JP2006021554A - Front-wheel driving and steering devices of bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a front-wheel driving device and steering device for a front-wheel drive bicycle based on the known principle, although not yet in practical use, that running with the front wheel drive system assures good effect in the kinetic characteristics (steering characteristic, slope climbing characteristic, stability at steep braking, and the running efficiency), allowing the rider to drive with the same driving feeling as for a conventional bicycle on the rear-wheel drive system, assuring more excellent motion characteristics, and free of the risk to impair the rigidity of the bicycle body. <P>SOLUTION: The invention includes a handle shaft located over the front wheel of a conventional rear-wheel drive bicycle and a frame to support the handle shaft in rotation and is configured so that the frame and the handle shaft are curved in a crank shape in the fit-in part of the handle shaft with the frame in such a way as opposing to each other and toward the axes of the wheels, wherein two sets of universal couplings able to expand and contract in the axial direction are installed in series in the inside of their cranks, and the power from a pedal is transmitted using a chain etc. to the front wheel through the universal couplings. Even if the handle is steered during running, the function of the two sets of universal couplings allows transmitting the driving force from the pedal to the front wheel, and also it is possible to obtain the same steering angle as the conventional rear-wheel drive bicycle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive device and a steering device that travel by front wheel drive instead of a known bicycle (rear wheel drive vehicle).

  Driving with the front wheels of a bicycle is effective in terms of motion characteristics, but has not yet been put into practical use.

As the front wheel drive method, the frame side is the primary drive, the handle side front wheel is the secondary drive, both are connected by a set of universal shaft joints, and the front wheel side of the frame side holding part of the universal shaft joint is released. There is a method of driving the front wheels.
JP 9-104385 A

  With one set of universal shaft joints, the steering angle of the front wheels does not reach the known steering angle of 90 ° for bicycles. In addition, rotation cannot be transmitted at a constant speed during steering (when the joint is bent), and the release of the frame side holding portion lacks rigidity, which causes anxiety during steering.

  Between the handle of the handle shaft penetrating through the frame and the frame at the top of the front wheel, each wheel shaft is curved in a crank shape in the opposite direction to each other, and the distance between the cranks Providing two sets of universal couplings that can be extended and retracted, and can be steered freely up to 90 ° to the left and right, and can drive and steer like a front-wheel drive and provide a drive and steering device that can drive stably.

  In the handle shaft for steering the front wheel of the known rear wheel drive bicycle and the frame for supporting the handle shaft, the frame is bent in a crank shape in the axial direction of the rear wheel, and the handle shaft is also supported by the frame up and down. , In the same direction as the crank of the front wheel in the direction of the axis of the front wheel in the opposite direction to the crank of the frame, each bearing is provided with a bearing in the axial direction of each wheel, A universal coupling is incorporated in series, and a sprocket is provided at the shaft end of both universal couplings. The driving force generated by striking the pedal is transmitted from the pedal sprocket to the frame-side sprocket by the chain, and then the driving force via the universal coupling is transmitted from the handle shaft-side sprocket to the sprocket fixed to the front wheel shaft. Drive the front wheels. When the steering wheel is operated, the direction of the front wheel is changed to change the course, and at the same time, the refraction angles of the two sets of universal couplings change. The amount of change in the sum of the refraction angles of the two sets of couplings is the same as the steering angle of the front wheels, and the handle shaft sprocket and the front wheel shaft sprocket always maintain the same distance and parallel relationship so that they are universal in any steering condition The coupling transmits the driving force. In addition, the total refraction angle when two sets of universal couplings are connected in series is twice the refraction angle of one set. If the refraction angle of a pair of universal couplings is 45 °, the steering angle of the steering wheel is 90 °, which can be steered left and right. By connecting two sets of universal couplings in series, rotation can be transmitted at a constant speed. That is, it has the same traveling function as that of a rear wheel drive bicycle, and the motion characteristics can be exceeded.

  It has the same running function as a known rear-wheel drive bicycle, and the motion characteristics can be surpassed. That is, the brake feeling generated during steering of the steering wheel is eliminated, climbing performance is improved, and steering can be performed smoothly.

  1, the first universal coupling 16 and the second universal coupling are applied from the first sprocket 4 of the pedal to the second sprocket 5 of the frame side crank 10-1 by the first chain 8. 17 and output to the third sprocket 6 of the handle shaft side crank 12-1 to transmit the driving force to the fourth sprocket 7 of the front wheel 1 through the second chain 9.

  In FIG. 2, the steering drive device that transmits the driving during steering, which is the most important in a front-wheel drive bicycle, in FIG. 2, bends the crank on the frame side outward, and similarly curves the crank 12-1 of the handle shaft in the opposite direction. Bearings 10-2 and 12-2 are provided in the part, and two sets of universal couplings 16 and 17 are supported in series, and the sprockets 5 and 6 are attached to the shaft ends 14 and 15, respectively. More specifically, the handle shaft 12 is bent with both ends of the crank supported by the frame 10. Rigidity comparable to that of a rear-wheel drive vehicle is maintained, and smooth operation can be performed without feeling anxiety when steering the steering wheel.

  3-5, the steering force and the driving force of the steering wheel are transmitted straight from FIG. 3 and FIG. 4 is in the right-turned state. The handle shaft universal coupling is refracted into the same body as the front wheel, and the sprocket 6 and the front wheel sprocket are transmitted. Keep the same distance as 7 and parallelism. On the contrary, in FIG. 5, the handle shaft coupling is also refracted in the same manner with the front wheel in the left turn state, and the distance and parallelism of the sprockets 6 and 7 are maintained.

In the known rear wheel drive bicycle, two sets of universal couplings are incorporated so that the steering wheel can be steered up to 90 ° right and left, respectively, so that the same steering angle can be obtained even in the front wheel drive vehicle of the present invention. 6 to 8, the coupling is a simple structure composed of a sphere 20 and a spherical cup 18, a spherical cap 19, a torque ball 21, and a torque ball groove 22, and one set of refraction angles can obtain a maximum of 45 °. The steering angle θ of the steering wheel requires a refracting angle of 1 / 2θ in one set of couplings, and the refracting angle may be maintained as θ by combining two sets. If one set of rings can be refracted up to 45 °, two sets can achieve a refraction angle of 90 °, in other words, a steering angle of 90 °. Of course, the driving force can be transmitted even in this state.

The universal couplings 16 and 17 incorporated in both cranks in FIG. 6 are the same type of coupling, but one of the spheres 20 in the coupling is a spline shaft 23 and is fitted into the spline hole 24 of one sphere 20 and driven. At the same time, it corresponds to the movement of the coupling in the axial direction during steering.

  Further, in FIG. 7, a black dot 13 indicates a shaft center of the steering wheel, and the handle shaft side crank is rotated around the black dot 13 during steering. When rotating around the black dot, the second universal coupling 17 on the handle shaft side changes the distance from the frame-side first universal coupling 16. In other words, when the steering angle is 0 °, it is farthest away. The change in the distance between the couplings is absorbed and expanded by the spline shaft 23 and the spline hole 24.

  As described above, the steering wheel can be steered even during traveling, and power is transmitted to the front wheels in the same manner as in the rear wheel driving bicycle in the front wheel driving simultaneously with the integration of the steering wheel and the front wheels.

  When the handle is operated, simultaneously with the front wheel, the drive system of the handle shaft side third sprocket 6 and the second chain 9 rotates with the front wheel. Instead of chains and sprockets, toothed belts and pulleys may be used for power transmission.

  A two-wheel drive bicycle is also possible by combining the front wheel steering and drive system of the present invention with the known rear wheel drive system.

  Further, the steering and driving device of the present invention can be applied to a motorcycle having a power source.

Front-wheel drive bicycle exterior view Relationship diagram of frame, handle shaft and universal coupling Diagram of handle and universal coupling when going straight Diagram of handle and universal coupling when turning right Diagram of handle and universal coupling when turning left Universal coupling diagram when the steering angle is 0 ° Universal coupling diagram when the steering angle is 60 ° Universal coupling diagram when the steering angle is 90 °

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front wheel 2 Rear wheel 3 Pedal 4 1st sprocket 5 2nd sprocket 6 3rd sprocket 7 4th sprocket 8 1st chain 9 2nd chain 10 Frame 10-1 Frame side crank 10-2 Frame side bearing 11 Handle 12 Handle Shaft 12-1 Handle shaft side crank 12-2 Handle shaft side bearing 13 Handle shaft center 14 Shaft end 15 Shaft end 16 First universal coupling 17 Second universal coupling 18 Spherical cup 19 Spherical cap 20 Spherical body 21 Torque ball 22 Torque Ball groove 23 Spline shaft 24 Spline hole

Claims (1)

The frame through which the handle shaft at the top of the front wheel of the bicycle penetrates is bent in a crank shape outward in the axial direction of the rear wheel, while the handle shaft is also bent in a crank shape outward in the axial direction of the front wheel on the opposite side of the frame It is exposed to the outside of the frame, bearing parts are provided on both curved parts, the shaft center of the handle passes through the inside of each crank, and the universal coupling is assembled in series in a state that it can be expanded and contracted in two sets of axial directions The front wheel drive of the bicycle that has sprockets on both shaft ends, transmits the driving force of the pedal to the sprocket with the chain, and transmits the driving force via the universal coupling from the sprocket at the curved part of the handle shaft to the sprocket of the front wheel with the chain -Steering device.

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