Patent ID: 6912783
Filing Date: 2005-07-05
Classification: F04B,Y10S,Y10T

Abstract:
1. A method of manufacturing a valve plate for a compressor which divides a suction chamber and a discharge chamber from a cylinder block, said method comprising the steps of: forming in the plate at least one suction port and at least one discharge port; and pressing a punch die with a tip end face having a plurality of fine pyramid-shaped convex portions arranged at a pitch between about 0.5 mm and 1.0 mm, against at least one of a peripheral portion of each suction port with which a reed portion of a suction valve is brought into contacts, and a peripheral portion of each discharge port with which a reed portion of a discharge valve is brought into contact, the punch die forming, through said pressing, a roughened surface on the at least one peripheral portion, the roughened surface having concave portions and return portions projecting from and formed in peripheral edges of said concave portions, a height of the return portions being between about 10 and 50 μm, and a depth of the concave portions being between about 50 and 250.