Patent ID: 7178327

Claim:
An internal combustion engine in which power is generated by burning a mixture of fuel supplied from a fuel injection device and air in a combustion chamber continuous with an intake port that is opened/closed by an intake valve and an exhaust port that is opened/closed by an exhaust valve, comprising: a valve opening characteristic setting device which changes a valve opening characteristic of at least one of the intake valve and the exhaust valve; a turbocharger which supercharges air taken into the combustion chamber; a supercharging pressure setting device which changes supercharging pressure generated by the turbocharger; a catalyst which purifies exhaust gas discharged from the combustion chamber; and a controller which controls the supercharging pressure setting device such that pressure of the air taken into the combustion chamber becomes larger than back pressure until it is determined that the catalyst has been activated, and which sets a valve overlap period during which both of the intake valve and the exhaust valve are opened, wherein the fuel injection device includes a port injector for injecting the fuel into the intake port, and an in-cylinder injector for injecting the fuel directly into the combustion chamber, and the controller causes the port injector to inject the fuel such that an air-fuel ratio of the mixture in the intake port becomes lean and causes the in-cylinder injector to inject the fuel until it is determined that the catalyst has been activated.