摘要 |
PROBLEM TO BE SOLVED: To improve calculation accuracy of a flow velocity of an air flow in a cylinder.SOLUTION: An air flow velocity calculation device for an air flow in an internal combustion engine includes: an air flow control valve 40; a flow velocity calculation part 70 for calculating a flow velocity of an air flow in a cylinder 12 on the basis of discharge maintaining times Ts1, Ts2, and Ts3 being times after the strat of a discharge between a center electrode 22a and a ground electrode 22b of an ignition plug 22 until the discharge is cut off by an air flow in the cylinder 12; and a discharge current control part for controlling a discharge current. Energy is supplied to the ignition plug 22 so as to maintain a fixed discharge current value by the discharge control part, during an ignition period which is a total amount of the discharge maintaining time Ts1 for an initial discharge in one cycle of the internal combustion engine, and the discharge maintaining times Ts2, Ts3... for discharges at the second time and after, performed between the center electrode 22a and the ground electrode 22b, subsequently to the initial discharge in one cycle of the internal combustion engine, after the initial discharge is cut off by an air flow in the cylinder 12.SELECTED DRAWING: Figure 13 |