US Patent 7086378 Direct fuel injection internal combustion engine

A direct fuel injection internal combustion engine includes a fuel injector arranged above a center portion of the piston and positioned higher than a combustion chamber upper surface of a cylinder head. The cylinder head includes a recess portion in which a tip of the fuel injector is disposed in a cross sectional view of the cylinder head in a plane perpendicular to a fuel injection center axis. The recess portion is provided with a channel extending longitudinally away from the tip of the fuel injector configured and arranged to reduce negative pressure within the recess portion. The channel is oriented in such a direction as to avoid the interference between the channel and other parts of the cylinder head. When the fuel injector is a multi-hole fuel injector, the channel can be oriented toward a direction along a centerline between two adjacent injection vents of the fuel injector.