1、小型履带式挖掘机结构设计（开题报告）一、 本课题的研究目的和意义： 小型履带式挖掘机是在机械传动挖掘机的基础上发展起来的。它的工作过程是以铲斗的切削土壤，铲斗装满后提升、回转至卸土位置，卸空后的铲斗再回到挖掘位置开始下一次的作业。因此小型履带式挖掘是一种周期作业的土方机械。 小型履带式挖掘机在国民经济建设的许多行业被广泛地采用，如工业与民用建筑、交通运输、水利电气工程、农田改造、矿山采掘以及现代化军事工程等等行业的机械化施工中。据统计，一般工程施工中约有60%的土石方量、露天矿山中80%的剥离量和采掘量是用挖掘机完成的。 小型履带式挖掘机因其体积小，主要应用于城市、相对狭窄的地区，替人力劳动，
2、其用途广泛，主要作业是挖掘、装载、整地，用于城市管道、道路、住宅建设、基础工程和园林作业等。它不仅体积小，机动灵活，且可附装各种工作装置，属多功能建设机械。采用小挖掘机可以大大减轻人力的劳动，缩短施工周期。 为节省劳动力、减轻繁重体力劳动，提高劳动生产率、加快建设速度，保证工程质量和降低成本，采用机械化施工是根本的措施。它对尽早发挥建设投资效果，促进国名经济的高速度发展有很大的作用。二、 文献综述（国内外研究情况及其发展）： 我国前些年大量投入使用的高速公路等基础设施，近来正越来越多地进入维护保养期，同时城市建设也由“大拆大建”逐渐向“精雕细刻”转变。随着我国城市化建设进程加快，今后小型工程机
3、械设备将逐步升温，小型挖掘机市场为业内人士普遍看好。小型液压挖掘机（以下简称小挖）在国外一般指级以下产品，国内目前尚没有明确分类，常指或级以下产品，国内市场目前主要存在这样两类小型挖掘机产品：一类是为工程施工配套的全回转、履带或轮胎行走的标准型液压挖掘机，另一类是面向广大农村市场的低档配置产品即农用挖掘机或汽车式挖掘机。三、 本课题的主要研究内容（提纲）和成果形式：根据查阅的资料提出若干解决问题的方案并加以讨论。进行小型履带式挖掘机总体结构设计，根据老师的要求，做必要的设计和绘图。（1）设计和校核主要零部件（2）绘制总体装配图（3）绘制重要零部件的零件图完成设计的图纸。四、 拟解决的关键问题：
4、（1）设计和校核主要零部件（2）零部件尺寸、参数设计（3）装配部位的结构形式任务书1.毕业设计（论文）的目的：挖掘机被誉为工程机械之王,广泛应用于土石方工程、市政工程、路面修复、农田改造、混凝土破碎、管道铺设、园林栽培及河沟清淤等基础建设中。在充分了有解和认识已的小型履带式挖掘机结构的基础上，对其进行机械设计。2.毕业设计（论文）任务的内容和要求：1、翻译一篇与挖掘机有关的英文文献，不少于5000字2、了解履带式挖掘机的发展历程和主要形式3、认识履带式挖掘机的主要工作原理4、设计和校核主要零部件3.主要参考文献：1 张宏,张箭.国内外小型挖掘机发展综述J. 工程机械. 2007(04)2 张银
5、南,凌勇坚.履带式挖掘机行走和回转液压控制系统J. 机械研究与应用. 2005(06)3 田奇,马鹏飞.液压挖掘机发展概况J. 筑路机械与施工机械化. 2000(03)4 陈进,庆飞,庞晓平.基于组合挖掘的反铲液压挖掘机工作装置优化设计J. 浙江大学学报(工学版). 2014(09)英文文献 About hydraulic excavatorThe hydraulic excavator plays a great role as representatives of engineering machinery products in the social construction, whic
6、h is widely used in the working strength, the construction quality and improved labor productivity having a very significant role, especially fully hydraulic excavator. It is the key factor that excavator working device performance decide to work efficiency. Its design directly determines the level
7、of performance of the excavator. The machine is a typical work device according to mechanical and hydraulic components. From the two aspects of comprehensive consideration undoubtedly, improving its performance is reasonable and method of wisdom.Hydraulic system and power system are the most importa
8、nt hydraulic excavator, its core system is the biggest in the cost of the proportion. Hydraulic system is as a transmission and energy distribution system to determine the driver most of the operating experience directly. Currently mainly focuse on industry in hydraulic system in several aspects of
9、the role in excavators: (1) the handling characteristics and flow distribution; (2) saving energy； (3) the energy density and reliability.A complete hydraulic system consists of five parts, namely, power components, the implementation of components, control components, auxiliary components (Annex) a
10、nd the hydraulic oil.The role of dynamic components is the original motivation of the mechanical energy into fluid pressure energy, the hydraulic system of pumps, which provide power to the entire hydraulic system. Structure of hydraulic pumps generally have gear pumps, vane pumps and piston pumps.I
11、mplementation of components (such as hydraulic cylinders and hydraulic motors) is to pressure the liquid can be converted to mechanical energy to drive the load for a linear reciprocating movement or rotational movement.Control components (ie all kinds of hydraulic valves) in the hydraulic system co
12、ntrol and regulation of fluid pressure, flow and direction. According to the different control functions, hydraulic valves can be divided into pressure control valves, flow control valves and directional control valve. Pressure control valve is divided into benefits flow valve (safety valve), pressu
13、re relief valve, sequence valve, pressure switch, etc.; flow control valves including throttle, adjusting valves, flow diversion valve assembly; directional control valve includes a check valve , check valve, shuttle valve, valve and so on. Under the control of different ways, hydraulic valves can b
14、e divided into switching control valves, control valves and the fixed value proportional control valve.Auxiliary components, including fuel tanks, filters, tubing and pipe joints, seals, quick couplings, high pressure ball valve, hose assembly, pressure fittings, pressure gauge, oil level, oil temperature meter and so on.Hydraulic system of hydraulic oil is the work of the energy transfer medium, a variety of mineral oil, emulsion, oil hydraulic molding Hop categories.
