Crankshaft and manufacturing method thereof

• Main Authors: SUEYASU YOKO, ABE TATSUHIKO
• Format: Patent
• Language: Chinese; English
• Published: 27.08.2024
• Subjects: ALLOYS; BEARINGS; BLASTING; CHEMISTRY; ELEMENTS OR CRANKSHAFT MECHANISMS; ENGINEERING ELEMENTS AND UNITS; FERROUS OR NON-FERROUS ALLOYS; FLEXIBLE SHAFTS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL ENGINEERING; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; SHAFTS; THERMAL INSULATION IN GENERAL; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS

Provided is a crankshaft which has excellent fatigue strength and in which the occurrence of quenching cracks is suppressed. A crankshaft (10) is provided with a pin section (12) and a pin top section (15), and the pin section (12) has: a sliding section (121) having a constant outer diameter; and a rounded portion (122) formed continuously with the sliding portion (121), the rounded portion (122) having a hardened region (122a) on the surface thereof, the hardened region (122a) having a hardness higher than that of the core portion of the sliding portion (121) by 100 HV or more, the thickness (d1) of the hardened region (122a) of the rounded portion (122) being 12.0% or more of the radius (R) of the sliding portion (121), and the prior austenite grain diameter of the pin top portion (15) being 60 [mu] m or less. 提供具有优异的疲劳强度、且抑制淬裂的产生的曲轴。曲轴(10)是具备销部(12)和销顶部(15)的曲轴，销部(12)具有：滑动部(121)，其具有恒定的外径；以及圆角部(122)，其与滑动部(121)连续地形成，圆角部(122)在表面具有硬化区域(122a)，所述硬化区域(122a)是硬度比滑动部(121)的芯部的硬度高100HV以上的区域，圆角部(122)的硬化区域(122a)的厚度(d1)是滑