CHANGEOVER DEVICE FOR CONTROLLING SPEED OF HYDRAULIC DRIVE, PARTICULARLY HYDRAULIC-ACTUATED CYLINDER

摘要

PURPOSE: To provide a switching device for speed control of a hydraulically actuated cylinder capable of starting and controlling a hydraulic drive device without shock. CONSTITUTION: A switching device for a hydraulic drive device in which each speed of the hydraulic drive device selected and set via an operation switch is subject to a different volume of hydraulic media is provided. In the inflow pipe and outflow pipe of a drive device Z, each of the nozzles 1∼3; 1'∼3' is subject to each drive speed stage. Nozzles 1, 1'; 2, 2'; 3, 3' subject to the same speed stage is subject to each switching position of a slide member V1 of a control valve of the drive device. The switching positions I∼III of the slide member V1 of the control valve of the drive device cover the increasing and reducing directions of speed stages in each operation direction of an operation switch K.