HYBRID CONSTRUCTION MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a hybrid construction machine capable of suppressing an assist of unnecessary power of an engine by an electric generator.SOLUTION: A hybrid construction machine of this invention includes an engine speed sensor 11A for detecting an engine speed NE of an engine 11, an engine state determination section 20B for determining a state of output torque TE of the engine 11, a load torque estimation section 20C for calculating load torque TP of a hydraulic pump 13, and an engine assist restriction section 20E for restricting an assist of power of the engine 11 by an electric generator 12 when the engine speed NE detected by the engine speed sensor 11A is equal to or more than an engine speed N0 and it is determined by the engine state determination section 20B that the output torque TE of the engine 11 does not reach minimum torque Tmin or when the load torque TP calculated by the load torque estimation section 20C is lower than torque T1.