Valve timing control for engine
AssigneeNissan Motor Co., Ltd.
InventorsTakao Kawasaki, Masahiro Arai
Life of this patent
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Abstract
A control system controls an intake air quantity to an engine by controlling an intake valve closing timing, instead of, or in cooperation with, a throttle valve. A controller estimates a quantity of internal EGR gases remaining in a cylinder, and controls the intake valve closing timing to a desired target timing determined in due consideration of the estimated internal EGR quantity. The estimated internal EGR quantity is a sum of a base quantity and an increase correction quantity determined in accordance with a valve overlap period, its middle angular position in crankshaft rotation and intake pressure. The target intake valve closing timing is determined in accordance with a target intake air quantity and the estimated internal EGR quantity.
Claims20
A control apparatus for controlling an intake air quantity to the engine by varying an intake valve closing timing of the engine, the control apparatus comprising:
- a controller configured
- to calculate a target air quantity in accordance with an engine operating state,
- to calculate an estimated internal EGR quantity of the engine in accordance with the engine operating state,
- to calculate a target intake valve closing timing in accordance with the target air quantity and the estimated internal EGR quantity, and
- to control an actual intake air quantity to the engine by controlling an actual intake valve closing timing of the engine to achieve the target intake valve closing timing.
A control apparatus for controlling an intake air quantity to an engine by controlling an intake valve closing timing of the engine, the control apparatus comprising:
- means for determining an estimated internal EGR quantity in accordance with an engine operating state;
- means for determining a target intake valve closing timing in accordance with at least the estimate internal EGR quantity;
- and
- means for controlling the intake air quantity to the engine by controlling an actual intake valve closing timing of the engine to the target intake valve closing timing.
A control process for varying valve timings of intake and exhaust valves of an engine, the control process comprising:
- estimating an internal EGR quantity in accordance with an engine operating state;
- and
- controlling an intake valve closing timing in accordance with a required intake air quantity and the internal EGR quantity.
Dependencies are inferred from the claim text.