柴油机工作性能和机体结构特性

应用试验模态分析技术研究柴油机机体的动态特性与工作性能的关系，结果表明：柴油机的漏油，漏水和漏气现象是由于机体接合部位的动态刚度不足及接合面的变形差异引起的。提出改善柴油机的密封性能，提高动态刚度的一些方法和措施，为柴油机结构的优化设计和可靠性设计提供依据。

THE RELATIONSHIP BETWEEN WORKING PROPERTY OF A DIESEL ENGINE AND DYNAMIC CHARACTERISTICS OF ITS CYLINDER BLOCK

The relationship between working property of a diesel engine and dynamic characteristics of its cylinder block is researched by the experimental technique of modal analysis. The results show that the leakage of oil, water, and gas of a diesel engine is caused by lack of dynamic stiffness of joins and by difference of dynamic deformation of the interfacial surfaces. It is found out that when the diesel engine works normal vibration will isolate and squeeze fluid film between the joint surfaces while tangential vibration moves the fluid. Therefore a conclusion can be drawn that the method of increasing the number of screw bolt as well as its tightening force, and improving the dynamic stiffness by adding brackets will ensure the contacting and sealing effects. The study of improving the sealed performance of a diesel engine and increasing its dynamic stiffness provides a basis for the optimum and reliability designs of diesel structure.