JP2578562Y2 - Front fork - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a front fork which is interposed between a vehicle body and an axle of a vehicle such as a motorcycle and serves as a shock absorber and a fork for damping vibration from a road surface.

[Prior Art] As a front fork of this type, for example,
The one disclosed in JP-A-21236 is known.

In this front fork, a wheel side tube is slidably inserted into a body side tube, a damper cylinder is erected in the center of the wheel side tube, and a piston rod is movably inserted into the damper cylinder via a piston. It is connected to the side tube. Further, a suspension spring is disposed outside the damper cylinder, and the suspension spring is connected to an upper portion of the vehicle body side tube via a spacer and a spring seat.

[Problem to be Solved by the Invention] Generally, in a front fork, there is a difference in rigidity between the rigidity of a vehicle body side tube and an inner tube and the rigidity of a damper cylinder and a piston rod, and a bending force is applied by an external force. And the amount of bending between the piston rod and the damper cylinder increases.

For this reason, in the front fork as described above, when the vehicle jumps like motocross traveling, the piston rod and the damper cylinder are bent, and the spring cylinder portion serving as a guide hits the outer periphery of the damper cylinder and the cylinder head, and between the two. There is a defect that scratches occur. Not only does this flaw lower the durability of the part, but there is a problem that chips generated from the flaw bite into the valve in the front fork, and the damping force cannot be generated as desired.

Therefore, an object of the present invention is to provide a front fork in which a spacer or a guide connected to a suspension spring does not hit the outer periphery of a damper cylinder or an oil lock case.

[Means for Solving the Problems] In order to achieve the above object, the configuration of the present invention is such that a vehicle body side tube and a wheel side tube are slidably fitted to each other, and a damper cylinder stands up in the wheel side tube. The piston rod is movably inserted into the damper cylinder via a piston, and a suspension spring is disposed between the outer periphery of the damper cylinder and the inner periphery of the wheel-side tube. A front fork, which is connected to an upper part of a vehicle body side tube via a spring guide slidingly contacting the periphery and a spacer coupled to the spring guide, and an upper part of the damper cylinder is provided with an oil lock case standing in the spacer. A ring is provided on the outer periphery of the oil lock case, facing the inner periphery of the spacer and any clearance, A guide that opposes the outer periphery of the damper cylinder by providing an arbitrary clearance on the inner periphery of the piston guide, and an oil lock piece that opposes the oil lock case is provided above the outer periphery of the piston rod. Things.

[Operation] The oil lock piece fits into the oil lock case during the compression operation to make the cushion by the oil lock pressure effective. Even if the piston rod and the damper cylinder are bent by an external force, the ring abuts on the inner periphery of the spacer, The guide abuts the outer periphery of the damper cylinder, and does not damage the outer periphery of the oil lock case or the damper cylinder.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

An inner tube as a wheel side tube 2 is slidably inserted into an outer tube as a vehicle body side tube 1, a damper cylinder 3 is erected from below into the wheel side tube 2, and a piston rod is inserted into the damper cylinder 3 via a piston. The upper part of the piston rod 7 is connected to the vehicle body side tube 1 via an upper cap member 8.

A suspension spring 9 is interposed between the wheel side tube 2 and the damper cylinder 3 along the axial direction, and a hollow spacer 10 is interposed between the suspension spring 9 and the cap member 8 in series. The body side tube 1 and the piston rod 7 are constantly urged in the extending direction via the cap member 8.

The spring guide 11 and the seat 5 are located below the spacer 10.
The bearing 12 provided on the outer periphery of the spring guide 11 is in sliding contact with the inner periphery of the wheel side tube 2.
Further, the spacer 10 is provided with an oil hole 19 so that the inner and outer oil chambers 20 and 2 are provided.
1 is connected.

A hollow oil lock case 13 is erected at the upper end of the damper cylinder 3, and an oil hole 14 is formed in the oil lock case 13.

A tapered surface 15 is formed on the inner periphery of the upper part of the spring guide 11, and the lower end of the spacer 10 is fitted through the tapered surface 15 to join them.

A ring 6 made of metal, resin, or the like is provided on the outer periphery of the upper part of the oil lock case.

A guide 17 made of metal, resin, or the like is provided on the inner periphery of the spring guide 11 so as to be free to float. The guide 17 faces the outer periphery of the oil lock case 13 and the outer periphery of the damper cylinder 3 via an arbitrary clearance.

In the case of a design in which the distance between the ring 6 and the spring guide 11 is short, it can be used without the guide 17.

Oil lock piece on the outer periphery of the upper part of piston rod 7
An oil lock case 18 is provided to face the oil lock case 13.

When the front fork expands and contracts, the spacer 10 and the spring guide 4 move up and down in conjunction with the piston rod 7.
When the piston rod 7 and the damper cylinder 3 are bent by an external force, the ring 6 slides on the spacer 10 and the guide 17 slides on the outer periphery of the damper cylinder 3 only.
The damper cylinder 3 is not damaged by the spring guide 4.

At the time of compression operation, the oil lock case 18 descends in conjunction with the piston rod 7 and gradually fits into the oil lock case 13 near the time of maximum compression to exert a cushion by the oil rod pressure.

[Effects of the Invention] According to the present invention, a ring is provided on the outer periphery of the oil lock case, and a guide is provided on the inner periphery of the spring guide. Therefore, even if the piston rod or the damper cylinder is bent by an external force, these rings and the guide can be used. Thus, since the position of the spring guide is restricted so as not to interfere with the oil lock case and the damper cylinder, a remarkable effect that the outer periphery of the oil lock case and the damper cylinder is not damaged and no chips are generated is obtained.

[Brief description of the drawings]

FIG. 1 is a front view, partially cut away, of a front fork according to the present invention. [Description of Signs] 1 ... Tube on body side 2 ... Tube on wheel side 3 ... Damper cylinder 6 ... Ring 7 ... Piston rod 9 ... Suspension spring 10 ... Spacer 11 ... Spring guide 13 ... Oil lock case 17 ... Guide

Claims (1)

(57) [Scope of request for utility model registration] A vehicle-side tube and a wheel-side tube are slidably fitted to each other, a damper cylinder stands up in the wheel-side tube, and a piston rod is movably inserted into the damper cylinder via a piston; A suspension spring is disposed between the outer periphery of the damper cylinder and the inner periphery of the wheel-side tube, and the upper portion of the suspension spring is provided with a spring guide sliding on the inner periphery of the wheel-side tube and a spacer coupled to the spring guide. In the front fork, which is connected to the upper part of the side tube and has an oil lock case that stands in the spacer above the damper cylinder, the oil lock case is opposed to the outer circumference of the oil lock case by providing any clearance with the inner circumference of the spacer. The outer ring of the damper cylinder and the optional clear run are provided on the inner circumference of the spring guide. Front fork, characterized in that the provided opposing guide freely floating is provided, provided the oil lock piece further facing the oil lock case to the outer peripheral upper portion of the piston rod.