POWER UNIT CONTROL METHOD OF CONSTRUCTION EQUIPMENT AND DEVICE THEREOF

摘要

PURPOSE: To realize a pressure raising function of a hydraulic source and a reduction function of the number of revolutions of an engine by an easy-to- operate operation system. CONSTITUTION: A case where all the operation levers 15 which control the operation of construction equipment are at neutral positions and a case where at least one operation lever is at a neutral position are detected by a pressure switch 14. A manually-operated lever top switch 16 is provided at a top end of the operation lever 15. When the lever top switch 16 is pressed and the pressure switch 14 detects the neutral condition of all the operation levers, a reduction control signal of the number of revolutions of an engine is outputted to an accelerator actuator 21 from a controller 12. When the pressure switch 14 detects that the levers are operating, a pressure raising valve 46 is switched and operated by a set relief pressure raise signal outputted from the controller 12. The set relief pressure is increased and changed by pilot pressure supplied to a variable relief valve 42 via the pressure raising valve 46.