Apparatus for computing the amount of intake air in internal combustion

Abstract

Disclosed is a device for calculating an amount of an air introduced to a cylinder of an engine. An air-intake passage introduces the air to the cylinder. An air-exhaust passage exhausts gas from the cylinder. Both passages respectively have an intake valve and an exhaust valve. Both valves are respectively driven by an intake valve drive mechanism and an exhaust valve drive mechanism in accordance with a rotation of a crank shaft to alternatively and selectively open and close, and simultaneously open during a valve overlap period to open the passages to the cylinder. A variable valve timing mechanism controls an operational timing of the valve drive mechanisms with respect to the crank shaft in accordance with a running condition of the engine to vary a timing of the valve driven by the valve drive mechanisms. The calculating device comprises a first detecting device, which detects a rotational speed of the crank shaft. A second detecting device detects an intake pressure in the air-intake passage. A third detecting device detects the operational timing of the valve drive mechanisms. A calculating device calculates a displacement of the operational timing according to the detected rotational speed of the crank shaft and the detected operational timing. A first computing device computes the amount of the air introduced to the cylinder in response to the rotational speed of the crank shaft, the intake pressure, and the displacement of the operational timing.