachment portion 35a. Further, two female screws 35e are formed through the weight mounting portion 35b at a predetermined interval in the longitudinal direction.

  Further, the magnetic beam 35 is formed with a storage cutout portion 35f extending in the longitudinal direction cut out from the lower surface side between the base attachment portion 35a and the weight attachment portion 35b to form a thin flexible rod portion 35g. Has been. The storage notch 35f is formed of a vertical side 35h whose both ends in the longitudinal direction extend upward from the lower end surface, and an inclined side 35i which extends obliquely upward and outward from the upper end of the vertical side 35h. Fitting recesses 35j penetrating in the front-rear direction are formed in the vertical side portions 35h of the respective portions.

  On the other hand, as shown in FIG. 3, the magnetostrictive beam 36 is formed in an elongated rectangular bar shape having a rectangular cross section, a magnetic coil 37 is wound around the both ends, leaving a predetermined length, and a flat rectangular parallelepiped shape at both ends. Permanent magnets 38A and 38B are fixed. Here, as shown in FIG. 5, the permanent magnets 38 </ b> A and 38 </ b> B are both magnetized in the longitudinal direction so that the left end side is an S pole and the right end side is an N pole.

  The magnetostrictive beam 36 is housed and held in the housing cutout 35f by fitting the permanent magnets 38A and 38B fixed at both ends thereof into the fitting recess 35j of the magnetic beam 35. For this reason, the magnetic flux emitted from the N pole of the permanent magnet 38A reaches the S pole of the permanent magnet 38B through the magnetostrictive beam 36, and the magnetic flux emitted from the N pole of the permanent magnet 38B becomes the weight mounting portion 35b of the magnetic beam 35. A magnetic path that reaches the south pole of the permanent magnet 38A through the flexible rod portion 35g and the base mounting portion 35a is formed.

  The power generation beams 31A and 31B having the above-described configuration are attached to an attachment female screw 24 formed on the upper surface of the cylindrical body 23 of the support base 10 so as to have a predetermined crossing angle θ. Here, as shown in FIG. 6, the crossing angle θ is an element that determines the resonance frequency of vibration that can be efficiently generated by the vibration power generation apparatus 10. The magnetic beam 35 is applied to the base 33 as in the present embodiment. The resonance frequency varies depending on whether it is supported rotatably or fixedly supported. When the magnetic beam 35 is rotatably supported on the base 33 as in the present embodiment, the resonance frequency is about 170 Hz when the crossing angle θ is 180 ° as shown by the characteristic curve L1 in FIG. As the crossing angle θ becomes smaller than 180 °, it decreases exponentially, and when the crossing angle θ is 30 °, the resonance frequency is lowered to 2.5 to 5 Hz.

  On the other hand, when the magnetic beam 35 is fixedly supported on the base 33, as shown by the characteristic curve L2 in FIG. 6, when the crossing angle θ is 180 °, the resonance frequency is about 190 Hz, and the crossing angle θ is 180 °. Although it decreases exponentially as it becomes smaller than °, the resonance frequency as a whole becomes higher than the characteristic curve L1, and becomes about 55 Hz when the crossing angle θ is 30 °.

  Therefore, when the magnetic beam 35 is rotatably supported by the base 33 as in the present embodiment, the selection range of the resonance frequency is widened, the frequency range of vibration that can be generated by vibration is widened, and particularly high speed. Since the vibration frequency when passing through vehicles such as roads and bridges is 2.8 to 3.7 Hz, it is necessary to rotatably support the magnetic beam 35 on the base 33 in order to resonate in this frequency range. .

As shown in FIGS. 1 to 3, the weight body 41 includes a central cylindrical portion 42 and disc-shaped flange portions 43 and 44 formed at the upper and lower ends of the central cylindrical portion 42. Yes. In the flange portions 43 and 44, 24 sets of through holes 45 corresponding to the female screw 35e of the weight mounting portion 35b of the magnetic beam 35 are formed at equal intervals in the circumferential direction.
As shown in FIGS. 1 and 3, the weight body 41 is attached to a position where the magnetic beam 35 of the pair of power generation beams 31 </ b> A and 31 </ b> B supported by the support base 20 intersects. To attach the weight body 41, first, the weight body attachment portion 35b of the magnetic body beam 35 of the pair of power generation beams 31A and 31B is inserted between the flange portions 43 and 44 of the weight body 41. Then, with the female screw 35e concentric with the through-hole 45, the bolt 46 is screwed into the female screw 35e through the through-hole 45 from the outside of the flange portions 43 and 44, and tightened, whereby a pair of power generation beams 31A and 31B and the weight body 41 are integrated.

In this state, as shown in FIG. 1, the lengths of the pair of power generation beams 31 </ b> A and 31 </ b> B are selected so that the center axis of the weight body 41 is aligned with the center axis of the cylindrical body 23 of the support base 20.
Here, the relationship between the mass of the weight body 41 and the resonance frequency of vibration was measured when the mass of the weight body 41 was measured in the range of 10 [g] to 70 [g], as shown in FIG. It was found that the resonance frequency of vibration decreases as the mass of the material increases. However, since the acceleration increases as the mass of the weight body 41 increases, the mass of the weight body 41 is set in consideration of the acceleration.

Next, the operation of the above embodiment will be described.
First, the crossing angle θ of the pair of power generation beams 31A and 31B is set according to the vibration frequency of the vibration source in which the vibration power generation apparatus 10 is installed. The setting of the crossing angle θ is performed so that the vibration frequency input to the vibration power generation apparatus 10 becomes the resonance frequency based on the characteristic curve L1 indicating the relationship between the crossing angle θ and the vibration resonance frequency in FIG. Set the crossing angle θ.

For example, on an expressway and a bridge, since aging progresses, it is necessary to arrange a structural health monitoring sensor such as an acceleration sensor, a vibration sensor, or a corrosion sensor to grasp a deterioration tendency.
These structural health monitoring sensors require a power source, but the storage battery has a limited life, and therefore needs to be replaced periodically, and its management becomes complicated. For this reason, the vibration power generation device 10 is applied as a power source of the structural health monitoring sensor.

In this case, the frequency of vibration generated when the vehicle passes through a highway or a bridge is a low frequency region of 2.8 Hz to 3.7 Hz, and the acceleration is in a range of 0.15 G to 0.5 G.
For this reason, it is necessary for the vibration power generator 10 to set the resonance frequency in the low frequency region. In this embodiment, the crossing angle θ is set to 30 ° based on the characteristic curve L1 of FIG.
For this reason, of the female screws 24 formed on the upper surface of the cylindrical body 23 of the support base 20, every other two female screws 24 that coincide with the crossing angle θ are selected, and a pair of power generation beams 31A and The base portions 33 of 31B are individually supported. At this time, the bolt 32 is screwed into the female screw 24 from the upper side through the through-hole 33c with the through-hole 33c of the base 33 concentrically adjusted, and is temporarily tightened to such an extent that the base 33 is slightly rotated.

  Next, the weight body 41 is attached to the crossing position on the tip end side of the pair of power generation beams 31A and 31B temporarily fastened to the support base 20. As described above, the weight body 41 is attached by inserting the weight body attachment portion 35b of the magnetic beam 35 constituting the pair of power generation beams 31A and 31B into the flange portions 43 and 44 of the weight body 41, and the flange portion. The bolts 46 are screwed into the female screws 35e from the upper and lower directions through the through holes 45 in a state in which the female screws 35e formed on the weight attaching portion 35b are aligned with the other through holes 45 formed in the holes 43 and 44, respectively.

Thereafter, the bolt 32 of the base portion 33 is finally tightened, and the bolt 46 on the weight body 41 side is finally tightened to keep the pair of power generation beams 31A and 31B on the support base 20 at a predetermined crossing angle θ (= 30 °). At the same time, the weight body 41 is disposed so that the center axis thereof coincides with the center axis of the cylindrical body 23 of the support base 20, thereby constituting the vibration power converter 30.
In the state in which the vibration power conversion unit 30 is configured, each of the pair of power generation beams 31A and 31B is supported by the base 33 so that the magnetic body beam 35 is rotatable. A weight body 41 is attached at the intersection of the tips. Since the rotation surfaces of the pair of power generation beams 31A and 31B are different, as shown in FIG. 2, the pair of power generation beams 31A and 31B rotate downward due to gravity when vibration is not transmitted to the support base 20. It is held in a horizontal state without moving. In this horizontal state, the magnetostrictive beam 36 is not bent and the lines of magnetic force do not change, so that no voltage (electric power) is output from the magnetic coil 37.

  In this state, when 2.5 to 4 Hz vibration is transmitted to the support base 20 by passing the vehicle through the highway or the bridge, the flexible rod is applied to the magnetic beam 35 of the pair of power generation beams 31A and 31B. By forming the portion 35g, the magnetic beam 35 of the pair of power generation beams 31A and 31B is repeatedly bent up and down across the horizontal line in response to vibration, and the pair of power generation beams 31A and 31B and the weight body 41 are formed. Resonant state. As a result, elongation and compression are repeatedly applied to the magnetostrictive beam 36, and the lines of magnetic force change alternately. This change in the lines of magnetic force generates an induced voltage (induced power) in the magnetic coil 37 according to the law of electromagnetic induction, and vibration power generation can be performed.

  At this time, since the pair of power generation beams 31A and 31B are arranged to intersect with each other and the weight body 41 is disposed at the intersection position on the front end side, the magnetic beam 35 constituting the pair of power generation beams 31A and 31B. Therefore, the twisting force is not generated, and the displacement is performed in the primary mode of only bending, and the twisting force is not transmitted to the magnetostrictive beam 36. For this reason, the power generation efficiency by the magnetostrictive beam 36 can be improved, and power of 2.5 mW or more can be generated.

In addition, since the magnetic beam 35 is supported so as to be rotatable in the vibration amplitude direction with respect to the base portion 33 fixedly supported by the support base 20, as is clear from FIG. Resonance is generated with respect to vibration in a low frequency range of 2.5 to 4 Hz generated when passing, and power can be generated reliably.
Further, the magnetostrictive beam 36 is made of a magnetostrictive material, and this magnetostrictive material is a ductile material and is more resistant to bending and impact than a piezoelectric material. Therefore, it is possible to increase the amount of power generation by applying large bending or impact. It is. Since the impedance of the vibration power generator 10 is higher than that of the piezoelectric material, there is little decrease in power generation efficiency due to connection of a load with low impedance.

Then, the electric power generated by the vibration power generation apparatus 10 is supplied as an operating power source to the environmental health monitoring sensor, and these environmental health monitoring sensors can be operated.
When the vibration frequency of the installation target where the vibration power generation apparatus 10 is installed is higher than 4 Hz, the crossing angle θ of the pair of power generation beams 31A and 31B is within a range of 180 degrees or less according to the characteristic curve L1 of FIG. Select with. Then, if the support position of the pair of power generation beams 31A and 31B on the support base 20 is set so as to have the selected crossing angle θ, it is possible to resonate at the vibration frequency of the installation target, and in a wide range of vibration frequencies. Vibration power generation can be performed efficiently.

  In addition, a storage cutout portion 35f extending in the longitudinal direction cut out from the lower surface side is formed between the base attachment portion 35a and the weight attachment portion 35b to form the thin flexible rod portion 35g. With this configuration, the magnetostrictive beam 36 around which the magnetic coil 37 is wound can be easily mounted on the magnetic beam 35, and the pair of power generation beams 31A and 31B can be easily assembled.

  In the above embodiment, when the magnetic beam 35 is rotatably supported with respect to the base 33 so as to be able to generate electric power with a low frequency vibration of about 2.5 to 4 Hz generated on a highway or a bridge. Explained. However, the present invention is not limited to the above-described configuration. When the vibration frequency region is 60 Hz or more, the magnetic material beam 35 is applied to the base 33 as represented by the characteristic curve L2 in FIG. Even with the fixed arrangement, vibrational power generation can be performed in a region other than the low frequency region.

In the above-described embodiment, the case where the storage cutout 35f is formed on the lower end side of the magnetic beam 35 has been described. However, the present invention is not limited to this, and the configuration shown in FIG. Even if the beam 36 is arranged upside down, the same effect as in the above embodiment can be obtained.
Further, in the above-described embodiment, the case where one magnetostrictive beam 36 of the magnetic beam 35 is mounted has been described. However, the present invention is not limited to this, and as shown in FIG. A magnetostrictive beam 36 can also be mounted on the slab.

Furthermore, in the above embodiment, the case where the magnetization directions of the permanent magnets 38A and 38B are the left side as the S pole and the right side as the N pole has been described. However, the present invention is not limited to this. The S pole may be magnetized.
Moreover, although the said embodiment demonstrated the case where the support stand 20 had the cylindrical body 23, it is not limited to this, When the crossing angle (theta) of a pair of power generation beam 31A and 31B is decided. , It can be formed in an arc shape or a linear shape only in the arc range corresponding to the crossing angle θ.

DESCRIPTION OF SYMBOLS 10 ... Vibration power generation device, 20 ... Support stand, 21 ... Board | substrate, 23 ... Cylindrical body, 24 ... Female screw, 30 ... Vibration power conversion part, 31A, 31B ... Power generation beam, 32 ... Bolt, 33 ... Mounting part, 35 ... Magnetic body beam, 35a ... Base attachment part, 35b ... Weight body attachment part, 35f ... Storage notch part, 35g ... Flexible bar part, 36 ... Magnetostrictive body beam, 37 ... Magnetic coil, 38A , 38B ... Permanent magnet, 41 ... body

Claims (5)

A support base through which vibration is transmitted;
A vibration power converter supported by the support,
The vibration power conversion unit has a pair of power generation beams supported so that the tip side intersects the support base, and a weight body fixed at an intersection position of the pair of power generation beams ,
Each of the pair of power generation beams is disposed in parallel with the mounting portion fixed to the support base, the magnetic beam supported by the mounting portion so as to be rotatable in the amplitude direction of vibration, and the magnetic beam. A magnetostrictive beam and a magnetic coil wound around the magnetostrictive beam,
The magnetic beam has a base portion pivotally attached to the support base at one end, an attachment portion for fixing the weight body at the other end, and an end surface perpendicular to the longitudinal direction between the base portion and the attachment portion. A vibration power generating apparatus characterized in that a flexible bar portion is formed on one side by forming a storage notch for storing the magnetostrictive beam wound with the magnetic coil in the longitudinal direction . The weight body includes a central cylindrical portion and upper and lower flanges extending in the radial direction from the upper and lower ends of the central cylindrical portion, and the magnetic beam mounting portion is mounted and fixed between the upper and lower flanges. The vibration power generator according to claim 1. The support base has an arcuate mounting surface centering on the center of the weight body for fixing the mounting portion of the pair of power generation beams, and at least one of the mounting position and the crossing angle of the pair of power generation beams. The vibration power generation apparatus according to claim 1 , wherein the vibration power generation apparatus is configured to be selectable . Claim wherein the support base is formed in an annular shape about the center of said weight body, characterized by Tei Rukoto be selectable forms at least one of the mounting position and angle of intersection of the pair of power generating beam 4. The vibration power generator according to any one of 1 to 3. 5. The vibration power generation apparatus according to claim 4 , wherein an intersection angle between the pair of power generation beams is set in accordance with a vibration frequency causing resonance .

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