Strength Analysis And Fatigue Life Evaluation Of Electronic Control Diesel Block

The electronic control fuel injection system is the main configuration and development direction of the newly built or modified diesel engine injection system,which can meet the requirements of the continuous improvement of the diesel engine power performance,economic performance and emission performance.All parts and components are supported and fixed by the block of an electrically controlled diesel engine.The block is complex and the bearing size and direction of the crankshaft vary with the working conditions,and the force and torque of the crankshaft are constantly changing,It is the key component that directly affects the reliability of the whole engine.Therefore,the block must be designed to ensure that it has sufficient strength and stiffness.Once fatigue damage occurs in the design life cycle,it is very difficult to repair it completely.Therefore,the reliability of the block determines the service life of the whole engine to a certain extent.In this paper,an electrically controlled diesel engine block is studied,The mechanical model of BF6MXP-3 diesel engine block was established by using ANSYS Workbench software,and the strength analysis,stiffness analysis and fatigue life evaluation of the block under three working conditions were carried out respectively.By observing the whole displacement diagram and the equal effect under various operating conditions of the body,we can find out:Due to the pretightening force of bolt.The main displacement position is near the cylinder head bolts,while the stress concentration is mainly near the upper part of the body and the bearing bolt.The maximum stress of the body is 232.67 MPa,under three conditions.The material of the block is gray cast iron 250.When the thickness of the cast iron is between 5and 10 mm,the tensile strength of the cast iron is 250 MPa.It can be seen from the cloud diagram of fatigue life of three kinds of working conditions that the life of the joints with larger body stress is higher than 10~7,meeting the design requirements.