ENGINE RPM CONTROL DEVICE

摘要

Provided is an engine rpm control device which gradually reduces the output speed of an engine drive object when reducing the engine rpm. The engine rpm control device (20) includes a target engine rpm correction means used upon detection of an engine failure. The target engine rpm correction means has a storage device (51) containing a map of the correlation characteristic between the engine rpm and the output speed of object to be driven by an engine (100). The target engine rpm correction means corrects the target engine rpm so that an instructed engine rpm (Nset) or a derating target engine rpm (Nset') is shifted to a predetermined failure-preventing engine rpm (N2) while maintaining the reduction ratio of the output speed of the drive object at a predetermined ratio.