Internal combustion engine with indirect fuel injection

Claim 1

In an internal combustion engine with indirect fuel injection, a cylinder having a cylinder axis, a piston located in said cylinder and having a piston head, a trough-shaped recess provided in said piston head, a cylinder head, a main combustion chamber formed between the cylinder head and the piston head, a hollow insert disposed in the cylinder head and having an axis forming an acute angle with the cylinder axis, said insert forming an auxiliary combustion chamber, a plug closing said insert at one end and having a central bore, a fuel injection nozzle protruding into said central bore in alignment with the axis of said insert, a lateral bore in the cylinder head extending also into said insert, a spark plug disposed in said lateral bore and protruding into said insert, the insert having an axial extension opposite the fuel injection nozzle and having a smaller diameter than the remaining portion of the insert, said extension protruding into the main combustion chamber in a peripheral area of said trough-shaped recess of the piston head, two overflow apertures provided in said extension and having axes being coplanar with the cylinder axis and intersecting inside the main combustion chamber, said axes of the overflow bores forming identical acute angles with a reference plane which is normal to the cylinder axis.