中国地质大学长城学院本科毕业设计外文资料翻译系 别： 工程技术系 专 业： 机械设计制造及其自动化 姓 名： 刘庆鹏 学 号： 05211602 年 月 日外文资料翻译原文R180柴油机曲轴工艺设计及夹具设计一、 研究目的及意义 曲轴是柴油机的关键零部件之一，主要用于往复运动的机械中，与连杆配合将作用在活塞上的气体压力变为旋转的动力。而随着机械化生产逐渐成为当今主流，传统的制造工艺已经不能满足人们的需求。结合实际进行理论分析，在保证产品质量，提高生产效率，降低生产成本的的前提下，对R180柴油机曲轴工艺进行优化设计。二、 R180曲轴工艺现状 从目前的整体水平来看，R180柴油机曲轴基本都是两种材质：一是钢锻曲轴；二是球墨铸铁曲轴。根据材质选择的不同，其生产方式也不同。为了保证生产精度，铸造方式生产的曲轴已经广泛运用于R180柴油机的运行。球墨铸铁具有良好的切削性能，并且可以进行各种热处理以及表面强化处理，故球墨铸铁被广泛运用于曲轴的生产。但是，曲轴毛坯的铸造工艺生产效率低下，工艺装备参差不齐，性能不够稳定、精度低、报废率高居不下，这一系列的问题都需要优化。从目前整体水平来看, 毛坯的铸造工艺存在生产效率低，工艺装备落后，毛坯机械性能不稳定、精度低、废品率高等问题。从以下几个工艺环节采取措施对提高曲轴质量具有普遍意义。熔炼 国内外一致认为,高温低硫纯净铁水的获得是生产高质量球铁的关键所在。为获得高温低硫磷的纯净铁水，可用冲天炉熔化铁水，经炉外脱硫，然后在感应电炉中升温并调整成分。球化处理 孕育处理 冲天炉熔化球铁原铁水,对铜钼合金球铁采用二次孕育。这对于防止孕育衰退，改善石墨形态，细化石墨及保证高强度球铁机械性能具有重要作用。合金化配合好铜和钼的比例对形成珠光体组织十分有利,可提高球铁的强度,而且铜和钼还可大大降低球铁件对壁厚的敏感性。 造型工艺气流冲击造型工艺优于粘土砂造型工艺，可获得高精度的曲轴铸件，该工艺制作的砂型具有无反弹变形量的特点,这对于多拐曲轴尤为重要。浇注冷却工艺采用立浇立冷，斜浇斜冷、斜浇反斜冷三种浇注方式较为理想,其中后一种最好。斜浇反斜冷的优点是：型腔排气充分，铁水充型平稳，浇注系统撇渣效果好，冒口对铸件的补缩效果好，适应大批量流水线生产。目前，国内大部分专业厂家普遍采用普通机床和专用组合机床组成的流水线生产，生产效率、自动化程度较低。曲轴的关键技术项目仍与国外相差12个数量级。国外的机加工工艺大致可归纳为如下几个特点。广泛采用数控技术和自动线，生产线一般由几段独立的自动化生产单元组成，具有很高的灵活性和适应性。采用龙门式自动上下料，集放式机动滚道传输，切削液分粗加工与精加工两段集中供应和回收处理。曲轴的主要加工工序基准中心孔，一般采用质量定心加工方式，这样在静平衡时，加工量很少。轴颈的粗加工一般采用数控铣削或车拉工艺。工序质量可达到国内粗磨后的水平，且切削变形小、效率高。铣削和车拉是曲轴粗加工的发展方向。国外的曲轴磨床均采用CNC控制技术，具有自动进给、自动修正砂轮、自动补偿和自动分度功能，使曲轴的磨削精度和效率显著提高。油孔的加工采用鼓轮钻床和自动线，近几年随着枪钻技术的应用，油孔的加工大多已采用枪钻自动线钻孔修缘抛光。曲轴的抛光采用CNC控制的砂带抛光机，所有轴颈一次抛光只需20多秒，粗糙度可达Ra0.4以下，大大减小了发动机的磨合期。动平衡一般采用CNC控制的综合平衡机，测量、修正一次完成。检验一般在生产线上配备MARPOSS或HOMWORK综合检测机，实现在线检测，对曲轴的几乎所有机加工项目均可一次完成检测、显示和打印。曲轴的清洗采用专用精洗机定点定位清洗，保证了曲轴清洁度要求。广泛采用了轴颈过渡圆角滚压技术。专用圆角滚压机自动控制，对所有轴颈圆角进行一次滚压，而且滚压力和滚压角度可自动调节，使圆角处产生最佳的残余压应力，提高了曲轴的疲劳强度。曲轴热处理的关键技术是表面强化处理。一般均正火处理，为表面处理作好组织准备。表面强化处理一般采用感应淬火或氮化工艺，少数厂家还引进了圆角淬火技术和设备。球铁曲轴具有诸多优点，国内外广泛采用。但整体水平与国外还有相当差距，除生产规模小、管理落后外，主要差距仍是制造工艺的落后。借鉴国外的先进技术和工艺方法是提高我国曲轴制造水平的捷径。外文资料翻译译文1.the purpose and significanceCrankshaft is one of the key components of diesel engines, mainly for reciprocating machinery, and the link will be acting on the piston with the gas pressure into motivation rotation. With mechanized production gradually become mainstream, conventional manufacturing processes can not meet peoples needs. Actual theoretical analysis, to ensure product quality, increase productivity, reduce production costs under the premise of R180 diesel engine crankshaft technology to optimize the design.2.R180 Status crankshaft technologyFrom the current point of view the overall level, R180 diesel engine crankshaft are basically two materials: one is forging steel crankshaft; two ductile iron crankshaft. Depending on the choice of materials, their production in different ways. In order to ensure the production of precision casting way to produce the crankshaft has been widely used to run R180 diesel engine. Ductile iron has good cutting, and can be a variety of heat treatment and surface hardening process, it is widely used in nodular cast iron crankshaft production. However, the crankshaft casting production inefficiencies, process equipment varies, an unstable, low accuracy, scrap rate remains high, this series of questions needs to be optimized.From the current overall level, the presence of low productivity, backward technology and equipment, rough mechanical properties of instability, low accuracy, scrap rate and other issues blank casting process. Take measures from the following step of the process to improve the quality of the crankshaft has universal significance. smelting and abroad agreed that the high temperature molten sulfur to obtain pure is the key to producing high-quality ductile iron. In order to obtain high-temperature low-parathion pure molten iron, can be used to melt iron cupola, the furnace desulfurization, then warmed in an induction furnace and adjust ingredients. ball handling inoculation of ductile iron melting cupola base iron, ductile iron alloy of copper and molybdenum using second inoculation. This is to prevent breeding of recession, to improve the graphite morphology, refined graphite and ensure the mechanical properties of high strength ductile iron plays an important role. alloyed with a good proportion of copper and molybdenum is very favorable for the formation of pearlite structure can improve the strength of ductile iron, and copper and molybdenum also greatly reduce the sensitivity of ductile iron pieces of wall thickness. molding process air impact molding process is better than clay sand molding process, the obtained precision casting crankshaft, the fabrication of sand with no rebound deformation characteristics, which is particularly important for multi-throw crankshaft. pouring cooling process using Li pouring - stand the cold, pouring oblique - oblique cold, oblique pouring - pouring in three ways backslash cold ideal, after one of the best of them. Ob