公开(公告)号：US20230116767A1

公开(公告)日：2023-04-13

申请号：US17909505

申请日：2021-03-11

Applicant: Hitachi Astemo, Ltd.

Inventor： Yasuhisa OMATA ,  Hideo NAGAYAMA ,  Kosuke TOKUNAGA ,  Ryo SHINATA ,  Reiji NAKAGAWA ,  Shoichiro SOETA

IPC: B24B21/02 ,  F16F9/32

Abstract: This cylinder device of the present aspect includes: a cylinder having a bottomed tubular shape; a seal member provided at an opening of the cylinder; and a piston rod that is provided to protrude from the opening of the cylinder and slides with respect to the seal member. A sliding surface of the piston rod has a chrome-plated layer. In the sliding surface, as characteristic evaluation parameters of a plateau structure surface described in JIS B 0671-2 and ISO 13565-2, a reduced valley depth Rvk is 0.06 μm or more and less than a plating thickness, a reduced peak height Rpk is 0 μm or more and 0.04 μm or less, and a core roughness depth Rk is 0.08 μm or more and 0.16 μm or less.