JPH11315878A - Front fork - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the inner diameter of an axle side tube from being distorted, and concurrently, lighten its weight, and reduce its cost. SOLUTION: In this front fork, in which a car body side tube 11 and an axle side tube are engaged with each other in such a way as to be freely slid, a half split axle bracket 14 is projected out of the outer circumference at the lower part of the axle side tube, and an axle is inserted into a mounting hole 15 provided in the axle bracket 14 so as to allow split clamping to be performed, the axle bracket is integrally provided in a position off-set from the axis O of the axle side tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front fork which is interposed between a vehicle body and an axle of a motorcycle and serves as a shock absorber and a fork for damping vibration from a road surface.

[0002]

2. Description of the Related Art In general, a motorcycle such as a motorcycle is provided with a front fork serving as a fork and a shock absorber between a front body and an axle.

In this front fork, a vehicle body side tube and an axle side tube are slidably fitted to each other, and the axle side tube is mounted on the axle side via an axle bracket.

In this case, a conventional axle-side tube and axle bracket, for example, those shown in FIGS. 4 to 6 have been developed.

That is, two brackets 2 and 3 for mounting a brake and an axle bracket 4 opposite to the brackets 2 and 3 are protrudingly provided on the outer periphery of a lower portion of the axle side tube 1.

The axle bracket 4 is used for the axle side tube 1.
Is provided integrally at the center of the outer periphery of the lower part of the bracket body, which is a half-shaped bracket body 4 projecting laterally from the tube body 1a.
a, an axle mounting hole 5 formed in the bracket main body 4a in the horizontal direction, a split tightening portion 6a, 6b integrally provided at an end of the bracket main body 4a, and a bolt mounting hole 8 formed in the split tightening portion 6a, 6b. After the axle is inserted into the axle mounting hole 5, the split tightening portions 6a and 6b are tightened by the bolts 7 inserted into the bolt mounting holes 8.

[0007]

In the above-mentioned conventional front fork, the axle bracket 4 is fastened with bolts 7 so that the axle bracket 4 is integrally provided on the central outer periphery corresponding to the center axis of the tube body 1a. Sometimes, stress acts on the thin central portion A of the tube main body 1a as shown in FIG. 6 to cause distortion in the inner diameter portion of the central portion A, whereby the axle-side tube 1 and the axle-side tube There is a possibility that the expansion and contraction operation between the vehicle body side tube and the fitting tube 1 may be adversely affected.

Therefore, if the outer diameter of the tube body 1a is increased or the thickness of the central portion A of the tube body 1a is increased in order to reduce the inner diameter distortion of the axle-side tube 1, the weight increases. Can not reduce the weight of
It is also a waste of material.

Accordingly, an object of the present invention is to provide a front fork capable of preventing the inner diameter distortion of the axle-side tube, and at the same time reducing the weight and cost.

[0010]

In order to achieve the above object, a means of the present invention is to provide a vehicle body side tube and an axle side tube which are slidably fitted to each other, and are formed in a half-split shape on the lower periphery of the axle side tube. In the front fork which protrudes the axle bracket and inserts the axle into the mounting hole provided in the axle bracket and performs split tightening, the axle bracket is integrally provided at a position eccentric from the axis of the axle side tube. The present invention is characterized in that strain generated in a central portion of a tube is reduced.

[0011]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given based on FIGS.

The front fork according to the present invention may be an upright front fork in which an inner tube serving as a vehicle body side tube is slidably inserted into an outer tube serving as an axle side tube, or conversely, an inner tube serving as an axle side tube may be used as a vehicle body. It can also be applied to an inverted front fork that is inserted into the outer tube that is the side tube.

One embodiment of the axle side tube is shown in FIGS.

The axle side tube 11 is a tube body 11a.
And two upper and lower brackets 12 and 13 for mounting a brake provided at a lower portion of the outer periphery of the tube main body 11a, and a half-split axle bracket 14 integrally protruding from the opposite side of the brackets 12 and 13 as well. .

As shown in FIGS. 1 and 3, the axle bracket 14 is provided at a position eccentric to the left or right with respect to the axis O of the tube body 11a.

The axle bracket 14 is used for the tube body 1.
1a, a half-split bracket main body 14a protruding from the eccentric position at the lower part of the outer periphery, an axle mounting hole 15 formed at the center of the bracket main body 14a, and a split inclined and integrally provided at an end of the bracket main body 14a. Fastening parts 16a, 16b,
A bolt mounting hole 18a is formed in the split tightening portions 16a and 16b along the inclined direction.

A slot 20 extending to the bracket body 14a side is formed between the two split fastening portions 16a and 16b. The axle is inserted into the axle mounting hole 15 and the bot 7 is inserted into the bolt mounting hole 18 to perform split tightening, whereby the axle is connected to the axle bracket 14, whereby the lower portion of the front fork is connected to the axle. .

In the present invention, as shown in FIG. 3, the bracket body 14a of the axle bracket 14 is
The connecting portion P between the base end side of the axle bracket 14 and the tube main body 11a is inevitably thickened at the time of molding due to being provided eccentrically with respect to the axis O of 1a. For this reason, the inner peripheral portion B of the tube main body 11a corresponding to the center X of the bracket main body 14a is close to the thick portion P, and when the split tightening portions 16a and 16b are tightened, the stress is reduced to the thick portion P. The inner peripheral portion B acts on the inner peripheral portion B through the inner peripheral portion B, and the inner peripheral portion B does not suffer from inner diameter distortion due to the strength of the thick portion P.

Incidentally, as shown in FIG.
The thickness of the portion a near the axle bracket 14 may be slightly increased along the circumferential direction.

[0020]

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

Since the axle bracket is integrally provided at a position eccentric from the axis of the axle-side tube, the connecting portion between the base end of the axle bracket and the tube body of the axle-side tube is inevitably thick during molding. As a result, even when stress is applied to the tube body when the axle is inserted into the axle mounting hole of the axle bracket to perform split fastening, the tube body is not distorted. For this reason, the expansion and contraction operation of the axle side tube and the body side tube is not adversely affected.

Similarly, since the tube main body of the axle side tube is not distorted, there is no need to bother the wall thickness of the tube main body, the weight can be reduced, the material can be saved, and the workability is excellent, so that the cost can be reduced. .

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of an axle side tube and an axle bracket of a front fork according to the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a cross-sectional view of an axle bracket of FIG. 1;

FIG. 4 is a partially cutaway front view of a conventional axle-side tube and axle bracket.

FIG. 5 is a side view of FIG. 4;

FIG. 6 is a cross-sectional view of the axle bracket part of FIG. 4;

[Explanation of symbols]

 11 Body side tube 14 Axle bracket 15 Mounting hole O Shaft core

Claims (1)

[Claims] 1. A vehicle body tube and an axle tube are slidably fitted to each other, and a half axle bracket is protruded from a lower outer periphery of the axle tube, and the axle is inserted into a mounting hole provided in the axle bracket. A front fork, wherein an axle bracket is integrally provided at a position eccentric from an axis of an axle side tube in a front fork which is inserted and tightened.