摘要曲轴是柴油机最重要的零件之一。根据柴油机型式和性能的不同,曲轴的毛坯型式、结构、材料、外形尺寸、重量是不同的,从而决定了加工方式的不同.加之生产类型的不同,工艺流程的长短及工序细化的程度、自动化程度差别更大,但基本的工艺流程大致相同。49490

曲轴负责将活塞往复运动转变为旋转运动，承受着复杂的交变应力，直接影响着内燃机的寿命，而设计的先进性和加工工艺的合理性是提高曲轴寿命、保证内燃机正常运转的重要保证。本文针对N490型柴油机曲轴加工工艺的设计，对曲轴加工中较为重要的工序，钻中心孔、动平衡、连杆颈加工、抛光等工艺进行了研究，提高了原产品的质量。还涉及N490曲轴的加工工艺方案设计及应用，突出了曲轴加工工艺中的重点、难点所在:属于典型的柔性件，细长轴类，工艺系统刚性差，必须采取加强加工工艺系统刚性的措施;同时须合理安排热处理工序以消除热处理变形对机械加工精度的影响等。

毕业论文关键词: 曲轴 工艺  中心孔 动平衡  基准 连杆颈

Abstract  The crankshaft is one of the most important parts of diesel engine. According to the diesel engine type and properties of different, crankshaft blank pattern, structure, material, dimensions, weight is different, which determines the ways of processing. In addition to production of different types, process and the length of the degree of automation of process optimization, the difference is greater, but the basic process is substantially the same as the.

The crankshaft is responsible for the reciprocating motion of the piston into rotary motion, under complex stress, directly affects the service life of engine, the advanced design and processing technology of rationality is to improve the life of crankshaft, to ensure normal operation of the internal combustion engine is important assure. This article in view of the N490type diesel engine crankshaft process design for crankshaft processing, more important process, center hole drilling, dynamic balance, connecting rod neck processing, polishing process are studied, to improve the original product quality. Also relates to N490crankshaft machining process design and application, highlighting the crankshaft processing in focus, difficulty: belongs to typical flexure, slender shaft, the rigidity of process system difference, must strengthen the processing system of rigid measures; at the same time must be rationally arranging heat treatment process to eliminate heat treatment deformation on mechanical the influence of processing precision.

Key words: crankshaft dynamic balance technology center hole base connecting rod neck

目  录

第一章 绪论 1

1.1 研究对象 1

1.2 曲轴和飞轮简介 1

1.3 国内外研究现状 1

1.4 主要研究内容 3

1.5 研究方法 3

第二章 曲轴飞轮的设计 4

2.1 柴油机技术参数说明 4

2.2 柴油机的工作原理 4

2.3 柴油机曲轴的功用 4

2.4曲轴的工作条件、结构型式和材料的选择 5

2.4.1  曲轴的工作条件和设计要求 5

2.4.2  曲轴的材料 6

2.4.3  曲轴结构型式的选择 6

2.4.4 曲轴强化的方法