초록 ▼

In an internal-combustion engine (1) of the Otto type, in which exhaust gases are used in order to drive a turbocompressor (14, 15) for supercharging the engine, the engine is designed in such a manner that it can, at high load, be run with a lean mixture during supercharging, the air/fuel ratio bei

In an internal-combustion engine (1) of the Otto type, in which exhaust gases are used in order to drive a turbocompressor (14, 15) for supercharging the engine, the engine is designed in such a manner that it can, at high load, be run with a lean mixture during supercharging, the air/fuel ratio being at least 19:1. The lean mixture is brought about by virtue of the fact that the charging pressure increases while the fuel quantity is maintained. The engine is advantageously provided with a divided exhaust-gas discharge in order to improve the operating characteristics.

대표청구항 ▼

1. Method of operating an internal-combustion engine of the Otto type, comprising:discharging exhaust gases from a plurality of cylinders of the engine for driving a turbocompressor which has an exhaust-gas driven turbine for supercharging the engine, wherein at low load, running the engine with a s

1. Method of operating an internal-combustion engine of the Otto type, comprising:discharging exhaust gases from a plurality of cylinders of the engine for driving a turbocompressor which has an exhaust-gas driven turbine for supercharging the engine, wherein at low load, running the engine with a stoichometric air-fuel mixture ratio, and at high load, running the engine with a lean air-fuel mixture ratio during supercharging, the fuel quantity being kept at a level corresponding to stoichiometric conditions at normal charging pressure, the method further comprising: increasing the charging pressure above the normal charging pressure in a single stage until the stoichometric air-fuel mixture ratio increases to the lean air-fuel mixture ratio of at least 19:1 while maintaining the fuel quantity level during a shift to the lean air-fuel mixture; and dividing an exhaust-gas discharge pulse from the cylinders such that a first part of the exhaust-gas discharge pulse is conducted to the turbine of the turbocompressor while a subsequent part of the same exhaust-gas discharge pulse is conducted past the turbine of the turbocompressor.