Electrohydraulic control device for parallel hydromotors - has main valve stage associated with each hydromotor and common pre-control stage

摘要

The electro hydraulic control device (10) uses respective valves (13,14) for controlling the direction and velocity of each hydrometer (11,12). The valves (13,14) each have a main stage (15,16) associated with a common pre-control stage (17), with a control circuit (54) having switching valves (36,37) for operation for both main stages (15,16) in alternation. Pref. the pre-control stage (17) is operated via a proportional magnet (45), with 4/2 way switching valves (36,37) between the pre-control stage (17) and the main valve stages (15,16), the latter having position sensors (28,31) providing signals fed back to the position regulator (52) coupled to the pre-control stage (17). ADVANTAGE - Reduced valve complexity.