JP2007146854A5 - - Google Patents

Claims (5)

In a method for controlling an in-cylinder injection engine with a supercharger that injects fuel directly into a cylinder of an engine and supplies supercharged air to the cylinder,
A first mode in which a lean combustion operation is performed by driving the supercharger in a region where the engine torque is lower than a predetermined value;
In-cylinder injection engine with a supercharger, wherein the supercharger is driven in a region where the engine torque is higher than the predetermined value, and the second mode in which the homogeneous combustion operation is performed near the stoichiometric air-fuel ratio is switched. Control method.   The control of a cylinder injection engine with a supercharger according to claim 1, wherein when the engine is cold started, the exhaust gas is directly supplied to a catalyst provided downstream of the turbine, bypassing the turbine provided in the supercharger. Method. If the output value of the temperature sensor is smaller than a predetermined value, open the bypass control valve,
If the output value of the temperature sensor installed upstream of the catalyst and measuring the temperature of the exhaust gas flowing into the catalyst is greater than a predetermined value, closing the bypass control valve;
The method for controlling an in-cylinder injection engine according to claim 2.   When the engine torque is increased at a constant engine speed, the indicated mean effective pressure (explosion pressure P megapascal generated in the combustion chamber divided by the combustion chamber volume V cubic meter) is approximately 9.5 bar. Function smoke number (FNS) ) Is controlled so as to be 0.5 or less.   The fuel consumption rate at a high load where the indicated mean effective pressure is 12 bar is ± 5% compared to the fuel consumption rate at a medium load where the indicated mean effective pressure is 8 bar. Control method.