VALVE SEAT RING AND MANUFACTURE THEREOF

摘要

PURPOSE:To improve seal performance of a valve seat and its close adhesion to a rubber material layer by forming a valve seat part and an edge plate part in their thickness less than specific values and the edge plate part in its thickness smaller toward the point end side. CONSTITUTION:A valve seat ring 20 has a thin plate-shaped valve seat part 20a forcing a valve unit 6 to come press contact with the internal surface, edge plate part 20b folded to the outer from both ends of the valve seat part 20a so as to form in its reverse side a recessed part 22 and a rubber material layer 24 integrally formed in the recessed part 22. The valve seat part 20a and the edge plate part 20b are formed in their thickness to not more than 1.5mm maximum. Further the edge plate part 20b forms its thickness thinner toward the point end side. Thus improving a seal condition, the edge plate part is prevented from easily exfoliating from the rubber material layer.