Patent ID: 9702296
Date: 2017-07-11
CPC Classifications: F02B,F02D,F02M,F02P,Y02T

Claim:
1. A turbocharged engine, comprising; an engine body including at least one cylinder; an intake passage for introducing air into the cylinder; an exhaust passage for discharging exhaust gas generated in the cylinder; a turbocharger including a turbine driven by energy of the exhaust gas passing through the exhaust passage and a compressor driven by the turbine to apply pressure to air in the intake passage; an EGR passage connecting the exhaust passage on an upstream side of the turbine and the intake passage on a downstream side of the compressor; an openable/closable EGR valve provided in the EGR passage; a bypass passage provided in the exhaust passage so as to bypass the turbine; an openable/closable waste gate valve provided in the bypass passage; and a controller for controlling the EGR valve and the waste gate valve so as to prevent boost pressure generated by the compressor from exceeding a predetermined limit pressure in a specific operation area set in at least part of a speed range in which an engine speed becomes equal to or higher than a predetermined first rotational speed, wherein the controller implements, when the boost pressure is increased to the limit pressure, a first boost pressure control of opening the EGR valve and closing the waste gate valve, and implements, after the first boost pressure control is started and when the engine speed is increased to a second rotational speed higher than the first rotational speed, a second boost pressure control of opening the waste gate valve in addition to the EGR valve.