Pressure limitation valve

摘要

The pressure relief valve has a spring element (21) whose bias determines the opening pressure of the valve and which is supported on a movable spring piston (22), so that the bias of the spring element is adjustable by displacement of spring piston. The spring piston movable by applying a control pressure at the control terminal (33) is hydraulically connected to a piston chamber (23) whose volume depends on the position of spring piston. A throttle element (32) is arranged between the control terminal and the piston chamber. Independent claims are included for the following: (1) hydraulic system; (2) movable tool; and (3) method for operating hydraulic system.