Patent ID: 8484969

Claim:
An engine comprising: a supercharger; an EGR device; and an electronic control unit, wherein the electronic control unit is configured to execute an isochronous control so as to keep a target rotation speed the same as that at idling or executes a droop control so as to reduce the target rotation speed a predetermined percentage corresponding to a load state when rotation speed of the engine is shifted from a no-load or light-load run to a high-load state, wherein the electronic control unit is configured to control an EGR valve of the EGR device such that the EGR valve is either closed to an opening smaller than a normal set opening corresponding to a load state for a predetermined opening or fully closed when an actual rotation speed of the engine is detected to be lower than the target rotation speed, wherein the electronic control unit is configured such that a condition for returning the opening of the EGR valve to the normal set opening corresponding to the load state is that a deficiency amount between the actual rotation speed against the target rotation speed is not larger than a predetermined amount, and wherein the electronic control unit is configured such that passage of a predetermined time at load shift state is also adopted as a condition for returning the opening of the EGR valve to the normal set opening corresponding to the load state so that the opening of the EGR valve is returned to the normal set opening corresponding to the load state after the passage of predetermined time even if the return condition is not satisfied that the deficiency amount of the actual rotation speed against the target rotation speed is not larger than the predetermined amount.