COMBINATION OF PISTON RINGS

• Main Authors: HADANO TOORU, NARUSE YOSHIO
• Format: Patent
• Language: English
• Published: 04.03.1997
• Edition: 6
• Subjects: ALLOYS; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES; BLASTING; CHEMISTRY; COMBUSTION ENGINES; CYLINDERS; CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ENGINEERING ELEMENTS AND UNITS; FERROUS OR NON-FERROUS ALLOYS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MECHANICAL ENGINEERING; METALLURGY; PISTONS; SEALINGS; THERMAL INSULATION IN GENERAL; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS

PROBLEM TO BE SOLVED: To suppress lubricant consumption cost performance after an engine has been used for a long time, and make excellent the scuffing resistant properties and crack resistant properties of a first pressure ring by making the friction velocity of the first pressure ring identical to that of a second pressure ring. SOLUTION: A first pressure ring 6 is made of stainless steel in a martensite system including 0.4 to 1.2% C by weight and 15 to 23% Cr by weight, and a nitriding layer 9 is formed over the whole surface of it. The surface hardness of the nitriding layer 9 at the outer circumferential surface is less than HV 1050. A second pressure ring 7 is made of stainless steel in a martensite system including 0.4 to 1.4%C by weight and 5 to 11% Cr by weight, and a nitriding layer 10 is formed over the whole surface of it. The surface hardness of the nitriding layer 10 at the outer circumferential surface is equal to or more than HV 1040. And the difference in surface hardness between the nitriding layers 9 and 10 at the outer circumferential surfaces of the first and second pressure rings 6 and 7, is less than HV 300.