CONTROLLER FOR CONSTRUCTION MACHINE AND METHOD FOR OPERATING INPUT TORQUE

A control apparatus of a construction machine according to the present invention includes a variable displacement hydraulic pump (10) driven by a prime mover (20), a hydraulic actuator (5) driven with pressure oil discharged from the hydraulic pump (10), and a rotation speed detection means (31) for detecting an actual rotation speed (Nr) of the prime mover (20). The control apparatus includes a prime mover control means (40B) for controlling a rotation speed of the prime mover (20) in accordance with an extent to which the operating means (14a) is operated, and an input torque control means (40A) for adjusting an input torque (T2) for the hydraulic pump (10) based on a deviation ( DELTA N) between the actual rotation speed (Nr) detected by the rotation speed detection means (31) and a control rotation speed (N&thetas;) set through an operation of the operating means (14a), and the input torque control means (40A) executes control to decrease the input torque (T2) if the control rotation speed (N&thetas;) is greater than the actual rotation speed (Nr) and the deviation ( DELTA N) between them is larger than or equal to a predetermined value (N2).