| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a prime mover revolution speed control system for a hydraulic construction machine capable of enhancing the operability during the excavation by reliably discriminating the excavation state, and further enhancing the workability. <P>SOLUTION: A control lever 44 is fully operated in the arm-crowding direction, and a control lever 43 is also operated. When the pump pressure PD is ≥13 MPa, all of the first discrimination conditions are all met, and the excavation state discrimination function 62 discriminates that excavation state has begun. The target number-of-rotation correcting function 64 adds the correction value ΔN to the standard target number-of-rotation NR0 to obtain the target number-of-rotation NR to start the speedup. During the excavation, when the control lever 44 is subjected to a half or greater operation in the arm crowding direction, and the pump pressure PD is ≥13 MPa, the second discrimination conditions are all met to discriminate that the excavation state persists, and the speedup sequence is continued. If the second discrimination conditions are not met, it is discriminated that the excavation state is completed, and the speedup is completed. <P>COPYRIGHT: (C)2012,JPO&INPIT |
