Skateboard and steering device

Abstract

To provide a skateboard capable of traveling on a curve more smoothly while generating a sufficient sideslip feeling, and a steering device.SOLUTION: A skateboard 1a includes a plate part 2, a front wheel unit 4 having a front wheel 3, and a rear wheel unit 6 having a rear wheel 5. The front wheel unit 4 includes a front wheel support portion 8 that rotatably supports the front wheel 3, and a front wheel seat portion 9 that supports the front wheel support portion 8 so as to be able to at least rotate around a front shaft L1. The rear wheel unit 6 includes a rear wheel support member 17 that rotatably supports the rear wheel 5, and a rear wheel seat portion 18 that supports the rear wheel support member 17 so as to at least rotate about a rear shaft L2. The front shaft L1 and the rear shaft L2 are disposed to be inclined upward from the front to the rear of the traveling body 1. The amount of rotation of the rear wheel support member 17 about the rear shaft L2 during curve traveling is set to be larger than the amount of rotation of the front wheel support member 8 about the front shaft L1.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a skateboard and a steering device. [Background technology]

[0002] Conventionally, skateboards are well known as vehicles that are wheeled and mounted on a flat board, as disclosed in Patent Document 1. The skateboard in Patent Document 1 has trucks made up of multiple parts on both the front and rear of the underside of the board. With this type of skateboard, when a load is applied to one side of the board in the width direction while the skateboard is running, the shaft with the wheel rotates in a twisting manner around the kingpin of the base plate, causing the skateboard to curve in the direction of the load. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-61024 Summary of the Invention [Problem to be solved by the invention]

[0004] When turning by applying a load to one side of the board in the width direction, it is important that the board can turn smoothly as intended, but at the same time there is also a desire to feel a sense of sideways sliding.

[0005] An object of the present invention is to provide a skateboard and steering device that can travel more smoothly around curves while generating a sufficient feeling of skidding. [Means for solving the problem]

[0006] A skateboard that solves the above problem comprises a board portion on which a user rides, a front wheel unit having a front wheel located at the front on the underside of the board portion, and a rear wheel unit having a rear wheel located at the rear on the underside of the board portion, wherein the front wheel unit has a front wheel support portion that rotatably supports the front wheel, and a front wheel seat portion that supports the front wheel support portion so that the skateboard can at least rotate around a front axis extending in a direction intersecting the board portion, and the rear wheel unit has a rear wheel support portion that rotatably supports the rear wheel, and a rear wheel seat portion that supports the rear wheel support portion so that the skateboard can at least rotate around a rear axis extending in a direction intersecting the board portion, wherein the front axis and the rear axis are arranged at an angle that extends upward from the front to the rear of the board portion, and the front wheel unit and the rear wheel unit are configured so that when the skateboard is traveling around a curve with the board portion tilted widthwise, the amount of rotation of the rear wheel support portion around the rear axis is greater than the amount of rotation of the front wheel support portion around the front axis. [Effects of the Invention]

[0007] The present invention allows smoother curve driving while generating a sufficient feeling of skidding. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a skateboard having a steering device according to an embodiment; [Figure 2] FIG. 1 is a top view of a skateboard. [Figure 3] FIG. [Figure 4] FIG. 2 is a perspective view showing the configuration of a steering device. [Figure 5] FIG. 1 is a side view of a skateboard. [Figure 6] FIG. 1 is a side view of a skateboard when traveling around a curve. [Figure 7] FIG. 1 is a top view of a skateboard when traveling around a curve. [Figure 8](a) is a rear view of the skateboard when traveling straight, and (b) is a rear view of the skateboard when traveling around a curve. [Figure 9] 1A and 1B show an outline of the operation of the steering device, where (a) is an outline diagram of going straight, (b) is an outline diagram of turning left, and (c) is an outline diagram of turning right. [Figure 10] 1(a) is a schematic diagram of the skateboard of this example running around a curve, and FIG. 1(b) is a schematic diagram of a general skateboard running around a curve. [Figure 11] 1A and 1B show an outline of the operation of the steering device, where FIG. 1A is a schematic diagram of the neutral state, and FIG. 1B is a schematic diagram of the state when the front and rear wheels are asynchronous. [Figure 12] 1A and 1B show an outline of the operation of the steering device, where (a) is a schematic diagram of the neutral state, and (b) and (c) are schematic diagrams when the front and rear wheels are asynchronous. [Figure 13] 1A and 1B show an outline of the operation of the steering device, where FIG. 1A is a schematic diagram of the neutral state, and FIG. 1B is a schematic diagram of the state when the front and rear wheels are asynchronous. [Figure 14] 1A and 1B show an outline of the operation of the steering device, where FIG. 1A is a schematic diagram of the steering device when traveling straight ahead, and FIG. 1B is a schematic diagram of the steering device when traveling around a curve. [Figure 15] 1A and 1B show an outline of the operation of the steering device, where FIG. 1A is a schematic diagram of the steering device when traveling straight ahead, and FIG. 1B is a schematic diagram of the steering device when traveling around a curve. [Figure 16] 10(a) to 10(c) are diagrams illustrating changes in driving feeling. [Figure 17] FIG. 1 is a perspective view of a skateboard having a display unit. [Figure 18] FIG. 10 is a cross-sectional view showing the structure of a linkage mechanism according to another example. [Figure 19] FIG. 10 is a perspective view of a skateboard according to another embodiment. [Figure 20] FIG. 10 is a plan view of a skateboard according to another embodiment. [Figure 21] FIG. 21 is a side view of the skateboard shown in FIG. 20. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present disclosure will be described below. (Training vehicle 1) As shown in Fig. 1, the running object 1 is a skateboard 1a that a user rides on a board 2. The skateboard 1a moves straight when the board 2 is in a neutral position. When the board 2 is tilted to one side in the width direction (the direction of arrow A in Fig. 1), the skateboard 1a curves in the tilted direction.

[0010] (Steering device 7) 1, the running body 1 is equipped with a steering device 7 that steers a front wheel unit 4 to which a front wheel 3 is attached and a rear wheel unit 6 to which a rear wheel 5 is attached. The traveling direction of the running body 1 is steered by the steering device 7. When the running body 1 is a skateboard 1a, when the board part 2 is tilted in the width direction, the steering device 7 causes the front wheel 3 and the rear wheel 5 to face in a direction corresponding to the tilt of the board part 2, causing the skateboard 1a to travel around a curve.

[0011] (Front wheel unit 4) 2 and 3, the front wheel unit 4 has a front wheel support portion 8 that rotatably supports the front wheel 3, and a front wheel seat portion 9 that rotatably supports the front wheel support portion 8. As shown in FIG. 3, the front wheel seat portion 9 has a seat body 10 fixed to the back surface of the plate portion 2, and a fitting protrusion 11 formed on the seat body 10 and into which the front wheel support portion 8 is rotatably fitted. The seat body 10 is preferably fixed at a position near the front of the back surface of the plate portion 2 by a fastening portion such as a screw. The fitting protrusion 11 is formed, for example, in the shape of a ring on an end surface of the seat body 10 with a diameter smaller than that of the end surface.

[0012] As shown in Figure 4, the front wheel support part 8 has a support body 12 that is connected to the front wheel seat part 9 and supports the front wheel 3. The support body 12 has a fitting recess 13 into which the fitting protrusion 11 is slidably fitted on the end face closer to the plate part 2. The support body 12 is rotatable around the axis of the fitting protrusion 11 due to the structure in which the fitting recess 13 is fitted into the fitting protrusion 11. The support body 12 has an axle support part 15 at the end opposite the plate part 2 that rotatably supports the axle 14 of the front wheel 3.

[0013] As shown in FIG. 5, the front wheel support part 8 is supported by the front wheel seat part 9 so as to be at least capable of rotation about a front axis L1 extending in a direction intersecting the axle 14 of the front wheel 3. The front axis L1 is disposed at an angle in an upward direction (the +Z-axis direction in FIG. 5) from the front to the rear of the running body 1 (plate part 2). In this example, the front axis L1 is the axis of rotation when the fitting recess 13 rotates relative to the fitting protrusion 11. Note that it is sufficient for the front wheel seat part 9 to support the front wheel support part 8 at least rotationally about the front axis L1. The angle θ1 formed by the front axis L1 with respect to the rear surface of the plate part 2 may be a value less than 90 degrees.

[0014] (Rear wheel unit 6) As shown in Figures 2 to 4, the rear wheel unit 6 has a rear wheel support part 17 that rotatably supports the rear wheel 5, and a rear wheel seat part 18 that rotatably supports the rear wheel support part 17. As shown in Figure 3, the rear wheel seat part 18, like the front wheel seat part 9, has a seat part main body 19 and a fitting protrusion 20. It is preferable that the seat part main body 19 is fixed at a position near the front of the rear surface of the plate part 2 by a fastening part such as a screw. It is preferable that the rear wheel seat part 18 has the same shape as the front wheel seat part 9.

[0015] The rear wheel support portion 17 has a structure in which a first part 21 and a second part 22 are combined. In this example, the first part 21 is connected to the rear wheel seat portion 18 and rotatably supports one side of the axle 23 of the rear wheel 5. The second part 22 is assembled to the first part 21 and rotatably supports the other side of the axle 23 of the rear wheel 5. As shown in FIG. 4 , the first part 21 has a mating recess 24 on the end face closer to the plate portion 2, into which the mating protrusion 20 is slidably fitted. The first part 21 and the second part 22 are rotatable around the axis of the mating protrusion 20 due to the structure in which the mating recess 24 is fitted into the mating protrusion 20.

[0016] As shown in FIG. 5, the rear wheel support part 17 is supported by the rear wheel seat part 18 so as to be at least capable of rotation about a rear axis L2 extending in a direction intersecting the axle 23 of the rear wheel 5. The rear axis L2 is disposed at an angle in an upward direction (the +Z-axis direction in FIG. 5) from the front to the rear of the running body 1 (plate part 2). The rear axis L2 is the axis of rotation when the fitting recess 24 rotates relative to the fitting protrusion 20. Note that it is sufficient for the rear wheel seat part 18 to support the rear wheel support part 17 at least rotationally around the rear axis L2. The angle θ2 formed by the rear axis L2 with respect to the rear surface of the plate part 2 may be less than 90 degrees. In this example, the angles θ1 and θ2 are set to the same value, for example.

[0017] (Arrangement of front wheels 3 and rear wheels 5) As shown in Figure 5, the front wheel 3 is disposed so that its rotation axis is located on the line of the front axis L1. The front wheel 3 does not necessarily have to be disposed on the line of the front axis L1, but may be disposed on the front side or rear side of the line of the front axis L1. The rear wheel 5 is disposed behind the rear axis L2 in a direction intersecting the rear axis L2 (the direction of arrow B in Figure 5).

[0018] (Number of wheels on running body 1) As shown in Figures 1 to 4, a pair of front wheels 3 are arranged on both sides of the front axle L1. In this way, a total of two front wheels 3 are provided in this example, with a pair of front wheels 3 arranged on both sides of the axle 14. On the other hand, one rear wheel 5 is provided. As described above, the running vehicle 1 of this example is a three-wheel type having two front wheels 3 and one rear wheel 5.

[0019] (Interlocking mechanism 27) As shown in FIGS. 1 to 3 and the like, the steering device 7 has an interlocking mechanism 27 that interlocks the front wheel support portion 8 and the rear wheel support portion 17 by connecting the front wheel support portion 8 and the rear wheel support portion 17 with a connecting shaft 28. The connecting shaft 28 is, for example, a cylindrical rod. As shown in FIG. 2, the connecting shaft 28 is disposed at an angle with respect to a reference line La that extends in the front-to-rear direction along which the front wheel unit 4 and the rear wheel unit 6 are aligned. Specifically, the connecting shaft 28 is disposed at an angle such that one end (front end) of the connecting shaft 28 is located farther from the reference line La than the other end (rear end) of the connecting shaft 28. Furthermore, the connecting shaft 28 is disposed on one of both sides of the reference line La in a direction intersecting the reference line La.

[0020] One end of the connecting shaft 28 is connected to the front wheel support part 8 so as to be at least rotatable about the front axis L1. Specifically, one end of the connecting shaft 28 is connected to the front wheel support part 8 via a first elastic body 29 that functions as a universal joint. In this example, one end of the connecting shaft 28 is slidably connected to a connecting part 30 of the front wheel support part 8 via the first elastic body 29. The connecting part 30 has a base end part 30a that forms the main body of the connecting part 30, and a protruding piece 30b that protrudes from a part of the base end part 30a. The connecting part 30 is preferably configured to be detachable from the support main body 12, for example. The protruding piece 30b is preferably formed in a plate shape, for example.

[0021] The other end of the connecting shaft 28 is connected to the rear wheel support part 17 so as to at least allow rotation about the rear axis L2. Specifically, the other end of the connecting shaft 28 is connected to the rear wheel support part 17 via a second elastic body 31 that functions as a universal joint. In this example, the other end of the connecting shaft 28 is slidably connected to a second part 22 of the rear wheel support part 17 via the second elastic body 31. In this example, the second part 22 has an axle support part 32a that forms the main body of the second part 22, and a protrusion 32b that protrudes from a portion of the axle support part 32a. The second part 22 is preferably configured to be detachable from the first part 21, for example. The protrusion 32b is preferably formed in a plate shape, for example.

[0022] As shown in Figure 3, one end of the connecting shaft 28 is slidably inserted into a hole 34 formed through the protruding piece 30b of the front wheel support part 8. The first elastic body 29 is fixed to the one end of the connecting shaft 28 inserted into the hole 34 and has a pair of annular elastic pieces 35, 36 arranged to sandwich the protruding piece 30b. The other end of the connecting shaft 28 is slidably inserted into a hole 38 formed through the protruding piece 32b of the rear wheel support part 17. The second elastic body 31 has a pair of annular elastic pieces 39, 40 similar to the first elastic body 29. The annular elastic pieces 35, 36, 39, 40 function as bushings (e.g., bearings) for the connecting shaft 28, for example.

[0023] A washer 41 and a nut 42 are disposed on both sides of the first elastic body 29 to fix the position of the first elastic body 29 attached to the connecting shaft 28. The nut 42 is, for example, screwed into a thread groove (not shown) formed at a predetermined position on the connecting shaft 28. The washer 41 and the nut 42 are also disposed on both sides of the second elastic body 31. The first elastic body 29 and the second elastic body 31 are made of, for example, resin or rubber.

[0024] With the above configuration, the interlocking mechanism 27 rotates in all directions around a front connecting point P1 (see FIG. 2, etc.), which is the point where one end of the connecting shaft 28 is connected to the front wheel support unit 8. The interlocking mechanism 27 also rotates in all directions around a rear connecting point P2 (see FIG. 2, etc.), which is the point where the other end of the connecting shaft 28 is connected to the rear wheel support unit 17. In this way, the interlocking mechanism 27 allows the front wheel support unit 8 and the rear wheel support unit 17 to be interlocked by the connecting shaft 28 through the omnidirectional rotation of the front connecting point P1 at one end of the connecting shaft 28 and the omnidirectional rotation of the rear connecting point P2 at the other end of the connecting shaft 28.

[0025] (Wheel rotation amount when driving on a curve) As shown in Figures 6 and 7, when the vehicle 1 travels around a curve, the operator riding on the plate portion 2 tilts the plate portion 2 in the width direction (the direction of arrow A1 in Figure 6). At this time, the load applied to the tilted plate portion 2 causes the front wheel support portion 8 to rotate about the axis of the front axle L1 (the direction of arrow C1 in Figure 6), and the rear wheel support portion 17 to rotate about the axis of the rear axle L2 (the direction of arrow C2 in Figure 6). In other words, the load applied to the plate portion 2 acts as a load for rotating the front wheel support portion 8 and the rear wheel support portion 17 about their axes, and the front wheel support portion 8 and the rear wheel support portion 17 rotate a predetermined amount.

[0026] As shown in Figure 7, in this example, the amount of rotation R of the front wheel support portion 8 is "R1," and the amount of rotation R of the rear wheel support portion 17 is "R2." In addition, in this example, the amount of rotation R is the angle that each of the front wheel support portion 8 and the rear wheel support portion 17 forms with respect to a reference line La that extends in the front-to-rear direction at the center of the width direction of the plate portion 2. The front wheel unit 4 and the rear wheel unit 6 are configured so that, when traveling around a curve with the plate portion 2 tilted in the width direction, the amount of rotation R2 of the rear wheel support portion 17 about the rear axle L2 is larger than the amount of rotation R1 of the front wheel support portion 8 about the front axle L1.

[0027] (Operation of the embodiment) Next, the operation of the running object 1 of this embodiment will be described. (When driving straight) As shown in Figures 2, 5, and 8(a), when the vehicle 1 travels straight, the steering device 7 is placed in a neutral position, so that the plate portion 2 is horizontal and not tilted. At this time, the amount of rotation R1 of the front wheel support portion 8 and the amount of rotation R2 of the rear wheel support portion 17 are both "0," i.e., the front wheel support portion 8 and the rear wheel support portion 17 are in a neutral position where they are not rotating. This causes the vehicle 1 to travel in a straight direction (the direction of the white arrow in Figure 2).

[0028] (When driving on a curve) As shown in Figures 6, 7, and 8(b), when the vehicle 1 travels around a curve, the steering device 7 is steered by applying a load to the plate portion 2 in one direction in the width direction to tilt it. In this example, the front axle L1 and the rear axle L2 are both tilted in an upward direction (the +Z-axis direction in Figure 6) from the front to the rear of the plate portion 2. Therefore, when the plate portion 2 is tilted in the width direction, the front wheel support portion 8 and the rear wheel support portion 17 rotate around the axes of the front axle L1 and the rear axle L2 in the direction opposite to the direction of the desired curve (the direction of arrows C1 and C2 in Figure 6). As a result, as shown in Figure 7, both the front wheel support portion 8 and the rear wheel support portion 17 are oriented diagonally rightward with respect to the traveling direction (the direction of arrows D1 and D2 in Figure 7).

[0029] 9(a) to 9(c) are explanatory diagrams showing the principle of movement of interlocking mechanism 27 when traveling around a curve. In these figures, the front axle L1, rear axle L2, front coupling point P1, and rear coupling point P2 of interlocking mechanism 27 are simply shown with a double circle or a circle. In these figures, the front axle L1, rear axle L2, front coupling point P1, and rear coupling point P2 are shown on the same horizontal plane.

[0030] As shown in FIG. 9(a), the connecting shaft 28 is disposed at an angle relative to the reference line La because the first distance Ls from the front axle L1 to the front connecting point P1 is different from the second distance Lt from the rear axle L2 to the rear connecting point P2. In this example, this structure generates a rotation difference between the rotation amounts R1 and R2. As a result, when the plate portion 2 is tilted, the rotation amount R1 around the axis of the front axle L1 of the front wheel support portion 8 is smaller, and the rotation amount R2 around the axis of the rear axle L2 of the rear wheel support portion 17 is larger. Therefore, this rotation difference acts as a moment that causes the running vehicle 1 to curve. In this example, this rotation difference causes the running vehicle 1 to curve in a direction that corresponds to the tilted orientation of the plate portion 2.

[0031] In this way, when the plate portion 2 is tilted to travel around a curve, the front wheel support portion 8 and the rear wheel support portion 17 rotate in the direction opposite to the curve direction. In other words, the front wheels 3 and the rear wheels 5 face in the direction opposite to the curve direction. Therefore, when the plate portion 2 is tilted to travel around a curve, it is possible to generate a moment in the direction opposite to the curve direction. Furthermore, since a rotational difference occurs between the rotational amounts R1 and R2 of the front wheel support portion 8 and the rear wheel support portion 17, the vehicle travels around the curve with a turning amount corresponding to this rotational difference. This makes it possible to travel around a curve while generating skidding corresponding to the orientation of the front wheels 3 and the rear wheels 5.

[0032] FIG. 10(a) is an image diagram of the skateboard 1a of this example traveling around a curve. FIG. 10(b) is an image diagram of a general skateboard 1b traveling around a curve. In the case of a general skateboard 1b, the skateboard 1b is always positioned on the trajectory of the curve, so a sufficient feeling of skidding cannot be obtained. On the other hand, in the case of the skateboard 1a of this example, the rear part of the board part 2 moves in a centrifugal force direction so as to jump out from the trajectory of the curve, so a sufficient feeling of skidding can be obtained.

[0033] Furthermore, as shown in FIG. 8(b), when the vehicle is traveling around a curve, the front wheels 3 stick to the road surface, but one side of the rear wheels 5 is lifted off the ground. In this way, the contact area of ​​the rear wheels 5 with the road surface is smaller than that of the front wheels 3. This reduces the resistance exerted on the wheels from the road surface when traveling around a curve, making it possible to minimize deceleration when traveling around a curve. This further contributes to improving the smoothness of traveling around a curve.

[0034] (Principle of movement of interlocking mechanism 27 when traveling on a curve) 9(a) to 9(b), when the vehicle 1 curves to the left relative to the straight-ahead direction, the front wheel support portion 8 rotates clockwise on the page about the front axis L1, and the rear wheel support portion 17 also rotates in the same direction as the front wheel support portion 8 with a difference in rotation amount R while being assisted by the connecting shaft 28. As a result, a traveling load is generated to the left relative to the straight-ahead direction, causing the vehicle 1 to curve to the left.

[0035] 9(a) to 9(c), when the vehicle 1 curves to the right relative to the straight-ahead direction, the front wheel support portion 8 rotates counterclockwise on the page about the front axis L1, and the rear wheel support portion 17 also rotates in the same direction as the front wheel support portion 8 with a difference in rotation amount R while being assisted by the connecting shaft 28. As a result, a traveling load is generated in the right direction relative to the straight-ahead direction, causing the vehicle 1 to curve to the right.

[0036] (Structural features of interlocking mechanism 27) FIG. 11(a) illustrates the interlocking mechanism 27 in which, for example, when the steering device 7 is in the neutral position, the front shaft L1, the rear shaft L2, the front connecting point P1, and the rear connecting point P2 are located on the reference line La. In the case of an interlocking mechanism 27 having this structure, when the connecting shaft 28 is in its initial position, the rear shaft L2 is located on the axis of the connecting shaft 28, so the connecting shaft 28 is likely to rotate around the rear shaft L2 in both the clockwise and counterclockwise directions. For this reason, as shown in FIG. 11(b), the front shaft L1 and the rear shaft L2 may rotate in opposite directions. Therefore, it is not desirable to adopt this structure for the interlocking mechanism 27.

[0037] FIG. 12(a) illustrates a linkage mechanism 27 in which, for example, when the steering device 7 is in the neutral position, the rear axle L2 is positioned on the axis of the connecting shaft 28, which is tilted relative to the reference line La. Even with this structure of the linkage mechanism 27, when the connecting shaft 28 is in its initial position, the rear axle L2 is positioned on the axis of the connecting shaft 28. This means that the connecting shaft 28 is likely to rotate around the rear axle L2 in both a clockwise and counterclockwise direction. As a result, as shown in FIG. 12(b), the front axle L1 and the rear axle L2 may rotate in opposite directions. Furthermore, as shown in FIG. 12(c), when the connecting shaft 28 rotates clockwise from its initial position, a radially outward force Fa may be applied to the rear axle L2. In this case, the rotation of the rear axle L2 is locked, preventing the front wheel support 8 from rotating around its axis. For these reasons, it is not desirable to adopt this structure for the linkage mechanism 27.

[0038] FIG. 13(a) illustrates an interlocking mechanism 27 in which, for example, when the steering device 7 is in the neutral state, the rear connecting point P2 of the connecting shaft 28, which is tilted relative to the reference line La, is positioned on the reference line La. In this structure, as shown in FIG. 13(b), when the front connecting point P1 rotates slightly from its initial position, the rear axle L2 is positioned on the axis of the connecting shaft 28. This results in a state similar to that shown in FIG. 12(c) above, where the rotation of the rear axle L2 about its axis is locked, i.e., the front wheel support section 8 does not rotate about its axis. Therefore, it is not desirable to adopt this structure for the interlocking mechanism 27.

[0039] On the other hand, as shown in FIGS. 9(a) to 9(c), in the case of the interlocking mechanism 27 of this example, within the rotation range of the front wheel support part 8 about the front axis L1, the rear axis L2 is not positioned on the axis of the connecting shaft 28. In other words, within the rotation range of the front axis L1, the front connecting point P1, the rear connecting point P2, and the rear axis L2 are not positioned on the same straight line. Therefore, the rotation of the front wheel 3 about the front axis L1 and the rotation of the rear wheel 5 about the rear axis L2 are unlikely to be in opposite directions. Furthermore, when the front wheel 3 rotates about the front axis L1, a situation in which a radially outward force Fa is applied to the rear axis L2 (see FIGS. 12(c) and 13(b)) is unlikely to occur.

[0040] As a result, it becomes easier to control the rear wheels 5 when the front wheels 3 rotate around the front axis L1, making it possible to easily link the front wheels 3 and the rear wheels 5. It also becomes easier to achieve "zero point hold," which keeps the rear wheels 5 in a straight line when traveling straight.

[0041] From another perspective, consider a case where, when the steering device 7 is in the neutral state, the connecting shaft 28 tilts in the opposite direction to that of the embodiment, as shown in FIG. 14(a). Specifically, consider a case where the other end (rear end) of the connecting shaft 28 is positioned farther from the reference line La than one end (tip end) of the connecting shaft 28. With this structure, when rotation occurs around the front shaft L1, it is possible for the rear shaft L2 to also rotate in the same direction. However, as shown in FIG. 14(b), the amount of rotation R2 around the axis of the rear shaft L2 becomes smaller than the amount of rotation R1 around the axis of the front shaft L1, resulting in the reversed direction of the curve.

[0042] From another perspective, consider the case where, as shown in Figure 15(a), when the steering device 7 is in the neutral state, the connecting shaft 28 is parallel to the reference line La in the fore-and-aft direction of the vehicle 1. In this structure, too, as shown in Figure 15(b), the amount of rotation R2 about the axis of the rear axle L2 becomes smaller than the amount of rotation R1 about the axis of the front axle L1, resulting in the vehicle turning in the opposite direction.

[0043] For the above reasons, it is preferable that the connecting shaft 28 be disposed in an inclined state so that one end (front end) of the connecting shaft 28 is positioned farther from the reference line La than the other end (rear end) of the connecting shaft 28. In other words, it is preferable that the rotation range around the front axis L1 (rear axis L2) be set so that the maximum rotation amount does not exceed the position where the connecting shaft 28 is parallel to the reference line La.

[0044] (Advantages of the interlocking mechanism 27 using the first elastic body 29 and the second elastic body 31) 3 and other figures, the interlocking mechanism 27 of this example has a structure in which the end of the connecting shaft 28 is connected to the front wheel support portion 8 and the rear wheel support portion 17 by the first elastic body 29 and the second elastic body 31. Therefore, the interlocking mechanism 27 does not require a complex structure because it simply connects the connecting shaft 28 to the front wheel support portion 8 and the rear wheel support portion 17 by an elastic member such as rubber. This makes it possible to simplify the structure of the interlocking mechanism 27 and, ultimately, the running vehicle 1.

[0045] Furthermore, the front wheel support portion 8 and the front wheel seat portion 9 may be formed so as to simply rotate about the axis of the front axis L1. Similarly, the rear wheel support portion 17 and the rear wheel seat portion 18 may be formed so as to simply rotate about the axis of the rear axis L2. Therefore, the structures of the portions connecting the front wheel support portion 8 and the front wheel seat portion 9 and the portions connecting the rear wheel support portion 17 and the rear wheel seat portion 18 are not complicated. This further contributes to simplifying the structure of the running vehicle 1.

[0046] (Change in the positions of the front coupling point P1 and rear coupling point P2) As shown in FIGS. 16(a) to 16(c), at least one of the front coupling point P1 and the rear coupling point P2 may be configured to be changeable in position in order to change the feeling of skidding or cornering. For example, the position of the front coupling point P1 can be adjusted by changing the shape of the coupling portion 30 of the front wheel unit 4. This may be achieved, for example, by replacing a plurality of coupling portions 30 having different shapes that are prepared. Furthermore, the position of the rear coupling point P2 can be adjusted by changing the shape of the second part 22 of the rear wheel unit 6. This may be achieved, for example, by replacing a plurality of second parts 22 having different shapes that are prepared.

[0047] Incidentally, the angle change in rotation of the front axle L1 and the rear axle L2 about their axes is approximately equal for the connecting shaft 28 shown by the solid line in Figure 16(b) and the connecting shaft 28 shown by the solid line in Figure 16(c). Furthermore, the angle change in rotation of the front axle L1 and the rear axle L2 about their axes is approximately equal for the connecting shaft 28 shown by the dashed line in Figure 16(b) and the connecting shaft 28 shown by the dashed line in Figure 16(c). Therefore, if the front connecting point P1 is located on the first widthwise line Lb that passes through the front axle L1 and is perpendicular to the reference line La, and if the rear connecting point P2 is located on the second widthwise line Lc that passes through the rear axle L2 and is perpendicular to the reference line La, it is possible to make the feeling equivalent when turning left and turning right.

[0048] (Display section 44) As shown in Fig. 17, the connecting shaft 28 may have a display unit 44 on which a design can be displayed. The display unit 44 has, for example, a display plate 44a where the design is displayed and a fixing portion 44b for fixing the display unit 44 to the connecting shaft 28. The display unit 44 is a part that is not related to the running of the running body 1, and rotates integrally with the connecting shaft 28. The display unit 44 (specifically, the display plate 44a) displays designs such as pictures, letters, and numbers. It is also possible to place advertisements and the like on the display unit 44.

[0049] (Effects of the embodiment) According to the steering device 7 (skateboard 1a) of the above embodiment, the following effects can be obtained.

[0050] (1) According to this configuration, the front axle L1 and the rear axle L2 are each disposed at an incline that rises from the front to the rear of the vehicle 1, so when the vehicle 1 is tilted in the width direction to travel around a curve, the front wheel support part 8 and the rear wheel support part 17 rotate in the opposite direction to the curve direction. Even if the front wheel support part 8 and the rear wheel support part 17 rotate in the opposite direction to the curve direction, a difference in the amount of rotation R occurs between these parts, so the vehicle 1 travels around a curve with a turning radius that corresponds to the difference in rotation in the direction in which the vehicle 1 is tilted.

[0051] As described above, when traveling around a curve, the front wheel support portion 8 and the rear wheel support portion 17 rotate in the direction opposite to the curve direction, causing the front wheels 3 and the rear wheels 5 to face in the opposite direction to the curve, making it possible to create a feeling of skidding in the traveling vehicle 1. Furthermore, even if it is possible to create a feeling of skidding in the traveling vehicle 1 when traveling around a curve, by creating a rotation difference between the front wheel support portion 8 and the rear wheel support portion 17, the traveling vehicle 1 also travels around the curve in the desired direction. Therefore, it is possible to travel around a curve more smoothly while creating a sufficient feeling of skidding.

[0052] (2) The skateboard 1a includes a steering device 7 that steers the front wheel unit 4 and the rear wheel unit 6. The steering device 7 has a linkage mechanism 27 that links the front wheel support portion 8 and the rear wheel support portion 17 by connecting the front wheel support portion 8 and the rear wheel support portion 17 with a connecting shaft 28. One end of the connecting shaft 28 is connected to the front wheel support portion 8 so as to enable at least rotation about the front axis L1. The other end of the connecting shaft 28 is connected to the rear wheel support portion 17 so as to enable at least rotation about the rear axis L2. With this configuration, the front wheel support portion 8 and the rear wheel support portion 17 are linked by the linkage mechanism 27, making it easier to point the front wheel 3 and the rear wheel 5 in the same direction when traveling around a curve. This allows the skateboard to travel around a curve in the direction intended by the user.

[0053] (3) The steering device 7 has a front coupling point P1, where one end of the connecting shaft 28 is coupled to the front wheel support unit 8, and a rear coupling point P2, where the other end of the connecting shaft 28 is coupled to the rear wheel support unit 17. The connecting shaft 28 is tilted relative to a reference line La, which extends along the longitudinal direction of the front wheel unit 4 and the rear wheel unit 6, because the first distance Ls between the front shaft L1 and the front coupling point P1 and the second distance Lt between the rear shaft L2 and the rear coupling point P2 are different. This configuration optimizes the positional relationship between the front shaft L1, the rear shaft L2, the front coupling point P1, and the rear coupling point P2, making it easier to point the front wheel support unit 8 and the rear wheel support unit 17 in the desired direction. This further contributes to realizing curve driving in the direction intended by the user.

[0054] (4) The connecting shaft 28 is disposed on one of both sides of the reference line La in the direction intersecting the reference line La. With this configuration, the interlocking mechanisms 27 can be disposed together on one side of the reference line La, thereby optimizing the component arrangement.

[0055] (5) One end of the connecting shaft 28 is connected to the front wheel support portion 8 via a first elastic body 29 that functions as a universal joint, and the other end of the connecting shaft 28 is connected to the rear wheel support portion 17 via a second elastic body 31 that also functions as a universal joint. With this configuration, the structure of the interlocking mechanism 27 can be a simple structure using an elastic member.

[0056] (6) The connecting shaft 28 has a display section 44 that can display designs. According to this configuration, the display section 44 provided on the connecting shaft 28 can display designs such as pictures, numbers, letters, and the like.

[0057] (7) The rear wheels 5 are disposed behind the rear axle L2 in a direction intersecting the rear axle L2. With this configuration, the rear wheels 5 are disposed at a position away from the front wheels 3. Therefore, when the vehicle 1, which has been tilted in the width direction during travel, is returned to its original neutral position, the rear wheels 5 can generate a large elastic force to return the rear wheels 5 toward the neutral position. Therefore, this elastic force can be utilized for acceleration.

[0058] (8) A pair of front wheels 3 are arranged on both sides of the front axle L1. One rear wheel 5 is arranged. This configuration allows the number of wheels to be reduced, which contributes to a reduction in the number of parts of the vehicle 1. It also contributes to a reduction in part costs.

[0059] (9) When driving around a curve, the front wheels 3 stick to the road surface, but one side of the rear wheels 5 is in a floating state, so the contact area of ​​the rear wheels 5 with the road surface is smaller than that of the front wheels 3. Therefore, the resistance acting on the wheels from the road surface when driving around a curve is kept low, making it possible to keep deceleration when driving around a curve to a minimum. This further contributes to improving the smoothness of driving around a curve.

[0060] (Other embodiments) This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0061] As shown in Fig. 18, bulging portions 45a, 45b that bulge by a predetermined amount may be formed at each axial end of the connecting shaft 28. The bulging portions 45a, 45b preferably have spherical surfaces and are formed circumferentially around the axis of the connecting shaft 28. In this configuration, the surface shape of the bulging portions 45a, 45b guides the smooth movement of each end of the connecting shaft 28 as a universal joint. This improves the functionality of the interlocking mechanism 27.

[0062] 19, the plate portion 2 may have a notch 49 formed therein to avoid interference with the front wheel unit 4 when tilted in the width direction. In this case, even if the plate portion 2 is configured to be tilted significantly when traveling around a curve, the plate portion 2 will not come into contact with the front wheel unit 4.

[0063] 20 and 21, the vehicle 1 may have a structure in which the front wheel unit 4 and the rear wheel unit 6 are not connected by the interlocking mechanism 27. Specifically, as shown in FIG. 20, the front wheel unit 4 and the rear wheel unit 6 each have two wheels, and these are independent structures without being connected by the interlocking mechanism 27. Then, as shown in FIG. 21, the angle θ2 of the rear axle L2 is set larger than the angle θ1 of the front axle L1. This makes it possible to generate a rotation difference of "R2 > R1" between the front wheels 3 and the rear wheels 5 when traveling around a curve with the plate portion 2 tilted, thereby enabling smooth traveling around a curve while generating a sufficient feeling of skidding.

[0064] The first elastic body 29 and the second elastic body 31 are not limited to being made up of a plurality of elastic pieces, and may be made up of only one member. The connecting shaft 28 may be disposed at an angle such that, when the steering device 7 is in the neutral state, its front end is close to the reference line La and its rear end is far from the reference line La. Furthermore, when the steering device 7 is in the neutral state, the connecting shaft 28 may be disposed parallel to the reference line La.

[0065] For example, in FIG. 9(a), the connecting shaft 28 may be configured such that the front connecting point P1 is located on one side of the reference line La in the left-right direction on the paper, and the rear connecting point P2 is located on the other side of the reference line La in the left-right direction on the paper.

[0066] The interlocking mechanism 27 may be configured to rotate both ends of the connecting shaft 28 about an axis. Specifically, one end of the connecting shaft 28 may be axially rotatably connected to the front wheel support portion 8, and the other end of the connecting shaft 28 may be axially rotatably connected to the rear wheel support portion 17.

[0067] The interlocking mechanism 27 is not limited to a rotary type in which the connecting shaft 28 rotates at both ends in response to the operation of the plate portion 2 in the width direction. For example, the interlocking mechanism 27 may be a slider type composed of slider members that can move linearly relative to each other in the axial direction.

[0068] The difference in rotation between the rotation about the front axle L1 and the rotation about the rear axle L2 may be generated, for example, by using the same number of wheels on the front and rear wheels but varying the wheel width. The front wheel unit 4 and the rear wheel unit 6 are not limited to structures using elastic members (first elastic body 29, second elastic body 31), but may also be structures using trucks, which are widely used as general structures, for example.

[0069] The running object 1 is not limited to a skateboard 1a, but may be, for example, a kickboard (registered trademark). While the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0070] 1...running body, 1a...skateboard, 2...board portion, 3...front wheel, 4...front wheel unit, 5...rear wheel, 6...rear wheel unit, 7...steering device, 8...front wheel support portion, 9...front wheel seat portion, 14...axle, 17...rear wheel support portion, 18...rear wheel seat portion, 23...axle, 27...linkage mechanism, 28...connecting shaft, 29...first elastic body, 31...second elastic body, 44...display portion, L1...front shaft, L2...rear shaft, R, R1, R2...amount of rotation, Ls...first distance, Lt...second distance, La...reference line.

Claims

1. A skateboard comprising: a board portion on which a user rides; a front wheel unit having a front wheel disposed at the front of the back surface of the board portion; and a rear wheel unit having a rear wheel disposed at the rear of the back surface of the board portion, the front wheel unit includes a front wheel support portion that rotatably supports the front wheel, and a front wheel seat portion that supports the front wheel support portion so that the front wheel can rotate at least around a front axis that extends in a direction intersecting the plate portion, the rear wheel unit includes a rear wheel support portion that rotatably supports the rear wheel, and a rear wheel seat portion that supports the rear wheel support portion so that the rear wheel can rotate at least around a rear axis that extends in a direction intersecting the plate portion, The front shaft and the rear shaft are disposed to be inclined upward from the front to the rear of the plate portion, The front wheel unit and the rear wheel unit are configured so that when the board portion is tilted in the width direction while traveling around a curve, the amount of rotation of the rear wheel support portion around the rear axis is greater than the amount of rotation of the front wheel support portion around the front axis.

2. a steering device that steers the front wheel unit and the rear wheel unit, the steering device has a linkage mechanism that links the front wheel support portion and the rear wheel support portion by connecting the front wheel support portion and the rear wheel support portion with a connecting shaft, one end of the connecting shaft is connected to the front wheel support portion so as to be at least rotatable around the front shaft, The skateboard according to claim 1 , wherein the other end of the connecting shaft is connected to the rear wheel support portion so as to at least allow rotation around the rear shaft.

3. the steering device has a front connection point where one end of the connecting shaft is connected to the front wheel support portion, and a rear connection point where the other end of the connecting shaft is connected to the rear wheel support portion, 3. The skateboard according to claim 2, wherein the connecting shaft is arranged at an angle with respect to a reference line extending along the fore-and-aft direction in which the front wheel unit and the rear wheel unit are aligned, because the distance between the front axis and the front connecting point and the distance between the rear axis and the rear connecting point are different.

4. The skateboard according to claim 3 , wherein the connecting shaft is disposed on one of both sides of the reference line in a direction intersecting the reference line.

5. 3. The skateboard according to claim 2, wherein one end of the connecting shaft is connected to the front wheel support portion via a first elastic body having a function of a universal joint, and the other end of the connecting shaft is connected to the rear wheel support portion via a second elastic body having a function of a universal joint.

6. The skateboard according to claim 2, wherein the connecting shaft has a display portion capable of displaying a design.

7. The skateboard of claim 1 , wherein the rear wheel is disposed rearward of the rear axle in a direction transverse to the rear axle.

8. The front wheels are arranged in pairs on both sides of the front shaft, The skateboard according to claim 1 , wherein the rear wheel is arranged as one.

9. a front wheel unit including a front wheel support portion that rotatably supports a front wheel of a traveling body, and a front wheel seat portion that supports the front wheel support portion so that the front wheel can rotate at least around a front axis that extends in a direction intersecting with the axle of the front wheel; a rear wheel unit including a rear wheel support portion that rotatably supports a rear wheel of the traveling body, and a rear wheel seat portion that supports the rear wheel support portion so that the rear wheel can rotate at least about a rear axis that extends in a direction intersecting the axle of the rear wheel; a linkage mechanism that links the front wheel support portion and the rear wheel support portion by connecting the front wheel support portion and the rear wheel support portion with a connecting shaft, one end of the connecting shaft is connected to the front wheel support portion so as to be at least rotatable around the front shaft, the other end of the connecting shaft is connected to the rear wheel support portion so as to be at least rotatable around the rear shaft, A steering device in which the connecting shaft is arranged at an angle with respect to a reference line extending in the fore-and-aft direction in which the front wheel unit and the rear wheel unit are aligned, because the distance between the front connecting point, where one end of the connecting shaft is connected to the front wheel support portion, and the front axle is different from the distance between the rear connecting point, where the other end of the connecting shaft is connected to the rear wheel support portion, and the rear axle.

10. The steering device according to claim 9 , wherein the connecting shaft is disposed on one of both sides of the reference line in a direction intersecting the reference line.

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