JP2002019684A - Front wheel driving power-assisted bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a front wheel driving power-assisted bicycle capable of improving a cornering property and an operation property while it has a drive part on a front wheel. SOLUTION: A main frame 1 of a bicycle main body is connected to a head pipe 2 provided in a front part and a seat tube 3. A human power driving part is provided with a pedal 7, a crank 8, and a chain 9, and a motor built in a panellike casing 20 is driven at the same torque as human power driving force to rotate the front wheel 5. A handle angle detection means is attached to a handle post of the head pipe 2 linking a handle 12 to the front wheel 5, and a voltage signal is inputted in a control circuit in accordance with the detected handle angle to control an electric driving force of an assist motor in accordance with the handle angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric bicycle for assisting a human driving force by a motor driving force.

[0002]

2. Description of the Related Art Recently, both a human-powered drive unit and a motor-driven electric drive unit are provided, and a motor is driven in accordance with the magnitude of the manual drive force, and the human-powered drive force is assisted by the motor drive force. Electric bicycles are gaining in popularity.

Conventionally, as such an electric bicycle, a so-called rear-wheel drive type electric assist bicycle, in which a rear wheel is directly rotated by a motor, as proposed by the present applicant, is known. In addition, Japanese Patent Application Laid-Open No. 7-329873 and Japanese Patent Application Laid-Open
As disclosed in JP-A-150981 and JP-A-8-207875, there is also known one in which a drive unit is provided on the front wheel.

[0004]

However, in such a conventional electric bicycle having a driving portion on the front wheel, the driving portion is provided on the front wheel, so that the weight of the front wheel becomes heavy, and the weight of the front wheel is increased when the steering wheel is operated. The steering wheel was difficult to operate, the cornering was poor, and it was very difficult to ride. Also, since the assist ratio is the same even when the steering wheel is turned, the straightness is the same as when traveling straight because the electric driving force is generated,
There was a problem that turning in the direction was difficult.

Accordingly, an object of the present invention is to provide a front-wheel drive electric bicycle that can improve cornering and has good operability while having a driving portion on the front wheels, while solving the above-mentioned problems. .

[0006]

In order to achieve the above object, a front-wheel drive electric bicycle according to claim 1 of the present invention is provided.
A human-powered drive unit that transmits a manual drive force from the pedal to the rear wheel, an electric drive unit that uses a motor as a drive source in the front wheel unit, and has a handle angle detection unit; The electric driving force is controlled accordingly.

A front-wheel drive electric bicycle according to a second aspect of the present invention has a human-powered drive unit that transmits a manual drive force from a pedal to a rear wheel, and an electric drive unit that uses a motor as a drive source in the front wheel unit. And a steering wheel angle detecting means, wherein the electric driving force is controlled in accordance with the steering wheel angle detected by the detecting means, and the electric driving force is continuously controlled such that the larger the steering wheel angle, the smaller the electric driving force.

A front-wheel drive electric bicycle according to a third aspect of the present invention has a human-powered drive unit that transmits a manual drive force from a pedal to the rear wheel, and an electric drive unit that uses a motor as a drive source in the front wheel unit. A steering angle detecting means for controlling the electric driving force in accordance with the steering wheel angle detected by the detecting means, and controlling the electric driving force to decrease to a predetermined value when the steering wheel angle is turned to a predetermined value or more. did.

A front-wheel drive electric bicycle according to a fourth aspect of the present invention has a human-powered drive unit for transmitting a manual drive force from a pedal to a rear wheel, and an electric drive unit using a motor as a drive source in the front wheel unit. A steering angle detecting means for controlling the electric driving force in accordance with the steering wheel angle detected by the detecting means. When the steering wheel angle is cut to a predetermined value or more, the electric driving force is reduced to a predetermined value, and the steering angle is reduced. The control is continuously performed so that the electric driving force becomes smaller as the value becomes larger than the predetermined value.

According to a fifth aspect of the present invention, there is provided a front-wheel drive electric bicycle having a human-powered drive unit for transmitting a manual drive force from a pedal to a rear wheel, and an electric drive unit using a motor as a drive source in the front wheel unit. A potentiometer is provided as the steering wheel angle detecting means, and the electric driving force is controlled in accordance with the steering wheel angle detected by the detecting means.

A front-wheel drive electric bicycle according to a sixth aspect of the present invention has a human-powered drive unit for transmitting a manual drive force from a pedal to a rear wheel, and an electric drive unit using a motor as a drive source in the front wheel unit. A potentiometer is provided between the handle shaft and the frame as handle angle detecting means, and the electric driving force is controlled according to the handle angle detected by the detecting means.

Thus, in the front-wheel drive electric bicycle of the present invention, the output drive force of the electric drive unit is reduced when the angle is large due to the turning angle of the steering wheel, so that the output of the electric drive force is smaller than when the vehicle is traveling straight. Since the straightness is reduced, the steering operation can be easily performed.

A front-wheel drive electric bicycle according to a seventh aspect of the present invention has a human-powered drive unit for transmitting a manual drive force from a pedal to a rear wheel, and an electric drive unit using a motor as a drive source in the front wheel unit. A steering angle detecting means and a torque sensor for detecting a manual driving force of the manual driving section, the electric driving force is controlled in accordance with a steering angle detected by the steering angle detecting means, and a detection value of the torque sensor is controlled. The driving force of the electric driving unit is controlled by the driving force.

With this, in the front-wheel drive electric bicycle, the driving force of the electric driving unit is controlled by the driving force corresponding to the detection value of the torque sensor. An elastic body that expands and contracts according to the level of human power is provided between the plate fixed to the crank linked to the front and the front sprocket, and a torque sensor can be attached around the plate, making the configuration simple and unitizing the plate part Can be easily assembled.

The front-wheel drive electric bicycle according to claim 8 of the present invention has a human-powered drive unit for transmitting the manual drive force from the pedal to the rear wheel, and an electric drive unit using a motor as a drive source at the front wheel unit. A steering angle detecting means and a torque sensor for detecting a manual driving force of the manual driving section, the electric driving force is controlled in accordance with a steering angle detected by the steering angle detecting means, and a detection value of the torque sensor is controlled. Controlling the driving force of the electric drive unit with the driving force, and reducing the driving force,
The ratio of the electric driving force to the manual driving force is reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of an electric bicycle of a front-wheel direct drive type will be described below with reference to the drawings. FIG. 1 is an overall perspective view of an electric bicycle of a front-wheel direct drive type. In the drawing, the electric bicycle main body is provided with an electric drive unit by a motor described later. The driving force of the electric drive unit is changed to drive the vehicle by assisting the power of the human power by the power of the electric driving unit. The present invention is not limited to this type, but may be a type in which the driving force of the electric drive unit is changed by the operation of a user such as an accelerator.

The main frame 1 of the front wheel drive electric bicycle main body is connected to a head pipe 2 provided at a front portion and a seat tube 3 provided below a saddle 4.
A handle 12 and a front wheel 5 are attached to the head pipe 2. The front wheel 5 is composed of spokes, rims, and tires. A rotating casing 10 in a hub of the front wheel 5 is provided with a disk-shaped casing 20 containing a motor. Have been. The front wheel 5 is steered by a steering wheel 12. The rear wheel 6 also includes spokes, rims, and tires, and is rotated by the driving force of the manual driving unit.

A handle post of the head pipe 2 connecting the handle 12 and the front wheel 5 is provided with a handle angle detecting means for detecting how much the handle is turned. In this embodiment, a potentiometer is used as the detecting means. The configured one is used.

FIGS. 4A and 4B show an outline of a steering wheel angle detecting means constituted by a potentiometer. FIG. 4 (A)
FIG. 4 is a perspective view of mounting a potentiometer, and FIG. 4B is a plan sectional view. The potentiometer 18 is fixed to the portion of the head pipe 2 constituting the frame, and is provided so that the rotating portion 18a of the potentiometer rotates with the rotation of the shaft of the handle 12. When the handle 12 is turned off, the resistance of the potentiometer 12 is reduced. Is changing. Then, a voltage signal is input to a control circuit described later in accordance with the steering wheel angle detected by the potentiometer 12 to control the electric driving force.

The human-powered drive unit includes a pedal 7, a crank 8, and a chain 9. When the user steps on the pedal 7, the crank 8 rotates, and the rear wheel 6 rotates via the chain 9. In this example, the chain is a transmission member of human power. However, the invention is not limited to this, and a chain, a belt, a rotating shaft or the like may be used instead of the chain.

Brake levers 13 and 13 are attached to both left and right ends of a steering wheel 12 for steering the front wheel 5, and brake devices 14 and 15 are provided for the front wheel 5 and the rear wheel 6, respectively. 13 and brake device 14,
15 is connected by a brake wire 16.

A seat tube 3 provided below the saddle 4 is provided with a battery unit 11 serving as a power supply for a motor. The battery section 11 includes a battery case slidably attached to and detachable from the seat tube 3 and a single rechargeable battery housed in the battery case. The power supply voltage is approximately 24 volts.

Reference numeral 17 denotes a front sprocket which rotates with the rotation of the pedal 7. A chain 9 is hung on the front sprocket 17, and the rotation of the front sprocket 17 is transmitted to the rear wheel 6. The crank 8 and the front sprocket 17 are called rotating members.

Between the plate fixed to the crank 8 and the front sprocket 17, there is provided a ring-shaped elastic body made of metal and having a partially cut-out elasticity, for example, a washer spring, and the pedal 7 is depressed. Since the human-powered driving force transmitted in step (1) causes the washer spring to bend through the crank 8, the torque sensor detects the use of the bending.

As described above, since the washer spring is provided between the plate fixed to the crank 8 and the front sprocket 17, a torque sensor can be attached to the periphery of the plate. Since the parts can be unitized, assembly is simplified.
Further, as described above, the torque sensor is not limited to being provided only on the rotating member of the front sprocket 17, and other known means can be adopted.

As shown in FIG. 2, the disc-shaped casing 20 is a rotating casing 21 which rotates in conjunction with the front wheel 5.
And a fixed-side casing 22 fixed to the front-wheel-drive electric bicycle main body. Further, the fixed-side casing 22 has a motor control circuit (not shown) fixed therein.

A stator 23 and a brush 25 of the motor are provided on a fixed casing 22 of the disc-shaped casing 20, and the whole is fixed to the axle 10. The rotor of the motor is fixed to the rotating casing 21 and the brush 2
The rotational force of the rotor 24, which is supplied with electric power from the motor 5 through the commutator 26, is transmitted through a reduction gear comprising a planetary gear unit.

As shown in FIG. 3, the planetary gear device serving as a speed reducer includes an internal gear 27, three planetary gears 28 and a sun gear 19 around the axle 10 in a rotary casing 21. The electric driving force transmitted to 21 drives front wheels 5.

Fixed side casing 2 of disc-shaped casing 20
2 is fixed to a fixing member by a screw, and the fixing member is screwed to a plate 29. The plate 29 is fixed to a bicycle frame so that the fixed casing 22 does not rotate due to a reaction force generated by a motor.

FIG. 5 shows an outline of a drive circuit for a front wheel drive assist motor according to the present invention. In the figure, a battery power supply 11
Output from the main switch 31 to the constant voltage circuit 3
3. A control circuit 32 which is made to be a constant voltage and constituted by a microcomputer
Supplied to The control circuit 32 is supplied with the current detection circuit 36, the voltage detection circuit 37, the output of the steering wheel angle sensor 18, and the output of the torque sensor 38, and based on these detection signals, sends drive signals to the motor drive circuit 35 according to a predetermined program. The drive circuit 35 controls the power supply to the assist motor M via the semiconductor element 39. Further, the control circuit 32 outputs a signal indicating the state of charge of the battery to the battery remaining amount display circuit 34.

Next, the electric driving force of the electric driving unit when the front-wheel drive electric bicycle of the present invention travels straight will be described. The washer spring bends by the amount of the manpower torque generated by the manpower driving force. By detecting the warpage, the washer spring is fixed to the fixed side casing 22 in the disc-shaped casing 20 as a change in the magnitude of the manpower torque. Is input to the control circuit 32 of the motor.

The control circuit 32 is programmed so that the magnitude of the inputted manual driving force is equal to the magnitude of the electric driving force, and the control circuit 32 is driven by the torque of the same magnitude as the inputted manual driving force. The motor built therein drives the front wheel 5 by the driving force of the motor. As described above, the rear wheel 6 is driven by the manual driving force, and the front wheel 5 is driven by the electric driving force having the same magnitude as the manual driving force.

Next, the electric driving force of the electric driving unit when the front wheel drive electric bicycle turns and changes the direction will be described. When the bicycle turns and changes direction, the steering wheel angle detecting means (potentiometer) 18 detects a voltage signal according to the steering wheel angle and inputs the voltage signal to the motor control circuit 32. The control circuit 32 controls the electric driving force according to the steering wheel angle.

Further, the control circuit 32 calculates the magnitude of the electric driving force according to the steering wheel angle detected by the steering wheel angle detecting means 18 from a built-in table. Is continuously controlled so that is smaller.

Further, when the steering wheel angle is cut to a predetermined value or more so as not to react excessively to a small steering operation, the control circuit 32 reduces the electric driving force to a predetermined value.
Perform value control. If necessary, when the steering wheel angle is cut to a predetermined value or more, the control circuit 32 performs binary control to reduce the electric driving force to a predetermined value, and the electric driving force decreases as the steering wheel angle becomes larger than the predetermined value. It is also possible to control continuously.

Further, assisting is performed by a driving force corresponding to the magnitude of the electric driving force according to the steering wheel angle detected by the steering wheel angle detecting means 18 and the detected value of the torque sensor 38 for detecting the manual driving force. The reduction of the driving force according to the angle is performed by reducing the ratio of the electric driving force to the manual driving force.

The control operation of the front wheel drive assist motor of the present invention will be described with reference to the control flow of FIG. Control is started in step S1. When the steering wheel angle is detected in step S2, it is determined in step S3 whether the steering wheel angle ≥ a predetermined value. If the steering wheel angle is smaller than the predetermined value, the process returns to step S2,
The steering wheel angle is detected again.

If the steering wheel angle ≧ the predetermined value, the process proceeds to step S4, and the assist force of the motor is calculated from the steering wheel angle at that time. Next, in step S5, it is determined whether the calculated assist force is greater than the current assist force. If it is determined in step S5 that the calculated assist force is smaller than the current assist force (No), the process proceeds to step S7, in which the assist force of the electric drive is reduced (do
The control circuit 32 issues a command to the motor drive circuit 35 as shown in wn).

If it is determined that the calculated assist force is larger than the current assist force (Yes), the process proceeds to step S6, where the control circuit 32 drives the motor so as to increase the electric power assist force (up). A command is issued to the circuit 35.
When a series of routines is completed, the process returns to step S2 again.
The same control is repeated.

In the above embodiment, a front-wheel drive electric bicycle of a type in which the driving force of the electric drive unit is changed by human torque has been described as an example. However, the present invention is not limited to this type, and the use of an accelerator or the like is not limited to this type. Needless to say, a type in which the driving force of the electric driving unit is changed by a user's operation may be used.

[0041]

As described above, in the front-wheel drive electric bicycle of the present invention, the output drive power of the electric drive unit is reduced when the angle is large, depending on the degree of the steering wheel angle being cut, so that the output of the electric drive power goes straight. The steering wheel can be easily turned because the straightness is reduced. Therefore, the steering wheel operation becomes easy even with the front wheel drive, and the turning performance can be improved.

In a front-wheel drive electric bicycle, the driving force of the electric driving unit is controlled by a driving force corresponding to the value detected by the torque sensor. An elastic body that expands and contracts according to the level of human power is provided between the plate fixed to the interlocked crank and the front sprocket, and a torque sensor can be attached to the periphery of the plate. Can be easily assembled.

[Brief description of the drawings]

FIG. 1 is an overall view of a front-wheel drive electric bicycle.

FIG. 2 is a sectional view of a board-shaped casing.

FIG. 3 is a layout diagram of a planetary gear device.

FIG. 4 is a schematic diagram of a steering wheel angle detecting means.

FIG. 5 is a schematic diagram of an assist motor drive circuit.

FIG. 6 is a control operation flow of the assist motor.

[Description of Signs] 1 Main frame 2 Head pipe 3 Seat tube 4 Saddle 5 Front wheel 6 Rear wheel 7 Pedal 8 Crank 9 Chain 10 Axle 11 Battery section 12 Handle 13 Brake lever 14, 15 Brake device 16 Wire 17 Front sprocket 18 Handle angle Detecting means (potentiometer) 19 sun gear 20 disc-shaped casing 21 rotating casing 22 fixed casing 23 motor stator 24 motor rotor 25 brush 26 commutator 27 internal gear 28 planetary gear 29 plate 31 main switch 32 control circuit 33 constant voltage circuit 34 battery remaining amount display circuit 35 drive circuit 36 current detection circuit 37 voltage detection circuit 38 torque sensor 39 semiconductor switching element

Continuing from the front page (72) Inventor Hiroaki Sagara 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Toshihiro Matsumoto 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka Inside Sanyo Electric Co., Ltd. (72) Inventor Seiki Inui 2-5-1-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (8)

[Claims] 1. A human-powered drive unit for transmitting a manual drive force from a pedal to a rear wheel, an electric drive unit using a motor as a drive source on a front wheel unit, a steering wheel angle detecting unit, An electric bicycle driven by a front wheel, wherein an electric driving force is controlled in accordance with a detected steering wheel angle. 2. The front-wheel drive electric bicycle according to claim 1, wherein the control is continuously performed such that the larger the steering wheel angle, the smaller the electric driving force. 3. The front-wheel drive electric bicycle according to claim 1, wherein when the steering wheel angle is turned to a predetermined value or more, the electric driving force is controlled to decrease to a predetermined value. 4. When the steering wheel angle is cut to a predetermined value or more, the electric driving force is reduced to a predetermined value, and the electric driving force is continuously controlled so that the electric driving force decreases as the steering wheel angle becomes larger than the predetermined value. The front-wheel drive electric bicycle according to claim 1, wherein 5. The front wheel drive electric bicycle according to claim 1, wherein said steering wheel angle detecting means is constituted by a potentiometer. 6. The front-wheel drive electric bicycle according to claim 5, wherein the potentiometer is provided between a handle shaft and a frame. 7. A driving apparatus according to claim 1, further comprising a torque sensor for detecting a manual driving force of said manual driving section, wherein the driving force of said electric driving section is controlled by a driving force corresponding to a detected value of said torque sensor. The front-wheel drive electric bicycle according to 1. 8. The front-wheel drive electric bicycle according to claim 7, wherein the reduction of the driving force reduces the ratio of the electric driving force to the manual driving force.