JP2002053089A - Transmission device for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start a transmission device of a motor-driven chain-changing type bicycle from the minimum displacement having low load in starting by saving a changing step by removing a battery. SOLUTION: A hub generator for illumination is used in stead of a battery, and a power supply unit connected to a capacitor through a rectifier is used. A signal transmitted from a brake sensor when braking is applied is processed by a controller, and the position is shifted to the minimum speed position and held.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle gear shifting device.

[0002]

2. Description of the Related Art FIGS. 3 and 4 show transmissions used in bicycles. The conventional method and principle will be described with reference to FIGS. A hanger 3 for holding a crankshaft 2 is attached to a body frame 1, and a foot pedal and a large and small chain ring are fixed to the crankshaft 2. Two large and small chain rings (also referred to as gears) 22 and 2 fixed to the crankshaft 2
This is a system in which high-speed and low-speed switching can be performed by replacing the chain 3 with the chain 24. A shift switch 7 is attached to a steering wheel and commands a set value at the time of shifting. 8
Is usually a DC motor. For example, when a positive voltage is applied, the motor rotates forward and changes the gear from small to large.
When a negative voltage is applied, the gear rotates in the reverse direction, and the gear is changed from large to small for shifting. Chain 24 is the chain guide 2
5 by shifting the position of the chain ring 22.
And 23 can be replaced. In some practical vehicles, four-stage chain rings (gears) can be used for four-stage shifting instead of two-stage chain rings (gears).

[0003] A chain guide 25 is a spur gear (not shown) that is a component of the reduction mechanism 10 in the power unit 12.
The rack gear 20 meshes with the extending portion of the rack gear 20.
A rotation angle sensor 11 is attached to the spur gear, and detects the amount of displacement of operation and stop of the motor, and operates the controller 9 in cooperation with the shift switch 7. The controller comprises signal processing means including a microcomputer and a driver for controlling motor driving power, and is mounted on the vehicle body frame 1. The power unit 12 is composed of the motor 8 and the speed reduction mechanism 10 and converts the motor power into linear motion, and operates so that the amount of the motion shifts only between the positions of the chain ring.

As a power source of the motor 8, four batteries 32 are housed in a battery holder 31 mounted on the vehicle body frame 1. The battery, which is a consumable, must be checked and replaced, which is troublesome and inconvenient. A motor power source without a battery was desired.

[0005]

When a hub generator mounted on a front wheel or rear wheel hub is used for lighting without using a battery as a power source of the motor, power generation is stopped at the same time as running is stopped. In this case, the position of the shift switching is waiting just before the stop. In some cases, the vehicle is waiting at the high-speed position instead of at the low-speed position, and attempts to start running in this state. SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery-free transmission that can be run lightly at a low speed position when starting.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems, and has been developed from a small-diameter chain ring (gear) having a small number of teeth to a large-diameter chain ring (gear) having a large number of teeth. In order to switch from low speed to high speed by changing the chain sequentially in several stages, the chain rings are arranged in order from small diameter to large diameter so that the chain can be changed in the opposite direction, and fixed to one axis A crank with a foot pedal is fixed to the shaft. The change of the chain to the transmission gear having such a configuration is performed by shifting the position of the chain guide, but the rotational force of the motor is converted into linear motion to shift the position of the chain guide. A transmission device for shifting the bicycle speed as described above, comprising a power unit having a motor for shifting the position of the chain guide, a controller for controlling the motor, and a shift switch for selecting the position of the chain guide. Transmission, comprising a brake sensor for detecting operation of a brake lever, a hub generator provided on a wheel hub, a rectifier for rectifying the output of the hub generator, and a power supply unit including a capacitor for smoothing the rectified output. are doing.

As a power source of the motor, a hub generator mounted for lighting is also used, and a capacitor is connected via a rectifier. And the capacitor is constantly charged.

When the controller receives a brake sensor output signal generated when the brake is operated, the motor is driven by the energy stored in the capacitor in the power supply unit even if the hub generator stops generating power. The control signal processing means in the controller operates so as to switch the speed to the high speed position.

[0009]

1 is a block diagram showing the concept of the present invention, and FIG. 2 is a front view and a side view of a main part of a transmission. In this figure, reference numeral 1 denotes a vehicle body frame, in which an upper portion is provided with a saddle, and a lower portion is provided with a hanger 3 for holding a crankshaft 2. The crankshaft 2 has a plurality of chain rings (gears) 22 and 23 having different numbers of teeth. It is fixed in the order of the size, and a crank with a foot pedal is also attached. When the chain is wound around a gear having a small number of teeth and a small number of teeth, the speed is changed to a low speed, and for a large diameter having a large number of teeth, the speed is changed to a high speed.

The luminaire 4 is connected to a hub generator 6 via a switch 5, and the hub generator is installed in a front wheel or rear wheel hub. The hub generator 6 branches its output and is connected to a capacitor 14 via a rectifier 13, and these constitute a power supply unit and constitute a power supply unit.
Supplies the peak current value to the motor 8 while being charged.

Now, while the bicycle is running, the shift switch 7
As a result, the position of the chain guide 25 is shifted by the power of the power unit 12, and the speed is changed. This mechanism is based on the motor 8 which is a component of the power unit 12.
The chain guide 25 is formed at the extension of the rack gear 20 that meshes with the last stage spur gear (not shown) of the speed reduction mechanism 10 to which the motor power is converted into linear motion. shift.

In the above control, a rotation angle sensor 11 is attached to a spur gear, which is a component of the speed reduction mechanism 10, to detect the displacement of the operation of the motor and to stop the motor, and to cooperate with the shift switch 7. The controller 9 is operated. The controller 9 comprises a control signal processing means 16 containing a microcomputer or the like and a driver 17 for controlling the motor drive power, and operates so as to shift only between positions designated by the shift switch 7 during running. . When the brake is operated by the brake lever 18, the output signal of the brake sensor 19 is transmitted to the control signal processing unit 16.
Is operated to shift to the lowest speed position, and the chain guide 25 stands by at the lowest speed position.

[0013]

According to the bicycle transmission of the present invention, the bicycle is shifted to the lowest speed position in conjunction with the brake operation while the bicycle is running, so that a light bicycle start that does not require a large torque can be obtained. Also, the hub generator can be miniaturized because the capacitor bears the peak current value to the motor. Moreover, since a troublesome battery is not required, it is convenient and contributes to resource saving, and has a large industrial value.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an embodiment of a bicycle transmission according to the present invention.

FIG. 2 is a front view and a side view of main parts of the transmission shown in FIG. 1;

FIG. 3 is a block diagram of a conventional bicycle transmission.

FIG. 4 is a front view and a side view of a main part of the transmission of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body frame 2 Crankshaft 3 Hanger 4 Lighting equipment 5 Switch 6 Hub generator 7 Shift switch 8 Motor 9 Controller 10 Reduction mechanism 11 Rotation angle sensor 12 Power unit 13 Rectifier 14 Capacitor 15 Power supply unit 16 Control signal processing means 17 Driver 18 Brake Lever 19 Brake sensor 20 Rack gear 22, 23 Chain ring (gear) 24 Chain 25 Chain guide 31 Battery holder 32 Battery

Claims (1)

[Claims] A power unit having a motor for shifting a chain guide, the power unit having a motor for shifting the chain guide, and controlling the motor. Sensor for detecting the operation of a brake lever, a hub generator provided on a wheel hub, and a hub generator provided on a wheel hub in a bicycle transmission having a shift switch for selecting a position of a chain guide. And a power supply unit comprising a rectifier for rectifying the output of the vehicle and a capacitor for smoothing the rectified output. When the controller receives a brake sensor output signal generated when a brake is operated, the controller in the power supply unit The motor is driven by the energy stored in the capacitor, Bicycle transmission, characterized in that the gear shift to the fast position.