US 2009/0260938 A1Published application

Shock absorber

OwnerKenji HIKOSAKAinventor

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Abstract

A shock absorber has a seat disk seated on a valve seat of a piston. A disk valve opens and closes a slot provided in the seat disk to extend in the circumferential direction thereof. In a low piston speed region, an orifice passage generates a damping force of orifice characteristics. In an intermediate piston speed region, the disk valve opens to generate a damping force of valve characteristics. In a high piston speed region, the seat disk opens to prevent an excessive increase in damping force. The disk valve partially opens the slot relative to the circumferential direction to gradually increase the flow path area, thereby preventing a sharp change in damping force in a transitional region from the low to intermediate piston speed region.

Claims12

Dependent claims

A shock absorber comprising:

a cylinder having a fluid sealed therein;
a piston slidably fitted in said cylinder;
a fluid passage in which a flow of fluid is induced by sliding movement of the piston in said cylinder;
and
a damping force generating mechanism that generates a damping force by controlling the flow of fluid in said fluid passage;
said damping force generating mechanism including:
an orifice passage that constantly allows the fluid to flow through said fluid passage;
an annular valve seat provided on a valve member through which said fluid passage extends;
a disk-shaped seat disk seated on said valve seat to form a valve chamber together with said valve seat, said seat disk being adapted to open upon receiving a pressure of fluid in said valve chamber;
a through-hole provided in said seat disk to communicate with said valve chamber;
and
a disk valve provided on said seat disk to open and close said through-hole, said disk valve having a pressure-receiving surface defined by a portion thereof that corresponds to said through-hole, said disk valve being adapted to open upon receiving a pressure of fluid in said valve chamber at the pressure-receiving surface;
said disk valve having a valve-opening pressure lower than a valve-opening pressure of said seat disk;
said through-hole being either one of a slot extending in a circumferential direction of said seat disk and a set of small holes arranged close to each other in the circumferential direction of said seat disk;
wherein, when it opens, said disk valve partially opens said through-hole relative to the circumferential direction, thereby gradually increasing a flow path area of said through-hole.

12 more elements

Dependencies are inferred from the claim text.