JP2002046684A - Power assisted bicycle with speed change gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power assisted bicycle with a speed change gear which can realize a small and light automatic speed change gear peripheral device and requires no exchange of a battery. SOLUTION: A bicycle provided with a speed change gear 1 for changing speed ratio, and a mechanism assisting a driving force of a driver, comprises a battery 2 for power assist, an assist motor 3 driven by the battery 2, a speed change gear driving portion 4 for driving the speed change gear 1, a control unit 5 for controlling the speed change gear driving portion 4 and the assist motor 3, so that power for the assist motor 3 and the speed change gear driving portion 4 are supplied by the battery 2 for power assist.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric assist bicycle with a transmission.

[0002]

2. Description of the Related Art In recent years, various types of bicycles have been proposed which can be driven more comfortably by automatically controlling a transmission of the bicycle.

[0003] Such an automatic transmission system is, for example, shown in FIG.
The chain stay 27 is connected to an internal transmission 26 provided on the rear wheel hub of the bicycle as shown in FIG.
The following device is built in the inside of the housing 20 attached to the device.

A motor 21 for driving a slider (not shown) of the internal transmission 26 is provided inside the housing 20.
A gearbox 22 for reducing the rotation of the motor 21, a control board 23 for controlling the rotation of the motor 21 according to the running state of the bicycle, a battery 24 for supplying power to the control board 23 and the motor 21, and the number of rotations of the wheels. A sensor 25 for detecting is provided. As described above, all the devices necessary for the automatic transmission, including the power supply, are housed in the housing.

On the other hand, bicycles in which the pedaling force of a bicycle driver is assisted by an electric motor (for example, assisting as much as human power) have become widespread. As this power source, a relatively large battery of about 3 amps is generally used, and a secondary battery such as a nickel-metal hydride battery is generally mounted behind the saddle.

[0006] Although the electric assist bicycle is equipped with a manual transmission of about three steps, even when the above-mentioned automatic transmission is combined, it is necessary to provide independent batteries including a power supply.

[0007]

As described above, in the above-described conventional apparatus, when a bicycle is to be equipped with both the electric assist function and the automatic shifting function, even if the bicycle has the electric assist function in advance. Since a battery for the transmission is required separately, there are the following inconveniences.

That is, in the conventional apparatus, since a battery is required for each mechanism, it is inevitable that the overall size becomes large and the weight increases. Furthermore, a primary battery such as an alkaline battery is used as the power source of the transmission due to the availability, but there is a problem that the operation is likely to be slow or uncertain due to the consumption of the battery. When the battery is exhausted, it is necessary to replace it. However, the cost of the battery increases, and some bicycle users are not accustomed to replacing the battery. There is also.

The present invention has been made in view of the above circumstances, and provides an electric power assisted bicycle with a transmission that can reduce the size and weight of peripheral devices of an automatic transmission and does not require replacement of a battery. The task is to

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned technical problems, the present invention has an electric assist bicycle with a transmission as follows.

That is, in the first configuration, in a bicycle including the transmission 1 for changing the speed ratio and the electric assist mechanism for assisting the driving force of the driver, the electric assist battery 2 and the battery 2 The vehicle includes an assist motor 3 to be driven, a shift drive unit 4 for driving the transmission 1, and a control unit 5 for controlling the shift drive unit 4 and the assist motor 3. It is configured to supply the electric power of the speed change drive unit 4.

Further, in the second configuration, a housing 6 accommodating only the shift drive unit 4 is provided in the transmission 1, and electric power for the shift drive unit 4 is supplied from the electric assist battery 2. . Hereinafter, important components of the present invention will be further described.

[Transmission 1] The transmission 1 is preferably of an internal type, but may be of an external type. In the case of the interior type, a shift rod pin is provided at the center of the hub of the rear wheel, and shifting is performed by sliding the rod pin.

[Electric Assist Battery 2] The electric assist battery 2 is preferably a secondary battery (rechargeable) of about 3 to 5 amps, such as a nickel hydrogen battery, a nickel cadmium battery, a lithium battery, a fuel cell, Lead batteries and the like can be used. It is desirable that this battery can be easily removed from the vehicle body and can be charged indoors.

[Assist motor 3] The assist motor 3 is a motor that propels the bicycle, is connected to the pedal crank, and has a structure in which a speed reducer is interposed.

[Shift drive unit 4] The shift drive unit 4 is a device for driving the transmission 1, and is composed of a motor and a speed reducer. Further, a shift sensor for detecting the shift position of the transmission 1 can be provided.

[Control Unit 5] The control unit 5 controls the amount of assist (output of the assist motor 3) and the speed change (change in the speed ratio between the output shaft and the input shaft). This is for performing selection (setting of the assist amount according to the pedal depression force) and shifting in conjunction therewith.
Specifically, an MPU (MICRO P
ROCESSING UNIT), Memory (RAM:
RANDOM ACCESS MEMORY / ROM:
READ ONLY MEMORY) and a power control circuit are arranged on an epoxy substrate. The installation location of the control unit 5 is preferably near the battery 2.

[Case 6] The case 6 is a case of the speed change drive unit 4, and is formed of a synthetic resin in a box shape. this,
It has a structure that can be fixed to the chain stay or seat stay by screws. The shock resistance may be improved by pouring a synthetic resin or the like into the space inside the housing 6.

As described above, since the housing 6 accommodates only the speed change drive unit 4 including the motor and the speed reducer, the power supply is shared with the electric assist, so that the entire apparatus can be reduced in weight and size. And the number of parts can be reduced and the cost can be reduced.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electric assisted bicycle with a transmission according to the present invention will be described in more detail with reference to the embodiments shown in FIGS.

In FIG. 2, a bicycle 10 having an electric assist function for assisting a driving force (pedal pressing force) of a driver is provided with an internal transmission 1 for changing a speed ratio. Further, behind the saddle 11, that is, between the seat post 12 and the rear fender 13, a battery 2 for electric assist and a control unit 5 for controlling the amount of assist and shifting are provided.

The pedal 14 of the bicycle 10 is provided with a torque sensor 15 composed of a strain gauge or the like, so that data for determining an assist amount can be obtained.

The pedal 14 is connected to the assist motor 3 to assist the driving force. On the other hand, a rotation speed sensor 17 is provided on the rear wheel 16, and the output is input to the control unit 5.

The control unit 5 controls the assist motor 3. The bicycle 10 is provided with an internal transmission 1, and the transmission 1 is connected to a transmission 4. The shift drive unit 4 is configured to be switched by the control unit 5.

As shown in FIGS. 3 and 4, the speed change drive unit 4 has a structure in which a motor 4a and a speed reducer 4b are connected inside a housing 6, and the speed reducer 4b and the speed change device 1 are connected. Has become. The housing 6 is provided with a mounting hole 6a, and a screw (6b) is attached to the chain stay 10a of the bicycle 10.
It has been stopped.

As shown in FIG. 4, the reduction gear 4b is provided with a rack gear on a rod pin 1a protruding from the transmission 1, and has a wide flat gear 4f meshing with the rack gear.
And a worm gear 4e provided on a shaft of the motor 4a is meshed with a flat gear 4f. Then, when the motor 4a is rotated, the spur gear 4f is rotated, and the rod pin 1a is moved in the insertion / removal direction to operate the gear shift.

It should be noted that the rod pin 1a has three stages (3
(In the case of a step shift), the shift sensor 4 for detecting the shift position of the transmission 1 is required.
c is provided. This shift sensor 4c has a structure in which electric contacts (not shown) are provided at three places, and a brush for contacting the electric contact with the rod pin 1a is provided. It should be noted that the shift sensor can of course be one using an optical sensor or a magnetic sensor.

The housing 6 is fixed to the chain stay 10a via a Ω-shaped bracket 4g. A cord 4d extending from the motor 4a and the shift sensor 4c extends from the housing 6, and is connected to the control unit 5.
The housing 6 has a volume less than half that of the housing of FIG.

As just described, the housing 6 accommodates only the speed change drive unit 4 including the motor 4a and the speed reducer 4b, so that it is possible to greatly reduce the size and weight, and reduce the number of parts and cost. Can also be achieved.

Further, since the power source is shared with the assist motor 3, it is not necessary to replace the battery, and a stable automatic shifting operation can always be performed. In addition, since the battery can be easily charged when the battery is exhausted, it is not necessary to replace the battery as in the related art, and the running cost can be reduced.

The power consumption of the automatic transmission is small, and the operation time is short, so that the load on the large-capacity electric assist battery 2 is not affected and the cruising distance is not affected.

[0032]

According to the electric assist bicycle with a transmission of the present invention, the power source for the automatic transmission is supplied from the battery for the electric assist, so that the battery for the automatic transmission is not required, and the transmission is provided. Peripheral devices can be significantly reduced in size and weight.

Further, since there is no need to replace the battery, there is no possibility that the operation will be impaired, and the performance of the automatic transmission mechanism can always be exhibited at its best.

[Brief description of the drawings]

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

FIG. 2 is a side view of the power-assisted bicycle with a transmission in the embodiment.

FIG. 3 is a perspective view showing an internal structure of a shift drive unit of the electric assist bicycle with a transmission in the embodiment.

FIG. 4 is a cross-sectional view showing an internal structure of a shift drive unit of the electric assist bicycle with a transmission according to the embodiment.

FIG. 5 is a perspective view showing a conventional automatic transmission for a power-assisted bicycle with a transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission 2 Battery for electric assist 3 Assist motor 4 Speed change drive part 5 Control part 6 Housing

Claims (2)

[Claims] 1. A bicycle comprising a transmission for changing a speed ratio and an electric assist mechanism for assisting a driving force of a driver, comprising: a battery for electric assist; an assist motor driven by the battery; And a control unit for controlling the shift drive unit and the assist motor, wherein the electric assist battery supplies power to the assist motor and the shift drive unit. Electric assist bicycle with transmission. 2. The transmission according to claim 1, wherein a housing accommodating only the shift drive unit is provided in the transmission, and power for the shift drive unit is supplied from a battery for electric assist. Electric assist bicycle with transmission.