Power generation module and tire

Abstract

This power generation module includes a power generation device and a circuit board. The power generation device includes a vibrating body and a housing that houses the vibrating body. The circuit board includes a sensor that is driven by power generated by the power generation device. The housing includes a side wall member that is parallel to a vibration direction of the vibrating body. The circuit board is fixed to the side wall member.

Description

Power generation module and tire

[0001] The present invention relates to a power generation module and a tire including the same.

[0002] In Patent Document 1, an in-tire power generation device is described. A sensor is connected to the in-tire power generation device described in Patent Document 1.

[0003] Specification of Japanese Patent No. 5508124

[0004] However, in a conventional in-tire power generation device, vibration noise based on the behavior of a mover that generates power (for example, a rotating body in Patent Document 1) occurs. When this vibration noise is transmitted to the sensor, it becomes noise during measurement of the sensor.

[0005] Therefore, an object of the present invention is to suppress the influence of vibration generated by power generation on a sensor.

[0006] A power generation module according to an embodiment of the present invention includes a power generation device and a circuit board. The power generation device includes a vibrating body and a housing that houses the vibrating body. The circuit board includes a sensor that is driven by the generated power of the power generation device. The housing includes a side wall member parallel to the vibration direction of the vibrating body. The circuit board is fixed to the side wall member.

[0007] In this configuration, since the circuit board is fixed to the side wall member where the influence of the vibration of the vibrating body is small, it is difficult for the vibration of the vibrating body to propagate to the circuit board.

[0008] According to the present invention, the influence of vibration generated by power generation on a sensor can be suppressed.

[0009] Figure 1 is an external perspective view of the power generation device according to the first embodiment. Figure 2 is a perspective view including a cross-section of the power generation device according to the first embodiment. Figure 3 is a cross-sectional view of the power generation device according to the first embodiment. Figure 4 is an enlarged cross-sectional view showing the positional relationship of the magnet, coil, and yoke. Figure 5 is a schematic diagram showing the magnetic path (magnetic field lines) generated by the magnet. Figures 6(A), 6(B), and 6(C) are diagrams showing examples of how the power generation vise according to the embodiment of the present invention is used. Figure 7 is a diagram for explaining the power generation principle by the power generation device according to the embodiment of the present invention. Figure 8 is an external perspective view of the side wall member of the housing according to the first embodiment. Figure 9 is a plan view of the side wall member of the housing according to the first embodiment. Figure 10(A) is an external perspective view of the first spring member according to the first embodiment, and Figure 10(B) is an external perspective view of the second spring member according to the first embodiment. Figure 11 is a plan view of the first spring member according to the first embodiment. Figure 12 is a plan view of the first spring member and the second spring member according to the first embodiment stacked on top of each other. Figures 13(A), 13(B), 13(C), and 13(D) are plan views showing the positional relationship between the first spring member, the second spring member, and the side wall member. Figure 14 is an enlarged cross-sectional view showing the projection sandwiched between the housing projection and the lid member. Figure 15(A) is an external perspective view of the first yoke, and Figure 15(B) is an external perspective view of the second yoke. Figure 16 is a cross-sectional view showing the spatial volume for vibration of the power generation device. Figure 17 is a plan view showing an example of a derived configuration of the spring member. Figures 18(A), 18(B), 18(C), and 18(D) are cross-sectional views showing an example of a derived configuration of the lid member. Figure 19 is a cross-sectional view showing an example of a derived configuration of the yoke. Figures 20(A) and 20(B) are cross-sectional views showing an example of a derived state of the housing and spring member being fixed together. Figure 21 is a cross-sectional view of the power generation device according to the second embodiment. Figure 22 is an external perspective view showing a derived example of the fixing member of the power generation device according to the second embodiment. Figure 23 is a perspective view including a cross-section of a power generation device according to the third embodiment. Figures 24(A) and 24(B) are cross-sectional views of a power generation device according to the fourth embodiment, respectively. Figure 25 is a cross-sectional view of a power generation device according to the fifth embodiment. Figure 26 is a cross-sectional view of a power generation device according to the sixth embodiment.Figure 27 is an external perspective view of the power generation module according to the seventh embodiment. Figure 28 is a cross-sectional view of the power generation module according to the seventh embodiment. Figure 29 is an external perspective view of the power generation module according to the eighth embodiment. Figure 30 is a cross-sectional view of the power generation module according to the eighth embodiment. Figure 31 is a cross-sectional view of the power generation module according to the ninth embodiment.

[0010] [First Embodiment] A power generation device according to the first embodiment of the present invention will be described with reference to the drawings. Figure 1 is an external perspective view of the power generation device according to the first embodiment. Figure 2 is a perspective view including a cross-section of the power generation device according to the first embodiment. Figure 3 is a cross-sectional view of the power generation device according to the first embodiment. The cross-sections shown in Figures 2 and 3 correspond to the A-A cross-section in Figure 1. Figure 4 is an enlarged cross-sectional view showing the positional relationship of the magnet, coil, and yoke. Note that "same," "coincident," "parallel," and "orthogonal" in the following description include manufacturing tolerances. In other words, "same," "coincident," "parallel," and "orthogonal" in the following description may include the meanings of "approximately the same," "approximately coincidental," "approximately parallel," and "approximately orthogonal."

[0011] (Basic configuration of the power generation device 10) As shown in Figures 1, 2, and 3, the power generation device 10 comprises a housing 20, a magnet 30, a first yoke 41, a second yoke 42, a first spring member 51, a second spring member 52, a first fixing member 61, a second fixing member 62, and a coil 70.

[0012] The housing 20 comprises a side wall member 21, a first lid member 221, and a second lid member 222. The side wall member 21, the first lid member 221, and the second lid member 222 are made of a non-magnetic material and are made of an insulator. The side wall member 21, the first lid member 221, and the second lid member 222 are made of, for example, an insulating resin.

[0013] The side wall member 21 is cylindrical in shape and has a first opening and a second opening. When viewed from above, the side wall member 21 has a circular inner circumferential surface F21i and an outer circumferential surface F21o. The axis AX20 of the housing 20 is a straight line that passes through the center of the inner circumferential surface F21i when viewed from above and is perpendicular to the first and second openings.

[0014] The side wall member 21 includes a plurality of first housing protrusions 231 and a plurality of second housing protrusions 232.

[0015] Multiple first housing protrusions 231 are arranged near the first opening in the side wall member 21 and protrude from the inner circumferential surface F21i. Multiple first housing protrusions 231 are arranged at equal intervals in the circumferential direction of the inner circumferential surface F21i.

[0016] Multiple second housing protrusions 232 are arranged near the second opening in the side wall member 21 and protrude from the inner circumferential surface F21i. The multiple second housing protrusions 232 are arranged at equal intervals in the circumferential direction of the inner circumferential surface F21i.

[0017] The first lid member 221 and the second lid member 222 are disc-shaped. The first lid member 221 is supported by a plurality of first housing protrusions 231 and is positioned in the first opening of the side wall member 21, closing the first opening. The second lid member 222 is supported by a plurality of second housing protrusions 232 and is positioned in the second opening of the side wall member 21, closing the second opening.

[0018] With this configuration, the housing 20 has an internal space IS20 surrounded by the side wall member 21, the first lid member 221, and the second lid member 222.

[0019] The magnet 30 is made of a permanent magnet. As shown in Figure 4, the magnet 30 has a cylindrical shape with a predetermined thickness and a circular first surface F301, a second surface F302, and a side surface F309. For example, the first surface F301 side of the magnet 30 is the north pole, and the second surface F302 side is the south pole.

[0020] The diameter of the magnet 30 is shorter than the diameter of the inner circumferential surface F21i of the side wall member 21.

[0021] The magnet 30 is placed in the internal space IS20 of the housing 20. In this arrangement, the magnet 30 is positioned so that its first surface F301 faces the first lid member 221 and its second surface F302 faces the second lid member 222.

[0022] The magnet 30 is positioned away from the side wall member 21. In other words, the side surface F309 of the magnet 30 and the inner circumferential surface F21i of the side wall member 21 are separated.

[0023] The first yoke 41 and the second yoke 42 are made of a material with high magnetic permeability. The first yoke 41 and the second yoke 42 are disc-shaped and have substantially the same shape. The diameters of the first yoke 41 and the second yoke 42 are substantially the same as the diameter of the magnet 30.

[0024] As shown in Figure 4, the first yoke 41 has a circular surface F411 and a circular back surface F412, and a side surface F419. The second yoke 42 has a circular surface F421 and a circular back surface F422, and a side surface F429.

[0025] The first yoke 41 is positioned on the first surface F301 of the magnet 30. At this time, the back surface F412 of the first yoke 41 faces the first surface F301 of the magnet 30 and is bonded to it.

[0026] When viewing the first yoke 41 and the magnet 30 from a plan view (viewed in the Z direction), the center of the first yoke 41 and the center of the magnet 30 coincide.

[0027] The second yoke 42 is positioned on the second surface F302 of the magnet 30. At this time, the back surface F422 of the second yoke 42 faces the second surface F302 of the magnet 30 and is bonded to it.

[0028] When viewing the second yoke 42 and the magnet 30 from a plan view (viewed in the Z direction), the center of the second yoke 42 and the center of the magnet 30 coincide.

[0029] The first spring member 51 and the second spring member 52 are made of a non-magnetic and elastic material. For example, the first spring member 51 and the second spring member 52 are plate members made of a non-magnetic metal. The first spring member 51 and the second spring member 52 have the same configuration.

[0030] The first spring member 51 comprises an inner end 511, an outer end 512, and a beam portion 513. The inner end 511 corresponds to the "first yoke side end" of the present invention, the outer end 512 corresponds to the "first lid member side end," and the beam portion 513 corresponds to the "first beam portion."

[0031] The first spring member 51 is circular when viewed in plan (in the Z-axis direction). The inner end portion 511 is made of a flat plate that includes the center of the circle when the first spring member 51 is viewed in plan. The outer end portion 512 is made of an annular body that forms the outer circumference of the circle when the first spring member 51 is viewed in plan. The beam portion 513 is made of a plurality of strip-shaped members. The plurality of strip-shaped members are spiral in shape when viewed in plan. One end of the beam portion 513 (the plurality of strip-shaped members) is connected to the inner end portion 511. The other end of the beam portion 513 (the plurality of strip-shaped members) is connected to the outer end portion 512.

[0032] The second spring member 52 comprises an inner end 521, an outer end 522, and a beam portion 523. The inner end 521 corresponds to the "second yoke side end" of the present invention, the outer end 522 corresponds to the "second lid member side end," and the beam portion 523 corresponds to the "second beam portion."

[0033] The second spring member 52 is circular when viewed in plan (in the Z-axis direction). The inner end portion 521 is made of a flat plate that includes the center of the circle when the second spring member 52 is viewed in plan. The outer end portion 522 is made of an annular body that forms the outer circumference of the circle when the second spring member 52 is viewed in plan. The beam portion 523 is made of a plurality of strip-shaped members. The plurality of strip-shaped members are spiral in shape when viewed in plan. One end of the beam portion 523 (the plurality of strip-shaped members) is connected to the inner end portion 521. The other end of the beam portion 513 (the plurality of strip-shaped members) is connected to the outer end portion 522.

[0034] The inner end 511 of the first spring member 51 is fixed to the first yoke 41 using the first fixing member 61. The first fixing member 61 has a portion that fits into a through hole TH 511 formed in the inner end 511 (see, for example, Figure 10(A)), and it is also acceptable for it to have a structure that can sandwich and fix the inner end 511 together with the first yoke 41. The outer end 512 of the first spring member 51 is fixed in a state where it is sandwiched between the first housing projection 231 and the first lid member 221.

[0035] In this case, the inner end 511 and the outer end 512 are separated in a direction parallel to the axis AX20 of the housing 20. In other words, the first spring member 51 is fixed in a shape that is capable of generating a biasing force in a direction parallel to the axis AX20.

[0036] The inner end portion 521 of the second spring member 52 is fixed to the second yoke 42 using the second fixing member 62. The second fixing member 62 has a portion that fits into the through hole TH 521 (see, for example, Figure 10(B)) formed in the inner end portion 521, and furthermore, it is sufficient if it has a structure that can sandwich and fix the inner end portion 521 together with the second yoke 42. The outer end portion 522 of the second spring member 52 is fixed in a state where it is sandwiched between the second housing projection 232 and the second lid member 222.

[0037] In this case, the inner end 521 and the outer end 522 are separated in a direction parallel to the axis AX20 of the housing 20. In other words, the second spring member 52 is fixed in a shape that is capable of generating a biasing force in a direction parallel to the axis AX20.

[0038] With this configuration, the magnet 30 is positioned in the housing 20 in a state that allows it to vibrate in a direction parallel to the axis AX 20. Therefore, when an impact is applied to the housing 20 in a direction parallel to the axis AX 20, the magnet 30 can easily and stably vibrate in a direction parallel to the axis AX 20 (vibration direction DV: see Figure 3) in response to this impact.

[0039] In this configuration, the magnet 30 is supported by a first spring member 51 and a second spring member 52 that sandwich it from both sides. This allows the magnet 30 to vibrate easily and stably in a direction parallel to the axis AX20 without the need for a guide rod as in the conventional technology. This reduces vibration losses caused by the magnet 30 sliding against a guide rod or the like. Therefore, the power generation device 10 can generate highly efficient vibrations.

[0040] Furthermore, the magnet 30 is positioned away from the side wall member 21. As a result, the magnet 30 does not slide against the side wall member 21. Therefore, the power generation device 10 can generate vibrations with even greater efficiency.

[0041] Furthermore, in a plan view, the centers of the first spring member 51, the magnet 30, and the second spring member 52 coincide. More specifically, in a plan view, the centers of the outer end 512 of the first spring member 51, the inner end 511 of the first spring member 51, the magnet 30, the inner end 521 of the second spring member 52, and the outer end 522 of the second spring member 52 coincide.

[0042] As a result, even when an impact along the axis AX20 is applied from the outside, the magnet 30 is difficult to be displaced in a direction orthogonal to the axis AX20. Therefore, the power generation device 10 can further suppress the contact and sliding between the magnet 30 and the side wall member 21, and can improve the vibration efficiency in the direction of the axis AX20.

[0043] The coil 70 includes a first coil 71 and a second coil 72. The first coil 71 and the second coil 72 are disposed on the outer peripheral surface F21o of the side wall member 21.

[0044] More specifically, the outer peripheral surface F21o of the side wall member 21 includes recesses C211 and C212 (see FIG. 4). The recesses C211 and C212 are annular. The recess C211 is formed on the first opening side with respect to the center of the side wall member 21 in a direction parallel to the axis AX20. The recess C212 is formed on the second opening side with respect to the center of the side wall member 21 in a direction parallel to the axis AX20.

[0045] The first coil 71 is wound around the inside of the recess C211. The second coil 72 is wound around the recess C212.

[0046] Here, as shown in FIG. 4 and the like, in the direction parallel to the axis AX20 (Z-axis direction), the arrangement position of the first coil 71 and the arrangement position of the first yoke 41 overlap. More specifically, in the default state where the magnet 30 is not vibrating, in the direction parallel to the axis AX20 (Z-axis direction), the front surface F411 and the back surface F412 of the first yoke 41 overlap the arrangement region of the first coil 7l. In other words, in a direction orthogonal to the axis AX20 and parallel to the diameter of the first yoke 41, the first coil 71 and the first yoke 41 are arranged side by side and adjacent to each other.

[0047] Furthermore, in the direction parallel to the axis AX20 (Z-axis direction), the arrangement positions of the second coil 72 and the second yoke 42 overlap. More specifically, in the default state where the magnet 30 is not vibrating, in the direction parallel to the axis AX20 (Z-axis direction), the front surface F421 and the back surface F422 of the second yoke 42 overlap the arrangement region of the second coil 72. In other words, in the direction orthogonal to the axis AX20 and parallel to the diameter of the second yoke 42, the second coil 72 and the second yoke 42 are arranged side by side and adjacent to each other.

[0048] FIG. 5 is a diagram schematically showing the magnetic path (magnetic field lines) generated by the magnet. As shown in FIG. 5, with the first yoke 41 and the first coil 71 in the above-described positional relationship, and the second yoke 42 and the second coil 72 in the above-described positional relationship, a magnetic path (magnetic field lines) can be formed that exits from the first surface F301 of the magnet 30, passes through the first yoke 41, the first coil 71, the second coil 72, and the second yoke 42, and returns to the second surface F302 of the magnet 30.

[0049] Thereby, the magnetic field generated by the magnetic force of the magnet 30 can be efficiently guided to the first coil 71 and the second coil 72.

[0050] The first coil 71 and the second coil 72 are connected in series to form the coil 70. The end of the coil 70 on the side of the first coil 71 is connected to a first external connection terminal 791 that protrudes from the outer peripheral surface F21o of the side wall member 21 (see FIG. 1). The end of the coil 70 on the side of the second coil 72 is connected to a second external connection terminal 792 that protrudes from the outer peripheral surface F21o of the side wall member 21.

[0051] In such a configuration, when the magnet 30 vibrates as described above, the magnetic flux density passing through the first coil 71 and the second coil 72 changes. Due to this change in magnetic flux density, an alternating current is excited in the coil 70 (the first coil 71 and the second coil 72). The alternating current is output to the outside of the power generation device 10 through the first external connection terminal 791 and the second external connection terminal 792.

[0052] As described above, the highly efficient vibration of the magnet 30 enables the power generation device 10 to achieve highly efficient power generation. Furthermore, as described above, the use of the first yoke 41 and the second yoke 42 enables the power generation device 10 to achieve even more efficient power generation.

[0053] Furthermore, by using the first yoke 41 and the second yoke 42 that sandwich the magnet 30, the desired amount of power can be obtained while suppressing an increase in the size of the magnet 30. As a result, the power generation device 10 can achieve high efficiency, miniaturization, and weight reduction.

[0054] Furthermore, in the power generation device 10, the coils 70 (first coil 71 and second coil 72) are arranged on the outer circumferential surface F21o of the side wall member 21. As a result, even if the magnet 30 vibrates in a direction different from the vibration direction DV, the magnet 30 will not collide with the coils 70 (first coil 71 and second coil 72). Therefore, the power generation device 10 can prevent damage to the coils 70 (first coil 71 and second coil 72) and has high reliability.

[0055] A power generation device 10 with such a configuration can be used, for example, as follows. Figures 6(A), 6(B), and 6(C) show an example of how the power generation vise according to an embodiment of the present invention can be used.

[0056] As shown in Figures 6(A) and 6(B), the power generation device 10 is mounted on a tire TR used in any vehicle such as an automobile, motorcycle, or construction machinery.

[0057] More specifically, the tire TR comprises an outer circumferential surface FTRO and an inner circumferential surface FTRI. The outer circumferential surface FTRO and the inner circumferential surface FTRI have a substantially straight cross-sectional shape perpendicular to the circumferential direction of the tire TR.

[0058] The power generation device 10 is mounted on the inner circumferential surface FTRI of the tire. In this case, the power generation device 10 is mounted such that its axis AX20 is perpendicular to the surface on the inner circumferential surface FTRI to which the power generation device 10 is mounted. In other words, the power generation device 10 is mounted on the inner circumferential surface FTRI of the tire such that the first cover member 221 or the second cover member 222 is in surface contact with the inner circumferential surface FTRI of the tire.

[0059] As shown in Figure 6(C), the power generation device 10 may also be embedded in the tire TR.

[0060] Figure 7 is a diagram illustrating the power generation principle of a power generation device according to an embodiment of the present invention. Figure 7 is a cross-sectional view of a tire TR cut by a plane parallel to the circumferential direction, and is an enlarged view of the portion that contacts the road surface.

[0061] As shown in Figure 7, when the tire TR rotates and comes into contact with the road surface, the tire TR deforms, and in a part of the circumferential direction, the outer surface FTRO of the tire becomes concave and the inner surface FTRI of the tire protrudes. This deformation of the tire TR applies an impact to the power generation device 10 in a direction parallel to the axis AX20.

[0062] When an impact is applied to the power generation device 10 in a direction parallel to the axis AX20, the magnet 30 vibrates as described above. This vibration excites an alternating current from the coil 70. The power generation device 10 outputs the excited alternating current to the outside.

[0063] The tire TR rotates at a predetermined rotational speed. Therefore, the power generation device 10 can generate electricity each time the part to which the power generation device 10 is attached comes into contact with the road surface. As a result, the power generation device 10 can achieve highly efficient power generation by utilizing the rotation of the tire TR.

[0064] Furthermore, when mounted on a tire TR, the magnet 30 is prone to vibrating in a direction different from the vibration direction DV. However, as described above, since the first spring member 51 and the second spring member 52, which are positioned on either side of the magnet 30, are stably fixed to the housing 20, stable vibration in the vibration direction DV can be achieved, and damage to the magnet 30 and other components can be suppressed. Also, as described above, since the coils 70 (first coil 71 and second coil 72) are positioned on the outer circumferential surface F21o of the side wall member 21, collisions between the magnet 30 and the coils 70 can be prevented. Therefore, the power generation device 10 can achieve high reliability even when mounted on a tire TR.

[0065] The power generation device 10 preferably further comprises the following configurations.

[0066] (Housing 20) Figure 8 is an external perspective view of the side wall member of the housing according to the first embodiment. Figure 8 is an external perspective view seen from the second opening side. Figure 9 is a plan view of the side wall member of the housing according to the first embodiment. Figure 9 is a plan view seen from the second opening side.

[0067] As shown in Figures 3, 8, and 9, the multiple first housing protrusions 231 and the multiple second housing protrusions 232 have the same shape. In the case of Figures 8 and 9, the circumferential length L231 of the first housing protrusion 231 and the circumferential length L232 of the second housing protrusion 232 are the same, but this is not the only case.

[0068] As shown in Figure 3, the multiple first housing protrusions 231 are positioned at a distance L1 from the first opening end F211 of the side wall member 21 in a direction parallel to the axis AX20. The distance L1 is approximately equal to the sum of the thickness of the first lid member 221 and the thickness of the outer end 512 of the first spring member 51. Note that the distance L1 should be at least greater than the thickness of the outer end 512.

[0069] As shown in Figure 3, the multiple second housing protrusions 232 are positioned at a distance L2 from the second opening end F212 of the side wall member 21 in a direction parallel to the axis AX20. The distance L2 is approximately equal to the sum of the thickness of the second lid member 222 and the thickness of the outer end 522 of the second spring member 52. Note that the distance L2 should be at least greater than the thickness of the outer end 522.

[0070] In the circumferential direction of the inner surface F21i, the positions of the multiple first housing protrusions 231 and the multiple second housing protrusions 232 are different. In the circumferential direction of the inner surface F21i, the first housing protrusions 231 and the second housing protrusions 232 are arranged alternately.

[0071] In other words, when viewed in a direction perpendicular to the first or second opening (a direction parallel to axis AX20), the multiple first housing protrusions 231 and the multiple second housing protrusions 232 are arranged so that they do not overlap with each other.

[0072] More specifically, in the examples of Figures 8 and 9, there are three first housing protrusions 231 and three second housing protrusions 232. The three first housing protrusions 231 are arranged at 120° intervals when viewed in a direction parallel to the axis AX20. The three second housing protrusions 232 are also arranged at 120° intervals when viewed in a direction parallel to the axis AX20. The positions of the three first housing protrusions 231 and the positions of the three second housing protrusions 232 are offset by 60°. Note that in the case of three, this interval and offset amount are set, but in cases other than three, i.e., two or four or more, the interval and offset amount should be set according to the respective number.

[0073] In Figure 9, the lengths L231 of the first housing projection 231 and L232 of the second housing projection 232 are set to 1 / 6 of the length of the circle, but this is not the only option. They can be set appropriately according to the shape of the outer end portion 512 of the first spring member 51 (length L514 of the projection 514 of the first spring member 51: see Figure 10, etc.) and the shape of the outer end portion 522 of the second spring member 52 (length L524 of the projection 524 of the second spring member 52: see Figure 10, etc.).

[0074] (First spring member 51 and second spring member 52) Figure 10(A) is an external perspective view of the first spring member according to the first embodiment, and Figure 10(B) is an external perspective view of the second spring member according to the first embodiment. Figure 11 is a plan view of the first spring member according to the first embodiment.

[0075] As shown in Figures 10(A) and 11, the first spring member 51 is circular in shape when viewed from above (in the Z-axis direction), with a portion of it having an outward projection. The first spring member 51 comprises an inner end 511, an outer end 512, and a beam portion 513.

[0076] The inner end portion 511 is composed of a disc having a through hole TH511. The inner end portion 511 is positioned to include the center of the circle when the first spring member 51 is viewed from above.

[0077] The outer end portion 512 is composed of an annular body that forms the circular outer circumference when the first spring member 51 is viewed in plan. The outer end portion 512 has a plurality of projections 514 at intermediate positions in the circumferential direction. The projections 514 correspond to the "first spring member projections".

[0078] The multiple protrusions 514 are configured to partially protrude outward from the outer circumference of the outer end portion 512. The multiple protrusions 514 are arranged at equal intervals along the circumferential direction of the outer end portion 512.

[0079] The multiple protrusions 514 are arc-shaped along the outer circumference of the outer end portion 512 and have a length L514. The length L514 is set to be less than the distance (length along the circumferential direction) between the multiple adjacent first housing protrusions 231 in the circumferential direction.

[0080] The ends of the arcs of the multiple protrusions 514 are connected to the outer end 512 by support portions 515 that extend in a direction perpendicular to the outer circumference of the outer end 512.

[0081] The beam section 513 is composed of multiple (three in this embodiment) strip-shaped members. The multiple strip-shaped members have a spiral shape when viewed from above. One end of each of the multiple strip-shaped members constituting the beam section 513 is connected to the outer circumference end of the inner end section 511. The other end of each of the multiple strip-shaped members constituting the beam section 513 is connected to the inner circumference end of the outer end section 512.

[0082] With this configuration, the first spring member 51 elastically deforms in a direction perpendicular to the planes of its inner end 511 and outer end 512. This elastic deformation allows the magnet 30 to be supported in a vibrating state.

[0083] The multiple strip-shaped members constituting the beam section 513 are arranged at equal intervals along the outer circumference of the inner end 511 and the inner circumference of the outer end 512.

[0084] In this way, by arranging the multiple strip-shaped members in a spiral shape, the length of the multiple strip-shaped members between the inner end 511 and the outer end 512 can be increased. This improves the springiness of the first spring member 51 and increases the amplitude of the magnet 30.

[0085] As shown in Figure 10(B), the second spring member 52 is circular in shape when viewed from above (in the Z-axis direction), with a portion of it having an outward projection. The second spring member 52 comprises an inner end 521, an outer end 522, and a beam portion 523.

[0086] The inner end portion 521 is composed of a disc having a through hole TH521. The inner end portion 521 is positioned to include the center of the circle when the second spring member 52 is viewed from above.

[0087] The outer end portion 522 is composed of an annular body that forms the circular outer circumference when the second spring member 52 is viewed from above. The outer end portion 522 has a plurality of protrusions 524 at intermediate positions in the circumferential direction. The protrusions 524 correspond to the "second spring member protrusions".

[0088] The multiple protrusions 524 are configured to partially protrude outward from the outer circumference of the outer end portion 522. The multiple protrusions 524 are arranged at equal intervals along the circumferential direction of the outer end portion 522.

[0089] The multiple protrusions 524 are arc-shaped along the outer circumference of the outer end portion 522 and have a length L524. The length L524 is set to be less than the distance (length along the circumferential direction) between multiple adjacent second housing protrusions 232 in the circumferential direction.

[0090] The ends of the arcs of the multiple protrusions 524 are connected to the outer end 522 by support portions 525 that extend in a direction perpendicular to the outer circumference of the outer end 522.

[0091] The beam section 523 is composed of multiple (three in this embodiment) strip-shaped members. The multiple strip-shaped members have a spiral shape when viewed from above. One end of each of the multiple strip-shaped members constituting the beam section 523 is connected to the outer circumference end of the inner end section 521. The other end of each of the multiple strip-shaped members constituting the beam section 523 is connected to the inner circumference end of the outer end section 522.

[0092] In this configuration, the second spring member 52 elastically deforms in a direction perpendicular to the planes of its inner end 521 and outer end 522. This elastic deformation allows the magnet 30 to be supported in a vibrating state.

[0093] The multiple strip-shaped members constituting the beam section 523 are arranged at equal intervals along the outer circumference of the inner end 521 and the inner circumference of the outer end 522.

[0094] In this way, by arranging the multiple strip-shaped members in a spiral shape, the length of the multiple strip-shaped members can be increased between the inner end 521 and the outer end 522. This improves the springiness of the second spring member 52 and increases the amplitude of the magnet 30.

[0095] Figure 12 is a plan view of the first spring member and the second spring member in a superimposed state according to the first embodiment. In other words, it is a plan view showing the state of members other than the first and second spring members as seen through, when the first and second spring members are fixedly arranged inside the power generation device 10. As shown in Figure 12, the first spring member 51 and the second spring member 52 are arranged so that their centers coincide when viewed from above.

[0096] In a plan view, the arrangement positions of the multiple protrusions 514 on the first spring member 51 and the arrangement positions of the multiple protrusions 524 on the second spring member 52 are different. In a plan view, the multiple protrusions 514 and the multiple protrusions 524 are arranged alternately.

[0097] In other words, in a plan view, the multiple protrusions 514 and the multiple protrusions 524 are arranged so that they do not overlap with each other.

[0098] More specifically, in the example shown in Figure 12, there are three projections 514 and three projections 524. The three projections 514 are arranged at 120° intervals when viewed in a direction parallel to the axis AX20 (in a plan view). The three projections 524 are arranged at 120° intervals when viewed in a direction parallel to the axis AX20 (in a plan view). The positions of the three projections 514 and the positions of the three projections 524 are offset by 60°. Note that in the case of three projections, this interval and offset amount are set, but in cases other than three, i.e., two or four or more projections, the interval and offset amount should be set according to the respective number.

[0099] The first spring member 51 and the second spring member 52 are arranged in the housing 20 as follows.

[0100] First, as a premise, the inner end 511 of the first spring member 51 is fixed to the first yoke 41 and the magnet 30 using the first fixing member 61. The inner end 521 of the second spring member 52 is fixed to the second yoke 42 and the magnet 30 using the second fixing member 62. This constitutes a vibrating body including the magnet 30, the first yoke 41, the second yoke 42, the first spring member 51, and the second spring member 52. In this vibrating body, the multiple protrusions 514 of the first spring member 51 and the multiple protrusions 524 of the second spring member 52 are arranged alternately along the circumferential direction so as not to overlap with each other (see Figure 12).

[0101] Figures 13(A), 13(B), 13(C), and 13(D) are plan views showing the positional relationship between the first spring member, the second spring member, and the side wall member. Figures 13(A) and 13(B) show the state in which the vibrating body is inserted into the internal space IS20 of the housing 20, and Figures 13(C) and 13(D) show the state in which the vibrating body is rotated within the internal space IS20. Figures 13(A) and 13(C) are views from the first opening side, and Figures 13(B) and 13(D) are views from the second opening side.

[0102] Multiple protrusions 514 on the first spring member 51 and multiple protrusions 524 on the second spring member 52 are arranged alternately in the circumferential direction of the vibrating body. Multiple first housing protrusions 231 and multiple second housing protrusions 232 on the side wall member 21 are arranged alternately in the circumferential direction of the inner circumferential surface F21i. Therefore, for example, when inserting the vibrating body from the first opening, the vibrating body is inserted into the inside of the side wall member 21 (internal space IS20) such that the multiple protrusions 524 pass between each of the multiple first housing protrusions 231. With the multiple protrusions 524 having passed the multiple first housing protrusions 231 in a direction parallel to the axis AX20, the vibrating body is rotated so that, when viewed from the first opening, the multiple protrusions 524 overlap the multiple first housing protrusions 231. After this, the vibrating body is further inserted into the inside of the side wall member 21 (internal space IS20).

[0103] As a result, as shown in Figure 13(A), when viewed from the first opening, the multiple protrusions 514 on the first spring member 51 are each positioned between the multiple first housing protrusions 231. As shown in Figure 13(B), when viewed from the second opening, the multiple protrusions 524 on the second spring member 52 are each positioned between the multiple second housing protrusions 232.

[0104] In this state, the vibrating body is further rotated so that, when viewed from the first opening, the multiple protrusions 514 overlap with the multiple first housing protrusions 231, and when viewed from the second opening, the multiple protrusions 524 overlap with the multiple second housing protrusions 232.

[0105] As a result, as shown in Figure 13(C), when viewed from the first opening, the multiple protrusions 514 overlap with the multiple first housing protrusions 231 and abut against the first opening side surface of the multiple first housing protrusions 231. As shown in Figure 13(D), when viewed from the second opening, the multiple protrusions 524 overlap with the multiple second housing protrusions 232 and abut against the second opening side surface of the multiple second housing protrusions 232.

[0106] Figure 14 is an enlarged cross-sectional view showing the state in which the protrusions are sandwiched between the housing protrusions and the lid member. As described above, with the vibrating body positioned relative to the side wall member 21, the multiple protrusions 514 are sandwiched between the multiple first housing protrusions 231 and the first lid member 221, as shown in Figure 14. Furthermore, the multiple protrusions 524 are sandwiched between the multiple second housing protrusions 232 and the second lid member 222. As a result, the vibrating body is positioned in the housing 20 in a state in which it can vibrate parallel to the vibration direction DV.

[0107] By adopting the above configuration for the housing 20, the first spring member 51, and the second spring member 52, the power generation device 10 can be easily manufactured.

[0108] Furthermore, with the above configuration, the vibrating body is held with equal force relative to the center of the vibrating body, including the magnet 30, when viewed from the first opening, by the combination of the multiple protrusions 514 of the first spring member 51 and the multiple protrusions 231 of the first housing 20. As a result, the posture of the vibrating body is stabilized, and vibration of the vibrating body in directions other than parallel to the vibration direction DV can be suppressed.

[0109] Similarly, the vibrating body is held relative to the housing 20 with a uniform force on the center of the vibrating body, including the magnet 30, as viewed from the second opening, by the combination of the multiple protrusions 524 of the second spring member 52 and the multiple protrusions 232 of the second housing. As a result, the posture of the vibrating body is stabilized, and vibration of the vibrating body in directions other than parallel to the vibration direction DV can be suppressed.

[0110] Furthermore, the multiple first support points for the vibrating body, which are composed of multiple protrusions 514 and multiple first housing protrusions 231, and the multiple second support points for the vibrating body, which are composed of multiple protrusions 524 and multiple second housing protrusions 232, are arranged alternately in the circumferential direction. As a result, when viewed from the first or second opening (in the direction perpendicular to the vibration direction DV), the vibrating body is supported with a more even distribution in the circumferential direction. This stabilizes the posture of the vibrating body and further suppresses vibration of the vibrating body in directions other than parallel to the vibration direction DV.

[0111] Furthermore, in the above configuration, the first spring member 51 has multiple projections 514 connected to its outer end 512 by multiple support parts 515. With this configuration, the first spring member 51 can also be elastically deformed in the circumferential direction. The second spring member 52 has multiple projections 524 connected to its outer end 522 by multiple support parts 525. With this configuration, the second spring member 52 can also be elastically deformed in the circumferential direction. As a result, the posture of the vibrating body is further stabilized, and vibration of the vibrating body in directions other than parallel to the vibration direction DV can be suppressed more reliably.

[0112] Furthermore, these configurations suppress unwanted deformation of the first spring member 51 and the second spring member 52 when an unwanted impact is applied to the housing 20. In addition, these configurations suppress collisions between the vibrating body and the magnet 30 and the side wall member 21.

[0113] Furthermore, even though the direction of vibration is restricted to a direction parallel to the vibration direction DV, the heights of the first fixing member 61 and the second fixing member 62 are adjusted so that the first fixing member 61 collides with the first lid member 221 or the second fixing member 62 collides with the second lid member 222, with priority given to the vibrating body (magnet 30, first yoke 41, and second yoke 42). In other words, the height to which the first fixing member 61 protrudes from the surface F411 of the first yoke 41 is greater than the depth of the recess (inner hole TH221i) on the first yoke 41 side of the first lid member 221. The height to which the second fixing member 62 protrudes from the surface F421 of the second yoke 42 is greater than the depth of the recess (inner hole TH222i) on the second yoke 42 side of the second lid member 222. This suppresses damage to the vibrating body, magnet 30, etc.

[0114] (First yoke 41 and second yoke 42) Figure 15(A) is an external perspective view of the first yoke, and Figure 15(B) is an external perspective view of the second yoke. As shown in Figures 15(A) and 15(B), the first yoke 41 and the second yoke 42 have the same configuration.

[0115] As shown in Figures 15(A) and 4, the first yoke 41 is composed of a disc having a surface F411 and a back surface F412. The first yoke 41 has an outer peripheral end 411, a central part 412, and a plurality of support parts 413, and has a plurality of first yoke through holes TH41 and through holes TH419. The outer peripheral end 411 is annular in shape when viewed from above. The width of the outer peripheral end 411 is set so that the magnetic field of the magnet 30 can be guided to the first coil 71 at a desired size.

[0116] The central portion 412 is circular in plan view. The central portion 412 is located inside the annular shape of the outer peripheral end portion 411. The central portion 412 has a through hole TH419. The through hole TH419 is a hole into which the first fixing member 61 is inserted and fitted. Multiple support portions 413 connect the outer peripheral end of the central portion 412 to the inner peripheral end of the outer peripheral end portion 411.

[0117] The portion between the outer peripheral end 411 and the central portion 412 where the multiple support portions 413 are not located becomes a plurality of first yoke through holes TH41. In other words, the plurality of support portions 413 are formed by the formation of a plurality of independent first yoke through holes TH41 between the outer peripheral end 411 and the central portion 412.

[0118] By providing multiple first yoke through-holes TH41, the first yoke 41 can effectively guide the magnetic field from the magnet 30 to the first coil 71 while achieving weight reduction. As a result, the power generation device 10 can achieve high-efficiency power generation and weight reduction.

[0119] As shown in Figures 15(B) and 4, the second yoke 42 is composed of a disc having a surface F421 and a back surface F422. The second yoke 42 has an outer peripheral end 421, a central portion 422, and a plurality of support portions 423, and has a plurality of second yoke through holes TH42 and through holes TH429. The outer peripheral end 421 is annular in shape when viewed from above. The width of the outer peripheral end 421 is set so as to effectively guide the magnetic field from the second coil 72 to the magnet 30.

[0120] The central portion 422 is circular in plan view. The central portion 422 is located inside the annular shape of the outer peripheral end portion 421. The central portion 422 has a through hole TH429. The through hole TH429 is a hole into which the second fixing member 62 is inserted and fitted. The multiple support portions 423 are in the shape of straight strips and connect the outer peripheral end of the central portion 422 to the inner peripheral end of the outer peripheral end portion 421.

[0121] The portion between the outer peripheral end 421 and the central portion 422 where the multiple support portions 423 are not located becomes a plurality of second yoke through holes TH42. In other words, the plurality of support portions 423 are formed by the formation of a plurality of independent second yoke through holes TH42 between the outer peripheral end 421 and the central portion 422.

[0122] By providing multiple through-holes TH42 in the second yoke, the second yoke 42 can guide the magnetic field from the second coil 72 to the magnet 30 at a desired level while achieving weight reduction. As a result, the power generation device 10 can achieve both high-efficiency power generation and weight reduction.

[0123] Furthermore, by having the first yoke 41 have multiple first yoke through holes TH41 and the second yoke 42 have multiple second yoke through holes TH42, the internal space volume of the housing 20 can be increased.

[0124] Figure 16 is a cross-sectional view showing the spatial volume for vibration of the power generation device. As shown in Figure 16, the spatial volume for vibration consists of a first spatial volume and a second spatial volume. The first spatial volume consists of the space on the side of the first lid member 221 from the magnet 30. The second spatial volume consists of the space on the side of the second lid member 222 from the magnet 30.

[0125] As shown in Figure 16, the first spatial volume is larger when the first yoke 41 has multiple first yoke through holes TH41 than when it does not have multiple first yoke through holes TH41. Similarly, the second spatial volume is larger when the second yoke 42 has multiple second yoke through holes TH42 than when it does not have multiple second yoke through holes TH42.

[0126] This allows the power generation device 10 to increase the spatial volume on both the first cover member 221 side and the second cover member 222 side of the magnet 30. Therefore, it is possible to suppress the restriction of vibration of the magnet 30 by the size of the spatial volume. As a result, the power generation device 10 can achieve highly efficient vibration and power generation.

[0127] Furthermore, the diameters of the first yoke 41 and the second yoke 42 do not have to be the same as the diameter of the magnet 30, but are preferably larger than the diameter of the magnet 30. This allows the power generation device 10 to achieve a higher magnetic field coupling between the magnet 30 and the first yoke 41 and the second yoke 42. In addition, the power generation device 10 can prevent the magnet 30 from directly contacting the inner circumferential surface F21i of the side wall member 21 due to unwanted impacts.

[0128] (First lid member 221 and second lid member 222) As shown in Figures 3 and 16, the first lid member 221 is disc-shaped with surfaces F221o and F221i. The first lid member 221 is placed in the first opening of the side wall member 21 with surface F221i facing the magnet 30.

[0129] The first lid member 221 has a recess C221 that is recessed from the surface F221i. The recess C221 is located in the center when the first lid member 221 is viewed from above.

[0130] Having such a recess C221 allows the volume of the space on the first lid member 221 side of the magnet 30 in the internal space IS20 of the housing 20 to be larger than in a configuration without the recess C221. This reduces the air resistance (air spring) in this space. Therefore, the power generation device 10 can vibrate the magnet 30 more efficiently.

[0131] Furthermore, even if the magnet 30 vibrates excessively, the presence of the recess C221 prevents the first fixing member 61 from unintentionally colliding with the first lid member 221.

[0132] As shown in Figures 3 and 16, the second lid member 222 is disc-shaped and has surfaces F222o and F222i. The second lid member 222 is positioned in the second opening of the side wall member 21 with surface F222i facing the magnet 30.

[0133] The second lid member 222 has a recess C222 that is recessed from the surface F222i. The recess C222 is located in the center when the second lid member 222 is viewed from above.

[0134] Having such a recess C222 allows the volume of the space on the second lid member 222 side of the magnet 30 in the internal space IS20 of the housing 20 to be larger than in a configuration without the recess C222. This reduces the air resistance (air spring) in this space. Therefore, the power generation device 10 can vibrate the magnet 30 more efficiently.

[0135] Furthermore, even if the magnet 30 vibrates excessively, for example, the presence of the recess C222 prevents the second fixing member 62 from unintentionally colliding with the second lid member 222.

[0136] Furthermore, in this configuration, the internal space IS20 of the housing 20 is not in communication with the outside of the housing 20. Therefore, it is possible to prevent foreign matter from entering the internal space IS20 of the housing 20 from the outside. For example, in an embodiment in which the power generation device 10 is embedded in the tire TR, it is possible to prevent the rubber resin constituting the tire TR from entering the internal space IS20 of the housing 20.

[0137] (First fixing member 61 and second fixing member 62) The first fixing member 61 is used to increase the joint strength when the inner end 511 of the first spring member 51 is joined to the first yoke 41. Furthermore, as shown in Figures 2 and 3, the first fixing member 61 protrudes further toward the first lid member 221 than the inner end 511 of the first spring member 51. As a result, even if the vibrating body (magnet 30, first yoke 41, second yoke 42, first spring member 51, and second spring member 52) vibrates undesirably and excessively, the power generation device 10 can suppress the joint between the first yoke 41 and the first spring member 51 from directly colliding with the first lid member 221.

[0138] Similarly, the second fixing member 62 is used to increase the joint strength when the inner end 521 of the second spring member 52 is joined to the second yoke 42. Furthermore, as shown in Figures 2 and 3, the second fixing member 62 protrudes further toward the second lid member 222 than the inner end 521 of the second spring member 52. As a result, even if the vibrating body (magnet 30, first yoke 41, second yoke 42, first spring member 51, and second spring member 52) vibrates excessively as desired, the power generation device 10 can suppress the joint between the second yoke 42 and the second spring member 52 from directly colliding with the second lid member 222.

[0139] (Examples of spring member variations) Figure 17 is a plan view showing an example of a spring member variation configuration. Figure 17 explains an example of a first spring member variation, but a similar variation can be adopted for the second spring member.

[0140] As shown in Figure 17, the first spring member 51DV is provided with a plurality of protrusions 514DV. The plurality of protrusions 514DV are formed by widening a portion of the outer end portion 512 and causing it to protrude outward.

[0141] The power generation device 10 can also employ a spring member with such a configuration. In this embodiment, for example, the area over which the spring member is sandwiched becomes larger. Therefore, the fixing strength of the spring member can be increased.

[0142] (Examples of derived lid members) Figures 18(A), 18(B), 18(C), and 18(D) are cross-sectional views showing examples of derived configurations of lid members. Figures 18(A), 18(B), 18(C), and 18(D) illustrate examples of derived first lid members, but similar derived examples can be adopted for second lid members.

[0143] In the example shown in Figure 18(A), the first lid member 221DV1 has a through hole TH221DV1. The through hole TH221DV1 is configured with a constant diameter. In this configuration, for example, the air pressure of the air spring can be effectively released, thereby improving vibration efficiency. The through hole TH221DV1 corresponds to the "lid member through hole".

[0144] In the example shown in Figure 18(B), the first lid member 221DV2 is composed of a mesh plate 2211M and a frame 2211S. In this configuration, for example, the air pressure of the air spring can be effectively released, thereby improving vibration efficiency. Furthermore, it is possible to suppress the intrusion of foreign matter from the outside into the internal space IS20 of the housing 20. For example, in an embodiment in which the power generation device 10 is embedded in the tire TR, it is possible to suppress the intrusion of the rubber constituting the tire TR into the internal space IS20 of the housing 20.

[0145] In the example shown in Figure 18(C), the first lid member 221DV3 has a through hole TH221DV3 that penetrates surfaces F221o and F221i. The through hole TH221DV3 is located in the center of the first lid member 221 when viewed from above. The through hole TH221DV3 corresponds to the "lid member through hole".

[0146] The through-hole TH221DV3 is composed of an inner hole TH221i and an outer hole TH221o. The inner hole TH221i has a shape in which a part of the surface F221i is recessed. The outer hole TH221o has a shape in which a part of the surface F221o is recessed. The inner hole TH221i and the outer hole TH221o overlap when viewed from above the first lid member 221 and communicate with each other. The diameter of the inner hole TH221i is longer than the diameter of the outer hole TH221o.

[0147] When the power generation device 10 is viewed from above (viewed in the Z-axis direction), the inner hole TH221i overlaps with the first fixing member 61.

[0148] Having such a through-hole TH221DV3 allows the space on the first lid member 221 side of the magnet 30 inside the housing 20 to communicate with the space outside the housing 20. As a result, the air on the first lid member 221 side of the magnet 30 inside the housing 20 is not sealed, and the air resistance (air spring) in this space can be reduced. Therefore, the power generation device 10 can vibrate the magnet 30 more efficiently.

[0149] In the example shown in Figure 18(D), the first lid member 221DV4 does not have a through hole. This configuration allows for increased strength of the first lid member 221DV1. Furthermore, it prevents foreign matter from entering the internal space IS20 of the housing 20. For example, in an embodiment where the power generation device 10 is embedded in the tire TR, it prevents the rubber constituting the tire TR from entering the internal space IS20 of the housing 20.

[0150] (Examples of York Derivations) Figure 19 is a cross-sectional view showing an example of a yoke derivative configuration. Figure 19 explains an example of a first yoke derivative, but a similar derivative can be used for the second yoke.

[0151] As shown in Figure 19, the first yoke 41DV has a recess C414 between the outer peripheral end 411 and the central portion 412. This gives the first yoke 41DV a thin-walled portion 414 between the outer peripheral end 411 and the central portion 412. In this case, it is preferable that the recess C414 is recessed from the surface F411.

[0152] The power generation device 10 can also employ a yoke with this configuration. This increases the contact surface between the first yoke 41DV1 and the magnet 30, thereby increasing the bonding strength between the first yoke 41DV1 and the magnet 30.

[0153] (Examples of variations in the fixed state between the housing and the spring member) Figures 20(A) and 20(B) are cross-sectional views showing examples of variations in the fixed state between the housing and the spring member. Figures 20(A) and 20(B) describe variations on the first spring member side, but similar variations can be adopted on the second spring member side as well.

[0154] In the configuration shown in Figure 20(A), a groove SLT is formed in the first housing projection 231 of the side wall member 21. The outer end portion 512 (projection 514) of the first spring member 51 is inserted and fitted into the groove SLT. The first lid member 221 is positioned directly on the first housing projection 231.

[0155] In the configuration shown in Figure 20(B), the housing 20X is integrally molded with a side wall member 21 and a first lid member 221. The outer end portion 512 (projection 514) of the first spring member 51 is inserted and fitted into the gap between the first lid member 221 and the first housing projection 231.

[0156] The power generation device 10 can also employ a fixed configuration in which the housing and spring member are fixed together.

[0157] In the above configuration, the first spring member 51 and the second spring member 52 have a vertically symmetrical shape in relation to their vertical movement, but symmetry is not necessarily required.

[0158] [Second Embodiment] A power generation device according to a second embodiment of the present invention will be described with reference to the figures. Figure 21 is a cross-sectional view of the power generation device according to the second embodiment.

[0159] As shown in Figure 21, the power generation device 10A according to the second embodiment differs from the power generation device 10 according to the first embodiment in that it includes a magnet 30A and a fixing member 60. The other components of the power generation device 10A are the same as those of the power generation device 10. Below, only the parts that differ in configuration will be described in detail.

[0160] The power generation device 10A comprises a magnet 30A and a fixing member 60. The magnet 30A has a through hole for the fixing member. The through hole is cylindrical and is formed in a shape that includes the center of the magnet 30A when viewed from above.

[0161] The fixing member 60 is composed of a main shaft 601, a first end member 6021, and a second end member 6022. The main shaft 601, the first end member 6021, and the second end member 6022 are integrally molded. The fixing member 60 corresponds to the "third fixing member".

[0162] The main shaft 601 is cylindrical and has an external shape that is approximately the same as the through hole formed in the magnet 30A. The main shaft 601 is inserted through the through hole in the magnet 30A.

[0163] The first end member 6021 is connected to one end of the main shaft 601. The first end member 6021 abuts against the inner end 511 of the first spring member 51 on the side opposite to the first yoke 41. The second end member 6022 is connected to the other end of the main shaft 601. The second end member 6022 abuts against the inner end 521 of the second spring member 52 on the side opposite to the second yoke 42.

[0164] With this configuration, the first spring member 51 and the second spring member 52 are fixed to the structure of the magnet 30A, the first yoke 41, and the second yoke 42 using a single fixing member 60. By using this fixing structure, the bonding strength of the first spring member 51 and the second spring member 52 to the structure composed of the magnet 30, the first yoke 41, and the second yoke 42 can be further increased.

[0165] Furthermore, because the magnet 30A has a through hole, the magnet 30A is made lighter, and the power generation device 10A is made lighter.

[0166] (Examples of Derived Fixing Members) Figure 22 is an external perspective view showing an example of a derived fixing member of a power generation device according to the second embodiment. As shown in Figure 22, the fixing member 60DV differs from the fixing member 60 described above in that it has a polygonal prism shape. The other components of the fixing member 60DV are the same as those of the fixing member 60, and the description of the similar parts will be omitted.

[0167] The fixing member 60DV comprises a polygonal prism main shaft 601DV, a first end member 6021DV, and a second end member 6022DV. The main shaft 601DV, the first end member 6021DV, and the second end member 6022DV are integrally molded.

[0168] The through-hole formed in the magnet 30A is a polygonal rectangular tube shape. The shape of this through-hole is the same as the shape of the main shaft 601DV. The polygonal prism main shaft 601DV is inserted through this polygonal rectangular tube-shaped through-hole.

[0169] With this configuration, the power generation device 10A can suppress the rotation of the magnet 30A relative to the main shaft 601DV, thereby suppressing the occurrence of undesirable vibration resonance modes. As a result, the power generation efficiency of the power generation device 10A is further improved.

[0170] [Third Embodiment] A power generation device according to a third embodiment of the present invention will be described with reference to the figures. Figure 23 is a perspective view including a cross-section of the power generation device according to the third embodiment.

[0171] As shown in Figure 23, the power generation device 10B according to the third embodiment differs from the power generation device 10 according to the first embodiment in that it includes a housing 20B. The other components of the power generation device 10B are the same as those of the power generation device 10, and a description of the similar parts will be omitted.

[0172] The power generation device 10B comprises a housing 20B. The housing 20B comprises a side wall member 21B. The side wall member 21B has a plurality of grooves SL21B on its inner circumferential surface F21i. The plurality of grooves SL21B are shaped to extend parallel to the axis AX20.

[0173] This configuration allows the power generation device 10B to avoid the detached magnets. Furthermore, the power generation device 10B improves the airflow during vibration of the magnet 30, suppressing displacement inhibition at minute displacements.

[0174] [Fourth Embodiment] A power generation device according to a fourth embodiment of the present invention will be described with reference to the figures. Figures 24(A) and 24(B) are cross-sectional views of the power generation device according to the fourth embodiment, respectively.

[0175] As shown in Figure 24(A), the first example of the power generation device 10C1 according to the fourth embodiment differs from the power generation device 10 according to the first embodiment in that the first fixing member 61 and the second fixing member 62 are omitted. The other components of the power generation device 10C1 are the same as those of the power generation device 10, and a description of the similar parts will be omitted.

[0176] In the power generation device 10C1, the inner end 511 of the first spring member 51 is directly joined to the first yoke 41. Also, in the power generation device 10C1, the inner end 521 of the second spring member 52 is directly joined to the second yoke 42. The joining here may be done by welding or by bonding with an adhesive.

[0177] This configuration allows for the omission of the first fixing member 61 and the second fixing member 62, thereby reducing the weight of the power generation device 10C1.

[0178] As shown in Figure 24(B), the second example of the power generation device 10C2 according to the fourth embodiment differs from the power generation device 10A according to the second embodiment in that the fixing member 60 is omitted. The other components of the power generation device 10C2 are the same as those of the power generation device 10A, and a description of the similar parts will be omitted.

[0179] In the power generation device 10C2, the first spring member 51 and the second spring member 52 are directly fixed to the magnet 30A using a resin material RM. The resin material RM is filled into through holes provided in the magnet 30A and protrudes from the surface of the magnet 30A on the first cover member 221 side and the surface on the second cover member 222 side. The first spring member 51 and the second spring member 52 are fixed to the magnet 30A by these protruding portions.

[0180] This configuration allows for further weight reduction of the power generation device 10C2.

[0181] [Fifth Embodiment] A power generation device according to the fifth embodiment of the present invention will be described with reference to the figures. Figure 25 is a cross-sectional view of the power generation device according to the fifth embodiment.

[0182] As shown in Figure 25, the power generation device 10D according to the fifth embodiment differs from the power generation device 10 according to the first embodiment in that it includes a back yoke BY. The other components of the power generation device 10D are the same as those of the power generation device 10, and a description of the similar parts will be omitted.

[0183] The power generation device 10D includes a back yoke BY. The back yoke BY is made of the same material as the first yoke 41 and the second yoke 42.

[0184] The back yoke BY is cylindrical in shape. The back yoke BY is positioned along the outer circumferential surface F21o of the side wall member 21.

[0185] The back yoke BY forms a closed magnetic circuit passing through the magnet 30, the first yoke 41, the first coil 71, the back yoke BY, the second coil 72, and the second yoke 42. As a result, the power generation device 10D can generate electricity more efficiently.

[0186] In each of the embodiments described above, it is preferable that the magnet is made of a material containing samarium cobalt. This suppresses the deterioration of the magnet's properties due to heat. Therefore, the power generation device can suppress the decrease in power generation efficiency due to the effects of heat.

[0187] Furthermore, in each of the embodiments described above, it is preferable that the first coil 71 and the second coil 72 are rectangular wires with a rectangular cross-section. This allows the first coil 71 and the second coil 72 to be arranged at a high density relative to the side wall member. As a result, the power generation device can achieve more efficient power generation.

[0188] [Sixth Embodiment] A power generation device according to the sixth embodiment of the present invention will be described with reference to the figures. Figure 26 is a cross-sectional view of the power generation device according to the sixth embodiment.

[0189] As shown in Figure 26, the power generation device 10M according to the sixth embodiment differs from the power generation device 10 according to the first embodiment in that it introduces magnetic fluid MF into the internal space IS20 of the housing 20. The other components of the power generation device 10M are the same as those of the power generation device 10 according to the first embodiment, and a description of the similar parts will be omitted.

[0190] The magnetic fluid MF is introduced (contained) in the internal space IS20 of the housing 20. The magnetic fluid MF is arranged to gather around the magnet 30 due to the influence of the magnet's magnetic force. In other words, the magnetic fluid MF covers the magnet 30.

[0191] As a result, the magnetic fluid MF acts as a buffer. Therefore, even if the magnet 30 of the power generation device 10M is about to collide with the side wall member 21 or the first lid member 221 and the second lid member 222, the magnetic fluid MF can mitigate the impact of the collision and suppress damage to the magnet 30.

[0192] [Seventh Embodiment] A power generation module according to the seventh embodiment of the present invention will be described with reference to the figures. Figure 27 is an external perspective view of the power generation module according to the seventh embodiment. Figure 28 is a cross-sectional view of the power generation module according to the seventh embodiment.

[0193] As shown in Figures 27 and 28, the power generation module 1 comprises a power generation device 10, a circuit module 90, and an elastic member 990. The power generation device 10 has the same configuration as the power generation device 10 shown in the first embodiment described above.

[0194] The circuit module 90 comprises a circuit board 900 and a plurality of circuit elements 91. The plurality of circuit elements 91 may include electrical circuit elements or electronic circuit elements as appropriate. For example, the plurality of circuit elements 91 may include at least one of an inertial sensor and an environmental sensor, and a communication IC.

[0195] Multiple circuit elements 91 are mounted on one main surface of the circuit board 900. The circuit board 900 is electrically connected to the first external connection terminal 791 and the second external connection terminal 792.

[0196] Multiple circuit elements 91 that require power (such as inertial sensors, environmental sensors, communication ICs, secondary batteries, and rectifier circuits) are driven by power based on the alternating current flowing through the first coil 71 and the second coil 72, which are excited by the vibration of the magnet 30. As a result, the circuit module 90 performs various measurements, for example, using inertial sensors and environmental sensors.

[0197] Thus, the power generation module 1 can not only generate electricity but also measure the state of the object to which it is attached. For example, by replacing the power generation device 10 shown in Figures 6(A) and 6(B) with the power generation module 1, the power generation module 1 can measure the state of the tire TR (e.g., degree of indentation, temperature, etc.). In this case, since the power generation module 1 uses the power generated by the power generation device 10, it can perform measurements without receiving power from an external source.

[0198] Furthermore, the circuit module 90 can transmit this measurement data to an external device via a communication IC. This allows users to remotely obtain information about the condition of the tire TR from an external source.

[0199] The other main surface of the circuit board 900 in the circuit module 90 is positioned on the end face of the housing 20 on the side of the first lid member 221. The elastic member 990 is positioned between the circuit board 900 and the housing 20.

[0200] With this configuration, the vibration of the vibrating body of the power generation device 10 can be attenuated based on the physical properties of the circuit board 900 and the elastic member 990. As a result, the power generation module 1 can protect the circuit module 90 from vibrations of the vibrating body.

[0201] The elastic member 990 may be, for example, an insulating adhesive. This allows the elastic member 990 to achieve both vibration damping and fixing the circuit module 90 to the power generation device 10.

[0202] [Eighth Embodiment] A power generation module according to the eighth embodiment of the present invention will be described with reference to the drawings. Figure 29 is an external perspective view of the power generation module according to the eighth embodiment. Figure 30 is a cross-sectional view of the power generation module according to the eighth embodiment.

[0203] As shown in Figures 29 and 30, the power generation module 1E comprises a power generation device 10E and a circuit module 90E. The power generation device 10E differs from the power generation device 10 shown in the first embodiment described above in the shape of the housing 20E and in the presence of a plurality of external connection terminals 7911, 7912, 7921, and 7922. The other components of the power generation device 10E are the same as those of the power generation device 10, and a description of the similar parts will be omitted.

[0204] The power generation device 10E includes a housing 20E. The housing 20E differs from the housing 20 of the first embodiment in that it includes a base portion 21PR. The other configurations of the housing 20E are the same as those of the housing 20, and a description of the similar parts will be omitted. The base portion 21PR is configured such that its outer peripheral surface F21o partially protrudes outward. The forming portion of the base portion 21PR on the outer peripheral surface F21o (the surface of the base portion 21PR) has a plane parallel to the axis AX20.

[0205] The side wall member 21E of the housing 20E is thicker than the first lid member 221 and the second lid member 222. Preferably, the side wall member 21E is thicker than the first lid member 221 and the second lid member 222, at least in the portion that includes the base portion 21PR.

[0206] The power generation device 10E is equipped with a plurality of external connection terminals 7911, 7912, 7921, and 7922.

[0207] External connection terminals 7911 and 7912 are positioned near the end of the base portion 21PR on the side of the first cover member 221. External connection terminals 7911 and 7912 protrude from the surface of the base portion 21PR.

[0208] External connection terminal 7911 is connected to one end of the first coil 71, and external connection terminal 7912 is connected to the other end of the first coil 71.

[0209] External connection terminals 7921 and 7922 are positioned near the end of the base portion 21PR on the side of the second cover member 222. External connection terminals 7921 and 7922 protrude from the surface of the base portion 21PR.

[0210] External connection terminal 7921 is connected to one end of the second coil 72, and external connection terminal 7922 is connected to the other end of the second coil 72.

[0211] The circuit module 90E comprises a circuit board 900E and a plurality of circuit elements 91. The plurality of circuit elements 91 may include electrical circuit elements or electronic circuit elements as appropriate. For example, the plurality of circuit elements 91 may include at least one of an inertial sensor and an environmental sensor, and a communication IC.

[0212] The circuit elements 91 of the circuit module 90E that require power (such as inertial sensors, environmental sensors, and communication ICs) are driven by power based on the alternating current flowing through the first coil 71 and the second coil 72, which are excited by the vibration of the magnet 30. As a result, the circuit module 90E performs various measurements, for example, using inertial sensors and environmental sensors.

[0213] Thus, the power generation module 1E, like the power generation module 1, can not only generate electricity but also measure the state of the object to which the power generation module 1E is attached. For example, by replacing the power generation device 10 shown in Figures 6(A) and 6(B) above with the power generation module 1E, the power generation module 1E can measure the state of the tire TR (e.g., degree of indentation, temperature, etc.). In this case, since the power generation module 1E uses the power generated by the power generation device 10E, it can perform measurements without receiving power from an external source.

[0214] Furthermore, the circuit module 90E can transmit this measurement data to an external device via a communication IC. This allows users to remotely obtain information about the condition of the tire TR from an external source.

[0215] Multiple circuit elements 91 are mounted on one main surface of the circuit board 900. In this case, the inertial sensors in the circuit elements 91 are mounted so that the measurement axis (measurement direction) of a physical quantity based on inertial force (e.g., acceleration) is parallel to the one main surface of the circuit board 900.

[0216] The circuit board 900E is placed on the base portion 21PR. At this time, the other main surface of the circuit board 900E faces and contacts the base portion 21PR. This contact may be made via an adhesive or the like.

[0217] As a result, the circuit board 900E is positioned on the side wall member 21E of the housing 20E with one main surface and the other main surface parallel to the vibration direction DV (see Figure 3) of the power generation device 10E. Note that the one main surface and the other main surface of the circuit board 900E do not need to be perpendicular to the vibration direction DV of the power generation device 10E, but it is best if they are parallel.

[0218] The circuit board 900E is fixed to the base portion 21PR in a position that includes the protruding portions of the multiple external connection terminals 7911, 7912, 7921, and 7922. The circuit board 900E has multiple through holes into which the multiple external connection terminals 7911, 7912, 7921, and 7922 are inserted and fitted. An electrode is formed in each of the multiple through holes and is connected to a circuit electrode pattern formed on the circuit board 900E.

[0219] In this way, the circuit board 900E of the circuit module 90E is positioned parallel to the vibration direction DV (see Figure 3) of the power generation device 10E, so that the circuit board 900E is positioned on the power generation device 10E in a posture that is less susceptible to the vibrations of the power generation device 10E. Therefore, the power generation module 1E can suppress the adverse effects of vibrations on the circuit board 900E and the circuit elements 91.

[0220] In particular, since the circuit element 91 includes an inertial sensor, and as described above, when the measurement axis of the inertial sensor is parallel to one main surface of the circuit board 900E, the detection of vibration noise by the inertial sensor can be suppressed for reasons such as the circuit board 900E being less likely to vibrate in a direction parallel to the main surface than in a direction perpendicular to the main surface. Therefore, false detections by the inertial sensor are suppressed, and a decrease in the detection sensitivity of the inertial sensor is suppressed.

[0221] Furthermore, when the power generation module 1E is mounted on the tire TR in the orientation shown in Figures 6(A) and 6(B) above, one main surface and the other main surface of the circuit board 900E become parallel to the vibration direction DV of the power generation module 1E and the radial vibration direction (see Figure 7) due to the deformation of the tire TR. As a result, the power generation module 1E can suppress the deflection of the circuit board 900E due to each vibration and ensure the reliability of the circuit module 90E.

[0222] Furthermore, with the above configuration, the path length of the electrical connection between the first coil 71 and the second coil 72 and the circuit board 900E can be shortened.

[0223] Furthermore, in the above configuration, multiple external connection terminals 7911, 7912, 7921, and 7922 are inserted through holes in the circuit board 900E. This ensures that even when various vibrations occur, the electrical connection between the multiple external connection terminals 7911, 7912, 7921, and 7922 and the circuit board 900E can be maintained stably.

[0224] Furthermore, by shortening the path length of the electrical connection between the first coil 71 and the second coil 72 and the circuit board 900E, the power generation module 1E can suppress transmission losses of AC current generated by power generation.

[0225] [Ninth Embodiment] A power generation module according to the ninth embodiment of the present invention will be described with reference to the figures. Figure 31 is a cross-sectional view of the power generation module according to the ninth embodiment.

[0226] As shown in Figure 31, the power generation module 1F according to the ninth embodiment differs from the power generation module 1E according to the eighth embodiment in that it is equipped with a back yoke BY. The other components of the power generation module 1F are the same as those of the power generation module 1E, and the description of the similar parts will be omitted. The back yoke BY corresponds to the "outer yoke of the housing," and the first yoke 41 and the second yoke 42 correspond to the "inner yoke of the housing."

[0227] The power generation module 1F comprises a power generation device 10F and a circuit module 90F. The power generation device 10F comprises a housing 20F including a side wall member 21F. The side wall member 21F has the same configuration as the side wall member 21E. The housing 20F has a configuration in which a back yoke BY is added to the housing 20E. The back yoke BY is positioned outside the outer peripheral surface F21o of the side wall member 21F, along the outer peripheral surface F21o. The back yoke BY is also positioned on the surface of the base portion 21PR.

[0228] The circuit module 90F has the same configuration as the circuit module 90E, and the circuit board 900F has the same configuration as the circuit board 900E.

[0229] In this configuration, a back yoke BY is positioned between the circuit board 900F and the housing 20F. This allows the power generation module 1F to suppress leakage of the magnetic field of the magnet 30 to the circuit board 900F. Therefore, the power generation module 1F can suppress the adverse effects of the magnetic field of the magnet 30 on the circuit elements 91 of the circuit module 90F.

[0230] Furthermore, the configurations of each of the above embodiments can be combined as appropriate, and effects can be achieved depending on the combination.

[0231] Furthermore, the applications of the power generation module configured as described above are not limited to tires for vehicles, etc., as mentioned above. It can be applied to various products and objects in environments where vibrations occur on a daily basis, such as engine mechanisms that generate vibrations due to piston motion, various amusement rides, or road surfaces and bridges that vibrate due to the movement of vehicles, etc.

[0232] In any of these cases, by selecting and arranging various sensors as needed, it is possible to measure the environment around the object on which the power generation module is installed and to remotely transmit the obtained information. Furthermore, since such measurement and communication can be achieved simply by installing the power generation module in a vibrating environment, installation is extremely easy.

[0233] 1, 1E, 1F: Power generation module 10, 10A, 10B, 10C1, 10C2, 10D, 10E, 10F, 10M: Power generation device 20, 20B, 20E, 20F, 20X: Housing 21, 21B, 21E, 21F: Side wall member 21PR: Base 30, 30A: Magnet 41, 41DV: First yoke 42: Second yoke 51, 51DV: First spring member 52: Second spring member 60, 60DV: Fixing member 61: First fixing member 62: Second fixing member 70: Coil 71: First coil 72: Second coil 90, 90E, 90F: Circuit module 91: Circuit element 221, 221DV1, 221DV2, 221DV3, 221DV4: First lid member 222: Second lid member 231: First housing projection 232: Second housing projection 411, 421: Outer peripheral end 412, 422: Central part 413, 423: Support part 414: Thin-walled part 511, 521: Inner end 512, 522: Outer end 513, 523: Beam part 514, 514DV, 524: Projection 515, 525: Support part 601, 601DV: Main shaft 791: First external connection terminal 792: Second external connection terminal 900, 900E, 900F: Circuit board 990: Elastic member 2211M: Mesh plate 2211S: Frame 6021, 6021DV: First end member 6022, 6022DV: Second end member 7911, 7912, 7921, 7922: External connection terminal AX20: Shaft BY: Back yoke C211, C212: Recess C221, C222: Recess C414: Recess DV: Vibration direction F211: First opening end F212: Second opening end F21i: Inner circumferential surface F21o: Outer circumferential surface F221i, F221o, F222i, F222o: Surface F301: First surface F302: Second surface F309: Side surface F411, F421: Front surface F412, F422: Back surface F419, F429: Side surface FTRI: Inner circumferential surface of tire FTRO: Tire outer peripheral surface IS20: Internal space RM: Resin material SL21B: Groove SLT: Groove TH221DV1, TH221DV3: Through hole TH221i, TH222i: Inner hole TH221o: Outer hole TH41: First yoke through hole TH419: Through hole TH42: Second yoke through hole TH429: Through hole TH511, TH521: Through hole TR: Tire

Claims

1. A power generation module comprising a power generation device and a circuit board, wherein the power generation device comprises a vibrating body and a housing for housing the vibrating body, the circuit board comprises a sensor driven by the power generated by the power generation device, the housing comprises a side wall member parallel to the vibration direction of the vibrating body, and the circuit board is fixed to the side wall member.

2. The power generation module according to claim 1, wherein the measurement direction of the sensor and the vibration direction are not orthogonal.

3. The power generation module according to claim 2, wherein the measurement direction of the sensor and the vibration direction are parallel.

4. The power generation module according to any one of claims 1 to 3, wherein the vibrating body is constructed using a magnet, the power generation device comprises a coil arranged on the side wall member and an external connection terminal connected to the coil, the external connection terminal protrudes from the outer peripheral surface of the side wall member, and the circuit board is fixed in a position including the protruding portion of the external connection terminal.

5. The power generation module according to claim 4, wherein the housing includes a base portion on which a part of the outer surface of the side wall member protrudes, and the external connection terminal protrudes outward from the base portion.

6. The power generation module according to claim 4 or 5, wherein the vibrating body comprises an internal yoke disposed on the magnet and an external yoke disposed on the outer circumferential surface of the side wall member, and the external yoke is disposed between the circuit board and the outer circumferential surface.

7. The power generation module according to any one of claims 1 to 6, wherein the housing comprises a lid member perpendicular to the vibration direction, and the side wall member is thicker than the lid member.

8. A tire on which a power generation module according to any one of claims 1 to 7 is attached.

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