论文活塞设计

BH135柴油机活塞的设计与分析技术

中文摘要

科技进步推动了内燃机行业的持续发展，发动机的强化指标逐渐提高，活塞及其组件所受的机械负荷与热符合也越来越高，它们的设计是否合理，将直接关系到内燃机的可靠性、寿命、排放、经济性等。因此在已有条件下，通过真实有效地计算分析，得出有益的解决方案成为目前内燃机行业的首选课题。

内燃机严酷的内部温度环境和负荷条件使得传统的设计实验很难取得令人满意的效果，为确保设计目标的实现、为了适应不断增长的高压环境和提高产品的强度和耐久性要求以及设计中的寿命要求，需要采用先进的设计和分析手段，科学的分析活塞的结构对活塞寿命以及工作的可靠性的影响，设计品质优良的活塞，从而使内燃机更好地工作。

本文把计算机辅助工程建模仿真技术应用到活塞结构设计及校核的实例领域，通过三维建模和有限元分析方法，为活塞建立了合适的数字模型，从而预估产品的强度负荷及寿命水平等，提高其设计效率和科学性。本文还描述了柴油机活塞的设计方法和过程，并通过对BH135柴油机活塞的三维建模和有限元分析的实例应用体现出计算机辅助工程技术在产品设计初期的优越性：即一方面建立一种基本的计算机分析模型，对其进行仿真模拟，从而指导产品设计；另一方面以此为虚拟分析平台并提供一些规范化或经验性的建模参考，同时也为提高企业在技术上的自主开发及创新能力而奠定基础。

关键词：内燃机；活塞设计；有限元分析；

Abstract

The development of science technology forced the industry of internal-combustion engine to develop, the strength target of engine was gradually heightened, the mechanical and thermal load of piston and subassembly of piston was higher and higher. Whether their design were in reason, related to the reliability、natural life、let 、economy and so on. Therefore, with own conditions, through true and effective calculation and analysis, getting useful project becomes the most important task of the industry of internal-combustion engine.

In severe environment of the internal thermal and mechanical load, the experiment is difficult to get approving effect. For the sake of realization of design target, adapting increasing high pressure, improving strength、wear and natural life of product, needing to adopt advanced design and analysis measure, analyzing construct of piston is good for piston reliability and natural life. Designing piston with excellent quality improves engine to work better. The simulation method of CAE will be applied to the design and check field of piston structures in this article. Through the numeric analysis and FEM, the strength and fatigue life level etc, are estimated for the subassembly. The article describes the design method and process of diesel engine piston. The theory research and engineering application, show the superiority of CAE to product design: one is instructing the design through the computer analysis model; the other is to provide a modeling reference to virtual platform, and to promote the self-exploitation ability for the enterprise.

Key words: Internal-combustion engine; Piston design; Finite element analysis;

目录

中文摘要

英文摘要

1．绪论

2．设计要求

3. 活塞的基本设计

3 .1 活塞的选型

3. 2 活塞的主要尺寸

3.21 活塞的高度H

3.22 压缩高度H1

3.23 顶岸高度h

3.24 活塞环的数目及排列

3.25 环槽尺寸

3.26 环岸高度

3.27 活塞顶厚度δ

3.28 裙部长度H2

δ

3.29 裙部厚度g

3.10 活塞销直径d和销座间隔B 3.3 活塞头部设计

3.4 活塞的裙部设计

3.5 活塞销座的设计

3.6 活塞与缸套的配合间隙

3.7 活塞大体尺寸