Seat faced engine valves and method of making the same

摘要

An improved process 30 for making an engine poppet valve 10 provides an unfinished poppet valve 10 with an initial diameter (d1) of a valve head 22 and an initial thickness (t1) of an interface 56 between a seat facing groove 54 and a combustion face 18 of the valve 50 prior to seat facing the valve 50 to prevent burn-through during the welding process 38. Coining 40 the valve head 22 after seat facing 38 decreases the initial thickness (t1) of the interface 56 to a selected thickness (t2) and increases the initial diameter (d1) to a final or desired diameter (d2) of the valve head 22. The method of the present invention eliminates any need for removing excess material and allows for hot forming the seat facing material 58 to reduce machining steps.