Endlessly rotating body

Abstract

To provide an endlessly rotating body in which a piezoelectric element is arranged in a spoke, which can be enhanced in efficiency of electric power generation.SOLUTION: A wheel 10 comprises a rim part 11, a hub mounting part 12, and a plurality of spokes 13 connecting the rim part 11 and the hub mounting part 12. A piezoelectric element 26 is arranged in each of the spokes 13. The piezoelectric element 26 is arranged on an inner surface in a vehicle width direction of each spoke 13. The piezoelectric element 26 is arranged at a position closer to the hub mounting part 12 than to the rim part 11 in each spoke 13. The wheel 10 is, for example, an aluminum wheel.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an infinite rotating body such as a tire wheel. [Background technology]

[0002] There are techniques for arranging piezoelectric elements on tires, wheels, etc. For example, Patent Document 1 describes attaching a piezoelectric sensor to the outer peripheral surface of the rim of a wheel. Patent Document 2 describes providing a coated piezoelectric part on the back surface of the tire's contact area. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-163230 A [Patent Document 2] Patent Publication No. 2022-47625 Summary of the Invention [Problem to be solved by the invention]

[0004] Although Patent Document 1 describes the idea of ​​placing a piezoelectric sensor on the outer peripheral surface of the rim, the outer peripheral surface of the rim of wheels in practical use has a complex shape. Further technical consideration is required to determine the best position for placing the piezoelectric element in accordance with this complex shape of the outer peripheral surface of the rim.

[0005] In Patent Document 2, power is generated according to the distortion caused on the tire's contact surface. As a result, there is a risk that the piezoelectric part arranged on the rear surface of the tire's contact surface may be damaged as the tire is repeatedly deformed. [Means for solving the problem]

[0006] The infinite rotating body for solving the above problems has the following features. [Aspect 1] A rim portion, A hub mounting portion; a plurality of spokes connecting the rim portion and the hub attachment portion, The spokes have piezoelectric elements disposed thereon. Infinite rotating body.

[0007] According to the above-mentioned configuration, power can be generated by the wheel. The spokes are locations where stress is concentrated more than other parts. Therefore, by arranging the piezoelectric elements in the spokes, power generation efficiency can be improved.

[0008] [Aspect 2] The infinite rotor according to [Aspect 1], wherein the piezoelectric element is disposed on an inner surface of the spoke in the vehicle width direction. According to the above configuration, the piezoelectric element is disposed on the inner surface of the spoke in the vehicle width direction, so that it can be made difficult to see from the outside in the vehicle width direction.

[0009] [Aspect 3] The infinite rotor according to [Aspect 1] or [Aspect 2], wherein the piezoelectric element is disposed at a position closer to the hub attachment portion than the rim portion of the spoke. According to the above configuration, a position of the spoke closer to the hub attachment portion than to the rim portion is a position where stress is concentrated more than a position closer to the rim portion than to the hub attachment portion. Therefore, by arranging the piezoelectric element on the inner surface of the spoke in a position closer to the hub attachment portion in the vehicle width direction, it is possible to further increase power generation efficiency.

[0010] [Aspect 4] The infinite rotating body according to [Aspect 1], wherein the spokes have inner faces that are flatter than the outer faces in the vehicle width direction. According to the above-mentioned configuration, the piezoelectric element can be stably arranged. In addition, as the piezoelectric element, for example, an inorganic piezoelectric material, which has poor flexibility but high power generation efficiency, can be used.

[0011] [Embodiment 5] The infinite rotating body according to [Embodiment 1], which is made of aluminum. According to the above configuration, the piezoelectric element can be disposed on the aluminum wheel. Effect of the Invention

[0012] According to the present invention, it is possible to increase the power generation efficiency in an infinite rotating body having piezoelectric elements arranged on the spokes. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of a vehicle wheel according to an embodiment, as viewed from the outer side in the vehicle width direction. [Diagram 2] FIG. 2 is a perspective view of the vehicle wheel according to the embodiment, as viewed from the inner surface in the vehicle width direction. [Diagram 3] FIG. 3 is a diagram showing stress distribution on the outer surface in the vehicle width direction of the vehicle wheel in the embodiment. [Figure 4] FIG. 4 is a diagram showing stress distribution on the inner surface in the vehicle width direction of the vehicle wheel in the embodiment. [Diagram 5] FIG. 5 is a characteristic diagram showing the relationship between elapsed time and voltage when a piezoelectric element is disposed on the inner surface of the inner bead seat portion. [Figure 6] FIG. 6 is a characteristic diagram showing the relationship between elapsed time and voltage when a piezoelectric element is disposed on the inner surface of the base of a spoke. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle wheel to which an endless rotating body according to the present invention is applied will now be described with reference to the drawings. <Overall wheel configuration> As shown in Figures 1 and 2, a vehicle wheel 10 according to this embodiment is a wheel used for passenger cars and the like. This wheel is an aluminum wheel, i.e., an aluminum wheel, and is a one-piece wheel produced by casting. Such a wheel 10 includes a substantially cylindrical rim portion 11 to which a pneumatic tire is attached, a hub attachment portion 12, and spokes 13 extending radially from the hub attachment portion 12 toward the rim portion 11.

[0015] The rim portion 11 includes an inner flange portion 15, an inner bead seat portion 16, a drop portion 17, an outer bead seat portion 18, and an outer flange portion 19. The inner flange portion 15 and the inner bead seat portion 16 are located on the inner side in the vehicle width direction, i.e., closer to the vehicle, than the outer bead seat portion 18 and the outer flange portion 19 when the wheel 10 is mounted on the vehicle.

[0016] The hub attachment portion 12 has a hub hole 21 formed in its center and a plurality of bolt holes 22 arranged around the hub hole 21. The spokes 13 are configured to connect the rim portion 11 and the hub attachment portion 12. A plurality of spokes 13 are formed at regular intervals in the circumferential direction when viewed from the outside (out) in the vehicle width direction. A plurality of openings 23 are provided between adjacent spokes 13 in the circumferential direction, connecting the space on the outside (out) in the vehicle width direction with the space on the inside (in) in the vehicle width direction. The openings 23 are, for example, decorative holes. In this embodiment, five pairs of spokes 13 are provided with a first interval 24a therebetween, with a second interval 24b wider than the first interval 24a.

[0017] Incidentally, the inner surface IN of the wheel 10 in the vehicle width direction is the mounting surface 13a for the vehicle. Therefore, the inner surface IN of the spoke 13 is relatively flat. In contrast, the outer surface OUT of the wheel 10 in the vehicle width direction is the design surface 13b. Therefore, the outer surface OUT of the spoke 13 has a complex shape composed of various shapes of bumps and recesses.

[0018] Furthermore, aluminum wheels are characterized by a thicker plate thickness at the rim portion 11 compared to steel wheels. And, each spoke 13 has higher rigidity at a position closer to the rim portion 11 than to the hub attachment portion 12 than at a position closer to the hub attachment portion 12 than to the rim portion 11. Therefore, stress is more concentrated closer to the base of the spoke 13.

[0019] <Piezoelectric element> A piezoelectric element 26, which is a power generating element, is attached to the mounting surface 13a, which is the inner surface of each spoke 13. The piezoelectric element 26 is disposed in an area of ​​the mounting surface 13a where stress is higher than in other areas. For example, the piezoelectric element 26 is disposed at a position on the mounting surface 13a of the spoke 13 closer to the hub mounting portion 12 than the rim portion 11, that is, at the base portion. The mounting surface 13a may be an inclined surface as an example, but is preferably a flat surface so that the piezoelectric element 26 can be stably disposed. Of course, the mounting surface 13a may have some irregularities, but is preferably flatter than the design surface 13b. By disposing the piezoelectric element 26 on the mounting surface 13a, it becomes difficult to see from the outside in the vehicle width direction.

[0020] Here, Fig. 3 is a diagram showing the stress distribution as viewed from the outer surface (out) of the wheel 10 when a vehicle load is applied to the wheel 10. Also, Fig. 4 is a diagram showing the stress distribution as viewed from the inner surface (in) of the wheel 10 when a vehicle load is applied to the wheel 10. The darker the color, the higher the stress.

[0021] 3 and 4, it can be seen that the stress is higher on both the inner (IN) surface and the outer (OUT) surface of the spoke 13 at the base portion closer to the hub attachment portion 12 than to the rim portion 11. It can also be seen that the stress tends to be higher on the inner (IN) surface of the spoke 13 than on the outer (OUT) surface of the wheel 10.

[0022] The piezoelectric element 26 is a piezoelectric element that generates a voltage when pressure is applied to the piezoelectric element 26. The piezoelectric element 26 generates a voltage in response to the distortion caused by applying pressure to the piezoelectric body. The piezoelectric element 26 is, for example, a piezoelectric body. The piezoelectric body is, for example, formed into a thin film. Either an inorganic piezoelectric body or an organic piezoelectric body is selected and used as the piezoelectric body depending on the placement position, etc. Inorganic piezoelectric bodies are poor in flexibility because they are mainly composed of ceramics, etc., but have high power generation efficiency. Organic piezoelectric bodies are excellent in flexibility but have low power generation efficiency. The type of piezoelectric element is selected depending on the conditions such as the shape of the placement location. Furthermore, the piezoelectric elements 26 placed in each spoke 13 are the same and have the same shape and output.

[0023] The piezoelectric elements 26 arranged on the spokes 13 are separate elements and are discontinuous. By arranging the piezoelectric elements 26 intermittently at equal intervals, it is possible to prevent the outputs of adjacent piezoelectric elements 26 from cancelling each other out.

[0024] The piezoelectric element 26, which is disposed on the mounting surface 13a of the spoke 13 at the base portion closer to the hub mounting portion than the rim portion 11, can obtain an output voltage with the same period. When the output voltage of the piezoelectric element 26 becomes higher, the output current also increases accordingly, and the generated power (power generation efficiency) also increases.

[0025] Here, in the wheel 10 shown in Figures 1 to 4, the output voltage was confirmed when the piezoelectric element 26 was placed on the vehicle widthwise inner surface IN of the inner bead seat portion 16 (point A in Figure 2) and on the vehicle widthwise inner surface IN of the base of the spokes 13 (point B in Figure 2). Figure 5 shows the output voltage on the inner surface IN of the inner bead seat portion 16, and Figure 6 shows the output voltage on the inner surface IN of the base of the spokes 13. The vertical and horizontal scales are the same in Figures 5 and 6. <Measurement conditions> ·Aluminum wheels for passenger cars Wheels / Tires: 18×8J / 225 / 45R18 Air pressure: 240kPa Test load: 6.15kN Test speed: 20km / h 5 and 6, it can be seen that a higher output voltage can be obtained from the inner "IN" surface of the root portion of the spoke 13 than from the inner "IN" surface of the inner bead seat portion 16. This is because the stress is higher at the root portion of the spoke 13 than it is at the inner "IN" surface of the inner bead seat portion 16.

[0026] The power generated by the piezoelectric element 26 is stored in a secondary battery such as a lithium ion secondary battery or a nickel hydrogen secondary battery. The secondary battery is, for example, for vehicle mounting and is arranged on the chassis. In this case, the power generated by the piezoelectric element 26 is stored in the secondary battery arranged on the chassis and is used as part of the power of the vehicle. The secondary battery may also be arranged on the wheel 10. For example, the wheel 10 may be decorated with light-emitting elements such as LEDs. The wheel 10 may also be arranged with a detection element such as a sensor for detecting an abnormality in fastening with the hub. These elements and communication elements for exchanging detection data and control data with other communication devices are supplied with power from the secondary battery arranged on the wheel 10. The power generated by the piezoelectric element 26 is stored in the secondary battery arranged on the wheel 10.

[0027] <Effects of the embodiment> The wheel 10 described above can provide the following effects. (1) By arranging the piezoelectric element 26 on the wheel 10, the piezoelectric element 26 is less susceptible to failure than if it were arranged in the tire.

[0028] (2) The spokes 13 are locations where stress is concentrated more than other portions. Therefore, by disposing the piezoelectric elements 26 on the spokes 13, power generation efficiency can be improved. (3) By arranging the piezoelectric element 26 on the mounting surface 13a, which is the surface on the inner side in the vehicle width direction of the spoke 13, the piezoelectric element 26 can be made less visible from the outer side out in the vehicle width direction.

[0029] (4) Since the piezoelectric element 26 is disposed on the mounting surface 13a of the spoke 13, wiring to the secondary battery is easy. For example, if the piezoelectric element 26 is disposed on the outer circumferential surface of the rim portion 11, a through hole or the like connecting to the inner circumferential side of the rim portion 11 is required for wiring. In this regard, if the piezoelectric element 26 is disposed on the mounting surface 13a, which is the surface on the inner side in the vehicle width direction of the spoke 13, there is no need to provide a through hole for wiring in the rim portion 11, whether the secondary battery is disposed on the vehicle or in the inner space of the wheel 10. Therefore, if the piezoelectric element 26 is disposed on the mounting surface 13a of the spoke 13, wiring to the secondary battery can be easily performed.

[0030] (5) Compared to the design surface 13b, which is the surface on the outside (OUT) of the spoke 13 in the vehicle width direction, the surface on the inside (IN) is the mounting surface 13a, which is a flat surface. Therefore, the piezoelectric element 26 can be stably disposed within the mounting surface 13a. Also, as the piezoelectric element 26, for example, an inorganic piezoelectric material that is poor in flexibility but has high power generation efficiency can be used.

[0031] (6) Piezoelectric elements can also be placed on aluminum wheels. The vehicle wheel 10 can also be modified as follows.

[0032] The metal of the wheel 10 may be steel, titanium alloy, magnesium alloy, etc. The mounting surfaces 13a of the spokes 13 may have projections and recesses.

[0033] The piezoelectric element 26 may be disposed on the mounting surface 13a of the spoke 13 at a position closer to the rim portion 11 than the hub mounting portion 12, or at an intermediate position. The piezoelectric element 26 may also be disposed over almost the entire mounting surface 13a.

[0034] The piezoelectric element 26 may be disposed only on the design surface 13b, or on the mounting surface 13a and the design surface 13b of the spoke 13. For example, the piezoelectric element 26 may be disposed on the outer surface (out) of the base of the spoke 13 in the vehicle width direction, to obtain substantially the same power generation efficiency. The piezoelectric element 26 can be stably disposed on any flat portion of the design surface 13b.

[0035] Furthermore, after the piezoelectric elements 26 are arranged on the spokes 13, they may also be arranged on the outer circumferential surface or inner circumferential surface of the rim portion 11. When arranged on the rim portion 11, it is preferable to arrange them on the drop portions 17.

[0036] In the case of an aluminum wheel, the wheel may be made up of two parts: a rim portion and a disc portion having a hub attachment portion and spokes. In this case, the rim portion and the disc portion are joined by bolts and nuts, welding, etc. Furthermore, the rim portion may be divided in the axle direction and made up of three parts.

[0037] In the case of aluminum wheels, the wheels are cast wheels, forged wheels formed by press drawing from steel plates, or forged aluminum wheels formed from bullets or castings. The infinite rotating body is not limited to large wheels used in commercial vehicles, etc. For example, it can be applied to wheels of passenger cars and work vehicles, bicycle wheels, and railway wheels. [Explanation of symbols]

[0038] 10...Vehicle wheels 11…Rim section 12...Hub mounting part 13…Spokes 13a…Mounting surface 13b…Design surface 15…Inner flange 16…Inner bead seat 17…Drop section 18...Outer bead seat 19…Outer flange 21…Hub hole 22…Bolt hole 23…Aperture 24a…1st interval 24b…Second interval 26...Piezoelectric element

Claims

1. A rim portion and A hub mounting portion; a plurality of spokes connecting the rim portion and the hub attachment portion, The spokes have piezoelectric elements disposed thereon. Infinite rotating body.

2. The piezoelectric element is disposed on an inner surface of the spoke in the vehicle width direction. The infinite rotating body according to claim 1 .

3. The piezoelectric element is disposed at a position closer to the hub attachment portion than to the rim portion of the spoke.

3. An infinite rotating body according to claim 1 or 2.

4. The spokes have an inner surface that is flatter than an outer surface in the vehicle width direction. The infinite rotating body according to claim 1 .

5. Made from aluminum The infinite rotating body according to claim 1 .

Images