Patent ID: 9182006
Filing Date: 2015-11-10
Classification: F16F

Abstract:
1. A hydraulic shock absorber comprising: a partitioning member which partitions a closed space and has a passage through which the closed space is continuous with an outside; and a valve which is a member fixed to the partitioning member on a central side of the valve and covering an open end of the passage in the partitioning member, the valve being deformable in a direction away from the partitioning member when the valve is applied with force from the partitioning member side, and the valve being configured to have a through-hole formed in a circumferential direction thereof, wherein the through-hole in the valve comprises a first corner portion, a second corner portion, a third corner portion, and a fourth corner portion, the first corner portion being positioned radially outward of a center of the through-hole and on a first end side in the circumferential direction, the second corner portion being positioned radially outward of the center of the through-hole and on a second end side in the circumferential direction, the third corner portion being positioned radially inward of the center of the through-hole and on the second end side in the circumferential direction, the fourth corner portion being positioned radially inward of the center of the through-hole and on the first end side in the circumferential direction, and the first corner portion and the second corner portion each consist of a respective radius of curvature that is larger than a respective radius of curvature of each of the third corner portion and the fourth corner portion, wherein the first and second corner portions define an outer edge of the through-hole in the circumferential direction.