CYLINDER FUEL INJECTION TYPE INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To improve fuel consumption performance by improving ignitability under lean combustion. SOLUTION: A smooth recession groove 3 is formed on a top surface of a piston 2. An ignition plug 4 is arranged-on a center portion of a cylinder head. An injector 5 is arranged on a peripheral portion of a cylinder for injecting fuel toward the groove 3. Spiral flow is generated around an axial center of the cylinder during intake and compression processes. In such an inner cylinder injection type internal combustion engine, a stepless flat wall surface 3c is formed on a portion where the fuel injected by the injector 5 is struck against the recession groove 3.