| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a lean burn engine with a supercharger reducing pumping loss of an engine while maintaining a super-lean air fuel mixture and suppressing the generation of RawNox by improving the efficiency of a compressor of a turbocharger in a high-speed range to achieve both improving fuel economy and securing desired high torque. <P>SOLUTION: A controller (PCM 10) sets a working gas fuel ratio G/F to 30 or more or sets an air-fuel ratio A/F to 30 or more in a low-load range at least after an engine body 1 has been warmed up and when an operation state is in a high-speed range, and sets the G/F to 30 or more while recirculating combusted gas to an intake side through an EGR passage 50 connecting an upstream side of a turbine 612 of the turbocharger in an exhaust side and a downstream side of a compressor 611 in an intake side with each other in a high-load range. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
