Toyota Jidosha Kabushiki Kaisha

Atsushi Goto

Senji Kato

Nobuhisa Ohkawa

Shigeru Sone

Tadahisa Naganawa

Kouji Endou

Kouji Endo

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.

Apparatus for computing the amount of intake air in internal combustion

A varying mechanism (VVT) for continuously varying the valve timing of an intake valve in a predetermined range is provided on a cam shaft in an engine. By controlling the VVT, the valve overlap period of the intake valve and an exhaust valve is continuously varied in a predetermined range, thus adjusting the amount of the internal EGR in combustion chambers. When determining that the operational load of the engine is small and intermediate based on the value of a manifold pressure, an electronic control unit (ECU) computes a target value for advancing the valve timing with respect to the rotational phase of a crankshaft based on a throttle angle, an engine speed, etc. The ECU also computes a limit value to restrict the target value in accordance with the value of the manifold pressure. When the target value is smaller than the limit value, the ECU controls the VVT based on the target value. When the target value is greater than the limit value, the ECU replaces the limit value with target value and controls the VVT based on this target value.

Valve timing control apparatus for engine

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Toyota, Japan

Atsushi Goto