CONTROL METHOD AND DEVICE FOR HYDRAULICALLY DRIVEN WINCH

摘要

PROBLEM TO BE SOLVED: To prevent occurrence of cavitation and a load swing at deceleration during high speed lowering in a small motor capacity state. SOLUTION: A sub route 18 with a pressure oil makeup valve 19 is connected to a lowering side line 5 of a hydraulic motor 3. At the high speed lowering operation, the sub route 18 supplies pressure oil to the motor lowering side line 5 along with a main route 17 passing a control valve 6. Even when a meter-in orifice of the control valve 6 is restricted at the deceleration during the high speed lowering, the sub route 18 supplies makeup pressure oil to maintain a constant motor inlet pressure or higher. COPYRIGHT: (C)2003,JPO