| 摘要 |
PURPOSE:To closely control engine vibration, by balancing maximum combustion pressures in each cylinder when combustion condition of each cylinder is varied to create scatter in the maximum combustion pressures and thereby to increase the engine vibration to a value more than a certain permissible limit. CONSTITUTION:Maximum values Pmax of present combustion pressure P in each cylinder which are outputted from a maximum combustion pressure detecting circuit 6 are read in step 20, and an average value P'max is calculated therein. In step 21, difference or scatter DELTAP in maximum combustion pressures Pmax among each cylinder is calculated from the read maximum combustion pressures Pmax. In step 22, the present difference DELTAP as calculated in the previous step 21 is compared and determined with a predetermined difference DELTAP0 corresponding to a permissible limit of engine vibration. As the result of this, when the engine vibration is increased to a level higher than a certain level, ignition timing of a cylinder having a maximum combustion pressure Pmax greater than the average value P'max is delayed to lower the maximum combustion pressure Pmax. Conversely, ignition timing of a cylinder having a maximum combustion pressure Pmax smaller than the average value P'max is advanced to increase the maximum combustion pressure Pmax. Thus, maximum combustion pressures Pmax of each cylinder are balanced. |
