| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for estimating ignition timing causing knocking in an internal combustion engine capable of estimating the ignition timing causing knocking with high accuracy without spending much man-hour and time. SOLUTION: The internal combustion engine is actually operated with a plurality of different ignition timing settings and a state quantity concerning self-ignition of the internal combustion engine is measured. A crank angle at which a self-ignition condition is satisfied is estimated based on the measured state quantity and the crank angle is calculated as a first judgment value C1. An unburned fuel quantity in a cylinder is calculated based on the measured state quantity and a limit crank angle at which unburned fuel of a quantity required for knock generation is calculated as a second judgment value Cb. Linear relation between setting values of ignition timing and the first judgment value C1 and linear relation between the setting values of ignition timing and the second judgment value Cb are calculated respectively and the ignition timing at which the first judgment value C1 and the second judgment value Cb agree with each other is calculated as ignition timing causing knocking based on the two linear relation. COPYRIGHT: (C)2008,JPO&INPIT |
