JP2002225688A - Rear wheel structure for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To balance the weight of a motorcycle better between the left and right, and facilitate a change of a rear wheel for another rear wheel of a different diameter via a simple structure. SOLUTION: A rear part of a power unit 21 is offset to one side from a width middle 26 of a vehicle body 2. Beside the rear part of the power unit 21, the rear wheel 23 is positioned on the middle 26 of the vehicle body 2. A drum brake 56 for the rear wheel 23 comprises a brake drum 57 integrally formed on a hub 41 of the rear wheel 23, a brake shoe 60 capable of frictional joint to an inner circumference of the brake drum 57, and a brake plate 58 mounted on the rear part of the power unit 21 to pivotally support the brake shoe 60. The brake drum 57 substantially as a whole is offset to the other side from the middle 26 of the vehicle body 2. The brake plate 58 is fitted in the hub 41, and a spoke part 43 of the rear wheel 23 comprises a plurality of wire spokes 54.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rear wheel hub,
The present invention relates to a rear wheel structure in a motorcycle in which a brake drum of a drum brake for rear wheel braking is integrally formed.

[0002]

2. Description of the Related Art Conventionally, motorcycles have been disclosed in
There is one disclosed in Japanese Patent No. 7144.

According to the above-mentioned publication, a power unit is disposed at a lower rear portion of a body frame of a motorcycle body, and a front portion of the power unit is arranged so that a rear side of the power unit can swing up and down. Is pivoted to. The rear part of the power unit is deviated to one side from the center in the width direction of the vehicle body, and is supported by the rear part of the power unit so as to be rotatable around an axis extending in the width direction of the vehicle body, and is driven by the power unit. An axle that is rotated and driven by applying a force is provided, and a rear wheel is disposed at the center of the vehicle body on a side of a rear portion of the power unit, and the rear wheel is supported by the axle so as to rotate with the axle. ing.

[0004] The rear wheel includes a hub mounted on the axle on the shaft center, a tire externally fitted to the hub,
And a spoke portion made of sheet metal for supporting the tire on the hub.

[0005] A drum brake for braking the rear wheel is provided, and the drum brake can be frictionally joined to a brake drum mounted on the hub on the shaft center and an inner peripheral surface of the brake drum. A brake shoe; and a brake plate attached to a rear portion of the power unit and pivotally supporting the brake shoe.

When a driving force is applied to the rear wheel from the power unit via the axle, the motorcycle can run. When the rider brakes the drum brake during this traveling, the brake shoe frictionally joins to the inner peripheral surface of the brake drum to apply a braking force to the rear wheel, and the traveling of the motorcycle is decelerated.

[0007]

By the way, in the above-mentioned prior art, the rear portion of the power unit is deviated to one side from the center of the vehicle body because the rear wheel needs to be arranged at the center of the vehicle body. Therefore, the right and left weight balance of the motorcycle with respect to the center of the vehicle body tends to be unbalanced.

Therefore, it is conceivable that the brake drum is displaced from the center of the vehicle body to the other side opposite to the rear of the power unit while the rear wheel is positioned at the center of the vehicle body.

However, as described above, if the hub also shifts to the other side as the brake drum shifts to the other side, the following problem occurs.

That is, there is a case where it is desired to change the rear wheel to another rear wheel having a different diameter from the rear wheel depending on the rider's preference or the like. In order to enable this change with a simple configuration, the spoke portion is connected to the hub. It is conceivable that the hub is made of wire spokes that can be detachably attached to the tire and the rim of the tire, and the hubs support tires having different diameters with wire spokes having different lengths.

However, since the wire spoke of the normal configuration is provided symmetrically with respect to the center of the hub located at the center in the width direction of the vehicle body, as described above,
When the hub is deviated from the center of the body to the other side, it is difficult to use the above-described wire spoke of the normal configuration, that is, the rear wheel is simply changed to another rear wheel having a different diameter from this. It is difficult to make it possible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and is intended to make the left-right weight balance of a motorcycle more even, and to replace the rear wheels with other rear wheels having a different diameter from the rear wheels. Another object of the present invention is to make it easy to change with a simple configuration.

[0013]

The rear wheel structure of the motorcycle according to the present invention for solving the above-mentioned problems is as follows.

According to the first aspect of the present invention, a power unit 21 is disposed at a lower rear portion of the vehicle body frame 3.
The front part of the power unit 21 is pivotally supported on the vehicle body frame 3 so that the rear part of the power unit 1 can swing up and down. And an axle 40 supported at the rear of the power unit 21 so as to be rotatable about an axis 39 extending in the width direction of the vehicle body 2 and driven to rotate by receiving a driving force from the power unit 21. A rear wheel 23 is arranged at the center 26 of the vehicle body 2 on the side of a rear portion of the unit 21, and the rear wheel 23 is supported by the axle 40 so as to rotate together with the axle 40. A hub 41 attached to the axle 40 on a center 39, a tire 42 fitted on the hub 41, and a tire 42
And a spoke portion 43 for supporting the
A drum brake 56 that can brake the rear wheel 23 is provided. In a motorcycle including a brake shoe 60 capable of being joined and a brake plate 58 attached to a rear portion of the power unit 21 and pivotally supporting the brake shoe 60,

Almost the entire brake drum 57 is displaced from the center 26 of the vehicle body 2 to the other side (right side),

The brake plate 58 is connected to the hub 41
The spoke portion 43 is constituted by a plurality of wire spokes 54.

[0017]

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

In FIGS. 2 to 4, reference numeral 1 denotes a motorcycle which is a saddle-ride type vehicle, and an arrow Fr indicates the front in the traveling direction. The left and right described below refer to the width direction of the vehicle body 2 of the motorcycle 1 facing forward.

The vehicle body 2 includes a vehicle body frame 3 serving as a skeleton thereof. The vehicle body frame 3 includes a vehicle body frame body 4 forming a front portion thereof, and a rear portion forming a vehicle body frame body 3 from a rear upper portion to a rear upper portion thereof. And a sheet support frame 5 extending toward the front.

The body frame body 4 has a head pipe 8 constituting the front upper end thereof, a main frame 9 and a down tube 10 extending from the head pipe 8 to a lower region thereafter, and A rear arm bracket 11 for connecting the rear ends (extended ends) of the frame 9 and the down tube 10 to each other is provided. The seat support frame 5 extends rearward and upward from the rear end of the main frame 9 via the upper end of the rear arm bracket 11.

The front fork 1 is attached to the head pipe 8.
A front wheel 17 is supported on the lower end of the front fork 16, and a handle 18 is mounted on the upper end of the front fork 16.

A power unit 21 is provided below the seat support frame 5 and behind a rear portion of the down tube 10 which is a lower portion of the vehicle body frame 3 and extends long in the front-rear direction. The power unit 21 has a front portion pivotally supported by a pivot mechanism 20 via a lower end portion of a rear arm bracket 11 at a rear portion of the down tube 10 so that a rear portion thereof can swing up and down. The power unit 21 is swingable around a pivot axis 22 of the pivot mechanism 20 extending in the width direction of the vehicle body 2, and is located below the seat support frame 5 and at the side of the rear of the power unit 21. A rear wheel 23 is provided, and the rear wheel 23 is pivotally supported at a rear portion of the power unit 21. In this case, the power unit 21 may be directly pivoted to the rear end of the down tube 10.

A shock absorber 25 is provided between the seat support frame 5 constituting the rear upper portion of the vehicle body frame 3 and the rear portion of the power unit 21. The front wheel 17 and the rear wheel 23 allow the vehicle body 2 to travel on a road surface. 27.

The rear part of the power unit 21 and the shock absorber 25
Is deflected to one side (left side) from the center 26 in the width direction of the vehicle body 2, whereby the rear wheel 23 is disposed at the center 26 in the width direction of the vehicle body 2 together with the front wheel 17. .

It is arranged at the center 26 of the vehicle body 2 and
A seat 29 that is disposed above the seat support frame 5 and extends in the front-rear direction is provided.
It is supported by the seat support frame 5.

In all the figures, the power unit 21
This power unit 2 is a traveling drive source of the motorcycle 1.
Reference numeral 1 denotes a four-stroke internal combustion engine 31 which constitutes a front part of the power unit 21 and forms a main part of the power unit 21;
And a power transmission device 32 that constitutes a rear portion and transmits the driving force from the internal combustion engine 31 to the rear wheel 23 side.

The internal combustion engine 31 includes a crankcase 34 pivotally supported by the rear arm bracket 11 of the body frame body 4 by the pivoting mechanism 20, and a cylinder 35 projecting forward from the crankcase 34. I have. Further, the power transmission device 32 constitutes an outer shell, and is connected to a rear portion of the crankcase 34. The power transmission case 36 is housed in the power transmission case 36 and has a driving force from the internal combustion engine 31. And a power transmission mechanism 37 for inputting the

The power transmission case 36 of the power unit 21 is supported by a rear portion of the power transmission case 36 so as to be rotatable around an axis 39 extending in the width direction of the vehicle body 2, and the driving force from the internal combustion engine 31 is transmitted to the power transmission mechanism 37. An axle 40 is provided which is driven to rotate by input through the rear wheel. The rear wheel 23 is supported by the axle 40 so as to rotate with the axle 40.

The rear wheel 23 includes a hub 41 made of a light alloy such as aluminum and the like, which is located at the center 26 in the width direction of the vehicle body 2 and is mounted on the axle 40 on the axis 39. 2 and the center 3
9, a tire 42 is externally fitted to the hub 41, and a spoke portion 43 for supporting the tire 42 on the hub 41.

The hub 41 is formed integrally with a boss portion 45 which is externally fitted to and fixed to the axle 40, and an end of the boss portion 45 on the other side (right side) in the width direction of the vehicle body 2. A circular plate 46, a cylindrical body 47 integrally formed on an outer edge portion of the circular plate 46 and externally fitted to the boss portion 45,
7 and a pair of left and right support pieces 48, 48 formed integrally with each other in the axial direction and protruding radially outward, respectively, and are surrounded by the boss 45, the disk 46, and the cylindrical body 47. An annular space 49 that forms the inside of the hub 41 opens toward the one side (left side), and the center between the left and right support pieces 48 is the center 26 of the hub 41 of the vehicle body 2.
Is matched.

The tire 42 includes a rim 51 supported on the hub 41 by the spokes 43 and a rim 51
Rubber elastic body 52 detachably supported on the tire
And

The spoke portion 43 is composed of a pair of left and right wire spokes 54 each composed of a plurality of wires, and these groups are arranged symmetrically with respect to the center 26 of the vehicle body 2 in the width direction. Each of the wire spokes 54 in each of the wire spoke groups 54 extends linearly and is arranged at a predetermined interval in the circumferential direction of the shaft center 39.

Each of the support pieces 48 of the hub 41 and the rim 51 of the tire 42 are formed with spoke holes, and the spoke holes are formed in these spoke holes.
By fitting and locking the end of the
The tire 42 is detachably supported on the hub 41. In this case, the tire 42 having a different diameter from the tire 42 is connected to each of the wire spokes 54.
The diameter of the tire 42 can be changed by supporting each wire spoke 54 having a length different from that of the tire 42.

When the rider performs a braking operation, the rear wheels 2
A drum brake 56 is provided for enabling the brake 3 to be braked. The drum brake 56 is formed integrally with the brake drum 57 integrally formed on the shaft 39 at the other end (right side) of the hub 41 and the power transmission case 36. A brake plate 58 attached to the power transmission case 36 and provided to close the opening of the space 49; and a brake shaft 58 housed in the space 49 and pivotally supported by the pivot shaft 59 with respect to the brake plate 58. And a brake shoe 60 capable of being frictionally joined to the inner peripheral surface of the brake shoe.

A braking operation mechanism 62 is provided for inputting a braking operation force by the rider to enable the brake shoe 60 of the drum brake 56 to be frictionally joined to the inner peripheral surface of the brake drum 57. The inner peripheral surface of the brake drum 57 is provided. If the brake shoe 60 is frictionally connected to the drum brake, the drum brake 56 performs a braking operation.

In the above configuration, almost the entire brake drum 57 extends from the center 26 of the vehicle body 2 to the other side (right side).
Is deviated to

For this reason, as described above, the rear portion of the power unit 21 is deviated to one side from the power unit 21 of the vehicle body 2 because the rear wheel 23 needs to be disposed at the center 26 of the vehicle body 2 as described above. In this case, the brake drum 57
Is shifted to the other side, so that the right and left weight balance of the motorcycle 1 is more balanced, which is preferable in terms of maneuverability.

The brake plate 58 is fitted in a space 49 inside the hub 41. Therefore, regardless of the position of the brake plate 58 in the axial direction of the axle 40,
Of the vehicle body 2 in the width direction is the center 26 of the vehicle body 2.
Can be matched.

The spoke portion 43 is composed of a plurality of wire spokes 54. Since the center of the hub 41 can be made to coincide with the center 26 of the vehicle body 2 as described above, The spokes 54 can be arranged symmetrically with respect to the center (center 26) of the hub 41, that is, the spokes 43 can be constituted by the wire spokes 54 having a normal configuration.

Therefore, as described above, the spoke portion 43
Can be configured with a wire spoke 54 having a normal configuration. According to the wire spoke 54, the tire 42 can be freely attached to and detached from the hub 41 with a simple configuration. That is, the rear wheel 23 can be replaced with another rear wheel having a different diameter. 23 can be easily changed with a simple configuration.

Although the above description is based on the illustrated example, the internal combustion engine 31 may have two cycles, or may be an electric motor instead.

[0042]

The effects of the present invention are as follows.

According to the first aspect of the present invention, a power unit is disposed at a lower rear portion of a vehicle body frame, and a front portion thereof is pivotally supported by the vehicle body frame so that a rear side of the power unit can swing up and down. The rear part of the unit is deflected to one side from the center in the width direction of the vehicle body, and is supported by the rear part of the power unit so as to be rotatable around an axis extending in the width direction of the vehicle body, and provides a driving force from the power unit. An axle that is driven to rotate is provided, and a rear wheel is arranged in the center of the vehicle body on the side of the rear part of the power unit, and the rear wheel is supported by the axle so as to rotate with the axle, and the rear wheel is A hub mounted on the axle on the axle, a tire externally fitted to the hub, and a spoke portion for supporting the tire on the hub, and capable of braking the rear wheel. A brake, which is integrally formed with the hub on the shaft center, a brake shoe that can be frictionally joined to the inner peripheral surface of the brake drum, and a drum brake attached to a rear portion of the power unit. A motorcycle provided with a brake plate pivotally supporting the brake shoe,

Almost the entire brake drum is deviated from the center of the vehicle body to the other side.

Therefore, as described above, the rear portion of the power unit is deviated to one side from the power unit of the vehicle body. In this case, the rear end of the brake drum is deviated to the other side. The left and right weight balance of the motorcycle is more balanced, which is preferable in terms of maneuverability.

Further, the brake plate is fitted inside the hub. For this reason, the center of the hub in the width direction of the vehicle body can be matched with the center of the vehicle body without being affected by the position of the brake plate in the axial direction of the axle.

The spoke portion is constituted by a plurality of wire spokes. Since the center of the hub can coincide with the center of the vehicle body as described above,
The wire spokes can be arranged symmetrically with respect to the center of the hub, that is, the spoke portions can be formed of wire spokes having a normal configuration.

Therefore, as described above, since the spoke portion can be formed by a wire spoke having a normal configuration, according to this wire spoke, the tire can be freely attached to and detached from the hub with a simple configuration. The other rear wheels with different diameters can be easily changed with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line 1-1 of FIG. 2;

FIG. 2 is an overall side view of the motorcycle.

FIG. 3 is a partially enlarged detailed view of FIG. 2;

FIG. 4 is a plan view of what is shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Body 2 Body frame 21 Power unit 23 Rear wheel 25 Shock absorber 26 Center 39 Axis 40 Axle 41 Hub 42 Tire 43 Spoke part 45 Boss part 46 Disk 47 Cylindrical body 48 Support piece 49 Space 51 Rim 52 Tire body 54 Wire spoke 56 Drum brake 57 Brake drum 58 Brake plate 60 Brake shoe

Claims (1)

[Claims] 1. A power unit is disposed at a lower rear portion of a lower part of a vehicle body frame, and a front portion thereof is pivotally supported by the vehicle body frame so that a rear side of the power unit can swing up and down. Is deflected to one side from the center in the width direction, and is supported by the rear portion of the power unit so as to be rotatable around an axis extending in the width direction of the vehicle body, and is driven to rotate by being supplied with a driving force from the power unit. An axle is provided, and a rear wheel is disposed at the center of the vehicle body at a side of a rear portion of the power unit, and the rear wheel is supported by the axle so as to rotate together with the axle. A hub mounted on the axle, a tire externally fitted to the hub, and a spoke portion for supporting the tire on the hub, and a drum brake capable of braking the rear wheel is provided. A brake drum integrally formed with the hub on the axis, a brake shoe capable of being frictionally joined to an inner peripheral surface of the brake drum, and a drum brake attached to a rear portion of the power unit. A motorcycle provided with a brake plate pivotally supporting a brake shoe, wherein substantially the entirety of the brake drum is displaced from the center of the vehicle body to the other side, and the brake plate is fitted into the hub, and the spoke is Rear wheel structure for motorcycles whose parts are composed of multiple wire spokes.