JPH04300794A - Automatic gear shifter for bicycle - Google Patents

Abstract

PURPOSE:To make an automatic speed change according to the increase/reduction of a road load by making constitution in which an epicyclic gear is arranged with a sun gear, integrated with a crank arm to whose tip part a pedal is fitted, as a center, a driven rotary body is located on the periphery of the epicyclic gear, and these gears are shaft-supported with rotation supporting plates. CONSTITUTION:Epicyclic gears 8 and 9, each one of them is composing a pair, are arranged rotatably by trisection or more on a circumference identical with that of a sun gear 7 with the sun gear 7 engagedly fixed to a crank arm 6 as a center, and a driven rotary body 15, in which a sprocket 14 is formed in the periphery of an internal gear 13, is arranged on the outer side of the epicyclic gears 8 and 9. These respective gears are engaged with gears mutually corresponding to be shaft-supported with rotatable rotation supporting plates 11 and 12 fitted on both side surfaces of them. These respective rotation supporting plates 11 and 12 are rotatably supported by interposing ball bearings 11c and 12c between bearing grooves 11a and 12a, provided on the inner side surfaces of the rotation supporting plates 11 and 12, and bearings 11b and 12b provided on both the side surfaces of the sun gear 7 and the driven rotary body 15. Also a one-way clutch 16 is provided between the frame side rotation supporting plate 11 and a hanger pipe 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for a bicycle provided on the crankshaft of the bicycle.

0002

[Prior Art] A multi-stage sprocket system is currently widely used as a bicycle transmission, and a transmission incorporating a planetary gear in the crankshaft is known as
There is one disclosed in Publication No. 58150.

0003

SUMMARY OF THE INVENTION The bicycle transmission devices according to the prior art described above all have a problem in that they all have a speed change change device and the speed change is performed manually.

0004

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a system in which a sun gear integrally fitted to a crank arm is fitted and fixed to a crankshaft, and the circumference is the same around the sun gear. A set of two planetary gears divided into three or more parts is rotatably arranged on the top, and a driven rotating body with a sprocket formed on the outer periphery of the internal gear is arranged on the outer periphery of the planetary gear, and each of these gears They mesh with corresponding gears, and are supported and clamped between rotatable rotary support plates on both sides. A one-way clutch is provided between the outer surface of the frame-side rotation support plate and the tip of the hanger pipe to prevent reverse rotation of the rotation support plate. Further, the automatic bicycle transmission device has a structure in which the timing of shifting can be adjusted using a lock mechanism provided between the outer surface of the crank arm side rotation support plate and the crank arm.

[0005]

[Operation] When the road load of the bicycle is light, each planetary gear does not rotate, and the gears corresponding to the sun gear and internal gear mesh with each other and are sandwiched between the rotating support plates, forming one body and moving in the direction of arrow A. Rotate to. Therefore, the driving force of the crank arm is directly transmitted to the chain via the sprocket of the driven rotor. The gear ratio in this case is 1:1.

When the bicycle is riding uphill or against a headwind, and the load exceeds the locking pressure of the lock mechanism provided on the crank arm, the lock is released from the lock hole provided on the outer surface of the rotation support plate on the crank arm side, and the rotation support plate is released. The rotation of the plate lags behind the rotation of the crank arm, and the planetary gear rotates in the direction of the arrow (see FIG. 5). In this case, as the load increases, the rotation support plate shifts from stopping to reverse rotation, but the reverse rotation of the rotation support plate is prevented by the operation of a one-way clutch provided on the outer surface of the frame side rotation support plate. Therefore, the driving force of the crank arm is transmitted to the internal gears through the sun gears by causing each planetary gear to rotate in the direction of the arrow. That is, the driving force of the crank arm is transmitted to the chain via the sprocket of the driven rotor in proportion to the number of teeth of the sun gear and the internal gear. The reduction ratio in this example is 1:1/2
．． It is 5.

[0007]

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings (see Figs. 1 and 2). In the drawing, 1 is the main pipe of the bicycle frame, 2 is the vertical pipe, 3 is the chainstay, 4 is the hanger pipe, and 5 is the main pipe of the bicycle frame. A crankshaft is pivotally supported on a hanger pipe 4 by a ball bearing 5a and a bearing one 5b, a crank arm 6 is fitted onto the crankshaft 5 and fixed with a washer 5d and a nut 5c, and a sun gear 7 is integrally fitted to the crank arm 6. , 8 and 9 are planetary gears, 15 is a driven rotating body having a sprocket 14 formed on the outer periphery of an internal gear 13, and 11 and 1 are planetary gears.
2 is a rotation support plate.

A pair of planetary gears 8 and 9 are rotatably disposed on the same circumference of the sun gear 7, which is integrally fitted into the crank arm 6, and divided into three or more equal parts. In the embodiment, the sprocket 14 is placed on the outer periphery of the internal gear 13.
A driven rotating body 15 having a shape formed therein is disposed around the outer periphery of the planetary gears 8 and 9. Each of these gears meshes with a corresponding gear, and rotatable support plates 11, 1 on both sides thereof.
2 to be pivoted and clamped. The rotation support plates 11 and 12 have bearing rings 11a and 12a provided on their inner surfaces, and bearing rings 11b provided on both sides of the sun gear 7 driven rotating body 15.
Ball bearings 11c and 12c are inserted between 12b, and a shaft 10 and countersunk screw 1 rotatably support planetary gears 8 and 9.
It is clamped and fixed at 0a.

A one-way clutch 16 is provided between the frame side rotation support plate 11 and the tip of the hanger pipe 4 (FIG. 3).
, 4). 16a is a ratchet formed on the outer surface of the frame side rotation support plate 11, 16b is a ratchet 16a
A claw 16 provided at the tip of the hanger pipe 4 so that it can be freely engaged and detached from the hanger pipe 4.
C is a coil spring that urges the pawl 16b to engage with the ratchet 16a. These ratchets 16a,
One-way clutch 1 is activated by pawl 16b and coil spring 16c.
6 is formed to prevent reverse rotation of the rotation support plates 11 and 12. The one-way clutch may also be of other configurations.

A ball lock 17 mechanism is provided between the base of the crank arm 6 and the crank arm rotation support plate 12. 1 and 2, 17a is a lock hole provided at several locations (one location in this embodiment) on the outer surface of the crank arm side rotation support plate 12, 17b is a ball that can be freely fitted into and detached from this lock hole 17a, and 17c is a A coil spring energizes the ball 17b to fit into the lock hole 17a; 17d is an adjustment screw that adjusts the strength of the coil spring 17c; and the locking pressure when the ball lock 17 is fitted into and removed from the lock hole 17a due to the above configuration. Adjust. The locking mechanism may be of other configurations.

[0011] In the bicycle automatic transmission device having the above configuration, each gear meshes with the corresponding gear and rotates as a unit as the road load of the bicycle increases or decreases, and the driving force of the crank arm is applied to the sprocket in a 1:1 ratio. An automatic bicycle transmission device that transmits deceleration power proportional to the number of teeth of the sun gear and internal gear to the chain via the sprocket, by stopping the rotating support plate and rotating the planetary gear. It is.

0012

Effects of the Invention According to the above configuration, the present invention arranges planetary gears on the same circumference around a sun gear integrated with the crank arm, and arranges a driven rotary body around the outer circumference of the planetary gears. It has a simple structure in which the bicycle is pivoted and clamped, and the gear changes automatically depending on the increase or decrease in the bicycle's road load. It provides the excellent effect of automatic shifting that is not available in conventional transmission devices. In addition, since each gear has a double-supported structure, the transmission efficiency of each gear is excellent, and the entire device can be made into a thin structure with reasonable strength. Therefore, it is easy to manufacture and has excellent durability.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view of the present invention.

FIG. 2 is a sectional view taken along line 1F-F of the present invention.

FIG. 3 is an enlarged top view of the one-way clutch section of the present invention.

FIG. 4 is a sectional view taken along line 3D-D of the present invention.

FIG. 5 is a diagram showing the rotation direction of each gear during deceleration according to the present invention.

[Explanation of symbols]

1 Main pipe of bicycle frame 2. Vertical pipe 3 Chain stay 4 Hanger pipe 5 Crankshaft 6 Crank arm 7 Sun gear 8, 9 Planetary gear 10 axis 11 Frame side rotation support plate 12 Crank arm side rotation support plate 13 Internal gear 14 Sprocket 15 Driven rotating body 16 One-way clutch 17 Ball lock mechanism 18 Chen

Claims (1)

[Claims] Claim 1: Centering around a sun gear that is integrally fitted into the crank arm, a set of two planetary gears are rotatably arranged on the same circumference, divided into three or more equal parts, and an internal gear. A driven rotating body having a sprocket formed on its outer periphery is arranged on the outer periphery of the planetary gear, and each of these gears meshes with a corresponding gear, and is pivotally supported and sandwiched between rotatable rotation support plates on both sides thereof. ing. A one-way clutch is provided between the outer surface of the frame-side rotation support plate and the tip of the hanger pipe to prevent reverse rotation of the rotation support plate. An automatic bicycle transmission device that allows the timing of gear changes to be adjusted using a lock mechanism provided between the outer surface of the crank arm side rotation support plate and the crank arm.