Patent ID: 8010260

Claim:
An engine control device which controls a power output of an engine for a working vehicle, comprising: one or more detectors which detect one or more of variable values which indicate a state or states of one or more work loads which consume a power output from an engine; and a controller which controls an upper limit output torque of said engine which said engine can output according to an engine rotational speed, based upon said detected one or more variable values which have been detected by said one or more detectors, wherein said one or more work loads include a work apparatus which is provided to said working vehicle, wherein said one or more detectors include a hydraulic oil pressure detector which detects a hydraulic oil pressure or pressures of one or more hydraulic cylinders which drive said work apparatus, and wherein the controller controls the power output capacity of said engine such when excavation begins, the engine switches from a low output mode to a high output mode, and such that when excavation is completed, the engine switches from the high output mode to the low output mode, wherein said controller determines that the excavation is being performed when the pressure of the hydraulic cylinders is lower than a predetermined pressure over a predetermined time period and thereafter rises above the predetermined pressure, and wherein said controller determines that the excavation is not being performed when (i) the pressure of the hydraulic cylinders has dropped below the predetermined pressure, and thereafter has maintained a state lower than the predetermined pressure over a second predetermined time period or (ii) a time period of the pressure of the hydraulic cylinders being higher than the predetermined pressure does not exceed a third predetermined period of time.