JPH0117515Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the piston structure of a front fork.

In a front fork in which an inner cylinder is slidably fitted into an outer cylinder via a piston fixed to one end of the inner cylinder, the piston is fixed to the inner cylinder by pin connection or welding. However, the pin connection increases the number of parts and the fixing work is troublesome, and the welding has the disadvantages of unavoidable adverse thermal effects.

The present invention was developed to effectively eliminate such inconveniences, and its purpose is to have a simple structure with a small number of parts, and to facilitate the work of assembling the piston into the inner cylinder. It is possible to provide a front fork piston structure.

In order to achieve such an object, the present invention provides a front fork in which an inner cylinder is slidably fitted into an outer cylinder via a piston fixed to one end of the front fork.
A concave groove is provided on the inner periphery of the inner cylinder, and a plurality of plate-like pieces are provided on the piston, some of which are to be fitted into the grooves provided on the inner periphery of the inner cylinder, protruding radially, and the piston is provided on the inner periphery of the inner cylinder. The gist is that it is press-fitted to the inner periphery.

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a partially cutaway side view of a front fork having a piston structure according to the present invention, and FIG. 2 is an enlarged cutaway side view of the upper part of the inner cylinder of the front fork.

In the front fork 1 shown in FIG. 1, 2 is an outer cylinder, and an inner cylinder 3 is inserted into the outer cylinder 2 from below.
is inserted, and the inner cylinder 3 is fitted to the inner periphery of the outer cylinder 2 via a piston 4 fixed to its upper end so as to be vertically slidable. A guide member 5 whose inner circumference slides on the outer circumference of the inner tube 3 is fitted on the inner circumference of the lower end of the outer tube 2, and the guide member 5 has a stopper ring 6.
The position is fixed at .

In addition, a spring receiver 7 is provided on the outer periphery of the intermediate portion of the inner cylinder 3 as shown in the figure.
is fixed by a stopper ring 8, and a coil spring 9 is stretched between the spring receiver 7 and the upper end surface of the guide member 5. Furthermore, a lower mounting member 10 is fixed to the lower end of the inner cylinder 3, and the outer peripheral sliding surface of the inner cylinder 3 is covered and protected by a bellows-shaped dust boot 11 installed between the inner cylinder 3 and the outer cylinder 2. has been done.

On the other hand, the upper end of the outer cylinder 2 is closed by an upper mounting member 12, and a stop lever 13 is fixed to the lower surface of the mounting member 12. A coil spring 14 is stretched between the mounting member 12 and the piston 4 as shown in the figure.

By the way, the piston 4 is molded from resin, and the lower surface of the upper wall 4a-1 of the main body 4a having a substantially cylindrical shape has a plate-like piece 4b having a protrusion 4b-1 at its lower end. is multiple (4 in the example shown)
) The upper wall 4a-
A ventilation hole 4c is bored in the center of the air conditioner 1.

On the other hand, a groove 3a is formed in the upper inner periphery of the inner cylinder 3, into which each projection 4b-1 of the plate-shaped piece 4b provided on the piston 4 is fitted.

The piston 4 is fixed to the upper end of the inner cylinder 3 by means of the peripheral wall 4a-4 of the piston 4, as shown in FIG.
2, while fitting the inner periphery to the outer periphery of the inner cylinder 3, the plate-like pieces 4b... protruding from the piston 4 are press-fitted into the inner periphery of the inner cylinder 3, and the protrusions 4b-1 are provided at the lower end of each plate-like piece 4b. This is accomplished by fitting into a groove 3a formed on the inner periphery of the inner cylinder 3.

Even if a force is applied to the piston 4 press-fitted to the upper end of the inner cylinder 3 in the direction of its removal (in the Z direction in FIG. 2), the plate-shaped piece 4b protruding from the piston 4
Each protrusion 4b-1 of... has a concave groove 3 provided on the inner periphery of the inner cylinder 3.
Since the piston 4 is fitted into the inner cylinder 3, the piston 4 does not come out from the inner cylinder 3. Further, the elastic force of the coil spring 14 stretched between the piston 4 and the mounting member 12 acts advantageously in the direction of preventing the piston 4 from coming off.

In the above front fork 1, the upper end of the outer cylinder 2 is connected to the vehicle body side via the upper mounting member 12, the lower end of the inner cylinder 3 is connected to the wheel side via the lower mounting member 10, and these inner and outer cylinders 3 and 2 move relative to each other. This relative expansion and contraction movement of the inner and outer cylinders 3 and 2 causes the internally incorporated coil spring 9 to expand and contract, and the shock applied from the outside is effectively absorbed and alleviated by the buffering action of the coil spring 9.

In the above arrangement, the piston 4 is easily fixed to the inner cylinder 3 by simply being press-fitted to the upper end of the inner cylinder 3, so that the work of assembling the piston 4 to the inner cylinder 3 is facilitated.

Furthermore, since the piston 4 is assembled without pin connection or welding as in the conventional method, the number of components of the piston section can be reduced and the structure can be simplified, and the piston section is not affected by adverse thermal effects.

As is clear from the above description, according to the present invention, a groove is provided on the inner periphery of the inner cylinder, and a plurality of plate-shaped pieces are provided on the piston, some of which are fitted into the grooves formed on the inner periphery of the inner cylinder. Since the pistons are protruded radially and fixed by being press-fitted into the inner periphery of the inner cylinder, the piston structure can be simplified and the work of assembling the pistons into the inner cylinder can be facilitated. I can do it.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a partially cutaway side view of a front fork having a piston structure according to the present invention, and FIG. 2 is a side view of the upper part of the inner cylinder of the front fork. FIG. 3 is an enlarged cutaway side view. In the drawing, 1 is the front fork, 2 is the outer cylinder, and 3 is the front fork.
is an inner cylinder, 4 is a piston, 4b is a plate-like piece, 4b-1
is a protrusion, and 9 and 14 are coil springs.

Claims (1)

[Scope of utility model registration request] In a front fork in which an inner cylinder is slidably fitted into an outer cylinder via a piston fixed to one end of the front fork, a groove is provided on the inner periphery of the inner cylinder, and a part of the inner cylinder is attached to the inner cylinder. A piston structure for a front fork, characterized in that a plurality of plate-like pieces are provided radially projecting to fit into the grooves provided on the inner periphery, and the piston is press-fitted into the inner periphery of the inner cylinder.