Method of combining grinding and EDM operation for finishing fuel injector nozzle bodies

摘要

A combined grinding and EDM apparatus has an indexable rotary turret with work heads secured thereon to locate a pair of nozzle body blanks with their longitudinal axes in spaced parallelism; and compound cross and longitudinal slide assemblies carrying either grinding tools or non-contact machining tools which work on the blanks to form a valve guide bore and a valve seat shaped as a frustrum of a cone whose axis is concentric with the bore; the valve seat cone surface having a small end diameter to large end diameter ratio in the order of 1-50.