JP2000238675A - Motor-driven bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor-driven bicycle capable of reducing a number of parts to reduce the cost and a weight, and superior in the appearance design. SOLUTION: This motor-driven bicycle comprises a battery 12, and a power unit 13 including an electric motor 14 operating by receiving the supply of electric power from the battery 12. On this occasion, the battery 12 and at least a part of the electric motor 14 are built in a down tube 7 extending from a head pipe 2 to a rear part of a bicycle body. As the battery 12 and at least a part of the electric motor 14 are built in the down tube 7, a cover and the like for covering a battery box for accommodating the battery 12 and the power unit 13, becomes unnecessary, and a number of parts is reduced, whereby the cost can be reduced, and a weight is lightened. Further as the battery 12 and a part of the electric motor 14 are not exposed to the external, the apperance of the motor-driven bicycle becomes smart, and the design of the motor-driven bicycle can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric bicycle equipped with a power unit including a battery and an electric motor that operates by receiving electric power from the battery.

[0002]

2. Description of the Related Art In recent years, electric bicycles have been proposed and put into practical use. The electric bicycle supplements the driving force of human power with an auxiliary power of an electric motor. It is indispensable to mount a power unit including an electric motor that operates by receiving supply of power from a battery.

[0003] By the way, in a conventional electric bicycle,
The battery and the power unit were mounted on a body frame or the like.

[0004]

However, if the battery and the power unit are supported on the body frame or the like as in the prior art, they are not only disadvantageous in terms of design because they are visible, but also a battery box or a power unit for accommodating the battery. A cover or the like that covers the device is required, and the number of parts increases, so that disadvantages in terms of cost and weight cannot be avoided.

The present invention has been made in view of the above problems, and an object thereof is to provide an electric bicycle which can reduce the number of parts, reduce cost and weight, and is excellent in external design. To provide.

[0006]

According to one aspect of the present invention, there is provided a power unit including a battery and an electric motor that operates by receiving power supplied from the battery. In the electric bicycle according to the present invention, at least a part of the battery and the electric motor is incorporated in a down tube extending rearward from the head pipe to the vehicle body.

According to a second aspect of the present invention, in the first aspect, at least a part of the electric motor is screwed into a rear end opening of the down tube.

Therefore, according to the present invention, since the battery and at least a part of the electric motor are incorporated in the down tube, a battery box for storing the battery, a cover for covering the power unit, and the like are not required. Points can be reduced, and cost and weight can be reduced.

In addition, since the battery and the electric motor are not entirely exposed to the outside, the appearance of the electric bicycle is clear, and the electric bicycle can be excellent in design.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of an electric bicycle according to the present invention,
FIG. 2 is a cutaway side view of the essential part of the electric bicycle, and FIG. 3 is a cross-sectional view of the down tube with the battery taken out.

In the electric bicycle 1 shown in FIG. 1, reference numeral 2 denotes a head pipe located at an upper front portion of a vehicle body, and a steering shaft 3 is rotatably inserted into the head pipe 2. A steering wheel 4 is attached to an upper end of the steering shaft 3, an upper end of a pair of left and right front forks 5 is attached to a lower end of the steering shaft 3, and a front wheel 6 is rotatably mounted to a lower end of the front fork 5. Supported.

A large-diameter round pipe-shaped down tube 7 extends obliquely downward toward the rear of the vehicle body from the head pipe 2, and a seat stay 8 extends from the middle of the down tube 7 to the rear of the vehicle body. It extends substantially horizontally toward the front. A seat tube 9 is fixed to a rear end of the seat stay 8, and a seat post 10 is fitted and held in the seat tube 9 so as to be vertically movable, and a saddle 11 is attached to an upper end thereof. I have.

In this embodiment, the battery 12 and a part of the electric motor 14 of the power unit 13 are incorporated in the down tube 7.

The power unit 13 has a drive system using human power and a drive system using an electric motor 14 arranged side by side.
This includes the electric motor 14, controller 15, treading force detecting means (not shown), and the like.

In the power unit 13, as shown in detail in FIG. 2, the electric motor 14 is erected in a forwardly inclined state, and a male screw 14a is engraved on the outer periphery thereof. The top of the electric motor 14 is fitted into the rear end opening of the down tube 7,
A part of the electric motor 14 is incorporated into the down tube 7 by screwing a male screw 14 a formed on the outer periphery into a female screw 7 a formed on the inner periphery of the rear end of the down tube 7. Is attached to and supported by the rear end of the down tube 7.

As shown in FIG. 3, an opening 7b is provided at one side of the intermediate portion except for the front end and the rear end of the down tube 7.
Is formed, and a rectangular storage space S is formed by three plates 16 therein. A damper 17 made of an elastic material is attached to the inner surface of each plate 16.

On the other hand, the battery 12 is formed by stacking a plurality of rechargeable rechargeable batteries 12a in a case 12b in two upper and lower stages. One end of the case 12b is connected to the outer peripheral surface of the down tube 7. An arc-shaped cover member 18 is attached.

The battery 12 is connected to the down tube 7.
The battery 12 taken out of the down tube 7 as shown in FIG. 3 is inserted into the storage space S in the direction of the arrow shown in FIG. 7 and removed from the down tube 7 by pulling out in the opposite direction. When the battery 12 is housed in the housing space S in the down tube 7 and assembled, the battery 12 is protected from vibration by the vibration absorbing action of the damper 17 and the lid member 18 is connected to the down tube 7 continuously. Connected to the down tube 7
A part of.

As shown in FIG. 1, a front end portion of a rear arm 19, which is bent and formed in a letter shape as viewed from the side, is pivotally attached to the power unit 13 by a pivot shaft 20 so as to be vertically swingable. A rear wheel 21 is rotatably supported at the rear end of the rear arm 19. A rear cushion 23 is interposed substantially horizontally between the bracket 22 provided between the down tube 7 and the seat stay 8 and the bent portion of the rear arm 19, and the rear cushion 23 is Rear wheel 2 supported by
1 is suspended from the vehicle body.

The power unit 13 has a lateral direction (FIG. 1).
Are supported rotatably, and cranks 25 (only one is shown in FIG. 1) are attached to the left and right ends of the crank shaft 24, respectively. A pedal 26 is pivotally supported at the end.

A large-diameter drive sprocket 27 is mounted on the crankshaft 24, and an endless endless sprocket is provided between the drive sprocket 27 and the small-diameter wheel sprocket 28 mounted on the rear wheel 21. A chain 29 is wound. The chain 29 is given a predetermined tension by tensioners 30 and 31.

The pedaling force of the rider while the electric bicycle 1 is traveling is detected by a pedaling force detecting means (not shown) built in the power unit 13, and a detection signal is input to the controller 15. Then, the controller 15
Supplies electric power according to the magnitude of the pedaling force from the battery 12 to the electric motor 14. Accordingly, the electric motor 14 generates auxiliary power according to the pedaling force and outputs the auxiliary power to the crankshaft 24. As a result, the crankshaft 24 is rotationally driven by both the pedaling force and the auxiliary power, and the rotation is transmitted to the rear wheel 21 via the drive sprocket 27, the chain 29, and the wheel sprocket 28, and the rear wheel 21 is rotationally driven to be electrically driven. The bicycle 1 is run. As described above, in the electric bicycle 1, the driving force of the rear wheel 21 is supplemented by the auxiliary power of the electric motor 14, so that the physical load on the rider is reduced by that much.

When the battery 12 is charged because the voltage of the battery 12 has dropped due to the use, the battery 12 is moved from the down tube 7 as described above.
Can be easily taken out and charged. When the charging of the battery 12 is completed, the battery 12
Is incorporated in the down tube 7 in the manner described above, the battery 12 can be used again.

In the above, in the present embodiment, since the battery 12 and a part of the electric motor 14 of the power unit 13 are incorporated in the down tube 7, a battery box for storing the battery 12 and the power unit 13 are provided.
This eliminates the need for a cover or the like, thereby reducing the number of parts, thereby reducing costs and weight.

Further, since the battery 12 and the electric motor 14 are not entirely exposed to the outside, the appearance of the electric bicycle 1 is clear, and the electric bicycle 1 can be excellent in design.

In the present embodiment, the power unit 1
Although only part of the electric motor 14 is incorporated in the down tube 7, the entire electric motor 14 may be incorporated in the down tube 7.

[0028]

As is apparent from the above description, according to the present invention, an electric motor including a battery and a power unit including an electric motor that operates by receiving power supplied from the battery is mounted. In a bicycle, since the battery and at least a part of the electric motor are incorporated in a down tube extending from the head pipe to the rear of the vehicle body, the number of parts can be reduced to reduce cost and weight, The effect is obtained that the appearance of the bicycle is clear and the electric bicycle can be made excellent in design.

[Brief description of the drawings]

FIG. 1 is a side view of an electric bicycle according to the present invention.

FIG. 2 is a cutaway side view of a main part of the electric bicycle according to the present invention.

FIG. 3 is a cross-sectional view of a down tube with a battery taken out.

[Explanation of symbols]

 Reference Signs List 1 electric bicycle 2 head pipe 7 down tube 12 battery 13 power unit 14 electric motor

Claims (2)

[Claims] 1. An electric bicycle including a battery and a power unit including an electric motor that operates by receiving power supplied from the battery, wherein a down tube extending rearward from a head pipe to a vehicle body. An electric bicycle, wherein the battery and at least a part of the electric motor are incorporated in the electric bicycle. 2. The electric bicycle according to claim 1, wherein at least a part of the electric motor unit is screwed into a rear end opening of the down tube.