PISTON MADE OF ALUMINUM ALLOY FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a piston made of aluminum alloy for internal combustion engine capable of largely reducing an amount of a blowby gas leaking in a crankcase from a combustion chamber. SOLUTION: In this piston made of aluminum alloy for an internal combustion engine, on a top ring groove 12 which is the nearest from a combustion chamber among a plurality of ring grooves 12, 14, 15, an anode oxide film 50 is formed with electrolyte of mixture of phosphate and fluoride, and fine holes of the anode oxide film 50 are impregnated with thermosetting resin. Thus, a sealing property of the top ring groove 12 can be improved.