Engine RPM control device

An engine rotation speed control device comprising:

• an actual engine rotation speed detection means;
• a target engine rotation speed command means;
• a means for calculating a fuel injection amount based on an actual engine rotation speed and a target engine rotation speed;
• an engine abnormality detection means;
• and
• a means for correcting the target engine rotation speed at the time of detecting engine abnormality,
• characterized in that:
• the means for correcting the target engine rotation speed at the time of detecting the engine abnormality has a storage unit, and
• the target engine rotation speed is corrected so as to make the target engine rotation speed shift to a predetermined abnormality aversion engine rotation speed based on a map of correlation characteristic between the actual engine rotation speed and an output speed of an object driven by the engine stored in the storage unit while a deceleration rate of the output speed of the object is increased with time from the start of the deceleration to the finish of the deceleration.