JPH03200498A - Auxiliary drive unit for bicycle - Google Patents

Abstract

PURPOSE:To improve practicability by transmitting the rotation of a secondary battery driving D.C. motor to a speed reducer by a flexible shaft, and transmitting the rotation of the speed reducer to a rear wheel through gears and a chain to perform travel. CONSTITUTION:On a slope or the like, a switch 21 provided at a handle bar 22 is put on to rotate a D.C. motor 5 by the electric power of a secondary battery 1. This rotation is transmitted to a speed reducer 9 by a driving shaft 6 and a flexible shaft 8. The rotating speed reduced at the speed reducer 9 is transmitted to an axle 16 through an output shaft 11, a gear 19, a chain 20 and a gear 18. The driving force of a motor 5 is thereby added to the driving force obtained by the stepping-in of a pedal to enable smooth running even on the slope or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for assisting foot pedal drive when riding a bicycle on a slope or in a headwind.

Conventional technology A conventional auxiliary drive device for a bicycle consists of a battery attached to the body of the bicycle, a DC motor operated by the battery, and a gear attached to the drive shaft of the motor, which drives the freewheel. An application has been filed and known for a type of device (Japanese Unexamined Patent Application Publication No. 63-263189).

Problems to be Solved by the Invention However, such prior art is based on the assumption that the battery has a large output and the drive motor has a large torque, so it is difficult to achieve energy efficiency in order to actually use it as an auxiliary drive means. There is one problem in terms of energy consumption and energy consumption, and it is difficult to drive.

SUMMARY OF THE INVENTION In view of the drawbacks of the prior art, it is an object of the present invention to provide an auxiliary drive device suitable for use in practice.

A means for solving the problem, that is, the present invention, is to connect a large gear pivoted to a frame and a self-driving freewheel attached to an axle supporting the rear wheel via a power transmission means such as a chain. In a bicycle configured to be interlocked, a secondary battery attached to the frame and the secondary battery! A DC motor connected to the pond via a conductor, a flexible shaft connected to the drive shaft of the DC motor, a reducer connected to the output shaft of the flexible shaft, and a gear attached to the reducer. It consists of a motor-driving freewheel attached to an axle that supports the rear wheels, connected by a power transmission means such as a chain, and the drive of the DC motor can be turned on or off by operating a switch.
This object is achieved by a bicycle auxiliary drive configured to be turned off.

The DC motor used has an output of 150 to 11110
W1 rotation speed 2.600 to 3.600 times/min, torque 7
kg/ctn or higher.

Further, the speed reducer used has a speed reduction ratio of about 1:15 to 1:20.

The secondary battery used is one used in car batteries, such as a lead-acid battery.

When the operation switch is turned on, power is supplied from the secondary battery to the DC motor, which starts rotating at, for example, 3,600 times/minute.

As the motor rotates, power is transmitted to the reduction gear via the flexible shaft.

When the reduction ratio is 1:20, the output shaft of the reducer is 180
The rotational speed is 1/min, and the power is transmitted to the freewheel for driving the motor via the gear and power transmission means mounted on the shaft.

This freewheel rotates the axle, which causes the bicycle to move forward.

Embodiments The present invention will be explained in detail below with reference to embodiments shown in the drawings.

FIG. 1 is a side view showing an embodiment in which an auxiliary drive device according to the present invention is installed, in which a secondary battery l used for a car battery is installed in the carrier of a bicycle. The secondary battery 1 is connected to a conductor 3 by a connector 2, and the other end of the conductor 3 is attached to a down tube 4 of the frame with an output of 150 to 180W, a rotation speed of 2.600 to 3.600
DC motor 5 with torque 7kg/c'IT1 or more
is connected to. The drive shaft 6 of the motor 5 is a universal joint 7
It is connected to the input shaft of a flexible shaft 8 via a, and the output shaft of the flexible shaft 8 is connected to the input shaft 10 of the speed reducer ls9 via a universal joint 7b.

The reducer 9 has a reduction ratio of about 1:15 to 1:20, and the chain stay 12 and back hawk 13
The output shaft 11 is joined to a fan-shaped plate 14 joined therebetween so as to be parallel to the axle 16 of the rear wheel 15.

As a result, the rotational speed of the output shaft 11 of the reducer 9 (130~
180 times/min.

The output shaft 11 of the reducer 9 is equipped with a gear 17 for human power driving of one wheel (attached to the axle 16) and a gear 1 for driving the motor.
A gear 19 having substantially the same number of teeth as 8 is connected, and the gear 19 and the gear 18 mounted on the axle 16 are configured to interlock with each other via a power transmission means 20 such as a chain.

Reference numeral 21 denotes a switch that is connected to the handlebar 22 via a wire (not shown) and turns the DC motor 5 on and off.

In the configuration described above, in the device according to this embodiment,
When the switch 21 attached to the bundle bar 22 is turned on on a slope or when there is a headwind, the motor 5 starts rotating by receiving power from the secondary battery 1, and the drive shaft 6. Rotation is transmitted to the speed reducer 9 via the flexible shaft 8.

The output shaft 11 of the reducer 9 is in a state where the rotation speed is lowered to a rotation ratio of 1:15 to 20. Gear 19. Chain 20. As a result of power being transmitted to the axle 16 via the gear 18, smooth running is possible due to the drive by the driver's pedal depression and the drive from the motor 5.

In this embodiment, it is possible to achieve a speed of about 251 mph/see on a flat road without using manual drive.

Also flexible shaft 8. Reducer9. Universal joint 7
Since it is configured to transmit rotational force using elements a, 7b, etc., the energy transmission efficiency is extremely high.

Furthermore, the rotation speed of the motor 5 is reduced using the reducer 9,
Since it is configured to increase torque, there will be no shortage of torque even on slopes.

When the switch 21 is turned off, power is no longer transmitted from the motor 5 to the gear 18 of the axle 16.

Since the gear 18 is constituted by a freewheel, the gear 18 does not rotate and does not affect foot drive.

In this embodiment, the flexible shaft 8 is configured to be exposed, but considering the safety of the driver, it is preferable to cover it with a cover.

Effects As described above, the auxiliary drive device according to the present invention can achieve running of a bicycle by driving a motor, which was not possible with conventional devices, and therefore its utility value is extremely high.

Further, since the power transmitted from the DC motor is configured to be efficiently transmitted by the flexible shaft and the universal joint, the transmission efficiency can be increased.

[Brief explanation of drawings]

1 and 2 show an embodiment of the auxiliary drive device according to the present invention. FIG. 1 is a side view of a bicycle equipped with the auxiliary drive device, and FIG. 2 is a diagram showing the transmission of power to the axle. FIG. 3 is a partially omitted rear view showing the state. 1... Secondary battery 2... Connector 3...
Conductor 4... Down tube 5... DC motor 6... Drive shaft 7... Universal joint 9... Reducer 11... Output shaft 13... Back hawk 15... Rear wheel 17...Manpower drive gear 19...Gear 21...Handlebar 8...Flexible shaft 10...Input shaft 12...Chain stay 14...Plate 16...Axle 18...・Motor drive gear 20...power transmission means

Claims (2)

[Claims] (1) In a bicycle configured to link a large gear attached to the frame and a self-driving freewheel attached to an axle supporting the rear wheel via a power transmission means such as a chain, A secondary battery attached to the frame,
A DC motor connected to the secondary battery via a conductive wire, a flexible shaft connected to the drive shaft of the DC motor, a speed reducer connected to the output shaft of the flexible shaft, and a speed reducer connected to the speed reducer. A freewheel for driving a motor attached to an axle supporting the rear wheel is connected to a gear for driving the motor by a power transmission means such as a chain, and the drive of the DC motor is turned on and off by operating a switch. An auxiliary drive device for a bicycle, characterized in that it is configured to: (2) The auxiliary drive device for a bicycle according to claim 1, wherein the input shaft and/or the output shaft of the flexible shaft are connected via a universal joint.