JP2012151983A - Vibration power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration power generator for converting kinetic energy by vibrations accompanied by reciprocation to electric power, which is excellent in electric power conversion efficiency even when a housing is small-sized and is capable of increasing an output voltage by easily changing a resonance frequency of the vibration power generator.SOLUTION: For the vibration power generator, a fixed body includes a buffer magnet for making reaction act with a magnet body on the side of an inner surface of a housing, and the buffer magnet provided in at least one fixed body comprises a magnet in a prescribed shape magnetized such that different magnetic poles appear in a radial direction and a circumferential direction. The fixed body includes a turning mechanism for turnably pivoting the magnet in the prescribed shape and fixing it at a prescribed angle to the fixed body, and the magnet in the prescribed shape generates the reaction to act with the magnet body.

Description

  The present invention relates to a vibration generator that converts kinetic energy due to vibration accompanied by reciprocation into electric power, and more particularly to a vibration generator that is excellent in power conversion efficiency and can increase output voltage even in a small casing.

  In a vibration generator that converts kinetic energy into electric power, when a person carries it or attaches it to a vibrating device, it generates a reciprocating vibration in the internal vibrating body, and the kinetic energy is converted with high conversion efficiency. There is a demand for conversion to electric power. In particular, a vibration generator including a reciprocating magnet or a reciprocating coil is disadvantageous in that the power generation efficiency tends to be low due to the limitation of the coil length or the configuration of the magnetic circuit when downsizing. There is a point. Therefore, conventionally, various vibration generators have been proposed to solve these problems.

  Conventionally, the battery includes a rechargeable battery, a cylindrical coil, a rod-like permanent magnet that is inserted into the axial core portion of the coil and is held by a spring so as to be movable in the axial direction, and a rectifier. In the portable generator that rectifies the AC voltage generated in the coil by the axial vibration of the permanent magnet based on vibration and swing when being carried by the rectifier and charges the battery with the rectified DC voltage, A portable type characterized in that an axial resonance frequency of a permanent magnet system composed of the permanent magnet and the spring is approximately matched with an average period of a main vibration source that generates the axial vibration when being carried. There is a generator. (Patent Document 1).

  An electromechanical device for converting mechanical vibration energy into electric energy, which is a velocity-damping resonator having a damping coefficient and a resonance frequency, and electric power output by the electromechanical device A power detector for detecting the power, a control device, and an attenuation coefficient adjuster for adjusting the attenuation coefficient of the electromechanical device, wherein the control device detects the power detected by the power detector. There is an electromechanical generator configured to control the attenuation coefficient adjuster according to an output (Patent Document 2).

JP 2002-374661 A (FIGS. 1 to 5) JP-T 2008-536470 (FIGS. 1-6)

  In general, in the electrodynamic vibration generator as described in Patent Document 1 or 2, the resonance frequency of the magnet body that vibrates the vibration generator and the vibration frequency of the reciprocating motion that excites vibration in the vibration generator are obtained. If they do not substantially match, there is a problem that it is difficult to extract a large current and a large voltage because the reciprocating speed of the magnet body is not maximized. The resonance frequency of the magnet body of the vibration generator is determined by the weight of the magnet body, the elastic force of the elastic body provided at both ends of the reciprocating motion, or the repulsive force of the repelling magnet that repels the magnet body. Since it is determined by the elastic force, there is a problem that it is substantially difficult to set the resonance frequency of the vibration generator to an arbitrary value in advance or to change the resonance frequency of the vibration generator after manufacturing.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is related to a vibration generator that converts kinetic energy due to vibration accompanied by reciprocation into electric power, and the resonance frequency of the vibration generator. It is an object of the present invention to provide a vibration power generator that can easily change the power generation efficiency and that is excellent in power conversion efficiency and can increase the output voltage even in a small casing.

  The vibration generator according to the present invention includes a coil, a cylindrical casing around which the coil is wound, a fixed body provided at each end of the casing, and a magnetized magnet. A magnet body installed so as to be capable of reciprocating along the inner surface of the housing, and the fixed body has a buffer magnet on the inner surface side of the housing for applying a repulsive force to the magnet body. The buffer magnet included in at least one of the fixed bodies is configured by a magnet having a predetermined shape magnetized so that different magnetic poles appear in the radial direction and the circumferential direction, and the fixed body has a predetermined shape with respect to the fixed body. The magnet has a rotation mechanism that pivotally supports the magnet and fixes the magnet at a predetermined angle, and the magnet having a predetermined shape generates a repulsive force acting between the magnet body.

  Preferably, in the vibration generator according to the present invention, the magnet having a predetermined shape constituting the buffer magnet is an annular magnet in which different magnetic poles appear in the radial direction and the circumferential direction.

  Preferably, in the vibration power generator of the present invention, a plurality of coils are provided in the housing, and the plurality of coils are connected in series and / or in parallel.

  The operation of the present invention will be described below.

  The vibration generator according to the present invention includes a coil, a cylindrical casing around which the coil is wound, a fixed body provided at each end of the casing, and a magnetized magnet. And a magnet body installed so as to be capable of reciprocating along the inner surface of the casing. In this vibration generator, when a magnet body installed so as to be able to reciprocate moves, the magnetic field of the magnet changes, and each coil provided corresponding to the range in which the magnet body reciprocates moves to each coil by electromagnetic induction. An electromotive force is generated.

  Here, in the vibration generator, the fixed body has a buffer magnet that applies a repulsive force to the magnet body on the inner surface side of the housing, and the buffer magnet included in at least one of the fixed bodies has a radial direction. And a magnet having a predetermined shape magnetized so that different magnetic poles appear in the circumferential direction. This fixed body has a rotation mechanism that pivotally supports a magnet having a predetermined shape relative to the fixed body and fixes the magnet at a predetermined angle, and the magnet having the predetermined shape acts between the magnet body and the fixed body. Generate repulsive force. Preferably, the buffer magnet included in at least one of the fixed bodies is configured by an annular magnet that is magnetized so that different magnetic poles appear in the radial direction and the circumferential direction. The buffer magnet constituted by the annular magnet generates a repulsive force acting between the magnet body. That is, the vibration power generator includes a buffer magnet that forms a repulsive magnetic field on at least one of the fixed bodies by an annular magnet that is magnetized so that different magnetic poles appear in the radial direction and the circumferential direction. The other fixed body may have a buffer magnet that applies a repulsive force to the magnet body on the inner surface side of the housing.

  The resonance frequency of the magnet body of this vibration generator is determined by the weight of the magnet body and the elastic force determined by the repulsive force of the fixed body buffer magnets provided at both ends of the casing. If the repulsive force by the magnet body and the buffer magnet of the fixed body is increased, the resonance frequency is increased, and if the repulsive force is decreased, the resonance frequency is decreased. For example, since the buffer magnet included in at least one of the fixed bodies is composed of an annular magnet magnetized so that different magnetic poles appear in the radial direction and the circumferential direction, the annular magnet is rotated and adjusted. This makes it possible to adjust the elastic force determined by the repulsive force.

  Specifically, in the vibration power generator according to the present invention, a fixed body having a buffer magnet made of a magnet having a predetermined shape pivotally supports a magnet magnetized to the fixed body and has a predetermined If a rotation mechanism that fixes at an angle is provided, the elastic force determined by the repulsive force can be adjusted, and as a result, the resonance frequency of the magnet body of the vibration generator can be adjusted. When the resonance frequency of the magnet body that vibrates the vibration generator and the vibration frequency of the reciprocation that excites vibrations in the vibration generator are substantially matched, the speed of the reciprocation of the magnet body is maximized. A large voltage can be taken out and the power generation efficiency can be improved.

  In the vibration power generator of the present invention, a plurality of coils may be provided in the housing, and the plurality of coils may be connected in series and / or in parallel. The winding direction of the plurality of coils, or the polarity of series connection and / or parallel connection is reversed according to the direction of the magnetic flux from the magnet body. By providing a plurality of coils at a position where the magnetic flux of the magnet body is effectively interlinked, that is, a position where the magnetic flux density is high, the output voltage at the coil can be further increased. In addition, if a plurality of coils are connected in series and / or in parallel, the output voltage can be made more continuous, and the power conversion efficiency can be increased even in a small casing. Can be further enhanced.

  Relating to vibration generators that convert kinetic energy due to vibration with reciprocation into electric power, the resonance frequency of the magnet body of vibration generators can be adjusted, and even in a small casing, power conversion efficiency is excellent and output voltage is increased The vibration generator which can be provided can be provided.

It is sectional drawing explaining the vibration generator 1 by preferable embodiment of this invention. Example 1 It is a figure explaining the fixed body 4a and the resonant frequency adjustment mechanism 5 of the vibration generator 1 by preferable embodiment of this invention. Example 1 It is a figure explaining the connection of the rectifier of 1 A of vibration generators by preferable embodiment of this invention. Example 1

  Hereinafter, although the vibration generator by preferable embodiment of this invention is demonstrated, this invention is not limited to these embodiment.

  FIG. 1 is a diagram illustrating a vibration generator 1 according to a preferred embodiment of the present invention. Specifically, FIG. 1 is a cross-sectional view along the center axis in the vertical direction shown in the figure. In the vibration power generator 1, the magnet body 10 that is a vibrator moves in the direction of the center axis and vibrates. FIG. 2 is a view for explaining a fixed body 4a and a resonance frequency adjusting mechanism 5 provided at one end of the vibration generator 1, FIG. 2 (a) is a plan view thereof, and FIG. It is sectional drawing. Furthermore, FIG. 3 is a diagram for explaining the connection of the vibration generator 1A and the vibration generator 1A including the rectifier. In addition, as will be described later, a part of the structure of the vibration generator 1 and an internal structure are omitted.

  The vibration generator 1 includes a coil 2, a cylindrical housing 3 around which the coil 2 is wound, a fixed body 4 a and a resonance frequency adjusting mechanism 5 provided at one end of the housing 3, and the other of the housing 3. A magnet body installed between the fixed body 4b and the buffer magnet 6b provided at the end and the magnetized magnet 11 so as to reciprocate along the inner surface of the housing 3 between the fixed bodies 4a and 4b. 10 is a vibration generator. The vibration generator 1 of the present embodiment is a small and light vibration generator having a substantially cylindrical shape having a major axis length of about 65 mm and a minor axis diameter of about 20 mm. For example, when the vibration generator 1 vibrates at an illustrated displacement Z0 due to external vibration, the magnet body 10 that is a vibrator vibrates at the displacement Z1 therein, so the vibration generator 1 is caused by the vibration of the magnet body 10. Kinetic energy can be converted into electric power.

  The magnet body 10 of the present embodiment includes a columnar rare earth magnet 11 having an outer diameter of about 10 mm and a length of about 20 mm. As shown in FIG. 1, the magnet 11 of the magnet body 10 is magnetized so that different magnetic poles (N pole, S pole) appear in the vibrating vertical direction. The rare earth magnet is an Nd—Fe—B type neodymium magnet or an Sm—Co type samarium cobalt magnet, which has a large maximum energy product (BH) max, An Nd—Fe—B rare earth magnet having a larger magnetization and coercive force and a strong coercive force even in a small volume may be used. Of course, the magnet 11 may be a ferrite magnet. The magnet body 10 may be provided with poles which are soft iron members connected to both end faces of the magnet 11 depending on circumstances.

  The cylindrical housing 3 is a hollow cylinder made of a non-magnetic material. In this embodiment, the cylindrical housing 3 is a straight pipe of a resin molded part having an inner diameter of about φ10.6 mm, and a magnet body along its inner surface. 10 is installed so that it can reciprocate. A coil 2 a and a coil 2 b are wound around the outer surface of the cylindrical housing 3 and are connected in series to constitute the coil 2. The coil 2a and the coil 2b are coils formed by winding a copper wire having a diameter of about 0.18 mm into about 14 layers with a winding width of about 18 mm. As shown in the drawing, the coil 2a and the coil 2b are wound around the casing 3 apart from each other in the vertical direction, and are connected in series so that currents flow in opposite directions of rotation in the coils 2a and 2b, respectively. The coil 2 outputs the coil electromotive force generated in the coil 2 a and the coil 2 b to the output terminal 21.

  The fixed bodies 4a and 4b are non-magnetic resin molded parts, and the fixed bodies 4a and 4b are fixed to both ends of the housing 3 with screws or an adhesive. As shown in FIG. 2, the fixed body 4 a has a resonance frequency adjusting mechanism 5 in which the buffer magnet 6 a and the rotating shaft 7 are arranged on the inner surface side of the housing 3 where the magnet body 10 reciprocates. Further, as shown in FIG. 2, the fixed body 4 b has a buffer magnet 6 b on the inner surface side of the housing 3 where the magnet body 10 reciprocates. Since the magnet body 10 is configured to repel the buffer magnet 6a or 6b, the buffer magnets 6a and 6b serving as the buffer body are fixed bodies 4a or 6b that are positioned at both ends of the housing 3 as the magnet body 10 moves. It is prevented from colliding with 4b vigorously and being destroyed by impact.

  The resonance frequency adjusting mechanism 5 of the present embodiment pivotally supports the buffer magnet 6a for applying a repulsive force between the magnet body 10 and the buffer magnet 6a so as to be rotatable in the R1 direction shown in the figure with respect to the fixed body 4a. A rotation mechanism including a rotation shaft 7. The buffer magnet 6 a is an annular magnet that is magnetized so that different magnetic poles appear in the radial direction and the circumferential direction, and the repulsion that acts between the buffer body 6 a and the magnet body 10 depending on the direction supported by the rotating shaft 7. Can generate power. Further, since the buffer magnet 6a is pivotally supported by the rotation shaft 7 and can be fixed at a predetermined angle, the repulsive force is adjusted to adjust the resonance frequency of the magnet body 10 of the vibration power generator 1. Can be adjusted.

  For example, the buffer magnet 6a of the resonance frequency adjusting mechanism 5 is an annular rare earth magnet having a diameter of about 10 mm and a thickness of about 10 mm. The buffer magnet 6a is rotatably supported in the R1 direction shown in the figure by being pivotally supported by a resin-made rotation shaft 7, and the rotation shaft 7 rotates to a predetermined position with respect to the fixed body 4a. Engageable to move and stop. Since the buffer magnet 6a is an annular magnet that is magnetized so that different magnetic poles appear in the radial direction and the circumferential direction about every 180 °, when the buffer magnet 6a is rotated, the buffer magnet 6a is moved between the magnet body 10 and the magnet body 10. The acting repulsive force changes.

  A vibration generator 1 </ b> A shown in FIG. 3 is a vibration generator including the vibration generator 1 described above and the rectifier 22. The vibration generator 1 outputs a coil electromotive force generated in the coil 2 to the output terminal 21. The rectifier 22 is a full-wave bridge rectifier circuit that connects the input side to the output terminal 21 of the vibration power generator 1, and converts the AC voltage into a DC voltage by full-wave rectification. That is, in the vibration power generator 1 </ b> A, the output terminal 21 of the vibration power generator 1 is connected to the rectifier 22 and the output is connected to the output terminal 23.

  When an external force is applied in the vertical direction shown in FIGS. 1 and 2 and an external force is applied to vibrate the vibration generator 1 with the displacement Z0, the magnet body 10 that is a vibrator vibrates with the displacement Z1. The magnet body 10 installed so as to be able to reciprocate along the inner surface of the housing 3 moves at a certain relative speed in the inner space of the coils 2 a and 2 b wound around the housing 3. Since the magnet body 10 is magnetized so as to form a DC magnetic field, when the magnet body 10 passes inside the coils 2a and 2b, changes in the DC magnetic field generated by the magnet body 10 in the coils 2a and 2b, respectively. An electromotive force that tries to cancel out is generated in proportion to the relative speed. In the vibration power generator 1 of the present embodiment, the magnet body 10 repeatedly vibrates in the vertical direction shown in FIG. 1 due to external vibration, so that the lower coil 2a has a lower end of the magnet body 10 in the lower coil 2a. The upper side of the magnet body 10 vibrates and goes in and out of the upper coil 2b. The vibration generator 1 can convert the kinetic energy generated by the vibration of the magnet body 10 into electric power as an AC coil electromotive force.

  Since the coil 2 a and the coil 2 b are connected in series in the opposite directions as described above, the absolute value of the relative velocity due to vibration between the magnet body 10 and the coil 2 is the same as that of the housing 3. It becomes large when moving near the center, and on the other hand, it becomes small when it reaches the fixed bodies 4a and 4b on the end side of the housing 3 and turns back. Therefore, when the magnet body 10 vibrates sinusoidally, the waveform of the coil electromotive force output to the output terminal 21 connected to the coil 2 of the vibration power generator 1 moves around the center of the housing 3. On the other hand, it becomes large (sinusoidal antinode), and on the other hand, when it reaches the fixed bodies 4a and 4b on the end side of the housing 3 and turns back (when the speed becomes minimum), it becomes small (sinusoidal node). ). The coils 2a and 2b are connected in series so that currents flow in opposite directions of rotation, but may be connected in parallel.

  A case where the resonance frequency of the magnet body 10 is adjusted in the vibration power generator 1 will be described with reference to FIGS. 1 and 2. In the case of the present embodiment, the resonance frequency adjusting mechanism 5 is realized as a rotating mechanism including a rotating shaft 7 that pivotally supports the buffer magnet 6a with respect to the fixed body 4a. In the magnetized buffer magnet 6a, the S pole appears on the upper surface side of the annular magnet in a range of a central angle of about 180 °. In the case shown in FIG. It is a relationship that makes the repulsive force act. If the rotation angle of the buffer magnet 6a in FIG. 1 is 0 °, in the case of FIG. 2, the buffer magnet 6a is fixed at a rotation angle of about 45 °.

  The resonance frequency when the magnet body 10 of the vibration generator 1 vibrates is determined by the weight of the magnet body 10 and the elastic force determined by the repulsive force of the buffer magnet 6a of the fixed body 4a provided in the housing 3. The repulsive force acting between the two magnets is proportional to the product of the relative area where the magnets confront each other and the magnetic flux density on the surface of each magnet, and inversely proportional to the square of the distance between the two magnets. When the repulsive force is converted into the stiffness of the primary resonance system and considered, the resonance frequency is proportional to the square root of the stiffness ((1/2) th power). Therefore, by rotating the buffer magnet 6a in the R1 direction illustrated by the rotation mechanism, if the repulsive force between the magnet body 10 and the buffer magnet 6a of the fixed body 4a increases, the resonance frequency increases and the repulsive force decreases. If so, the resonance frequency is lowered.

  For example, when the rotation angle of the buffer magnet 6a shown in FIG. 1 is approximately 0 °, the magnetic flux density at the top of the buffer magnet 6a closest to the magnet body 10 is about 2.42 × 10 ^ (− 5 In contrast to [Wb], when the rotation angle of the buffer magnet 6a shown in FIG. 2 is about 45 °, the area of the south pole exposed on the upper side decreases and the area of the north pole increases. Therefore, the magnetic flux density at the same top portion is reduced to about 1.71 × 10 ^ (− 5) [Wb]. Therefore, the repulsive force acting between the magnet body 10 and the buffer magnet 6a is about 0.704 times in the case of FIG. 2 as compared with the case of FIG. 1, and the reduction rate of the resonance frequency is about 0. .839 times. Therefore, for example, when the resonance frequency of the magnet body 10 of the vibration power generator 1 is about 100 Hz, the resonance frequency can be set to about 84 Hz after the vibration power generator 1 is manufactured.

  In the case of the present embodiment, the buffer magnet 6a included in the fixed body 4a is rotated by the rotation mechanism including the rotation shaft 7. Therefore, when the buffer magnet 6a is further rotated, the magnet body 10 and the buffer magnet 6a. The repulsive force acting between and can be made almost zero. That is, in this embodiment, even in the resonance frequency adjusting mechanism 5 including the small buffer magnet 6a, it is possible to increase the adjustment range of the elastic force determined by the repulsive force. Since the resonance frequency of the magnet body 10 of the vibration generator 1 can be adjusted within a predetermined range after the vibration generator 1 is manufactured, the resonance frequency of the magnet body 10 that vibrates in the vibration generator 1 and the vibration generator 1 can be adjusted. The vibration frequency of the reciprocating motion that excites vibration is substantially matched, the speed of the reciprocating motion of the magnet body 10 is maximized, and a large current and a large voltage can be taken out, so that the power generation efficiency can be improved.

  In the vibration power generator 1, the coil 2a and the coil 2b constituting the coil 2 may be connected in parallel, and a plurality of coils may be further added. In the coil 2, the winding direction of a plurality of coils, or the polarity of series connection and / or parallel connection can be reversed according to the direction of the magnetic flux from the magnet body. By providing a plurality of coils at a position where the magnetic flux of the magnet body is effectively interlinked, that is, a position where the magnetic flux density is high, the output voltage at the coil can be further increased. The coils 2 may be connected with the same polarity so that the coil electromotive force generated in the coils 2a and 2b is output to the output terminal 21 without canceling each other.

  Further, the buffer magnet 6b included in the fixed body 4b may include the buffer magnet 6a and the rotating shaft 7 similar to the resonance frequency adjusting mechanism 5 provided in the fixed body 4a. The resonance frequency adjusting mechanism 5 is a magnet in which the buffer magnet 6a to be supported is magnetized so that different magnetic poles appear in the radial direction and the circumferential direction, and depending on the direction in which the rotating shaft 7 is supported, The present invention is not limited to the above embodiment as long as the repulsive force acting between the magnet body 10 and the magnet body 10 is changed. The buffer magnet 6a may be an annular magnet that is radially magnetized so that different magnetic poles appear at every 90 ° in the center angle, or may be at other angles, and of course the shape is rectangular. It may be of a predetermined shape. Since the resonance frequency of the magnet body 10 of the vibration generator 1 can be adjusted within a predetermined range after the vibration generator 1 is manufactured, the resonance frequency of the vibrating magnet body 10 and the vibration generator 1 are excited. The power generation efficiency can be improved by substantially matching the vibration frequency of the reciprocating motion.

  The vibration generator of the present invention can also be applied to a generator including a rectifier, a storage battery, a charging circuit, etc., a charging battery, and a charger. In addition, since the electronic device including the vibration generator of the present invention is excellent in portability, it is particularly suitable as a mobile device carried by a user or a generator attached to a vehicle that generates a lot of vibrations.

DESCRIPTION OF SYMBOLS 1, 1A Vibration generator 2, 2a, 2b Coil 3 Case 4a, 4b Fixed body 5 Resonance frequency adjustment mechanism 6a, 6b Buffer magnet 7 Rotating shaft 10 Magnet body 11 Magnet 21, 23 Output terminal 22 Rectifier

Claims (3)

The casing includes a coil, a cylindrical casing around which the coil is wound, a fixed body provided at each end of the casing, and a magnetized magnet. A magnet body installed so as to be capable of reciprocating along the inner surface of
The fixed body has a buffer magnet that acts a repulsive force between the fixed body and the magnet body on the inner surface side of the housing;
The buffer magnet included in at least one of the fixed bodies is configured by a magnet having a predetermined shape magnetized so that different magnetic poles appear in the radial direction and the circumferential direction, and the fixed body is A pivot mechanism that pivotally supports a magnet of a predetermined shape and fixes the magnet at a predetermined angle, and the magnet of the predetermined shape generates the repulsive force acting between the magnet body;
Vibration generator. The magnet having a predetermined shape constituting the buffer magnet is an annular magnet in which different magnetic poles appear in the radial direction and the circumferential direction.
The vibration generator according to claim 1. A plurality of coils are provided in the housing, and the plurality of coils are connected in series and / or in parallel.
The vibration generator according to claim 1 or 2.

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