1. Field of the Invention
The present invention relates to an internal combustion engine.
2. Description of the Related Art
In a known direct injection type engine, a fuel injector is arranged on the inner wall of the cylinder head in the vicinity of the intake valve. Fuel is injected by the fuel injector during the compression stroke when the engine is operating under a light load, and fuel is injected by the fuel injector during the intake stroke when the engine is operating under a heavy load (see Japanese Unexamined Utility Model Publication No. 1-173416). In this direct injection type engine, when the engine is operating under a heavy load, fuel is injected toward the rear face of the valve head of the intake valve, which is open. The fuel that has impinged upon the rear face of the valve head of the intake valve spreads along the rear face of the valve head of the intake valve toward the surrounding region of the intake valve and is distributed in the combustion chamber, thereby increasing the usage rate of the air therein.
However, if the injected fuel is forced to flow along the rear face of the valve head of the intake valve after impinging upon the rear face of the valve head of the intake valve, a large part of the injected fuel spreads from the rear face of the valve head of the intake valve in the fuel injection direction. As a result, the injected fuel is concentrated in a particular restricted region of the combustion chamber, thereby making uniform distribution of the injected fuel in the combustion chamber impossible.