JP2000247282A - Bicycle with rear suspension - Google Patents

Abstract

(57) [Summary] [Object] To provide a bicycle with a rear suspension that can suppress a change in the behavior of a vehicle body due to chain tension. A rear wheel is rotatably supported at a rear end of a rear arm which is pivotally attached to a vehicle body by a pivot shaft so as to be vertically movable, and is provided between the rear arm and a seat tube (body frame). Rear suspension 20 interposed
By suspending the rear arm 17 and the rear wheel 19 on the vehicle body, an endless chain 26 is wound around a drive sprocket 24 attached to the crankshaft 21 and a wheel sprocket 25 attached to the rear wheel 19. In the bicycle 1 with a rear suspension, the pivot shaft 18 is connected to a substantially extended line L on the tight side of the chain 26.
It is located above and in front of the crankshaft 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle with a rear suspension in which a rear arm and a rear wheel are suspended from a vehicle body by a rear suspension interposed between the rear arm and a vehicle body frame.

[0002]

2. Description of the Related Art FIG. 6 shows an electric bicycle 101 having a rear suspension. The electric bicycle 101 has a battery box 112, a controller 115 and a power unit 113 mounted thereon. Supplemented by auxiliary power.

In the electric bicycle 101 with a rear suspension, a front end of a rear arm 117 is pivotally connected to a down tube 108 by a pivot shaft 118 so as to be vertically swingable. A rear wheel 119 is rotatably supported. And
A rear suspension 120 is interposed between the seat tube 109 and the rear arm 117. The rear suspension 120 suspends the rear arm 117 and the rear wheel 119 supported by the rear suspension 120 from the vehicle body.

[0004]

By the way, in the electric bicycle 101 with the rear suspension, the pivot shaft 118 of the rear arm 117 must be located on the tight side of the chain 126 in order to suppress a change in the behavior of the vehicle body due to the tension of the chain 126. It is desirable to be located on the extension L, but it was impossible to arrange the pivot shaft 118 on the extension L on the tight side of the chain 126 in order to avoid interference with the power unit 113.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a bicycle with a rear suspension that can suppress a change in behavior of a vehicle body due to chain tension.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a rear wheel is rotated at the rear end of a rear arm whose front end is pivotally mounted on a vehicle body with a pivot shaft. The rear arm and rear wheel are suspended on the vehicle body by a rear suspension interposed between the rear arm and the body frame, and the drive sprocket mounted on the crankshaft and the wheel sprocket mounted on the rear wheel In a bicycle with a rear suspension in which an endless chain is wound therebetween, the pivot shaft is disposed substantially on an extension of the tension side of the chain and in front of the crankshaft. .

According to a second aspect of the present invention, in the first aspect, the bicycle with the rear suspension is an electric bicycle including a battery and a power unit, and the battery, the power unit, and the rear suspension are arranged around a pivot axis. I do.

Therefore, according to the first aspect of the present invention, since the pivot shaft of the rear arm is disposed on an extension of the chain side and in front of the crankshaft, a change in the behavior of the vehicle body due to the tension of the chain is prevented. It can be minimized, and higher ride comfort can be secured.

According to the second aspect of the present invention, since the battery, the power unit, and the rear suspension are arranged around the pivot shaft, these heavy parts are concentrated at the lower center in the front-rear direction of the vehicle body. The steering stability of the electric bicycle can be improved, and the covers that cover the power unit and the like can be reduced.

[0010]

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

<Embodiment 1> FIG. 1 is a side view of an electric bicycle 1 with a rear suspension according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 2 denotes a head pipe located at an upper front part of a vehicle body. 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, and a pair of left and right front forks 5 is mounted to a lower end of the steering shaft 3.
The front wheel 6 is rotatably supported at the lower end of the front fork 5.

A top tube 7 and a down tube 8 extend from the head pipe 2 toward the rear of the vehicle body. The down tube 8 extends under the top tube 7 obliquely downward toward the rear of the vehicle body. ing. A seat tube 9 erected diagonally upward toward the rear of the vehicle body is attached to each rear end of the top tube 7 and the down tube 8. A seat post 10 is provided in the seat tube 9. The saddle 11 is fitted and held so as to be vertically movable, and a saddle 11 is attached to an upper end thereof.

A battery box 12 is detachably provided in a triangular space surrounded by the top tube 7, the down tube 8 and the seat tube 9, and is provided at a rear end of the down tube 8. Is the power unit 13
Is attached. A plurality of rechargeable secondary batteries (not shown) are stored in the battery box 12.

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

A front end portion of a rear arm 17 bent and formed in a laterally-viewing shape is pivotally attached to a bracket 16 attached to a lower portion of a rear end of the down tube 8 by a pivot shaft 18 so as to be vertically swingable. A rear wheel 19 is rotatably supported at the rear end of the rear arm 17. A rear suspension 20 is inclined and interposed between the seat tube 9 and an intermediate upper portion of the rear arm 17, and the rear arm 20 and the rear wheel 19 supported by the rear suspension 20 are attached to the vehicle body. Suspended.

On the other hand, a crankshaft 21 disposed in a lateral direction (a direction perpendicular to the paper surface of FIG. 1) is rotatably supported by the power unit 13, and a crank 22 (FIG. Are mounted on each of them, and a pedal 23 is pivotally supported at an end of each crank 22.

A drive sprocket 24 is mounted on the crankshaft 21. An endless chain is provided between the drive sprocket 24 and the multi-speed transmission wheel sprocket 25 mounted on the rear wheel 19. 26 are wound. A predetermined tension is applied to the chain 26 by tensioners 27 and 28.

In this embodiment, the rear arm 1
7 with the pivot shaft 18 on the tight side of the chain 26 (FIG. 1).
On the extension line L (more precisely, in a state where one occupant gets on the vehicle when the wheel sprocket 25 for the multi-stage transmission is positioned at the middle position), and It is located in front. The battery box 12, the power unit 13, and the rear suspension 20 are arranged around the pivot shaft 18.

Next, the operation of the electric bicycle 1 with a rear suspension according to the present embodiment will be described.

The electric bicycle 1 includes a left and right pedal 2 for a rider.
3 is alternately rowed. The rider's treading force input to the pedal 23 is detected by treading force detecting means (not shown) incorporated 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 in the battery box 12 to the electric motor 14,
Therefore, the electric motor 14 generates an auxiliary power corresponding to the pedaling force and outputs this to the crankshaft 21. As a result, the crankshaft 21 is rotationally driven by both the pedaling force and the auxiliary power, and the rotation is transmitted via the drive sprocket 24, the chain 26, and the wheel sprocket 25 to the rear wheel 1
9, the rear wheel 19 is rotated and the electric bicycle 1 is driven. As described above, in the electric bicycle 1, the driving force of the rear wheel 19 is supplemented by the auxiliary power of the electric motor 14, so that the physical load on the occupant is reduced by that much.

While the electric bicycle 1 is traveling, the front wheel 6 and the rear wheel 19 can be stroked along the road surface unevenness to a position shown by a chain line in FIG. 1, but are added to the front wheel 6 from the road surface. The shock is absorbed and alleviated by the buffer action of the front fork 5.

The up and down stroke of the rear wheel 19 is made by swinging up and down around the pivot shaft 18 of the rear arm 17. Since the damping force is generated, the impact that the rear wheel 19 receives from the road surface is absorbed and reduced by the rear suspension 20. In the present embodiment, as described above, the pivot shaft 18 of the rear arm 17 is on the extension line L on the tension side of the chain 26,
In addition, since the vehicle body is arranged in front of the crankshaft 21, a change in the behavior of the vehicle body due to the tension of the chain 26 can be minimized, and higher riding comfort can be secured.

In this embodiment, since the battery box 12, the power unit 13 and the rear suspension 20 are arranged around the pivot shaft 18, these heavy parts are concentrated at the lower center in the front-rear direction of the vehicle body. As a result, the steering stability of the electric bicycle 1 is improved, and the size of the covers that cover the power unit 13 and the like can be reduced.

Second Embodiment A second embodiment of the present invention will be described below with reference to FIG. FIG. 2 is a side view of the electric bicycle with a rear suspension according to the present embodiment. In this figure, the same elements as those shown in FIG. 1 are denoted by the same reference numerals. Omitted.

Also in this embodiment, the rear arm 17
Is located on the extension line L on the tension side of the chain 26 and in front of the crankshaft 21. The rear suspension 20 is disposed on the down tube 8 and the rear arm 20 is provided via a link mechanism. The controller 15 is attached to the seat tube 9.

That is, the front end of the rear arm 17 extends forward of the vehicle body with respect to the pivot shaft 18, and the bracket 29 fixed to the seat tube 9 is rotatable about the intermediate portion of the link arm 30 bent in a square shape. One end of the link arm 30 is connected to the front end of the rear arm 17 via a link rod 31.

One end of the rear suspension 20 on the cylinder side is connected to the down tube 8 via a bracket 32.
, And the other end on the rod side is connected to the other end of the link arm 30.

When the rear wheel 19 strokes up and down while the electric bicycle 1 is running with the upper limit of the chain line position shown in FIG. 2, the vertical stroke of the rear wheel 19 is increased by the rear arm 17, the link rod 31 and the link. The rear suspension 20 is converted by the arm 30 into expansion and contraction movements, and the shock applied to the rear wheel 19 from the road surface is absorbed and reduced by the damping force generated in the rear suspension 20.

As described above, also in this embodiment,
As described above, since the pivot shaft 18 of the rear arm 17 is disposed on the extension line L on the tension side of the chain 26 and in front of the crankshaft 21, the behavior change of the vehicle body due to the tension of the chain 26 is minimized. As a result, the riding comfort of the electric bicycle 1 is further enhanced.

Further, since the battery box 12, the power unit 13 and the rear suspension 20 are arranged around the pivot shaft 18, the steering stability of the electric bicycle 1 can be improved as in the first embodiment, and the power unit 13 and the like can be improved. Can be made smaller.

Third Embodiment A third embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a side view of the electric bicycle with a rear suspension according to the present embodiment. In this figure, the same elements as those shown in FIGS. 1 and 2 are denoted by the same reference numerals. Is omitted.

The only difference between the present embodiment and the second embodiment is the arrangement of the rear suspension 20.
Other configurations are the same as those of the second embodiment.

In this embodiment, the rear suspension 2
0 is disposed along the lower surface of the down tube 8, and an intermediate portion of the link arm 30 is rotatably supported by a bracket 29 attached to a portion of the seat tube 9 protruding below the down tube 8, One end of the link arm 30 is connected to a front end of the rear arm 17 via a link rod 31.

One end of the rear suspension 20 on the cylinder side is connected to the down tube 8 via a bracket 32.
, And the other end on the rod side is connected to the other end of the link arm 30.

Thus, the electric bicycle 1 according to the present embodiment
Also, since the pivot shaft 18 of the rear arm 17 is located on the extension line L on the tension side of the chain 26 and in front of the crankshaft 21, the change in the behavior of the vehicle body due to the tension of the chain 26 is minimized. Therefore, the electric bicycle 1 can have higher riding comfort.

Further, since the battery box 12, the power unit 13 and the rear suspension 20 are arranged around the pivot shaft 18, the steering stability of the electric bicycle 1 can be improved as in the first and second embodiments, and the power unit can be improved. It is possible to reduce the size of the covers that cover 13 and the like.

<Fourth Embodiment> A fourth embodiment of the present invention will be described below with reference to FIG. FIG. 4 is a side view of the electric bicycle with a rear suspension according to the present embodiment. In this figure, the same elements as those shown in FIG. 1 are denoted by the same reference numerals. Omitted.

Also in the present embodiment, the rear arm 17
Is located on the extension line L on the tension side of the chain 26 and in front of the crankshaft 21. One end of the rear suspension 20 on the cylinder side is connected to the down tube 8 via the bracket 32. Connected to
The other end on the rod side is directly connected to the front end of the rear arm 17. The controller 15 is attached to the lower part of the rear end of the down tube 8.

In this embodiment as well, the pivot shaft 18 of the rear arm 17 is located on the extension line L on the tension side of the chain 26 and in front of the crankshaft 21. The change in the behavior of the vehicle body due to the tension of 26 is minimized, and the electric bicycle 1 is secured with even higher riding comfort.

Further, since the battery box 12, the power unit 13 and the rear suspension 20 are arranged around the pivot shaft 18, the steering stability of the electric bicycle 1 can be enhanced as in the first to third embodiments. At the same time, the covers that cover the power unit 13 and the like can be reduced.

<Fifth Embodiment> A fifth embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a side view of the electric bicycle with a rear suspension according to the present embodiment. In this figure, the same elements as those shown in FIG. 1 are denoted by the same reference numerals. Omitted.

The basic structure of the electric bicycle 1 according to the present embodiment is the same as that of the conventional electric bicycle 101 shown in FIG. 6, but in the present embodiment, the rear arm 17 is similar to the first to fourth embodiments. The pivot shaft 18 is disposed on the extension line L on the tension side of the chain 26 and in front of the crankshaft 21.

Therefore, in the present embodiment, the same effects as in the first to fourth embodiments can be obtained.

Although the present invention has been described with reference to the case where the present invention is particularly applied to an electric bicycle, it goes without saying that the present invention is similarly applicable to bicycles with a rear suspension other than the electric bicycle.

[0045]

As is apparent from the above description, according to the present invention, the rear wheel is rotatably supported at the rear end of a rear arm whose front end is pivotally mounted on the vehicle body by a pivot shaft. And
A rear suspension interposed between the rear arm and the vehicle body frame suspends the rear arm and the rear wheel on the vehicle body, and has an endless chain between the drive sprocket mounted on the crankshaft and the wheel sprocket mounted on the rear wheel. In the bicycle with a rear suspension, the pivot shaft is substantially on the extension line of the tension side of the chain and is disposed in front of the crankshaft, so that the behavior change of the vehicle body due to the tension of the chain is reduced. The effect of being able to suppress is obtained.

[Brief description of the drawings]

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

FIG. 2 is a side view of an electric bicycle with a rear suspension according to a second embodiment of the present invention.

FIG. 3 is a side view of an electric bicycle with a rear suspension according to Embodiment 3 of the present invention.

FIG. 4 is a side view of an electric bicycle with a rear suspension according to a fourth embodiment of the present invention.

FIG. 5 is a side view of an electric bicycle with a rear suspension according to a fifth embodiment of the present invention.

FIG. 6 is a side view of a conventional electric bicycle with a rear suspension.

[Explanation of symbols]

 Reference Signs List 1 electric bicycle with rear suspension 7 top tube (body frame) 8 down tube (body frame) 9 seat tube (body frame) 12 battery box 13 power unit 17 rear arm 18 pivot shaft 19 rear wheel 20 rear suspension 21 crankshaft 24 drive sprocket 25 Wheel sprocket 26 Chain L Extension line on the tight side of the chain

Claims (2)

[Claims] A rear suspension rotatably supports a rear wheel at a rear end of a rear arm pivotally attached to a vehicle body with a front end pivotably at a front end thereof, and is interposed between the rear arm and the vehicle body frame. A bicycle with an endless chain wound between a drive sprocket attached to the crankshaft and a wheel sprocket attached to the rear wheel, while suspending the rear arm and the rear wheel on the vehicle body, A bicycle with a rear suspension, wherein a pivot shaft is disposed substantially on an extension of a tension side of the chain and in front of the crankshaft. 2. An electric bicycle including a battery and a power unit, wherein the battery, the power unit, and the rear suspension are arranged around the pivot axis.