HYDRAULIC CYLINDER, AND LOOPER FOR ROLLING MILL

摘要

PROBLEM TO BE SOLVED: To provide a hydraulic cylinder with small friction resistance which can smoothly control the displacement with constantly high accuracy, and a looper for a rolling mill which can adequately remove the slackness of a strip under the rolling operation. SOLUTION: The hydraulic cylinder 10 includes a cylinder tube 11, a piston 14 movably disposed therein, and a piston rod 17 connected to the piston 14. Fluid passages 14a and 14d or the like are formed in the piston 14 so that the fluid of the limited quantity for hydrostatic support flows only in one direction from each end face (each of both end faces of the piston) toward a piston side surface along an inner surface of the cylinder tube 11.