Patent ID: 11927241
Assignee: HITACHI ASTEMO, LTD.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A shock absorber comprising:
a cylinder which is filled with a working fluid;
an outer tube which is provided on an outer circumferential side of the cylinder;
a reservoir chamber which is formed between the outer tube and the cylinder;
a piston which comes into sliding contact with an inner surface side of the cylinder and divides the inside of the cylinder into a one side chamber and an opposite side chamber;
a piston rod in which the piston is fixed to one end and an opposite end extends out of the cylinder;
a seal member which comes into sliding contact with the piston rod and prevents the working fluid from leaking out of the cylinder;
a rod guide which is provided at a position on a side defined by the seal member of the cylinder and guides the piston rod; and
a friction generating member which is provided at a position on a side defined by the seal member of the cylinder and comes into sliding contact with the piston rod,
wherein the friction generating member has an annular elastic rubber portion which comes into sliding contact with the piston rod and a base portion to which the elastic rubber portion is fixedly attached,
wherein the elastic rubber portion is formed such that an upstream side and a downstream side of the elastic rubber portion are able to communicate with each other when a differential pressure between the one side chamber of the cylinder and the reservoir chamber reaches a predetermined pressure,
wherein a cross-sectional area of a communication path formed in the base portion is smaller than a cross-sectional area of a communication path between the piston rod and the rod guide, and
wherein the upstream side and the downstream side are communicate with each other via
the communication path between the piston rod and the rod guide, and
the communication path formed in the base portion.