JPS6242873Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a front fork of a two-wheeled vehicle in which a fork pipe is slidably fitted into a bottom case.In particular, the fork pipe is placed at a certain interval inside the open end of the bottom case. This relates to a fixed-fit type front fork in which a guide bush that slides is inserted.

A sectional view of the main parts of a conventional front fork of this type is shown in FIG. As shown in the figure, the conventional fixed-fitting type front fork has a guide bushing with a constant length enlarged diameter part 2a at the open end of the bottom case 2 side into which the fork pipe 1 is inserted, and a Teflon layer coated on both ends of the enlarged diameter part 2a. The bushes 3a and 3b are fitted and fixed, and the fixing means is either by using circlips or by inserting a collar between the bushes 3a and 3b to fix them at a constant interval. An oil seal 4 is provided at the open end to prevent oil from flowing out. Furthermore, fork pipe 1
A piston 5 having a shock absorbing mechanism is provided at the lower end of the piston 5, and a shock absorbing effect is performed during the compression stroke and the extension stroke, respectively. The chamber A partitioned by the guide bushes 3a, 3b, the bottom case 2, and the fork pipe 1 is originally filled with oil to make the fork pipe 1 slide smoothly, but no oil flows in, so the chamber A is separated by the bottom case 2 and fork pipe 1. As the guide bushing 3a is used for a period of time, the oil therein gradually leaks from the oil seal 4 side, causing oil to run out while the guide bushing 3a is in operation, resulting in higher friction. As a result, the fork pipe 1 is damaged and dust is allowed to enter, which impairs running performance.

The present invention eliminates these conventional drawbacks by providing an oil passage in the guide bushing on the axle side (lower side) so that oil in the bottom case enters between the guide bushings when the cushion is operated. . An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a sectional view of essential parts showing one embodiment of the front fork of the two-wheeled vehicle of the present invention, and parts having the same functions as those in FIG. 1 are given the same reference numerals. As shown in the figure, an oil passage is formed in which pressurized oil in the bottom case 2 enters a chamber A partitioned between the guide bushes 3a and 3c by the action of a cushion on the guide bush 3c on the axle side (lower side). 6. For example, as shown in FIG. 3, a vertical groove or a through hole is provided on the outer periphery of the guide bush 3c.

In this way, even if the oil in the chamber A runs out due to long-term use, the oil in the bottom case 2 is pressed in when the cushion is operated and is always replenished, thereby preventing the oil from running out.

As explained in detail above, the present invention lubricates the sliding movement between the oil seal, guide bushing, and fork pipe and reduces friction, resulting in a long life and stable running performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing a conventional front fork, FIG. 2 is a sectional view of a main part showing an embodiment of a front fork of a two-wheeled vehicle of the present invention, and FIG. 3 is a plan view of a guide bush. 1...Fork pipe, 2...Bottom case,
3a, 3b, 3c...Guide bush, 4...Oil seal, 5...Piston, 6...Oil passage.

Claims (1)

[Scope of utility model registration request] In a fixed-fit front fork, in which a guide bushing that slides on the fork pipe is inserted at a certain interval inside the open end of the bottom case, an oil passage communicating with the oil chamber of the bottom case is provided in the guide bushing on the axle side. The front fork of a two-wheeled vehicle is characterized by