METHOD OF MAKING GROOVE-TYPE PORT IN ROTARY CONTROL VALVE FOR FLOW RATE

摘要

PURPOSE:To attain high accuracy and productivity for a groove-type valve port, by using a rotary tool to provide a groove of a width less than the desired final width of the port and by thereafter using reciprocating grooving tool to cut both the side edges of the groove to provide the groove-type valve port of final width. CONSTITUTION:An end mill 100 is inserted into a valve sleeve 16 so that the end mill is inclined as to the axis of the sleeve. A groove A of a width T1 less than the desired final width T2 of a valve port groove is made by the rotary cutting action of the tip of the end mill 100. The position of the groove A in indexed by the indexing device of a tool head or a work table. Both the ends of the groove A are closed by the valve sleeve 16. A tool 101 provided with a tip 102 of a cutting edge width equal to the final width T2 is reciprocated to cut both the side edges of the groove A.