| 主权项 |
1. A control apparatus for an internal combustion engine, the internal combustion engine including:
a fuel injection valve configured to supply fuel into the internal combustion engine; a turbo-supercharger including a compressor arranged in an intake passage and a turbine arranged in an exhaust passage; a waste gate valve configured to open and close an exhaust bypass passage that bypasses the turbine; an intake port being one part of the intake passage; an exhaust port being one part of the exhaust passage; and a valve train configured to drive an intake valve that opens and closes the intake port and an exhaust valve that opens and closes the exhaust port, wherein one or a plurality of the exhaust valves are provided with respect to one cylinder, wherein the valve train includes an exhaust variable valve train, and wherein the exhaust variable valve train configured to: set, as valve opening periods of the one or plurality of exhaust valves, a first valve opening period that includes an exhaust stroke and adopts exhaust top dead center as an end point and a second valve opening period in which one or all of the one or plurality of exhaust valves are opened and closed during an intake stroke that follows the exhaust stroke; and change valve opening characteristics of the one or all of the one or plurality of exhaust valves in the second valve opening period, the control apparatus comprising a controller, the controller being programmed to: open the waste gate valve if switching operation modes is performed from supercharged lean burn operation in which combustion is performed at a lean air-fuel ratio greater than a stoichiometric air-fuel ratio with supercharging of intake air by the turbo-supercharger to stoichiometric burn operation in which combustion is performed at the stoichiometric air-fuel ratio, and if a requested air amount for the stoichiometric burn operation performed after the switching is less than a requested air amount for the supercharged lean burn operation performed before the switching; control the exhaust variable valve train so that, during an intake-port-pressure decreasing period in which intake port pressure decreases accompanying opening the waste gate valve, the first valve opening period and the second valve opening period are set and at least a part of the second valve opening period overlaps with a valve opening period of the intake valve that opens at or after the exhaust top dead center in an intake stroke; control the fuel injection valve during the intake-port-pressure decreasing period so as to inject fuel of an amount required for realizing the stoichiometric air-fuel ratio under a requested air amount for the stoichiometric burn operation performed after the switching of the operation modes; and control the valve opening characteristics of the one or all of the one or plurality of exhaust valves that open and close in the second valve opening period so that, during the intake-port-pressure decreasing period, an amount of air charged into a cylinder comes close to the requested air amount. |
