JPH10147280A - Bicycle with driving auxiliary force - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a wheel base, etc., from being made huge and obtain proper front and rear wheel load distribution by providing an electric motor between the crankshaft of a pedal and a rear wheel, providing the electric motor within the line of a drive chain by a side face view and overlapping a part of the electric motor with a chain line by a plane view. SOLUTION: An electric motor 26 is arranged between a crankshaft 27 and a rear wheel 17. Therefore, even in the case of a small diameter wheel, degradation of steering stability caused by improper front and rear wheel load distribution, etc., due to the making huge of a wheel base and a retreat of a saddle 21 can be prevented. The electric motor 26 is installed close to the right side within a easing 38, that is, a side in which a drive chain 33 exists and is located within the chain line of the drive chain 33 by a side face view. Further, at least a part of the electric motor 26 is arranged to be overlapped with the chain line by a plane view. As a result, space of a pedal 29 can be reduced and the pedal 29 becomes easy to be worked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an electric motor mounted on the body of a bicycle, and assists pedaling force with a driving assist force provided by the electric motor, thereby facilitating traveling uphill or traveling while receiving a headwind. The present invention relates to a bicycle with driving assistance force.

[0002]

2. Description of the Related Art In a bicycle with a driving assist force of this kind, it is necessary to dispose an electric motor near a crankshaft on which a pedal pressing force acts in order to easily combine the pedal depression force and the driving assistance force. Many of the conventional bicycles with driving assistance power are
The electric motor is disposed in front of the crankshaft, or the electric motor is disposed between the crankshaft and the rear wheel (for example, Japanese Utility Model Application Laid-Open No. 56-46494 and Japanese Patent Application Laid-Open No. 56-57589).
Bicycle with driving assist force described in the publication.

[0003]

However, in the case where the electric motor is disposed in front of the crankshaft, the distance between the head pipe of the front part of the body frame and the crankshaft becomes longer, so that the wheel diameter is relatively large. Although there is no particular problem in the case of a bicycle with a driving assist force (about 24 to 26 inches), the following problem occurs when the wheel diameter is relatively small (about 18 to 22 inches).

[0004] That is, in the bicycle with driving assisting power of small diameter wheels, the position of the head pipe is low, and the main pipe extending backward from the head pipe lies low at a shallow angle.
In order to secure the minimum ground clearance while installing the electric motor below the main pipe, the main pipe must be extended, which further increases the distance from the head pipe to the crankshaft and increases the wheelbase In addition, since the saddle moves away from the handlebar toward the rear wheel, steering stability is impaired, and an appropriate load distribution between the front and rear wheels cannot be obtained.

On the other hand, if the electric motor is arranged between the crankshaft and the rear wheel, the above problem can be solved. However, the conventional driving assist force in which the electric motor is arranged behind the crankshaft is used. In the bicycle with the electric motor, the electric motor is arranged away from the drive chain so that the electric motor does not overlap the chain line of the drive chain in plan view. For this reason, when a large-sized electric motor with high output is installed, the distance between the left and right pedals increases, making it difficult to pedal.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and enables an electric motor to be arranged without increasing the wheel base and the distance between pedals even in the case of small-diameter wheels. It is an object of the present invention to provide a bicycle with a driving assist force capable of obtaining stability and appropriate load distribution between front and rear wheels.

[0007]

In order to achieve the above object, a bicycle with a driving assisting force according to the present invention has an electric motor mounted on a bicycle body, and the pedaling force of an occupant and the driving assisting force provided by the electric motor are reduced. An electric motor is arranged between the crankshaft on which the pedaling force acts and the rear wheel, and the electric motor The electric motor is positioned within the chain line of the drive chain when viewed, and at least a portion of the electric motor overlaps the chain line when viewed in plan.

According to this structure, since the electric motor is installed between the crankshaft and the rear wheel, the steering stability is prevented from deteriorating due to an increase in the length of the wheel base and an inappropriate load distribution between the front and rear wheels. . Moreover, even if the electric motor is brought close to the drive chain, it is difficult for the electric motor to interfere with the chain line. Therefore, even when a large-sized electric motor with high output is adopted, the pedal interval can be kept small.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a left side view of a bicycle with a driving assistance force according to the present invention.

The bicycle 1 with a driving assist force has a body frame 2 close to a bicycle. The body frame 2 is made of, for example, a metal pipe, and a main pipe 4 extends obliquely rearward and downward from a head pipe 3 provided on the front of the body frame.
As shown in FIG. 2, a hanger bracket 5 made of a sheet metal press is fixed to the rear end of the main pipe 4. A seat pipe 6 extending upward is fixed to the hanger bracket 5, and a pair of left and right chain stays 7 extending rearward is bolted, and a pair of left and right seat stays 8 extending obliquely downward from the upper end of the seat pipe 6. Is connected to the rear end of the chain stay 7 via a rear end 9.

The front pipe 3 of the body frame 2 has a front wheel.
A front fork 12 that supports 11 is pivotally supported so as to be rotatable left and right. A handle bar 14 is fixed to the upper part of the front fork 12 via a handle post 13 so as to be integrally rotatable.
Further, components such as a basket 15, a brake device 16, and a front fender 17 are provided.

On the other hand, a rear wheel 17 is pivotally supported on the rear end 9 of the body frame 2 and is covered with a rear fender 18. A saddle 21 is installed on the seat pipe 6 via a saddle post 20, and the hanger bracket 5 is driven. An auxiliary device 22 is provided. The front wheel 11 and the rear wheel 17 are small wheels having a diameter of about 18 to 22 inches.

As shown in FIGS. 2 and 3, the hanger bracket 5 is formed in a substantially "C" shape surrounding the drive assist device 22 from above in a side view, and the drive assist device 22 extends in the vehicle width direction. It is fixed to the hanger bracket 5 by the suspension bolts 23. Note that a control unit 24 is provided above the hanger bracket 5.

An electric motor 26 is built in the drive assist device 22, and a crankshaft 27 extending in the vehicle width direction is supported on the drive assist device 22. Cranks 28L and 28R (see FIG. 4) are fixed to both ends of the crankshaft 27 so as to rotate integrally with each other.
A pedal 29 is rotatably provided at the tip of each of 28L and 28R. The drive assist device 22 is mounted on the crankshaft 27.
A drive sprocket 31 located on the right side of the shaft is mounted on the shaft, and a drive chain 33
Is wound.

The crankshaft 27 is driven to rotate in the direction shown by the arrow A by the rider sitting on the saddle 21 pedaling the pedal 29 with his / her foot, and the drive sprocket 31 rotates the crankshaft 27 and the driving assist provided by the electric motor 26. Upon receiving the resultant force, the crankshaft 27 rotates in the same direction as the crankshaft 27. The rotation of the drive sprocket 31 is transmitted to the driven sprocket 32 via the drive chain 33, and the rear wheel 17 is driven.

A battery unit 35 is detachably provided on the main pipe 4 of the body frame 2. The battery unit 35 is a power supply for operating the electric motor 26 of the drive assist device 22. Further, a frame cover 36 made of a synthetic resin or the like provides a body frame 2.
Of the main pipe 4 and the drive assist device 22 are covered.

FIG. 4 is a cross-sectional view of the drive assist device 22 along the line IV-IV in FIG. 3, and FIG. 5 is a right side view of the drive assist device 22.

The drive assisting device 22 has a casing 38 made of, for example, an aluminum alloy, and has a crankshaft
An electric motor 26 is arranged at the rear of the crankshaft 27. Therefore, the electric motor 26 is
It will be arranged between 27 and the rear wheel 17.

Both ends of the crankshaft 27 protrude left and right from the casing 38, and the protruding portions are connected to the cranks 28L and 28R.
Are fixed with bolts 39. An intermediate device 40 is coaxially provided at an intermediate portion of the crankshaft 27. The resultant device 40 is configured to smoothly combine the rotational force (pedal pressing force) of the crankshaft 27 and the driving assist force provided by the electric motor 26 and output the resultant to the drive sprocket 31.

The electric motor 26 is located on the right side in the casing 38, that is, on the side where the drive chain 33 is located, and is located in the chain line of the drive chain 33 in a side view as shown in FIGS. . Further, as shown in FIG. 4, at least a part of the electric motor 26 is arranged so as to overlap the chain line in plan view.

In this embodiment, the main shaft of the electric motor 26 is
Only a bearing 42 that supports the right end of 41, a wiring cord 43, and a bulging portion 38a formed in the casing 38 so as to surround these members 42, 43 overlap with the chain line of the drive chain 33. However, for example, the electric motor 26
The motor case 44 itself overlaps the chain line to the extent that it does not interfere with the right crank 28R,
Other parts of the casing 38 may overlap the chain line.

A planetary roller reduction mechanism 46 is provided on the left side of the electric motor 26, and a reduction gear train is provided in front of the planetary roller reduction mechanism 46.
47 is arranged, and the driving assist force of the electric motor 26 is 3
The speed is reduced in stages and transmitted to the resultant device 40.

When the bicycle 1 with driving assist force travels, the crankshaft 27 rotates in the direction A by receiving pedaling force, and the rotation of the crankshaft 27 is transmitted to the resultant device 40. On the other hand, the driving assist force of the electric motor 26 is also reduced and transmitted to the resultant force device 40. The resultant force device 40 combines the pedal depression force and the driving assist force and outputs the resultant force to the drive sprocket 31. Rotate to.

The rotation of the drive sprocket 31 is transmitted to the rear wheel 17 by the drive chain 33 and the driven sprocket 32. Therefore, the pedaling force is assisted by the driving assisting force of the electric motor 26, and the bicycle 1 with the driving assisting force can be easily run with a small pedaling force. The control unit 24 controls the output of the electric motor 26 so that the pedaling force and the driving assist force always have a constant ratio (for example, 1 to 1).

In this embodiment, since the electric motor 26 of the drive assist device 22 is disposed between the crankshaft 27 and the rear wheel 17 as described above, even in the case of a small-diameter wheel such as the bicycle 1 with drive assist force. , Longer wheelbase and saddle 21
The steering stability can be prevented from deteriorating due to improper front and rear wheel load distribution due to retreat.

Further, the electric motor 26 is positioned in the chain line of the drive chain 33 in a side view,
Since at least a part of the electric motor 26 is overlapped with the chain line in plan view, the electric motor 26 can be moved toward the drive chain 33 to reduce the distance between the pedals 29. For this reason, even when a large-sized electric motor with high output is employed, the distance between the left and right pedals 29 can be kept small, and the pedals 29 can be easily rowed.

Further, in the case of the drive assist device 22 in which the electric motor 26 and the resultant device 40 are sealed in the casing 38 as in the bicycle 1 with the drive assist force, the distance between the electric motor 26 and the resultant device 40 is increased. Since the size can be reduced, the side profile of the entire casing 38 can be reduced.

[0028]

As described above, in the bicycle with a driving assist force according to the present invention, the electric motor is disposed between the crankshaft on which the pedaling force acts and the rear wheel, and the electric motor is driven in a side view. The chain is located in the chain line of the chain, and at least a part of the electric motor is overlapped with the chain line in a plan view. In addition, the distance between the pedals can be reduced by preventing the electric motor from interfering with the chain line, and pedaling can be facilitated.

[Brief description of the drawings]

FIG. 1 is a left side view of a bicycle with a driving assistance force according to the present invention.

FIG. 2 is an enlarged view showing the vicinity of a hanger bracket of a vehicle body frame.

FIG. 3 is an enlarged view showing a hanger bracket and a drive assist device.

FIG. 4 is a diagram showing an embodiment of the present invention by a cross section of the drive assist device taken along line IV-IV in FIG. 3;

FIG. 5 is a right side view of the drive assist device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bicycle with drive assist power 2 Body frame 11 Front wheel 17 Rear wheel 27 Crankshaft 33 Drive chain 22 Drive assist device 26 Electric motor 29 Pedal 31 Drive sprocket 32 Driven sprocket 33 Drive chain 38 Casing 40 Casing device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kohei Tomita 300 Suzuki Co., Ltd., Takatsukacho, Hamamatsu City, Shizuoka Prefecture

Claims (1)

[Claims] An electric motor is mounted on a bicycle body, and a combined force of a pedal depression force of a passenger and a driving assist force provided by the electric motor is output to a rear wheel by a drive chain. In bicycles with driving assistance power,
The electric motor 26 is disposed between the crankshaft 27 on which the pedal depressing force acts and the rear wheel 17, and the electric motor 26 is located in the chain line of the drive chain 33 in a side view, and the electric motor 26 A bicycle 1 with a driving assist force, wherein at least a part of the bicycle is overlapped with a chain line.