JPS6332074Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a front fork for a two-wheeled vehicle with improved operability.

(Conventional front fork) The conventional front fork shown in Figures 1 and 2 is
An inner tube 2 is slidably inserted into an outer tube 1, and an axle support portion 3 is provided on the outer tube 1.

The axle support portion 3 is located between the bearing portions 4 and 5 of the outer tube 1. Since the axle support part 3 is positioned between the bearing parts 4 and 5 in this way, for example, when a force in the direction of the arrow is applied to the axle support part 3, the same direction is applied to both the bearing parts 4 and 5. .
When a force acts in the same direction in this way, the force is shared between both bearing parts 4 and 5, and therefore the frictional force acting on each bearing part 4 and 5 becomes smaller accordingly. If the frictional force is reduced, the operability of the front fork will be improved accordingly.

(Problems to be Solved by the Present Invention) In the conventional front fork as described above, when a load is applied to the inner tube 2, the inner tube 2 protrudes from the lower end of the outer tube 1, and its protruding end touches the road surface. There was a risk of coming into contact with. In particular, in cars with small tire diameters, the risk becomes even greater when the stroke of the front fork is set to be large.

For example, in off-road vehicles designed for motocross, the stroke of the front fork is set to be large relative to the tire diameter. Moreover, since this off-road vehicle runs on a highly uneven course, the amount of protrusion of the inner tube 2 inevitably becomes large. When driving in deep ruts or cornering with a large inner tube protruding, the inner tube would come into contact with the road surface, often causing the car to overturn.

To that end, this conventional front fork
There was a problem that it could not be used for vehicles such as off-road vehicles. .

The purpose of this invention is to take advantage of the above-mentioned conventional advantages of reducing the frictional force of the bearing, while
The purpose is to prevent the axle support portion from protruding significantly from the lower end of the guide pipe.

(Means for Solving the Problem) This invention has a damper cylinder with sliding parts at both ends slidably installed inside the guide pipe, and the piston rod end of this damper cylinder fixed to the upper end of the guide pipe. , a spring is interposed between the upper end portion and the damper cylinder, and an axle is attached to the sliding portion on the opposite side of the piston rod, and the guide pipe is provided with a spring that extends over the stroke range of the slider. A notch is formed, and the axle is movable along the notch, and when the front fork is fully extended, the axle protrudes from the guide pipe, and under normal conditions, the axle is positioned below the guide pipe. The feature is that the spring force of the spring is set so as to

(Operation of the present invention) Since the present invention is configured as described above, the axle is located within the guide pipe when the driver is riding on the vehicle. Since the axle is located below the guide pipe in the normal state, the guide pipe does not protrude excessively from the mounting position of the axle.

(Embodiment of the present invention) In the embodiment shown in Figs. 3 and 4, the guide pipe 1
0 is provided with a bracket 11 for attaching the front fork to the vehicle body,
A damper cylinder 1 is installed inside this guide pipe 10.
2 are slidably fitted together.

A piston is slidably provided in the damper cylinder 12, and one end of a piston rod 13 is fixed to the piston. The other end of this piston rod 13 is connected to the guide pipe 10.
An eye 14 that protrudes inward and is provided at the protruding end,
It is fixed to a pin 15 provided at the upper end of the guide pipe 10.

The eye 14 is provided with a spring receiver 16, and a spring 17 is interposed between the spring receiver 16 and the damper cylinder 12.

The damper cylinder 12, which is slidably installed inside the guide pipe 10 as described above, is provided with sliding parts 12a and 12b at both ends thereof, and an axle support part 18 is provided in one sliding part 12b located on the lower side. ,
An axle 19 is fixed to this axle support part 18, and this axle 19 is made perpendicular to the guide pipe 10.

The guide pipe 10 is formed with a notch 20 in its axial direction.
The lower end of the axle 19 is open to the lower end of the guide pipe 10, and its width is slightly larger than the diameter of the axle 19.
9 can move up and down along this notch 20.

Thus, when the front fork is fully extended, the axle 19 is located outside the guide pipe 10 together with one sliding portion 12b located on the lower side.
When the vehicle is in a normal state, axle 1
The spring force of the spring 17 is set so that the spring 9 moves to the position shown by the chain line in FIG.

Note that the above-mentioned normal state refers to a state where the vehicle is stationary with a driver on board, or a state where the vehicle is running at a constant speed on a flat road.

In the normal state indicated by the chain line, the axle 19 is maintained within the guide pipe 10 at its lower end.

In this normal state, the axle 19 and the lower end of the guide pipe 10 are maintained at substantially the same position, so that the amount of protrusion of the lower end of the guide pipe 10 with respect to the position of the axle 19 is reduced.

Therefore, in the normal state, the axle 19 and the lower end of the guide pipe 10 are held at substantially the same position, and the guide pipe 10 is inserted from below the axle 19.
The bottom edge does not protrude.

Further, since the amount of protrusion of the guide pipe in the normal state is almost negligible, the amount of protrusion can be reduced even when the front fork is in the most compressed state.

Furthermore, even if a force is applied to the axle 19 in the direction of the arrow in FIG.
Since a reaction force in the same direction acts on each of the sliding parts, the frictional force at these sliding parts becomes small, and the operability of the front fork is not inhibited as in the conventional case.

(Effects of the Present Invention) Since the present invention is constructed as described above, the guide pipe does not protrude downward onto the axle in a so-called normal state. Since the amount of protrusion of the guide pipe is small in this way, the lower end of the guide pipe will never come into contact with the road surface even if it is installed on a car with a small tire diameter.

Further, as described above, since the amount of protrusion of the guide pipe in the normal state is small, the amount of protrusion of the guide pipe is also small even when the front fork is in the most compressed state.

[Brief explanation of the drawing]

Figures 1 and 2 show a conventional front fork, with Figure 1 being a partial sectional view and Figure 2 showing the front fork.
FIGS. 3 and 4 are enlarged sectional views of the circled portions of the drawings, and show embodiments of this invention. FIG. 3 is a sectional view, and FIG. 4 is a front view of the main parts. DESCRIPTION OF SYMBOLS 10... Guide pipe, 12... Damper cylinder, 12a, 12b... Sliding part, 13... Piston rod, 17... Spring, 19... Axle.

Claims (1)

[Scope of utility model registration request] A damper cylinder with sliding parts at both ends is slidably installed inside the guide pipe, and the piston rod end of the damper cylinder is fixed to the upper end of the guide pipe, and a damper cylinder is provided between the upper end and the damper cylinder. While a spring is interposed therebetween, an axle is attached to the sliding portion on the opposite side of the piston rod, and a notch is formed in the guide pipe over the stroke range of the slider. A two-wheeled vehicle in which the axle is movable, and the spring force of the spring is set so that the axle protrudes from the guide pipe when the front fork is fully extended, and the axle is positioned below the guide pipe in a normal state. For front fork.