JPH09188286A - Electric bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cycling feeling and simplicity of handling similar to those of an ordinary bicycle by notching an armature in a DC brushless motor in the specific radial direction, arranging a space, and arranging component parts of an electric bicycle in the space. SOLUTION: For example, the number of poles in a rotor 204 is 8 while an armature 201, which is constructed by notching an armature with 12 poles in the radial direction by a radial angle of 90 degrees, is provided with 9 poles. In each pole 203, winding 202 is applied by a concentrated wire winding method, and a proper phase is energized to be driven on the basis of position detection of the rotor 204. The armature 201 is notched by the angle of 90 degrees in the radial direction, so that a required space is generated in the specific radial direction of the electric motor 200. A crankshaft 505 of a manual driving system, a joint A302, a joint B303, and the like are arranged in the space. In this way, a distance between the crankshaft 505 and an electric motor shaft 206 can be shortened to about two thirds of that of a bicycle constructed without notching an armature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric bicycle that combines a human power driving force and an electric motor driving force.

[0002]

2. Description of the Related Art In recent years, an electric bicycle using an electric motor has been attracting attention for assisting human power. This type of bicycle is equipped with an electric motor and a battery power supply unit that supplies electric power to this motor in a normal bicycle, and additionally assists a predetermined motor driving force according to the human driving force to reduce the human power load. I try to reduce it. In addition, the auxiliary driving force by this motor does not exceed the driving force of human power. Furthermore, when the traveling speed is up to 15 km / h, 100% assistance is provided, and when it exceeds 15 km / h, Gradually decreases,
The motor assistance is controlled to be cut off at 24 km / hour or more.

Such electric bicycles are already known. However, many proposals have been made for a method of constructing an electric bicycle, that is, a method of arranging an electric motor, a speed reducer, a battery unit, and the like.

For example, in Japanese Unexamined Patent Publication No. 07-40878, a power unit is arranged coaxially with a crankshaft, an electric motor is arranged in front of the crankshaft and below the main pipe, and a battery is arranged behind the crankshaft and It is proposed to place it along a standing pipe. As a result, the center of gravity of the vehicle approaches the center of the shape of the vehicle body, so that the original sense of running of the bicycle is not impaired.

Further, Japanese Patent Laid-Open No. 05-262273 proposes an example in which a power unit is provided on a rear tire hub shaft, and an electric motor and a speed reducer are mounted inside.

[0006]

However, in the first conventional example, the electric motor has a structure protruding long in front of the power unit, and the battery is also arranged at a high position. The center of gravity becomes high, making it difficult to handle. Therefore, it is difficult for the elderly and children to handle. Further, since the electric motor output is input perpendicularly to the crankshaft, the output shaft of the electric motor and the crankshaft are perpendicular to each other.
Therefore, a complicated speed reducing mechanism such as a bevel gear is required, and the power unit becomes large in size.

Further, in the second conventional example, since the heavy weight of the power unit is provided at the rear tire hub portion, the center of gravity of the bicycle is extremely biased toward the rear portion, and the original running feeling of the bicycle is impaired. Also, when pulling a bicycle around, the center of gravity of the entire bicycle is high, so it requires physical strength to handle it.
There is a problem that it is difficult for the elderly and children to handle.

[0008]

In order to solve the above problems, the present invention uses a DC brushless motor as an electric motor in an electric bicycle that combines a human-powered driving force and an electric motor driving force. A specific radial direction of the armature is cut out to provide a space, and the components of the electric bicycle are arranged in the space.

It is characterized in that the component is a crankshaft of a human power drive system.

It is characterized in that the component is an output transmission mechanism component of a human power drive system or an electric motor drive system.

The above-mentioned component is a pedaling force detection mechanism for detecting the pedaling force of the driver.

In an electric bicycle which combines a human power driving force and an electric motor driving force, the electric motor is arranged so that the electric motor shaft and the crank shaft are arranged in parallel.

In an electric bicycle that combines a human-powered driving force and an electric-motor driving force, the installation position of the electric motor is adjacent to the crankshaft and is lower than the height of the crankshaft.

In an electric bicycle which combines a human-powered driving force and an electric motor driving force, the battery is arranged such that the electric power is supplied to the battery in front of the crankshaft, adjacent to the crankshaft, and below the main frame. It is characterized by being on the side.

It is characterized in that any one or more of claims 1 to 7 is combined.

[0016]

The electric motor is a DC brushless motor, and the armature is partially cut away in the radial direction to provide a space,
A compact power unit can be constructed by arranging the components of the electric bicycle. For example, by using a crank shaft of a manual drive system as the above-mentioned component, the distance between the electric motor and the crank shaft is about two-thirds as compared with the case where the power unit is composed of an electric motor without a notch. Can be shortened to The same effect can be obtained even if the component is an output transmission mechanism of a human power drive system or an electric motor drive system, or a pedal effort detection mechanism that detects the pedal effort of the driver.

Further, by disposing the electric motor so that the shaft of the electric motor and the crankshaft are parallel to each other, the reduction gear can be constituted by spur gears or the like without providing a complicated reduction gear such as a bevel gear. , The power unit body can be made compact.

In addition, the electric motor is installed at a position adjacent to the crankshaft and is located below the height of the crankshaft so that the power unit is constructed.
It can be installed at a position where the speed reducer and the battery are lower than before. Therefore, since an electric bicycle having a lower center of gravity can be configured as compared with the conventional bicycle, a similar running sensation can be obtained despite a large increase in weight as compared with a general bicycle. Therefore, it is possible to provide a bicycle that is easy to handle even for elderly people and children with weak physical strength.

Further, in an electric bicycle which combines a human-powered driving force and an electric motor driving force, the battery is arranged such that the battery is supplied with electric power in front of the crankshaft, adjacent to the crankshaft, and on the main frame. By setting it to the lower side, the center of gravity of the entire electric bicycle is lowered in the same manner as described above, and the same effect can be obtained.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the embodiments shown in FIGS.

FIG. 1 is a diagram showing the overall construction of an electric bicycle according to an embodiment of the present invention.

In this embodiment, the electric bicycle 400 is
As with conventional bicycles, the rear wheels 50 are placed in front of and behind the frame body.
2. The front wheel 503 is mounted on the shaft. Also, the frame body is
A main pipe 508 on the front fork 506 side and a standing pipe 507 provided above the main pipe 508.
The saddle 501 on which the user sits is provided at the upper end of the standing pipe 507. A power unit 402 having a crankshaft 505 is mounted below the standing pipe 507.
A pedal 504 is pivotally supported at the tip of a pedal arm 509 attached to the. In addition, the power unit 402
A battery unit 401 is attached at a front adjacent position and below the main pipe 508. Further adjacent to the power unit 402 and the main pipe 50
An electric bicycle drive circuit 403 composed of a motor drive circuit and a control circuit is arranged in a space sandwiched between 8 and the standing pipe 507.

Further, the power unit 402 accommodates an electric motor, a speed reducer, a human power / motor driving force combining mechanism, and a pedaling force detecting means, and a crankshaft 505 to which a pedal 504 is connected is connected to the combining mechanism. The output of the synthesizing mechanism is connected to a front sprocket (not shown). And this front sprocket and rear wheel 5
A driven sprocket (not shown) coaxially fixed to 02 is connected by a chain (not shown) hung between the two. Although not shown in the drawings, basically, the same brake lever, brake mechanism, night driving light and the like provided on the steering wheel are the same as those of the conventional bicycle.

The front wheel 503 is steered by the handle 505 provided on the front fork 506, while the rear wheel 502 travels in the same manner as a normal bicycle when the user pedals the pedal 504. That is, when the pedal 504 is pedaled by the human power of the user, the front sprocket is rotationally driven, the driving force of the front sprocket is transmitted to the rear sprocket of the rear wheel through the chain, and the rear wheel 502 is rotationally driven. Then, the electric bicycle moves forward.

The battery unit 401 is composed of a single battery or a plurality of batteries to obtain a predetermined voltage. Then, the electric power from the battery unit 401 is supplied to the electric motor and various devices such as sensors and circuits.

The motor drive circuit is mainly composed of a MOS-FET circuit which is a switching element for electric power,
By the chopper control by the high-speed switching operation of this FET circuit, the effective voltage supplied to the traveling electric motor is increased or decreased to control the electric motor output. Further, this switching control is executed based on a command from the control circuit that is determined based on the detected human power and traveling speed.

The control circuit is composed of a microcomputer which receives sensor signals from the torque detection mechanism of the power unit 402, a traveling speed sensor, an external environment sensor, etc. and outputs a control signal to the motor drive circuit.
This microcomputer performs an A / D converter that converts each input signal into a digital signal, an I / O port that reads / takes this digital signal into / from a memory space, and performs predetermined processing / determination based on the read data signal. It has a CPU, a memory, and the like. Therefore, based on the detection signals from the various sensors, processing is performed according to a program stored in the memory, and an appropriate operation command such as a duty setting signal is output to the motor drive circuit.

Therefore, when the user turns on the main key switch, electric power is supplied from the battery 401 to each on-board device, and the human-powered auxiliary drive by the electric motor becomes possible. That is, in this state, when the user pedals the pedal 504, the pedaling force detecting means detects the driving force of human power in response to this, and the speed sensor detects the traveling speed, and the control circuit based on these detection signals. Outputs an appropriate operation command to the motor drive circuit. Based on this operation command, the motor drive circuit increases or decreases the drive power supplied to the traveling motor to adjust the output of the traveling electric motor. And
The generated electric motor driving force is converted into an appropriate torque by the speed reduction mechanism, and this motor driving force is added to the human power driving force by the combining mechanism and transmitted to the rear wheel 502, and the electric bicycle is assisted by the motor power. Therefore, it is provided for comfortable forward traveling.

2 to 4 are block diagrams of the power unit in this embodiment. FIG. 2 is a sectional view of a power unit showing an embodiment of the present invention, and particularly shows a structure around an electric motor, a speed reducer, and a crankshaft. FIG. 3 is a side view of a power unit showing an embodiment of the present invention, and particularly shows a structure around an electric motor and a crankshaft. FIG. 3 is also a side view of the power unit showing the embodiment of the present invention, and particularly showing the arrangement of the speed reducer which controls deceleration from the motor shaft to the crank shaft.

The configuration of the power unit of this embodiment will be described with reference to FIGS. Note that FIG. 2 is a sectional view developed along the train wheel of the speed reducer, and the vertical dimension of the drawing is different from the actual size.

First, the force transmission paths of the human power drive system and the electric motor drive system will be described. The human power drive system is input by the driver stepping on the pedal as in a general bicycle. The input force is transmitted to the front sprocket member 304 via the one-way clutch mechanism A301, the joint A302 and the joint B303. The one-way clutch mechanism A301 is provided in the human power drive system in order to cut off the transmission of force to the front sprocket when the driver reversely rotates the pedal. Next, the electric motor drive system will be described. The electric motor 200 generates a required rotation speed and torque according to a signal from the control circuit. The force generated by the motor is the first stage speed reducer 101, 2
The speed is reduced by the third speed reducer 102 and the third speed reducer 103,
Input to the front sprocket member 304. A one-way clutch mechanism B305 is provided between the third stage speed reducer 103 and the front sprocket member 304. This one-way clutch mechanism is to cut off the transmission of force between the electric motor and the front sprocket when the electric motor 200 is not rotating, that is, when the human power assist drive is not being performed. Therefore, the one-way clutch mechanism can prevent the mechanical loss generated in the speed reducer, the mechanical loss generated in the electric motor, and the iron loss. A human-powered drive system and an electric motor drive system are configured by the above configuration, and the forces of both drive systems are combined by the front sprocket member 304 to become the drive force of the electric bicycle. Further, in the present embodiment, the torque detection mechanism 306 is used to detect the torque when the driver depresses the pedal. That is, the elastic body 307 is interposed between the joint A 302 and the joint B 303, and the torque difference is obtained by converting the phase difference between both joints into rotation of the potentiometer by the torque detection mechanism 306.

Next, the details of the present invention will be described.

As shown in FIG. 3, the electric motor in this embodiment has a structure in which the armature 201 is cut out in the radial direction at a spread angle of 90 degrees. In the present embodiment, an example is shown in which the rotor 204 has eight poles, and the armature 201 has a 12-pole armature with a 90 ° opening angle in the radial direction, and a 9-pole notch. A winding 202 is applied to each pole 203 by a concentrated winding method, and an appropriate phase is excited and driven by detecting the position of the rotor 204. Armature 201
By shaving a 90 ° spread angle in the radial direction, a required space is created in a specific radial direction of the electric motor 200. In this embodiment, in the space, a crank shaft 505 of a human power drive system, a joint A302, a joint B3.
An example in which 03 and the like are arranged is shown. As a result, the distance between the crank shaft 505 and the electric motor shaft 206 can be reduced to about two-thirds as compared with the example in which the armature is not cut out. Actually crankshaft 505 and electric motor shaft 2
It has been confirmed that it is possible to construct a power unit for an electric bicycle within a distance of 100 mm from the axis 06.

Further, since the electric motor 200 is arranged so that the electric motor shaft 206 and the crankshaft 505 are parallel to each other, as shown in FIG. 4, the reduction mechanism is a spur gear reducer 101, 102, 103. Can be easily configured. Further, since the armature 201 of the electric motor is cut out in the radial direction, the axial distance between the crankshaft 505 and the motor shaft 206 can be selected relatively freely. The degree of freedom of setting such as and gear ratio increases.

Further, as shown in FIG. 1, in the power unit 402 in this embodiment, the electric motor 200 has the crankshaft 5
It is arranged below the height of 05. That is, FIG.
In the side view of the power unit shown in FIG.
05 side is on the upper side, and the electric motor 200 side is on the lower side. Therefore, the power unit is arranged at a lower position than before, and the center of gravity of the entire electric bicycle can be lowered. Further, since another heavy object can be placed in the space occupied by the electric motor in the conventional example, the center of gravity of the electric bicycle can be further lowered. For example, as shown in FIG. 1, the battery unit 401 is located in front of the crankshaft 505, adjacent to the crankshaft 505, and below the main frame 508.
A large heavy object can be placed near the height of the crankshaft 505. In addition, the electric bicycle drive circuit 403 includes a main pipe 508 and a standing pipe 5 on the upper side of the crankshaft 505.
It can be placed in a portion sandwiched by 07. Further, a power unit 402, an electric bicycle drive circuit 403,
By covering the battery unit 401 and the like with the same plastic cover 404, a sense of unity is created, and an electric bicycle having an excellent appearance can be configured.

For actual running of the bicycle, a road clearance of about 200 mm is required between the bottom of the vehicle body and the ground. With the configuration of this embodiment, the load clearance between the bottom surface of the power unit 402 and the ground is 2
It has been actually confirmed that the distance can be set to 00 mm or more.

In this embodiment, the crankshaft of the human power drive system and the output transmission mechanism of the human power drive system are shown as the components arranged in the notched space of the armature. It goes without saying that the same effect can be obtained even with a pedaling force detection mechanism for detecting the pedaling force of a person, an output transmission mechanism of an electric motor drive system, or the like.

[0038]

The present invention is configured as described above,
The center of gravity of the entire electric bicycle can be lowered while maintaining sufficient road clearance. Therefore, despite the large increase in weight as compared with a general bicycle, similar running feeling and ease of handling can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing the overall configuration of an electric bicycle of the present invention.

FIG. 2 is a sectional view of the power unit of the present invention.

FIG. 3 is a side view of the power unit according to the present invention.

FIG. 4 is a side view of the power unit according to the present invention.

[Explanation of symbols]

 101.1 stage reducer 102.2 stage reducer 103.3 stage reducer 104. Reduction gear 200. Electric motor 201. Armature 202. Winding 203. Paul 204. Rotor 205. Field magnet 206. Motor shaft 301. One-way clutch mechanism A 302. Joint A 303. Joint B 304. Front sprocket member 305. One-way clutch mechanism B 306. Torque detection mechanism 307. Elastic body 400. Electric bicycle 401. Battery unit 402. Power unit 403. Electric bicycle drive circuit 404. Cover 501. Saddle 502. Rear wheel 503. Front wheel 504. Pedal 505. Crankshaft 506. Front fork 507. Standing pipe 508. Main pipe 509. Crank arm

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Nakazato 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation

Claims (8)

[Claims] 1. An electric bicycle for combining a human-powered driving force and an electric motor driving force, wherein a DC brushless motor is used as an electric motor, and a specific radial direction of an armature of the DC brushless motor is cut out to provide a space, and An electric bicycle characterized by arranging components of the electric bicycle in a space. 2. The electric bicycle according to claim 1, wherein the component is a crankshaft of a human power drive system. 3. The electric bicycle according to claim 1, wherein the component is an output transmission mechanism component of a human power drive system or an electric motor drive system. 4. The electric bicycle according to claim 1, wherein the component is a pedaling force detection mechanism for detecting a pedaling force of a driver. 5. An electric bicycle for synthesizing a human-powered driving force and an electric-motor driving force, wherein an electric motor is arranged such that an electric motor shaft and a crank shaft are arranged in parallel with each other. 6. An electric bicycle for combining a human-powered driving force and an electric motor driving force, wherein an electric motor is installed at a position adjacent to a crankshaft and lower than a height of the crankshaft. Electric bicycle to do. 7. In an electric bicycle that combines a human-powered driving force and an electric motor driving force, the battery is arranged such that the battery is supplied with electric power at a position in front of the crankshaft and adjacent to the crankshaft. An electric bicycle characterized by being on the lower side of the frame. 8. An electric bicycle characterized by combining any two or more of claims 1 to 7.