水平对置与直列四缸发动机曲轴的模态与动态分析

发布时间：2018-04-05 09:00

本文选题：曲轴　切入点：水平对置发动机　出处：《华北电力大学》2016年硕士论文

【摘要】：汽车如今已经走进了千家万户,而人们对汽车的了解却并不多,大多数人只是从汽车的品牌和口碑来选择自己的车型。而对发动机的了解,则是少之又少。本文通过介绍两种不同汽车的发动机,将使人们对不同类型发动机的特点产生相应的认知。并对两种发动机的曲轴分别进行模态和动态分析,比较分析两种不同发动机所表现出的异同,可以使人们对汽车的认识有一个新的提升。本文以斯巴鲁和雪佛兰两种相同排量(2.0升)的发动机作为研究对象,对发动机的曲轴分别进行模态与动态分析。因斯巴鲁发动机为水平对置四缸结构,而雪佛兰发动机为直列四缸结构,故其输出特性有着很大的不同。本文主要探讨两种不同发动机曲轴的输出特性的问题。首先,使用三维造型软件分别对两种发动机曲轴系的相关零件进行模型的建立,并将曲轴系进行装配。在建模时,忽略了一些对分析影响较小的细节部分,同时验证装配的准确性。其次,在ANSYS中对两种曲轴分别进行自由模态分析和约束模态分析,并根据所产生的模态结果对两种曲轴进行比较分析。接着,将进行了模态分析的曲轴进行柔性化处理,将处理后的曲轴导入到多体动力学分析软件,代替刚性曲轴,并施加相关的力与约束。最后,对以柔性曲轴为核心的曲轴系进行动力学分析,并分析比较两种不同的曲轴在其各自所对应的转速下,所产生的异同之处。通过对两种不同的发动机的曲轴的输出性能的对比,对两种曲轴所产生的异同进行相应的分析,其分析结果会使人们对不同的发动机的输出特性产生更进一步的认识。
[Abstract]:Cars have now entered thousands of households, but people do not know much about cars, most people only choose their own car from the car brand and word of mouth.But the understanding of the engine, is very little.This paper introduces two different kinds of automobile engines, which will make people know the characteristics of different types of engines.The modal and dynamic analysis of the crankshafts of the two kinds of engines are carried out, and the similarities and differences of the two different engines are compared and analyzed, which can make people have a new understanding of the automobile.In this paper, the engine with the same displacement of Subaru and Chevrolet (2.0 liter) is taken as the research object, and the crankshaft of the engine is analyzed by modal and dynamic analysis, respectively.Since the Subaru engine is a horizontal four-cylinder structure and the Chevrolet engine is an in-line four-cylinder structure, its output characteristics are very different.This paper mainly discusses the output characteristics of two different engine crankshafts.Firstly, three dimensional modeling software is used to model the two kinds of engine crankshaft system, and the crankshaft system is assembled.In modeling, some details that have little effect on the analysis are ignored, and the accuracy of assembly is verified.Secondly, the free mode analysis and constrained modal analysis of the two crankshafts are carried out in ANSYS, and the two crankshafts are compared and analyzed according to the resulting modal results.Then, the crankshaft which has carried out modal analysis is treated with flexibility, and the treated crankshaft is imported into the multi-body dynamic analysis software instead of the rigid crankshaft, and the relative force and constraint are applied.Finally, the dynamic analysis of the crankshaft system with flexible crankshaft as the core is carried out, and the similarities and differences between the two different crankshafts under their respective rotational speeds are analyzed and compared.By comparing the output performance of two different engine crankshafts, the similarities and differences between the two crankshafts are analyzed accordingly. The results of the analysis will make people have a better understanding of the output characteristics of different engines.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464

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