JPS62265087A - Front-wheel shock absorber for two-wheel barrow - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) This invention relates to improvements in front wheel shock absorbers for motorcycles.

(Prior art) A front wheel shock absorber for a motorcycle equipped with a so-called telescopic type front fork in which inner and outer cylinder members are telescopically fitted with a spring interposed therebetween.In this case, the shock from the road surface is absorbed by the front fork However, in the front fork, which is arranged at an angle, the force perpendicular to the direction of expansion and contraction generates a 7-reaction between the inner and outer cylinders, and this is especially true at the beginning of sliding between the inner and outer cylinders. 7 riction is large, and if the load acting on the front fork is less than this initial 7 riction, there is a problem in that the buffering operation is not performed and the riding comfort is reduced.

To improve this problem, a buffer gc arrangement as shown in FIG. 5 is disclosed in Japanese Patent Publication No. 57-49432. This will be explained below.

1 is the front fork that supports the front wheel, and the front 7
The oar 1 has a built-in hydraulic shock absorbing mechanism, includes an outer tube 2 that is an outer cylindrical member, and an inner tube 3 that is an inner cylindrical member that are fitted into each other, and is configured to be freely expandable and retractable in the axial direction. The front fork 1 is installed at an angle due to caster and trail, and the upper end of the inner tube 3 is connected to the bracket tube 6 of the vehicle body frame 5 via upper and lower brackets 4.4, and a steering handle is mounted on the bracket 4. 7 is arranged.

One end of a link 10 is pivotally attached to the lower end of the outer tube 2 via a pin part 11, and a sub-cushion unit 12 is arranged vertically between the other end of the link 10, which extends rearward and approximately horizontally, and the outer tube 2. placed, link 1 (
) The axle 9 is coupled to the hole in the road.

The sub-cushion unit 12 has a rod 13 connected to one end of the link 10 via a pin 14, and a cylindrical body 15 that slidably houses a piston 16 connected to the rod 13. It is connected to a bracket (2a) protruding from the bracket. Inside the cylindrical body 15 is a conical cushion rubber 17 that comes into contact with the upper surface of the piston 16.
A donut-shaped stopper rubber 18 that comes into contact with the lower surface of the piston 16 is installed inside.

When the front fork 1 is under a large initial load of 7, the sub-cushion unit 12 is operated to expand and contract, and the wheel 8 is pivoted using the lower end of the front fork 1 as a fulcrum to perform a buffering operation. The front fork 1 operates to extend and contract for the first time.

Therefore, an effective and appropriate buffering operation is performed over the entire load range from the initial load, and the riding comfort can be improved.

(Problems to be Solved by the Invention) By the way, in such a shock absorber, the cushion rubber 17 of the sub-cushion unit 12 is compressed via the link 10 due to the increased load on the front wheel during braking, and the link 10 is Because it rotates counterclockwise around 9,
Accordingly, the point of application T on the extension of the 70-nt fork approaches the grounding point H side, and this reduction in trail causes a problem in that straight-line running performance deteriorates.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to suppress the reduction of the trail during braking, reduce the 7-slip, and improve maneuverability during braking.

(Means for Solving the Problem) Therefore, the present invention attaches an L-shaped link to the lower end of the front fork so that it can rotate freely with its middle part as a fulcrum, and attaches the L-shaped link to the horizontal end of the link extending forward from the lower surface of the front fork. In addition to supporting the axle, a support part for braking torque is attached to the upright end of the link that rises along the rear side of the front fork, and elastic bodies are respectively inserted between the link and the lower and side surfaces of the front fork. do.

(Function) During braking, the link rotates in response to the braking torque and uses the axle as a fulcrum to push up the lower end of the front fork, reducing nose dive and moving the axle relatively backwards, which improves the trail. Shrinkage is suppressed.

These significantly improve steering stability during braking.

(Embodiment) In FIGS. 1 and 2, a bracket 22 is formed at the lower end of the seven outer tubes 21 of the front fork 20 and extends obliquely downward to the rear, and an I-shaped link is connected to the bracket 22 via a pin 23. 24 are connected for free rotation.

The link 24 supports the axle 25 at a horizontal end 24A extending forward and approximately horizontally on the lower surface of the outer tube 21, while a brake caliper 26 is attached to an upright end 24B extending obliquely upward along the rear surface of the outer tube 21. It is attached to the brake disc 27 in a predetermined positional relationship. 2
6A and 26B are holes for attaching the caliper.

Then, the link horizontal end 24A and the outer tube 21
There is a combination B rubber 28 between the bottom surface and the link upright end 24B and the outer tube 2111111.
Bump rubbers 29 and 30 are interposed between the surfaces. Note that the bump rubbers 29 and 30 are arranged at different distances from the bin 23 (support axis of the link), and normally the bump rubber 2
The bump rubbers 29 and 30 are designed to provide a soft cushioning for the wheel adhesive band, while the bump rubbers 29 and 30 absorb heavy loads during jumps and the like.

Reference numeral 31 indicates a well-known anti-nose valve Isokare which restricts the flow of pressure side hydraulic oil of the front fork 20 during braking and suppresses sinking.

At the beginning of the action of the compression side load, such as when a two-wheeled vehicle is traveling on a rough road and ends up on a bump on the road surface, the front 7t-2 () functions as a rigid body due to the 7-rection of the inner and outer cylinders, and the link 24 rotates counterclockwise around the pin 23, whereby the compression rubber 21) is compressed against the bottom surface of the bottom case 21, effectively and appropriately cushioning the initial load.

After the initial load buffering operation in the large toe range of the initial 7 riction of the front fork 20, the compression rubber 2
8 acts as a stopper at its stroke limit, and at the point when it exceeds the range of the initial 7 riction a of 7 riction 20,
The inner and outer cylinders begin to contract in the axial direction, providing a cushioning effect.

Further, the rotation of the link 24 in the clockwise direction in the figure is restricted by the bump rubbers 29 and 30 interposed between the side surface of the outer tube 21, and this increases the followability of the front fork extension side. To maintain good landing conditions after a wheel bounces.

On the other hand, when braking, anti-nose dive l'jlNIt31
While suppressing the sinking of the front fork 20,
The link 24 rotates clockwise in the figure in response to the braking torque acting on the brake caliper 26, and as a result, the axle 25 moves relative to the pin 23 from point a to point 1, so trail correction is performed. Amount l and nose gip reduction amount I+
is obtained.

That is, if we consider the movement of the axle 25 from point a to point b with the pin 23 as a fulcrum by the rotation of the link 24 in the clockwise direction in terms of horizontal and vertical displacement, first the axle 25 This means that the front fork is relatively pushed upward by a force of 20'11 because it cannot actually be displaced in the vertical direction.This pushing up compensates for the amount of sinking that occurs with braking, and the 7-'s dive It exerts an inhibitory effect.

In addition, in the horizontal direction, the axle 25 is displaced backward by an amount I relative to the axis of the front 7 orifice 20. The distance between the perpendicular line and the point where the road surface intersects increases, and straightness during braking is maintained well.

Note that since the compression rubber 28 has a seat portion 32 that is slidably fitted into the guide hole 33 of the link 24, the initial load can be adjusted using the adjustment bolt 34 depending on the usage conditions and the like.

In FIG. 3, the axle 25 is located on the center line of the front fork 20, which is a layout with a so-called center axle tendency, whereas the axle 25 is mounted at a different position to improve straight running performance. It is offset to the rear of the front fork 20 to create a layout that tends to be a leading axle.

In this case, a stopper 35 is provided on the link 24 so as to project from the brake shoe (not shown) of the drum brake. Note that, due to the layout, only one bump rubber 29 is provided on the side surface of the front fork 20.

(Effects of the Invention) In summary, according to the present invention, an L-shaped link is attached to the lower end of the front 7 oak so that the L-shaped link can rotate freely with its intermediate portion as a fulcrum, and the horizontal end of the link extends forward from the lower surface of the front fork. In addition to supporting the axle on the front fork, a support part for braking torque is attached to the upright end of the link that rises along the rear side of the front fork, and an elastic body is inserted between the link and the lower and side surfaces of the front fork. As a result, it is possible to suppress sinking during braking, improve steering performance, and correct trail changes to maintain good straight-line driving performance.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a partially cutaway side view, Fig. 3 is a partially cutaway side view showing another embodiment, and Figure tttJ4 is a block diagram showing a prior art. It is. 20...Front fork, 21...Outer tube, 23...Pin, 24...L-shaped link, 25...
... Axle, 26... Brake caliper, 27... Brake disc, 28... Compression rubber,
29.30...Bump rubber. Figure 3 Procedural amendment (voluntary) July 11, 1985

Claims (1)

[Claims] An L-shaped link is attached to the lower end of the front fork so that it can rotate freely using its middle part as a fulcrum, and the axle is supported by the horizontal end of the link that extends forward from the lower surface of the front fork, and stands up along the rear side of the front fork. A front wheel shock absorbing device for a two-wheeled vehicle, characterized in that a support part for braking torque is attached to the upright end of the link, and elastic bodies are interposed between the link and the lower and side surfaces of the front fork.