Anti-reflux valve seat for intake duct of cylinder head of average cylinder capacity diesel engine, has lateral surface with impact surfaces for chamfers, where impact surfaces are oriented in same manner as that of lower surface

摘要

The valve seat (31) has an internal lateral surface (31A) joining an upper surface (31B) and a lower surface (31C). The lateral surface defines a passage opening of an axis (S) and includes chamfers (33, 34) located at junction of the lateral surface and the lower surface. The lateral surface has impact surfaces (35, 36) for the chamfers in a distinct manner, where the impact surfaces are oriented in a same manner as that of the lower surface. Each impact surface is extended in width lower than 3 millimeters.