Patent ID: 9407174
Filing Date: 2016-08-02
CPC Classification: E02F,H02P

Claim Text:
1. A shovel comprising: an internal combustion engine in which an amount of fuel injection is controlled so that a revolution speed is controlled to constantly be a first target revolution speed; a variable capacity hydraulic pump configured to vary an output limit value and connected to the internal combustion engine; a generator connected to the internal combustion engine; and a control unit for controlling the generator, wherein the control unit has a function of controlling a load of the variable capacity hydraulic pump applied onto the internal combustion engine by variably limiting the output limit value of the variable capacity hydraulic pump, the control unit controlling the amount of fuel injection of the internal combustion engine to increase an output torque so as to recover the revolution speed in response to a drop of the revolution speed of the internal combustion engine caused by an increase of the load on the variable capacity hydraulic pump, wherein the control unit varies the output limit value so as to increase the load of the variable capacity hydraulic pump applied onto the internal combustion engine and simultaneously causes the generator to start performing an electrical power generating operation when the output limit value becomes a predetermined value and the revolution speed of the internal combustion engine is lower than the first target revolution speed in order to prevent the revolution speed of the internal combustion engine from rising for a predetermined period of time.