TURBOCHARGED ENGINE AND METHOD OF OPERATING TURBOCHARGED ENGINE

摘要

A turbocharged engine includes an intake port and an exhaust port connected to a combustion chamber, a surge tank, and a turbocharger including a turbine installed midway in an exhaust passage and a compressor that rotates together with the turbine. The turbocharged engine further includes a wastegate valve that controls the supercharging pressure of the turbocharger, a throttle valve installed in an intake passage between the compressor and surge tank, and a controller to control the operations of a control valve and the throttle valve. When the engine operation range is in a full-load operation range, the controller sets the maximum opening degree of the throttle valve to an opening degree less than a full-throttle opening degree, and controls the throttle valve so that the compressor efficiency of the compressor is higher than a full-throttle compressor efficiency. When the engine operation range is in the full-load operation range, the compressor efficiency increases, so the engine output is further increased.