HYDRAULIC CRANE AND A METHOD FOR REGULATING THE MAXIMUM ALLOWED WORKING PRESSURE IN SUCH A CRANE

摘要

The invention relates to a hydraulic crane (1 ) comprising at least: - a liftable and lowerable first crane boom (5), which is articulately fastened to a column (4), - a first hydraulic cylinder (6) for lifting and lowering the first crane boom in relation to the column, - a liftable and lowerable second crane boom (7), which is articulately fastened to the first crane boom, and - a second hydraulic cylinder (8) for lifting and lowering the second crane boom in relation to the first crane boom, - a regulating unit (40), which is adapted to regulate the maximum allowed working pressure for the first hydraulic cylinder in dependence on values of variables defining the prevailing position of the crane booms of the crane, these variables comprising at least a variable (a) representing the swing-out angle of the first crane boom and a variable (ß) representing the swing-out angle of the second crane boom. The invention also relates to a method for regulating the maximum allowed working pressure in a hydraulic crane.