INTERNAL COMBUSTION ENGINE

摘要

An internal combustion engine 20 includes a combustion chamber 26, a fuel injector 31 injecting fuel into the combustion chamber 26, a cylinder 22, a piston 24 having a crown and reciprocating in the cylinder 22, the crown being exposed to the combustion chamber 26, and an ignition delay enhancer prolonging an ignition delay of a fuel-air mixture in the combustion chamber 26. A ceramic member 24a is disposed on at least a fuel injection port, to which fuel is injected from the fuel injector 31, of the crown of the piston 24.

主权项

1. An internal combustion engine, comprising:
a combustion chamber; a fuel injector injecting fuel into the combustion chamber; a cylinder; a piston having a crown and reciprocating in the cylinder, the crown being exposed to the combustion chamber; and an ignition delay enhancer prolonging an ignition delay of a fuel-air mixture in the combustion chamber, wherein a ceramic member is disposed on at least a fuel injection port of the crown of the piston, the fuel injector injecting fuel to the fuel injection port, the crown of the piston has a cavity defining part of the combustion chamber, the fuel injector injecting fuel to the cavity, the ceramic member is disposed on at least a portion of the crown of the piston, the portion facing the cavity, and an overhang ratio ranges from 0.57 to 0.96, the overhang ratio being represented by the ratio d1/d2 where d1 is a diameter of a boundary between the ceramic member and any other member on a top surface of the crown of the piston and d2 is a maximum diameter of the boundary between the ceramic member and the other member in a radial direction of the piston.