JP2000274476A - Front fork of suspension device for two wheeler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent abrasion of the inner periphery and shaving-off of a part of an inner peripheral surface even if an inner tube is an aluminum material by arranging an annular groove on the inner tube inner periphery, fitting a pipe of a hard material to this groove, and guiding the suspension spring outer periphery in the shaft direction by the pipe inner periphery. SOLUTION: A suspension spring 9 is arranged inside an inner tube 2 freely slidable in an outer tube 1, and this suspension spring is telescopically installed between a guide 11 and spring guides 8, 8a. An annular groove 12 corresponding to an arranging position of an upper bracket 6 and an under bracket 7 is formed in the shaft direction on the inner periphery of the tube 2, a pipe 2a composed of a hard material such as iron is fitted in the groove 12 by hydraulic bulge work and press-in, and the outer periphery of a spring 9 is guided in the shaft direction by this inner periphery. Thus, even if competition is caused between the tube 2 and the spring 9 when the tube 2 vertically slides, since the pipe 2a is hard, abrasion and shaving-off of the inner periphery by the spring 9 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a manten bike,
Used as a front wheel suspension device for motorcycles and other motorcycles,
The present invention relates to a front fork which also serves as a shock absorber and a fork for attenuating vibration from a road surface.

[0002]

2. Description of the Related Art Generally, bicycles such as mountain bikes,
In a motorcycle such as a motorcycle, a front fork serving also as a shock absorber and a front fork is interposed between a vehicle body and a front wheel axle as a front wheel suspension device.

As shown in FIG. 4, this front fork includes an outer tube 1 connected to the axle side, an inner tube 2 movably inserted into the outer tube 1, and a damper standing in the outer tube. It has a cylinder and a piston rod 3 movably inserted into the damper cylinder via a piston.

The lower end of the outer tube 1 is connected to the front wheel axle via a bracket 4, and the upper end of the inner tube is connected to the vehicle body via a bracket 5, an upper bracket 6 and an under bracket 7. .

A spring guide 8 extends downward from a cap connected to the upper end of the inner tube 2 and the piston rod 3, and a coil-shaped suspension spring 9 is interposed between the spring guide 8 and the damper cylinder. The suspension spring 9 constantly urges the inner tube 2 and the piston rod 3 in the extending direction.

Reference numeral 10 denotes a breath installed between the left and right front forks, and the breath 10 prevents bending and twisting of the front fork when an impact from a road surface is input.

[0007]

The above-described conventional front fork is not particularly defective in function, but in order to reduce the weight, when the inner tube 2 is formed from a material such as aluminum material, the inner fork is not used. When the tube 2 slides up and down, its inner circumference slides on the outer circumference of the suspension spring 9,
The inner periphery of the inner tube 2 may be worn or shaved due to both of the auctions.

As a result, not only is the durability of the inner tube 2 impaired, but also shavings and cutting powder are mixed into the oil as contamination, resulting in drastic damping force and malfunction.

Accordingly, an object of the present invention is to provide an inner tube having an inner periphery worn or a part of an inner peripheral surface cut off even when the inner tube is formed of a material such as aluminum. It is an object of the present invention to provide a front fork for a suspension device for a motorcycle, which does not have to be used.

[0010]

In order to achieve the above-mentioned object, the present invention is directed to an inner tube, wherein an inner tube is slidably inserted into an outer tube, and a suspension spring is inserted into the inner tube. Always urges the inner tube in the extension direction, and connects the inner tube to the vehicle body via the upper bracket and the under bracket. A pipe made of iron or other hard material is fitted into the annular groove, and the outer circumference of the suspension spring is guided in the axial direction by the inner circumference of the pipe.

In this case, it is preferable that the pipe is provided at a position corresponding to the mounting position of the upper bracket and the under bracket.

Another means is a two-wheeled vehicle in which an inner tube is slidably inserted into an outer tube, a suspension spring is inserted into the inner tube, and the suspension spring constantly urges the inner tube in an extending direction. In the front fork of the suspension device for use, a belly-wound synthetic resin band is wound around the outer periphery near the center of the suspension spring, and the outer periphery of this band is slid on the inner periphery of the inner tube.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 show an embodiment of the present invention. , And FIG.

That is, the inner tube 2 is slidably inserted into the outer tube 1, and a suspension spring 9 is disposed inside the inner tube 2, and the suspension spring 9 is provided on a guide 11 provided above the damper cylinder. And a spring guide 8 and 8a suspended from the cap side. A reservoir chamber R including a gas chamber and an oil chamber is provided inside the inner tube 2.

On the inner periphery of the inner tube 2, an annular groove 12 corresponding to the position where the upper bracket 6 and the under bracket 7 are disposed is formed along the axial direction, and a hard material such as iron is formed in the annular groove 12. The pipe 2a is fitted by hydraulic bulging, press fitting, or the like, and the inner circumference of the pipe 2a guides the outer circumference of the suspension spring 9 along the axial direction.

For this reason, even if the inner tube 2 slides up and down to cause warpage with the suspension spring 9, the pipe 2
Since a is hard, the inner circumference of the pipe 2a is prevented from being worn or shaved by the suspension spring 9, so that the occurrence of contamination can be prevented and the durability of the inner tube 2 is impaired. Can be prevented.

Further, since the mounting position of the pipe 2a corresponds to the upper bracket 6 and the under bracket 7,
When these brackets are tightened, the pipe 2a reinforces the inner tube 2 and prevents its bending and deformation.

FIG. 3 shows a front fork according to another embodiment of the present invention. In this front fork, a suspension spring 9 is interposed between the upper end seat portion 13 of the damper cylinder D and a spring guide 8b suspended from the cap side.

Furthermore, a belly-wound synthetic resin band 1 is provided at an arbitrary position of the suspension spring 9, preferably at the outer periphery near the center.
4, and the outer circumference of the band 14 is brought into sliding contact with the inner circumference of the inner tube 2.

The other structure is the same as that of the front fork shown in FIGS.

In this case, when the inner tube 2 slides, it comes into sliding contact with the outer periphery of the inner peripheral band 14 of the inner tube 2. The band 14 prevents the suspension spring 9 from falling down, and Therefore, the inner periphery of the inner tube 2 is prevented from being worn or shaved by the suspension spring 9.

Further, since the band 14 itself is made of a synthetic resin and is soft, the band 14 does not wear or scrape the inner periphery of the inner tube 2 to prevent the occurrence of contamination, and There is no loss of durability.

[0023]

According to the present invention, the following effects can be obtained.

According to the first and second aspects of the present invention, since the hard pipe is fitted on the inner circumference of the inner tube, the inner circumference of the pipe is worn or cut even when the suspension spring slides on the pipe. And the inner tube of the inner tube is worn out, since this pipe prevents the settle between the inner tube and the suspension spring.
As a result, the durability of the inner tube is improved, and the occurrence of contamination is prevented.

According to the second aspect of the present invention, since the pipe is provided at a position corresponding to the bracket such as the upper bracket and the under bracket, even when the bracket is tightened, the pipe bears this tightening force, and the inner tube has Bending deformation can be prevented.

According to the third aspect of the present invention, since the band is provided on the outer periphery of the suspension spring, the band prevents the warp between the inner tube and the suspension spring, thereby reducing the inner periphery of the inner tube. It is possible to prevent the suspension spring from being worn or chipped, thereby preventing the occurrence of contamination and improving the durability of the inner tube.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view of a front fork according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of FIG.

FIG. 3 is a partially cutaway sectional view of a front fork according to another embodiment of the present invention.

FIG. 4 is a partially cutaway sectional view of a conventional front fork.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer tube 2 Inner tube 2a Pipe 6, 7 Bracket 9 Suspension spring 12 Annular groove 14 Band

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takamasa Kamioka 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. F-term (reference) 3D014 DD06 DE08 DE13 DE15 DE16 3J069 AA46 CC01 DD39

Claims (3)

[Claims] 1. An inner tube is slidably inserted into an outer tube, a suspension spring is inserted into the inner tube, and the suspension spring constantly urges the inner tube in an extending direction, so that the inner tube is connected to the upper bracket. In a front fork of a motorcycle suspension system which is connected to a vehicle body via an under bracket, an annular groove is provided in an inner periphery of an inner tube, and an iron or other hard material pipe is fitted into the annular groove. A front fork of a motorcycle suspension device in which an outer periphery of a suspension spring is guided in an axial direction by an inner periphery of the pipe. 2. The front fork of a motorcycle suspension according to claim 1, wherein the pipe is disposed at a position corresponding to a mounting position of the upper bracket and the under bracket. 3. A two-wheeled vehicle suspension device in which an inner tube is slidably inserted into an outer tube, a suspension spring is inserted into the inner tube, and the suspension spring constantly urges the inner tube in a direction of extension. A front fork for a motorcycle suspension device in which a belly-wound synthetic resin band is wrapped around an outer periphery near a center of a suspension spring in a front fork, and the outer periphery of the band is slidably contacted with the inner periphery of an inner tube.