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AssigneeToyota Jidosha Kabushiki Kaisha
InventorsNobuhisa Ohkawa, Tadahisa Naganawa, Kouji Endou, Senji Kato, Shigeru Sone, Atsushi Goto
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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.
A valve timing control apparatus for an engine having an air-intake passage for introducing air to a combustion chamber and an air-exhaust passage for exhausting gas from the combustion chamber, wherein the air-intake passage includes an intake valve and wherein the air-exhaust passage includes an exhaust valve therein, said intake and exhaust valves alternately and selectively opening and closing, and wherein the intake valve and the exhaust valve are simultaneously open during a valve overlap period, in synchronism with a rotation of a crankshaft to join the passages with the combustion chamber, wherein said apparatus controls at least one of a valve opening timing of the intake valve and a valve opening timing of the exhaust valve in accordance with a running condition of the engine, said apparatus comprising:
A valve timing control apparatus for an engine having a combustion chamber communicating with an air-intake passage and an air-exhaust passage, said air-intake passage being arranged to introduce air to the combustion chamber through a throttle valve wherein an opening degree of the throttle valve regulates an amount of the air introduced into the combustion chamber, said air-exhaust passage being arranged to exhaust gas from the combustion chamber, wherein the air-intake passage includes an intake valve and wherein the air-exhaust passage, includes an exhaust valve, said intake and exhaust valves alternately and selectively opening and closing, and wherein the intake valve and the exhaust are simultaneously open during a valve overlap period, wherein the intake valve and the exhaust valve are opened and closed in synchronism with a rotation of a crankshalt to selectively open the intake and exhaust passages to the combustion chamber, wherein said apparatus controls at least one of a valve timing of the intake valve and a valve timing of the exhaust valve in accordance with a running condition of the engine, said apparatus comprising:
A valve timing control apparatus for an engine having an air-intake passage for introducing air to a combustion chamber and an air-exhaust passage for exhausting gas from the combustion chamber, wherein the air-intake passage includes an intake valve and wherein the air-exhaust passage includes an exhaust valve therein, said intake and exhaust valves alternately and selectively opening and closing, and wherein the intake valve and the exhaust valve are simultaneously open during a valve overlap period, in synchronism with a rotation of a crankshaft to join the passages with the combustion chamber, wherein said apparatus controls at least one of a valve opening timing of the intake valve and a valve opening timing of the exhaust valve in accordance with a running condition of the engine, said apparatus comprising:
Dependencies are inferred from the claim text.