| 摘要 |
PROBLEM TO BE SOLVED: To operate a spark ignition type engine provided with an EGR device at high thermal efficiency in an area close to a knocking limit while avoiding knocking irrespective of change of EGR quantity. SOLUTION: In a method for avoiding knocking in a spark ignition type engine, the engine is provided with an ignition timing change device and the EGR device, advancement and retardation of ignition timing are repeated at a predetermined cycle by the ignition timing change device, and simultaneously ignition timing at a roughly center of a change width of a crank angle of the ignition timing is controlled to get close to a target ignition timing by slowly opening an open close valve of the EGR device. Preferably, opening of the open close valve of the EGR device is limited at a predetermined limiter value and ignition timing at the center of the change width is controlled to keep knocking intensity at roughly threshold at the limiter value. COPYRIGHT: (C)2008,JPO&INPIT |
