The Study On Effect Of The Fatigue Durability With Roller Grinding To Crankshaft In Diesel Engine

Crankshafts are one of the important parts of the internal combustion engine. The fatigue alternating stress, which are highly variable in time , subject the crankshaft to very high and complex loading that induced to fatigue breakdown. The crankshaft design and manufacture must therefore precise calculations of the fatigue characteristics. This study deals with the influence of rolling to strengthen the fatigue resistanceNodular cast iron is less cost and easyer machining than steel, The fatigue resistance of crankshafts can be strengthen by useing deep rolling on the journals that be applied in the diesel instead of steel crankshaft .The study and information are limit in the literature about the roll internationally. Domestic manufactures have to grind the journals according to the experience and measure the quality with the fatigue bending machine.In the paper , author discuss the preference during grinding. The crankshaft than be studied match to a six cylinder dieselFirst , fatigue mechanism is introduced. Here author explain the definition of the fatigue property and fatigue measurement. The property is measured precisely only by fatigue bending machine .So the fatigue analysis and the measurement must be explained first.The experiments included bench test. Monotonic and cyclic deformation behaviors, Experimen of drawing S-N curves of the crankshafts from the bench test obtained under R=-1. Constant benching loading conditions are also evaluated and compared. Fatigue properties obtained from specimen testing. The predicted lives are compared with bench test results. The method to obtain a S-N curve is a cost and difficult work, statistic is applied very much..The bending moment is representation of fatigue value in test. The equation including the strain and bending moment be established in the adjust test.Second ,author analysis the preferences during the grinding.There are two kinds of means to strengthen the fatigue resistance: quenching combining the rolling and nitriding combining the rolling. According to the test the second mean is instability , so the next test are all quenching.Structure of crankshaft influence the fatigue resistance, too, The fatigue resistance is damaged by groove at journal circumferentially and. Improved...