| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a hydraulic shock absorber mounted on a vehicle, wherein it is difficult to generate hitting sound, namely, contact sound between an annular groove formed in a piston inserted into a cylinder and a piston ring made of a synthetic resin material and housed in the annular groove. <P>SOLUTION: A piston ring 10, made of a synthetic resin material and fixed to a piston 3 inserted into a cylinder 1, includes: an outer peripheral surface 13 slid in contact with the inner peripheral surface of the cylinder 1; one end surface 11 facing one sidewall surface 3c of an annular groove 3b formed in the outer peripheral side part of the piston 3 so as to contact; an other end surface 12 facing the other sidewall surface 3d in the annular groove 3b so as to contact; and an inner peripheral surface 17 facing an inner bottom surface 3e in the annular groove 3b. One or both, of the contact area of the one end surface 11 to the one sidewall surface 3c and the contact area of the other end surface 12 to the other sidewall surface 3d, are set smaller than an axial direction projection area which is an end surface area seen from the axial direction. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
