JP2015047003A - Vibration power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a vibration power generator used in a state where it is mounted to a tire to generate electric power irrespective of that a rotation speed of the tire is low or high, and to enable the vibration power generator to be easily mounted to the tire.SOLUTION: Sub springs 14, which are brought into contact with a movable-side unit 40 when the movable-side unit 40 is displaced from a vibration neutral position radially outward by a specified quantity and are compression-elastically deformed when the movable-side unit 40 is further displaced radially outward, are arranged in a fixed-side unit 20. Thus, when a rotation speed of a tire 2 is low, the movable-side unit 40 is vibrated against an elastic force of main springs 12 to generate power, and on the other hand, when the rotation speed of the tire 2 increases and the movable-side unit 40 is largely displaced radially outward by a centrifugal force, the movable-side unit 40 is vibrated by the centrifugal force and elastic force of the sub springs 14 to generate power. This power generation is achieved while a vibration power generator 10 is downsized, and mounting of the vibration power generator 10 to the tire 2 having a limited mounting space is facilitated.

Description

  The present invention relates to a vibration power generator configured to generate an induced electromotive force using vibration, and more particularly to a vibration power generator used in a state of being mounted on a tire of a vehicle or the like.

  2. Description of the Related Art Conventionally, a portable vibration power generation apparatus configured to be able to automatically generate power by a human walking action or the like is known.

  For example, in “Patent Document 1” and “Patent Document 2”, an induced electromotive force is generated by vibrating a movable-side unit supported by a fixed-side unit via a coil spring using the elastic force of the coil spring. A vibration power generator configured as described above is described.

  On the other hand, in “Patent Document 3”, the movable side unit is supported by the frame member (that is, the movable structure 805a) via the first spring, and further this frame member is supported by the fixed side unit via the second spring. A vibration power generator is described.

Special table 2008-543254 gazette JP 2004-159407 A Japanese Patent No. 4663035

  If such a vibration power generation apparatus is used in a state where it is mounted on a tire such as a vehicle, it is possible to generate electric power using the rotation of the tire.

  Specifically, when the portion of the tire where the vibration power generation device is mounted contacts the ground, the movable unit vibrates in the radial direction of the tire against the elastic force of the coil spring by the impact force that the vibration power generation device receives from the road surface. By doing so, it is possible to generate an induced electromotive force.

  However, simply attaching a conventional vibration power generation device to a tire has the following problems.

  In other words, in order to generate power when the tire rotation speed is low, if the coil spring is set to a small value to make the coil spring easy to vibrate, when the tire rotation speed increases, The acting centrifugal force is larger than the elastic force of the coil spring, and the movable unit does not vibrate. On the other hand, if the spring constant of the coil spring is set to a large value in order to generate power when the tire rotational speed is high, the coil spring will not be elastically deformed when the tire rotational speed is low.

  On the other hand, if a vibration power generation device as described in the above-mentioned “Patent Document 3” is mounted on a tire, it can be moved at two different resonance frequencies by the first and second springs arranged in a double manner. The side unit can be vibrated. As a result, it is possible to generate power by vibrating the movable side unit even when the rotational speed of the tire is low or high.

  However, when such a configuration is adopted, there are the following problems.

  In other words, the vibration power generation apparatus mounted on the tire has a limited mounting space, and therefore is required to be as small as possible. However, in the vibration power generation apparatus described in the above-mentioned “Patent Document 3”, the first and second springs are configured to be doubled inside and outside through the frame member. Therefore, there is a problem that it is difficult to reduce the size of the vibration power generator.

  The present invention has been made in view of such circumstances, and in a vibration power generation apparatus used in a state of being mounted on a tire, it can generate power even when the rotation speed of the tire is low or high, And it aims at providing the vibration electric power generating apparatus which can be easily mounted | worn with respect to a tire.

  The present invention is intended to achieve the above object by adopting a configuration in which a predetermined auxiliary spring is additionally arranged with respect to the original main spring.

That is, the vibration power generator according to the present invention is
A vibration power generator used in a state of being mounted on a tire,
A stationary side unit and a movable side unit supported by the stationary side unit via a main spring, and the movable side unit is guided by vibrating in a radial direction of the tire using the elastic force of the main spring. In a vibration power generator configured to generate an electromotive force,
When the movable side unit is displaced by a predetermined amount radially outward from the neutral position of the vibration, the fixed side unit abuts on the movable side unit and is compressed and elastically deformed when the movable side unit is further displaced radially outward. A secondary spring is disposed.

  The type of the “main spring” is not particularly limited, and for example, a coil spring or a leaf spring can be used.

  The above-mentioned “sub spring” is not particularly limited as long as the movable side unit is configured to be elastically deformed by compression when the movable unit is displaced from the neutral position to the outside in the radial direction by a predetermined amount. It is not something.

  The specific value of the “predetermined amount” is not particularly limited.

  As shown in the above configuration, the vibration power generator according to the present invention has a configuration in which the movable side unit supported by the fixed side unit via the main spring vibrates in the radial direction of the tire using the elastic force of the main spring. However, the fixed side unit is in contact with the movable side unit when the movable side unit is displaced by a predetermined amount radially outward from the neutral position of vibration, and the movable side unit is further displaced radially outward. Since the auxiliary spring which is sometimes compressed elastically deformed is arranged, the following effects can be obtained.

  That is, when the tire equipped with the vibration power generation device according to the present invention rotates, when the rotational speed is low, the movable unit vibrates using the elastic force of the main spring to generate power, and the rotation When the speed increases and the movable side unit is greatly displaced radially outward by the centrifugal force, the movable side unit vibrates by the centrifugal force and the elastic force of the auxiliary spring, thereby generating electric power. Therefore, power generation can be performed by vibration of the movable side unit even when the rotational speed of the tire is low or high.

  At that time, the secondary spring is arranged on the fixed side unit in such a manner that it comes into contact with the movable side unit when the movable side unit is displaced by a predetermined amount from the neutral position of the vibration to the radially outer side. In this way, it is possible to eliminate the need for a configuration in which the first spring and the second spring are disposed in duplicate inside and outside the frame member. Therefore, the vibration power generator can be easily reduced in size, and can be easily mounted on a tire having a limited mounting space.

  As described above, according to the present invention, in the vibration power generation apparatus used in a state where the tire is mounted, the power generation can be performed even when the rotation speed of the tire is low or high, and this can be easily performed on the tire. Can be installed.

  In the above configuration, if the spring constant of the auxiliary spring is set to a value larger than the spring constant of the main spring, power can be generated even in a high-speed rotation region where the tire rotation speed is higher.

  At that time, in order to efficiently generate power in the high-speed rotation region, it is preferable to set the spring constant of the secondary spring to a value that is five times or more than the spring constant of the main spring. In order to maintain the vibration of the movable unit due to the deformation, it is preferable to set the spring constant of the auxiliary spring to a value not more than 100 times the spring constant of the main spring.

  In the above configuration, when a plurality of auxiliary springs are arranged in parallel, even when the spring constants of the individual auxiliary springs are reduced, the spring constants of the plurality of auxiliary springs as a whole can be increased.

  In the above configuration, the conductive coil is arranged in the fixed side unit and the magnetic circuit unit is arranged in the movable unit, and the conductive coil is arranged radially outside the neutral position of the vibration. As a result, the power generation efficiency can be sufficiently increased even when the rotational speed of the tire is low or high.

The front view which shows the vibration electric power generating apparatus which concerns on one Embodiment of this invention. II-II sectional view of FIG. The figure which shows the use condition of the said vibration power generator The principal part front view of the said vibration electric power generating apparatus which shows a mode when the said movable side unit vibrates. The graph which shows the result of the simulation performed in order to verify the effect | action of the said embodiment

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a front view showing a vibration power generation apparatus 10 according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG.

  As shown in these drawings, the vibration power generation apparatus 10 includes a fixed side unit 20 having a conductive coil 22 and a movable side unit 40 having a magnet 42.

  The movable side unit 40 is supported by the fixed side unit 20 via the four main springs 12, and can vibrate in the direction indicated by the arrow in FIG. ing.

  FIG. 3 is a diagram illustrating a usage state of the vibration power generation apparatus 10.

  As shown in the figure, the vibration power generation apparatus 10 is mounted on a tire 2 such as a vehicle or an aircraft, and other devices (for example, the air pressure of the tire 2 and the road surface state) are used to detect the usage environment of the tire 2 ( (Not shown) as a power source.

  At this time, the vibration power generation apparatus 10 is mounted on the inner peripheral wall 2 a of the tire 2 in a state where the vibration direction thereof matches the radial direction of the tire 2 in the internal space of the tire 2. In the vibration power generation device 10, when the tire 2 rotates in the direction indicated by the arrow, the vibration power generation device 10 is connected to the road surface when the portion of the tire 2 on which the vibration power generation device 10 is mounted is grounded. 4, the movable side unit 40 vibrates in the radial direction of the tire 2 against the elastic force of the main spring 12, thereby generating an induced electromotive force in the conductive coil 22 (which will be described later). It is like that.

  Next, a specific configuration of the vibration power generator 10 will be described.

  First, the configuration of the fixed side unit 20 will be described.

  The stationary unit 20 includes a case 30 and a coil holder 24 and a circuit board 32 disposed in the case 30.

  The case 30 includes a pair of front and rear resin half members 30A and 30B. The case 30 has a rectangular outer shape close to a square when viewed from the front, and is formed with a constant front-rear width.

  The coil holder 24 is a plate-like member having a rectangular outer shape close to a square when viewed from the front, and is arranged in a state extending in the vertical direction.

  The coil holder 24 has a configuration in which a friction reducing film is attached to both front and rear surfaces of a resin holder body in which a coil housing portion 24a for housing the conductive coil 22 is formed.

  An inverted U-shaped positioning recess 24b is formed at the left and right center position of the lower end surface of the coil holder 24, and large rectangular cutouts 24c are formed on the left and right sides thereof.

  The case 30 is configured such that the upper and lower ends thereof are sandwiched from both the front and rear sides in a state where the coil holder 24 is positioned in the vertical and horizontal directions by the pair of half members 30A and 30B. At this time, a movable space C for vibrating the movable side unit 40 in the vertical direction is formed between the upper and lower ends of the coil holder 24 in the case 30.

  On the upper end wall 30a of the movable space C in the case 30, a cushion material 26 extending in a strip shape in the left-right direction is attached. When the movable side unit 40 vibrates in the vertical direction and the amplitude becomes a certain value or more, the cushion material 26 abuts on the elastic member and elastically deforms. As a result, the movable side unit 40 vibrates with an excessive amplitude. In addition, the impact force at the time of contact is relieved.

  On the other hand, the lower end wall 30b of the movable space C in the case 30 is formed at a position where it comes into contact with the lower end surface of the movable side unit 40 when the movable side unit 40 vibrates with the maximum allowable amplitude.

  A pair of main spring accommodating portions 30c for accommodating the main springs 12 are formed on the left and right sides of the case 30, and the main springs 12 are provided on the upper and lower sides of the main spring accommodating portions 30c. A locking pin 30d for locking is formed.

  A circuit board housing portion 30 e for housing the circuit board 32 is formed in the upper portion of the case 30. Further, a pair of left and right auxiliary spring accommodating portions 30f for accommodating a pair of left and right auxiliary springs 14 (which will be described later) are formed in the lower part of the case 30.

  The conductive coil 22 has a horizontally long oval winding shape. The conductive coil 22 has a pair of coil terminals (not shown) electrically connected to the circuit board 32. The electricity generated by the vibration power generator 10 is supplied from the circuit board 32 to the other devices via the cord 34.

  Next, the configuration of the movable unit 40 will be described.

  The movable side unit 40 is configured as a magnetic circuit unit formed so as to surround the coil holder 24 with a space therebetween.

  That is, the movable side unit 40 has a configuration in which a yoke 44 and a pair of upper and lower magnets 42 are attached to each of a pair of magnet holders 46 disposed on both front and rear sides of the coil holder 24.

  Each magnet holder 46 is formed of a resin member having a laterally long rectangular outer shape when viewed from the front. Each magnet 42 is a neodymium magnet, for example, and has a horizontally long rectangular parallelepiped shape. Each yoke 44 is made of a soft iron plate and has the same outer shape as each magnet holder 46 in a front view.

  In the movable unit 40, a pair of upper and lower magnets 42 is fitted in each of a pair of upper and lower through-holes formed in each magnet holder 46, and the inner side surface of each magnet holder is connected to each magnet holder. In a state of being substantially flush with the inner side surface of 46, each yoke 44 is attracted by a magnetic force, and at that time, positioning and fixing to each yoke 44 is surely performed by using an adhesive.

  The pair of upper and lower magnets 42 are arranged with their polarities reversed, and the polarity is reversed between the pair of front and rear yokes 44 (that is, the polarity of the upper and lower two pairs of magnets 42 is reduced). In a state of matching in the positional relationship of cliffs).

  As a result, in the movable unit 40, a magnetic circuit that generates a magnetic flux across the space between each pair of magnets 42 is formed by the two pairs of upper and lower magnets 42 and a pair of front and rear yokes 44. ing.

  Further, in the movable side unit 40, the four main springs 12 are locked at both the upper and lower ends of both sides of the pair of front and rear magnet holders 46.

  The coil housing part 24a of the coil holder 24 is formed in a positional relationship overlapping with the movable unit 40 in a front view. At this time, the coil housing portion 24a is movable on the movable side in a state where the movable side unit 40 is in a neutral position of vibration (that is, in a state where the vibration power generator 10 is upright with the tire 2 not rotating). The unit 40 is formed at a position slightly displaced downward from the center position of the unit 40, whereby the conductive coil 22 is arranged on the radially outer side of the tire 2 with respect to the neutral position.

  Next, the configuration of the four main springs 12 will be described.

  The four main springs 12 are arranged on both the upper and lower sides of the movable unit 40 on both the left and right sides of the coil holder 24. These four main springs 12 are coil springs having the same configuration, and are arranged so as to extend in the vertical direction in the pair of left and right main spring accommodating portions 30c.

  At that time, the pair of left and right main springs 12 positioned on the upper side of the movable side unit 40 has its upper end portion locked by a locking pin 30d formed on the upper portion of the case 30, and its lower end portion is movable. Locked to the unit 40. On the other hand, the pair of left and right main springs 12 positioned on the lower side of the movable side unit 40 has its lower end engaged with an engagement pin 30d formed at the lower part of the case 30, and its upper end is movable. Locked to the unit 40.

  Next, the configuration of the two auxiliary springs 14 will be described.

  The two auxiliary springs 14 are accommodated in a pair of left and right auxiliary spring accommodating portions 30 f formed in the lower part of the case 30 below the movable unit 40. These two auxiliary springs 14 are coil springs having the same configuration, and are arranged to extend in the vertical direction. At this time, each of the auxiliary springs 14 has a spring constant of 10 to 200 times (for example, about 100 times) with respect to the spring constant of each main spring 12. Each of the auxiliary springs 14 is not formed with a spring locking portion like the main springs 12.

  Each secondary spring accommodating portion 30 f of the case 30 is formed as a cylindrical recess having an inner diameter slightly larger than the winding diameter of each secondary spring 14. And each subspring 12 is arrange | positioned so that the upper end part may protrude from the lower end wall 30b of the movable space C to the movable space C in the state accommodated in each subspring accommodating part 30f.

  The notches 24c formed on the lower end surface of the coil holder 24 are engaged with the auxiliary springs 12 from above. As a result, the secondary springs 12 are prevented from being detached from the secondary spring accommodating portions 30f.

  The distance from the lower end surface of the movable side unit 40 in the neutral position to the upper end edge of each auxiliary spring 12 is set to a value substantially equal to the distance from the upper end surface of the movable side unit 40 in the neutral position to the lower surface of the cushion material 26. Has been.

  Next, the operation of this embodiment will be described.

  FIG. 4 is a front view of the vibration power generation apparatus 10 showing a state when the movable side unit 40 vibrates in the vertical direction (that is, the radial direction of the tire 2). In the figure, the front half member 30B of the case 30 is removed and the coil holder 24 is omitted.

  FIG. 4A is a view showing a state where the tire 2 is not rotating and the movable unit 40 is in a neutral position of vibration, and FIG. 4B is a view when the rotation speed of the tire 2 is low. It is a figure which shows the vibration state of the movable side unit 40, and the same figure (c) is a figure which shows the vibration state of the movable side unit 40 when the rotational speed of the tire 2 is high.

  As shown in FIG. 5A, in the state where no external load is applied to the vibration power generator 10, the elastic forces of the two upper and lower main springs 12 are balanced with each other, and the movable unit 40 is neutral in vibration. Held in position. However, in this neutral position, the pair of left and right main springs 12 located on the upper side of the movable unit 40 is slightly more than the pair of left and right main springs 12 located on the lower side by the weight of the movable unit 40. The spring length is large.

  The conductive coil 22 overlaps with the movable unit 40 in the neutral position of the vibration when viewed from the front, but is located at a position displaced downward with respect to the center position of the movable unit 40.

  As shown in FIG. 4B, when the tire 2 rotates at a low speed, the vibration power generation apparatus 10 moves in the vertical direction against the elastic force of the main spring 12 from the neutral position due to the impact force from the road surface 4. Vibrate. At that time, if the movable unit 40 is largely displaced upward from the neutral position, the over-amplitude is restricted by contacting the cushion material 26, and if the movable unit 40 is largely displaced downward from the neutral position, the auxiliary spring 14 is moved. The over-amplitude is regulated by contact.

  In the state where the tire 2 is rotating at a low speed, the centrifugal force F acting on the vibration power generation apparatus 10 is small, and therefore the vibration of the movable unit 40 is performed around a position slightly below the neutral position. .

  As shown in FIG. 5C, when the tire 2 rotates at a high speed and a large centrifugal force F acts on the vibration power generator 10, the movable unit 40 resists the elastic force of the two upper and lower main springs 12. Then, it is displaced to a position where it comes into contact with the pair of auxiliary springs 14, or is further displaced to a position where the pair of auxiliary springs 14 is subjected to compression elastic deformation. In this state, when the vibration power generation apparatus 10 receives an impact force from the road surface 4, the movable side unit 40 vibrates in the vertical direction.

  As described above, the conductive coil 22 is displaced downward from the neutral position of the vibration, but the downward displacement amount is when the rotational speed of the tire 2 is low as shown in FIGS. However, even when it is high, the value is set such that the movable side unit 40 vibrates around the position overlapping the conductive coil 22 in front view.

  FIG. 5 is a graph showing the results of a simulation performed to verify the operation of this embodiment.

  In this simulation, the induced electromotive force generated in the conductive coil 22 due to the vibration of the movable unit 40 was measured as the capacitor charging voltage, and this was analyzed in relation to the vehicle speed.

  In this simulation, it is assumed that the spring constant of each auxiliary spring 14 is 100 times the spring constant of each main spring 12 (that is, the spring constant of the two auxiliary springs 14 as a whole is two pairs of upper and lower main springs). The analysis was performed (assuming 50 times the spring constant of 12 as a whole).

  A graph A indicated by a solid line in the figure is a graph showing the power generation characteristics when the secondary spring 14 is disposed together with the main spring 12 as in the vibration power generation apparatus 10 according to the present embodiment.

  On the other hand, a graph B indicated by a two-dot chain line in the figure is a graph showing power generation characteristics when only the main spring 12 is arranged without the secondary spring 14.

  In the same figure, as shown in the graph B, when only the main spring 12 is arranged, the voltage increases in accordance with the increase in the vehicle speed in the low vehicle speed region (that is, when the rotation speed of the tire 2 is low). However, when the vehicle speed increases in the middle vehicle speed region, the voltage does not increase, and when the vehicle speed increases in the high vehicle speed region, the voltage decreases.

  This is considered to be due to the fact that the centrifugal force F acting on the movable side unit 40 is greater than the elastic force of the main spring 12 due to an increase in the rotational speed of the tire 2 and the movable side unit 40 does not vibrate.

  On the other hand, as shown in the graph A in the figure, when the auxiliary spring 14 is disposed together with the main spring 12, the voltage increases as the vehicle speed increases not only in the low vehicle speed region but also in the medium and high vehicle speed regions. Yes.

  This is because even if the centrifugal force F acting on the movable side unit 40 is larger than the elastic force of the main spring 12 due to the increase in the rotational speed of the tire 2, the movable side unit is affected by the centrifugal force F and the elastic force of the auxiliary spring 14. This is considered to be due to the vibration of 40.

  As described in detail above, the vibration power generation apparatus 10 according to the present embodiment is configured such that the movable side unit 40 supported by the fixed side unit 20 via the main spring 12 vibrates against the elastic force of the main spring 12. However, when the movable side unit 40 is displaced by a predetermined amount from the neutral position of the vibration to the outside in the radial direction, the fixed side unit 20 abuts on the movable side unit 40 and further moves the movable side unit 40 in the radial direction. Since the secondary spring 14 that is compressed and elastically deformed when displaced outward is provided, the following operational effects can be obtained.

  That is, when the tire 2 equipped with the vibration power generation device 10 according to this embodiment rotates, when the rotation speed is low, the movable unit 40 vibrates against the elastic force of the main spring 12 to generate power. In addition, when the rotational speed is increased and the movable side unit 40 is greatly displaced radially outward by the centrifugal force F, the movable side unit 40 vibrates by the centrifugal force F and the elastic force of the auxiliary spring 14, As a result, power generation is performed. Therefore, even when the rotation speed of the tire 2 is low or high, power can be generated by the vibration of the movable unit 40.

  At this time, the secondary spring 14 is disposed on the fixed side unit 20 in such a manner that it comes into contact with the movable side unit 40 when the movable side unit 40 is displaced by a predetermined amount from the neutral position of the vibration to the outside in the radial direction. It is possible to eliminate the need for a configuration in which the first spring and the second spring are doubled inside and outside through the frame member as in the vibration power generator. Therefore, the vibration power generation apparatus 10 can be easily reduced in size and can be easily mounted on the tire 2 having a limited mounting space.

  As described above, according to the present embodiment, in the vibration power generation apparatus 10 used in a state where the tire 2 is mounted, the power generation can be performed even when the rotation speed of the tire 2 is low or high, and this is applied to the tire 2. Can be easily mounted.

  In the present embodiment, since the spring constant of the auxiliary spring 14 is set to a value larger than the spring constant of the main spring 12, power generation can be performed even in a high-speed rotation region where the rotation speed of the tire 2 is higher.

  Specifically, in the present embodiment, each secondary spring 14 has a spring constant of 10 to 200 times the spring constant of each main spring 12, whereby the two secondary springs 14 as a whole are used. Is set to a value 5 to 100 times larger than the spring constant of the two upper and lower main springs 12 as a whole, so that the vibration of the movable unit 40 due to the compression elastic deformation of each auxiliary spring 14 is reduced. In addition, power generation in the high-speed rotation region can be performed efficiently.

  In the present embodiment, since the two auxiliary springs 14 are arranged in parallel, the vibration of the movable side unit 40 in the high-speed rotation region is smoothly performed without the movable side unit 40 being inclined. be able to. In addition, by adopting a configuration in which a plurality of auxiliary springs 14 are arranged in this manner, even when the spring constant of each auxiliary spring 14 is reduced, the spring constant of the plurality of auxiliary springs 14 as a whole is increased. Can do.

  In the present embodiment, the conductive coil 22 is arranged in the fixed side unit 20 and the movable side unit 40 is configured as a magnetic circuit unit, on which the conductive coil 22 is radially outward from the neutral position of vibration. Therefore, even when the rotation speed of the tire 2 is low or high, the power generation efficiency can be sufficiently increased.

  In particular, in the present embodiment, the movable unit 40 and the conductive coil 22 are viewed from the front when the displacement amount of the conductive coil 22 from the neutral position of vibration to the radially outer side is high or low when the rotation speed of the tire 2 is low or high. Since it is set to a value that vibrates around the overlapping position, the power generation efficiency can be maximized.

  In the above embodiment, two auxiliary springs 14 are arranged in parallel. However, a configuration in which three or more auxiliary springs are arranged is also possible, and a single auxiliary spring is also possible. It is also possible to adopt a configuration in which are arranged.

  Instead of adopting a configuration in which a pair of left and right main springs 12 are respectively disposed on both upper and lower sides of the movable side unit 40 as in the above embodiment, a main spring composed of a pair of left and right coil springs disposed on the upper side of the movable side unit 40 is used. It is also possible to adopt a configuration in which the movable side unit 40 is suspended and supported by the fixed side unit 20 by a spring.

  In the above-described embodiment, the conductive coil 22 is disposed in the fixed unit 20 and the movable unit 40 is configured as a magnetic circuit unit. However, the magnetic circuit unit is disposed in the fixed unit 20. In addition, a configuration in which the conductive coil 22 is arranged in the movable unit 40 is also possible.

  In addition, the numerical value shown as a specification in the said embodiment is only an example, and of course, you may set these to a different value suitably.

  The invention of the present application is not limited to the configuration described in the above embodiment, and configurations with various other changes can be employed.

DESCRIPTION OF SYMBOLS 2 Tire 2a Inner peripheral wall 4 Road surface 10 Vibration power generation device 12 Main spring 14 Sub spring 20 Fixed side unit 22 Conductive coil 24 Coil holder 24a Coil accommodating part 24b Positioning recessed part 24c Notch part 26 Cushion material 30 Case 30A, 30B Half member 30a Upper end Wall 30b Lower end wall 30c Main spring accommodating portion 30d Locking pin 30e Circuit board accommodating portion 30f Sub spring accommodating portion 32 Circuit board 34 Cord 40 Movable side unit 42 Magnet 44 Yoke 46 Magnet holder C Movable space

Claims (4)

A vibration power generator used in a state of being mounted on a tire,
A stationary side unit and a movable side unit supported by the stationary side unit via a main spring, and the movable side unit is guided by vibrating in a radial direction of the tire using the elastic force of the main spring. In a vibration power generator configured to generate an electromotive force,
When the movable side unit is displaced by a predetermined amount radially outward from the neutral position of the vibration, the fixed side unit abuts on the movable side unit and is compressed and elastically deformed when the movable side unit is further displaced radially outward. A vibration power generation device characterized in that a secondary spring is disposed.   The vibration power generator according to claim 1, wherein a spring constant of the auxiliary spring is set to a value larger than a spring constant of the main spring.   The vibration power generator according to claim 1 or 2, wherein a plurality of the secondary springs are arranged in parallel. A conductive coil is arranged on the fixed side unit, and a magnetic circuit unit is arranged on the movable side unit,
The vibration power generator according to any one of claims 1 to 3, wherein the conductive coil is disposed radially outside the neutral position of the vibration.

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