Valve timing controller, valve timing control method and engine control unit for internal combustion engine

Abstract

A valve timing controller for use in a direct injection type internal combustion engine is provided for enabling a valve timing to be appropriately set in accordance with a load on the engine even in a stratified combustion mode. The internal combustion engine has a valve timing changing mechanism for changing a valve timing of at least one of an intake valve and an exhaust valve so that it is operated in a combustion mode switched between a uniform combustion mode in which a fuel is injected into a cylinder during an intake stroke and a stratified combustion mode in which a fuel is injected into a cylinder in a compression stroke. The valve timing controller comprises a required torque determining unit for determining a required torque outputted by the internal combustion engine based on the engine rotational speed and accelerator pedal opening, and a valve timing determining unit for determining the valve timing in accordance with the required torque and the engine rotational speed.