JPS602076Y2 - Motorcycle rear fork device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a rear fork device that swingably supports the rear wheel of a motorcycle.

The rear wheel of a motorcycle is supported via an axle by the rear end of a rear fork whose front end is pivotally connected to the body frame. The impact is buffered by the swinging of the rear fork and the damping effect of the cushion unit.

To attach such a rear fork to the vehicle body, pivot pipes are installed horizontally at the front ends of the left and right members of the rear fork, and ratio shafts are provided inwardly protruding from the left and right members at the rear lower part of the frame. The rear fork is pivotally attached to the frame by fitting into both ends of the pivot pipe via bearings.

In such a conventional pivot structure, since a horizontally long pivot pipe is pivoted to the frame side at both ends, centering the pivot points at both ends of the pivot pipe is troublesome and complicated, and it is difficult to maintain centering accuracy. There are problems such as it is difficult to do so, there is a risk of twisting the ratio axis and frame side because it is supported at both ends, and the assembly structure becomes complicated.

In particular, in shaft drive type rear forks, a housing for the joint that connects the drive shafts is installed inside the pivot part at one end, and the housing is pivoted on the outside across the space of this housing, so it is connected to the other end. It is difficult to produce the same axis between the two, and there are also disadvantages in assemblability, such as requiring troublesome and complicated adjustments during assembly.

The present inventor devised the present invention in order to solve the above-mentioned disadvantages of the conventional rear fork pivot of a motorcycle.The purpose of this invention is to fix the pivot shaft horizontally to the rear fork, To provide a motorcycle suspension fork which is pivoted to a support part on the engine side via a bearing, and which has a simplified pivot structure, improved ease of assembly, and a simplified and compact frame structure. .

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional plan view of the rear fork pivot. The figure shows a shaft drive type. The rear fork 1 consists of left and right members 2 and 3, and one member 3 is a hollow cylinder for passing the propeller shaft 12. member 2, 3
A cross member 4 is horizontally fixed between the front parts of the .

A pivot shaft 5 is horizontally fixed between the front ends of each member 2 and 3, and the shaft 5 is attached to a C-shaped holding member at the front end of a holding member 6 which is tied to the front part of one member 2. It is held together with screws etc.

A joint housing 7 is fixed to the front end of the other member 3, and one end of the aforementioned pivot shaft 5 is joined to the inner wall of the joint housing 7 by welding or the like.

The pivot shaft 5 thus installed and fixed between the front ends of the rear fork 1 is rotatably supported between left and right brackets 9, 9 protruding from the rear lower part of the engine 8 via bearings 10 and 10.

A drive shaft 11 extending rearward from a portion near one side of the engine 8 is connected to a propeller shaft 12 via a joint 13, and the center of the joint 13 is aligned with the axis of the pivot shaft 5.

The joint 13 is surrounded by a housing 7, and a flexible boot 14 is provided between the open end of the joint 13 and the engine.
is forced to intervene.

In the above, brackets 9, 9 are installed protruding from the rear of the engine 8,
The pivot shaft 5 is connected to the bearing 10 between the left and right members 2°3, specifically between the holding member 6 and the joint housing 7.
, 10, FIG. 2 shows an embodiment in which a hanger unit is attached to the engine 8 to pivotally support the pivot shaft.

The hanger unit 20 has a planar U-shape, and has bracket portions 21 and 21 protruding from the rear wall thereof spaced apart from side to side, and a pivot shaft is inserted through and pivotally supported through this portion via a bearing. It is also possible to attach the hanger member to the engine 8 at two points above and below the bent pieces 22 and 22, and attach such a hanger member to the engine to pivotally support the pivot shaft.

Next, the functions and effects will be described. The rear end of one member 3 of the rear fork 1 is connected to the gear box of the rear wheel, and the rear fork 1 swings up and down by a bearing 10 with the pivot shaft 5 as a fulcrum.

By the way, the pivot shaft 5 is supported not at both ends but at two points in the middle, so the bearing can be attached to the engine or hanger unit to support the shaft, and there is no need for a specific shaft from the frame side. Furthermore, since the frame does not require a pivot shaft support structure, the frame structure is simplified and the degree of freedom in design, etc. is greatly improved.

Since the pivot shaft is not pivoted at both ends, it is also smaller in the width direction and can be made more compact.In addition, in the case of a shaft drive type, it is not fixed on the outside of the joint housing, making it easy to align the axis. Moreover, it is easy to align the joint and the axis, and furthermore, the ease of assembly is greatly improved.

Moreover, the number of parts is reduced, and in addition to the above, a large cost advantage is obtained.Furthermore, since the pivot shaft is pivotally supported on the engine side, the center of the engine and the pivot shaft can be easily set parallel to each other.

According to the present invention, there are many advantages as described above, and the practicality is extremely high.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a cross-sectional plan view of a rear fork pivot, and FIG. 2 is a perspective view of a modified embodiment of the pivot structure. In the drawing, 1 is the rear fork, 5 is the pivot shaft, and 8 is the rear fork.
is an engine, 9 is a pivot, and 20 is a pivot member.

Claims (1)

[Scope of utility model registration request] In a shaft drive type motorcycle in which one of the left and right members constituting the rear fork is formed into a cylindrical shape and a propeller shaft is inserted into the cylindrical member, the propeller shaft is attached to the front end of the cylindrical member. A housing is provided to cover the joint, a pivot shaft is horizontally fixed between the housing and the front end of the other member, and a bracket is provided that projects rearward from the engine side, and an intermediate portion of the pivot shaft is attached to the bracket. A motorcycle fork device characterized by being pivotally supported via a bearing.