JPH0976980A - Power transmission device of bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bicycle which is smooth in propulsion and acceleration, and little in fatigue by stabilizing the stepping-in force of a pedal to improve the rotational efficiency by the pedal. SOLUTION: A coil spring 15 which is coiled in the direction opposite to the rotational direction of a forward gear 13 is built in an inner circumferential wall pad 14 on the inner side of the forward gear 13, the torque by the excessive stepping-on pressure of a pedal arm 12 is accumulated in the coil spring 15 by the effect of the coil spring 15 through incorporation between a pedal shaft 11 and a forward gear shaft, and the accumulated torque is supplemented when the pedal input is in short to improve the rotational efficiency by the pedal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for a bicycle, and more specifically, a winding spring is incorporated in a portion such as between a pedal shaft and a front gear, and the rotation torque of a pedal arm is stabilized by the action of the winding spring. The present invention relates to a power transmission device for a bicycle, which is designed to be obtained smoothly and smoothly.

[0002]

2. Description of the Related Art In a conventional bicycle, in order to improve pedaling efficiency, an oval gear is used for the front gear, and rotation input by pedaling pressure is stabilized by the inertia of its own weight including the bicycle. .

[0003]

However, in the conventional method, the chain is easily bent and the degree of wear is large. Therefore, lack of uniformity of force, lack of smoothness of propulsion and acceleration, and reduction of fatigue. It lacked sex.

The present invention has been made in view of the above-mentioned problems of the prior art. The purpose of the present invention is to stabilize the pedal pressure input of the pedal more actively than the conventional measures for improving the pedaling efficiency. Measure the improvement of rotation efficiency with the pedal,
Therefore, the purpose of the present invention is to provide a bicycle that can be smoothly propelled and accelerated and has a light and comfortable ride without fatigue.

[0005]

To this end, the present invention relates to a front gear in which a winding spring wound in a direction opposite to the direction of rotation of the front gear is incorporated in the inner peripheral wall of the front gear, or a pedal shaft. It is installed between the front gear shaft and the winding spring to store the torque due to the excessive pedaling pressure of the pedal arm in the winding spring, and when the pedal input is insufficient, the accumulated torque is supplemented to improve the rotation efficiency of the pedal. It is characterized by an improved configuration.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view of an example of a power transmission device according to the present invention with some parts omitted, and FIG. 2 is an end view seen from two directions in FIG.
A pedal shaft 11 rotatably supported by the pedal arm 11 is fixed to a pedal arm 12, and a front gear 13 is fixed to the pedal arm 12.
Is designed to rotate integrally with the pedal arm 12. A peripheral wall portion 14 centering on the pedal shaft 11 is projectingly provided inside the front gear 13, and a winding spring 15 wound in the peripheral wall portion 14 in a direction opposite to the rotation direction of the front gear 13. And one end portion 16 thereof is engaged with a part of the peripheral wall portion 14, and the other end portion 17 thereof is
1 is engaged with a part of the coil spring receiving plate 18 which is eccentric to and integrally rotates, and when the pedal position is approximately 45 degrees above the front, the coil spring 15 is coiled through the engagement of both end portions 16 and 17. ,
When the pedal position is approximately 135 degrees below the front, both ends 16, 1
The winding is released by releasing the engagement of any one of 7 and the winding spring 15 becomes 0 (zero).

As is well known, the rotation input of the pedal shaft 11 of the bicycle is such that the pedal position is approximately 45 degrees above the front and approximately 1 below the front.
It is a wave input that is input during about 35 degrees and increases or decreases twice during one rotation of the pedal shaft 11, and since there is a large loss for becoming an excessive input at the maximum point, With the configuration, the rotational force of the pedal shaft 11 is transmitted to the front gear 13 via the winding spring 15 that is wound around when the pedal position is approximately 45 degrees above the front, and the loss due to excessive pedaling pressure is wound into the winding spring 15. When the pedal input is insufficient, this accumulated force is added to the rotational force.

In FIG. 3, the coil spring 15 has a space 20 between the pedal shaft 11 and the front gear shaft 19 which is the rotation shaft of the front gear 13.
The first end 16 of the coil spring 15 is engaged with a part of the inner wall surface of the front gear shaft 19, and the other end 17 is engaged with a part of the pedal shaft 11 to start the vehicle. When the pedal arm 12 rotates during operation, the pedal shaft 1
1 and the front gear 13 and the front gear shaft 19 rotate with respect to the frame 21, and when the pedal position is approximately 45 degrees above the front, the coil spring 1
5 is wound up to 100% and the pedal position is close to the front lower 135 degrees and the engagement with the end of the winding spring is released.
Returns to 0 (zero), the winding spring 15 is repeatedly wound and unwound during the rotation of the pedal arm 12, and torque due to excessive pedaling pressure is stored in the winding spring 15, and when the pedal input is insufficient, By supplementing this accumulated force, the rotation efficiency of the pedal is improved.

The embodiment shown in FIG. 4 has a winding spring 1
5 is a coil-shaped spring instead of the spring (leaf spring) -shaped spring shown in FIG. 3, and other configurations and operational effects are the same as those shown in FIG. . Therefore, its explanation is omitted.

In FIG. 5, a coil spring 15 (only a coil spring is shown) is incorporated in a space 26 between the rear gear shaft 23 of the rear gear 22 and the shaft portion 25 of the rear wheel hub 24. In the embodiment, one end portion 16 of the winding spring 15 is engaged with a part of the inner wall surface of the rear wheel hub shaft portion 25, and the other end portion 17 is engaged with a part of the outer peripheral surface of the rear wheel axle 23. The winding spring 15 is wound and unwound by the start, and the unevenness of the torque remaining in the rear gear 22 is stabilized and transmitted to the driving wheel.

[0011]

As described above, according to the present invention, the action of the winding spring wound by the start improves the rotation efficiency of the pedal, and the propulsion and acceleration are smoother and easier to ride than the conventional vehicle, and A bicycle with less fatigue can be provided and obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view with a part omitted in an example of a power transmission device according to the present invention.

FIG. 2 is an end view as seen from two directions in FIG.

FIG. 3 and FIG. 4 are partially omitted partial cross-sectional views showing another example of the present invention.

FIG. 5 is a half sectional view showing still another example of the present invention.

[Explanation of Codes] 10 Pedal Bearing 11 Pedal Shaft 12 Pedal Arm 13 Front Gear 14 Circumferential Wall 15 Winding Spring 16 Winding Spring One End 17 Winding Spring Other End 18 Winding Spring Bearing Plate 19 Front Gear Shaft 20, 26 Space 21 Frame 22 Rear gear 23 Rear gear shaft 24 Rear wheel hub 25 Shaft

Claims (3)

[Claims] 1. A winding spring wound in a direction opposite to the rotation direction of the front gear is incorporated in an inner peripheral wall of the front gear, and a torque generated by excessive pedaling pressure of a pedal arm is wound by the action of the winding spring. A power transmission device for a bicycle, characterized in that the torque stored in a spring is supplemented when the pedal input is insufficient to improve the rotation efficiency of the pedal. 2. The power transmission device for a bicycle according to claim 1, wherein the coil spring is incorporated between the pedal shaft and the front gear shaft. 3. The power transmission device for a bicycle according to claim 1, wherein the coil spring is incorporated between the rear gear shaft and the rear wheel hub.