JPS6332073Y2 - - Google Patents

Description

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

(Prior art) 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, a force in the same direction is applied to both the bearing parts 4 and 5. act. If a force acts in the same direction in this way, the force will be shared between both bearings 4 and 5, so
The frictional force acting on the individual bearings 4, 5 is correspondingly reduced. If the frictional force is reduced, the operability of the front fork will be improved accordingly.

(Problem to be solved by the 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 contact. 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 often came into contact with the road surface and caused the vehicle to fall.

Therefore, there was a problem that this conventional front fork 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 includes a damper cylinder installed inside the guide pipe, a piston rod of the damper cylinder facing inside the guide pipe, a slider provided at the tip of the piston rod, and a slider provided at both ends of the slider. A sliding part that contacts the inside of the guide pipe is provided, and an axle is attached to the lower sliding part located on the opposite side of the damper cylinder. Moreover, the guide pipe has a notch that extends over the stroke range of the slider. A spring is interposed between the damper cylinder and the slider, and the action of this spring causes the axle to move into the guide pipe when the front fork is fully extended. The main feature is that the axle protrudes from the guide pipe, and the axle is located below the guide pipe in the normal state.

(Operation of the present invention) Since the present invention is configured as described above, the axle is located within the guide pipe in the normal state when the driver rides 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
A bracket 11 for attaching the guide pipe to the vehicle body is provided at the upper end of the guide pipe 10, and a damper cylinder 12 is fitted inside the guide pipe 10.

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 the piston rod 13 projects outward from the cylinder 12 and faces into the guide pipe 10.

A slider 14 is connected to the tip of the piston rod 13, and a spring 15 is interposed between the slider 14 and the damper cylinder 12.

Furthermore, the slider 14 is provided with sliding parts 14a and 14b at both ends thereof, and an axle support part 16 is formed on one of the sliding parts 14b located on the lower side, and an axle 17 is formed on this axle support part 16. fixed,
This axle 17 is made perpendicular to the guide pipe 10.

A notch 18 is formed in the guide pipe 10 in the axial direction thereof. This notch 18
has its lower end open to the lower end of the guide pipe 10, and its width is slightly larger than the diameter of the axle 17. Therefore,
Axle 17 perpendicular to guide pipe 10
can move up and down along this notch 18.

In the figure, reference numeral 19 is a brake stopper provided on the slider 14, and 20 is a dust cover attached to the lower end of the guide pipe 10.

Thus, when the front fork is fully extended, the axle 17 is located outside the guide pipe 10 together with the one sliding portion 14b located on the lower side.
When the vehicle is in a normal state, axle 1
The spring force of the spring 15 is set so that the spring 7 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 shown by the chain line position above,
The axle 17 is maintained within the guide pipe 10 at its lower end.

In this normal state, the axle 17 and the lower end of the guide pipe 10 are maintained at substantially the same position, so the amount of protrusion of the lower end of the guide pipe 10 is reduced relative to the position of the axle 17.

Further, as mentioned above, 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. Further, as shown in FIG. 4, when the force W acts on the axle 17, both the sliding parts 14a, 14
Since the reaction forces P and Q in the same direction act on b, the frictional force at these sliding parts is reduced, and the operability of the front fork is not inhibited as in the prior art.

(Effects of the Present Invention) With the above structure, the guide pipe does not protrude below the axle in a so-called normal state. In this way, since the amount of protrusion of the guide pipe is small, the lower end of the guide pipe will not 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. Figure 1 is a partial sectional view, Figure 2 is an enlarged sectional view of the circled part in Figure 1, and Figures 3 and 4 are views of this front fork. This shows an example of the invention, and Fig. 3 is a cross-sectional view;
FIG. 4 is a front view of the main parts with the dust cover removed. 10... Guide pipe, 12... Damper cylinder, 13... Piston rod, 14... Slider, 14a, 14b... Sliding part, 15... Spring, 17... Axle.

Claims (1)

[Scope of utility model registration request] A damper cylinder is installed inside the guide pipe, the piston rod of this damper cylinder faces inside the guide pipe, a slider is provided at the tip of this piston rod, and sliding parts that contact the inside of the guide pipe are provided at both ends of this slider. With,
The axle is attached to a lower sliding part located on the opposite side of the damper cylinder, and a notch is formed in the guide pipe over the stroke range of the slider, and the axle is moved along this notch. On the other hand, a spring is interposed between the damper cylinder and the slider, and due to the action of this spring, the axle protrudes from the guide pipe when the front fork is fully extended, and the axle is placed below the guide pipe in the normal state. A front fork for two-wheeled vehicles with a positioning configuration.