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压缩包内含有CAD图纸和说明书,咨询Q 197216396 或 11970985摘 要该方法用于铆接的摆动，铆钉杆是铆接方法和局部加压，并形成一个连续的摆动中心，直至形成铆钉。“辗”技术是一种先进的处理压力和压力处理方法相比，艺术与和技术和轧制设备，其中的一个优势。【1】本文设计的结构型材铆接机。首先，通过参考数据的研究现状和发展现有铆接；在此基础上，分析的基本原理，提出设计方案，振动压实机铆接；然后对主要零件的设计和强度校核；最后，制图软件AutoCAD的铆钉装配图和主要零件图。通过这次设计，建设大学的专业知识，例如：、机械设计、材料力学、宽容和互换性和机械制图，掌握产品设计方法和经验的起重机使用AutoCAD软件，对今后的工作生活是非常重要的。关键词：摆动碾压【2】；铆接机；液压缸；设计压缩包内含有CAD图纸和说明书,咨询Q 197216396 或 11970985AbstractThe so-called swing grinding riveting method, is by the rivet rod on the rivet local pressurization and around the forming center for swing until the rivet and riveting method. Rotary forging is a kind of advanced processing technology and technology, compared with the traditional pressure processing technology and technology, the technology and equipment of rotary forging has incomparable advantages.This paper describes the design of the mechanical structure of the profile riveting machine.First, access to information through understanding existing riveting machine of the present situation of research and development; then put forward swing rolling riveting machine design scheme in the analysis based on the basic principle; and then, the design and strength check of the main parts is discussed. Finally, through the AutoCAD drawing software drawn the riveting machine assembly drawing and the main parts of the map.Through the design, the consolidation of the University of the professional knowledge, such as: mechanical principles, mechanical design, mechanics of materials, tolerance and interchangeability theories, mechanical drawing; master the design method of hoisting machinery products and be able to skillfully use AutoCAD drawing software, for the future work in life is of great significance.Key words: Swing rolling; Riveting machine; Hydraulic cylinder; Design目 录摘 要IIAbstractIII1 绪 论11.1 研究的背景及意义11.2 摆动辗压的定义及优点11.3 摆动辗压研究现状及发展21.4 本文研究的目的与内容32 总体方案设计42.1 设计要求42.2 方案设计42.3 技术设计路线53 主要零部件的设计63.1 电机的选择63.2 轴及轴上零件的设计与校核63.3 伸缩液压缸设计93.4 铆接头的设计153.5 底座的设计173.6 支架的设计174 其他方面194.1 摆动辗压变形特征及其力学分析194.2 摆辗件变形时产生的缺陷及防止方法205 结 论23参考文献24附 录25致 谢26VIII1 绪 论1.1 研究的背景及意义新技术的迅速发展，旋转锻造早已已引发世界各国的密切关注。在国际展览机近年来，也有追求旋锻机设备上技术是不可见的旋转锻造为德国西方，特木科说，“消失”，但正在大力研究和新进展。旋转锻造技术开始提出锻造、英国和波兰做了大量的研究工作，但作为一个摆动辊热锻，目前该领域中的设备和工具，有一些问题，没有很多的从国家在这方面，做了大量的研究，对汽车半轴的倾斜和热锻，取得了令人鼓舞的，值得进一步研究。旋转锻造锻件技术能够与其他成型辊的艰苦训练，如汽车VE泵凸轮机构，差速器锥齿轮、离合器盘、汽车半轴、齿轮、端面棘轮启动摩托车磁电机套、配重隔离器的速度差，导向轮，扬声器磁体，火力调节帽冠，方向，高压电接触固定和移动接触，如接触件的形状复杂零件的精度高，已在汽车、摩托车、五金、AR，设备等行业得到了广泛的应用应加强研究和技术扩散强度的旋转锻造，不仅具有巨大的经济效益，有着广阔的发展前景。1.2 摆动辗压的定义及优点该方法摆碾铆接，铆钉杆是用铆钉铆加压，围绕一个中心连续摆动，直到形成铆钉。根据该方法冷碾印铆接【3】。铆接可分为轨道法你们铆接铁路更容易理解。这是一个固定的周向和径向铆接运动是梅花形的运动范围，在粉碎的虚幻膨胀铆钉中心轴达到铆钉，每个轨道花形梅花的POINT中央铋钉。表面接触铆钉杆完成一个类似的运动在轧制金属铆钉。“旋转锻造”技术是一种先进的处理压力和压力处理方法相比，技术和技术工艺和轧制设备，其中的一个优点：加工、5%到20%摆辗力只有常规锻造，大大降低了设备，工厂，基本形成薄盘类零件，形状复杂，加工厂的成本可以在普通压力和困难的小吨位设备代替大将军，他可以相对普通平机建立一个低投资说谎的5倍以上，更一般的类锤装置；效率提高3倍以上。同时，旋转锻造与触摸，结构简单，容易更换模具，模具使用寿命长，是一大优势。振动加工设备零件、金属流线，最好，尤其是倾斜的冷作硬化后，由于抗拉强度和硬度提高，因此，低碳合金钢可用，成型后的高强度合金钢的碳。（1）高精度的尺寸，良好的表面质量的培训是没有影响振动磨静载荷小于成形力，培训，设备是比较大的，工件的大小可以达到0.025毫米，粗糙度值表面0.4-1.6um RA可以达到。（2）省力：旋转锻造连续局部塑性变形累积实现整体塑性成形，成形力一般是15120整体锻造变形力。相对于锻造成形的全过程；硬币的大小相同，其所需的轧制变形力大大降低，使旋转锻造设备吨位较小的期望。（3）对成形件薄圆盘型：旋转锻造可以形成高径比H / D是非常低的，成形的锻件常见的不可能，特别是薄的圆盘，形成了一个蛋糕，法兰，半轴和撤销备件，大大扩大了伪造的产品。（4）生产效率高：倾斜的生产力可达1015分钟。（5）的工作条件，形成旋转锻造是静态的，无振动，噪音小，易于实现机械自动化，良好的工作条件。1.3摆动辗压研究现状及发展1.3.1摆辗设备研究目前已设计，制造的额定压力36，100300、1000、3000、4000 1600年，2000年，垂直6300 KN和其他规格的旋转锻造机，额定压力为10004000 KN水平摆的冷轧机和方法铆接机摆动的钟摆。此外，一机多用、轧辗复合机旋转，压辊。机身结构的锻造旋转的差异外，除了框架式、四柱，焊接结构，振动头的滚动轴承结构类型和外球面轴承式静压轴承和静压锻压机械的计划。旋转的摆头运动轨迹是由两个内环和外环实现偏心旋转，旋转锻造机摆头运动轨迹主要采用楔形块偏心。周德成，王家勋，张萌，陆其仁，大量的研究刘汉贵等对计算机辗摆头驱动电机功率的计算旋转锻压设备。【4】裴伟才，需要特别裴兴华，程培源，刘汉贵，王广春等对机构运动轨迹的摆动运动进行了详细的分析和研究。【5】1.3.2摆辗成形理论研究使用电气测量，用云纹法、光塑性法、网格法与小孔的方法和输入旋转锻造变形区内的应力分布和单元和接触面上的压力分布；切向应力分布，模拟和实验被旋转锻造变形压力，理论分析和实验结果相结合的旋转锻造时，金属元素的中心拉薄薄的critre.le方法主应力法、能量、元件上限法基于有限元一桶，金属流动规律，在环形振荡元件的轧制过程中，缺陷的形成原因和旋转锻造，变形力和力矩的计算。不同的观点，使用的计算方法和工程几何组合筒、环件辗接触的接触区域轮廓的计算、分析和研究。1.3.3摆辗机的设计理论根据弹性理论，应用有限元法对身体的旋转锻造机、支架、摆头、应力分布、研究和分析。1.3.4摆辗成型发展新技术的迅速发展，旋转锻造早已引发世界各国的密切关注。在国际展览机近年来，也有追求旋锻机设备上affichage.la技术是不可见的旋转锻造为德国西方，特木科说，“消失”，但正在大力研究和新进展。【6】旋转锻造技术开始提出锻造、英国和波兰做了大量的研究工作，但作为一个摆动辊热锻，目前该领域中的设备和工具，有一些问题，没有很多的从国家在这方面，做了大量的研究，对汽车半轴的倾斜和热锻，取得了令人鼓舞的，值得进一步研究。锻造轨道的一侧，趋势是冷或热锻，多年来，公司英国有热轧厚重的趋势温度E冷，这一点我们应该特别注意。轧制技术发展的铆接，旋转锻造技术提供了新的应用领域，它比铆接和液压冲击具有更多的优点，各国的重视，得到了广泛的应用。1.4 本文研究的目的与内容目的是培养学生能综合运用所学的理论基础、专业知识和专业基本技能剖析和解决实际问题，内容包括如下：（1）家用铆接机的设计计算；（2）家用铆接机装配图绘制；（3）家用铆接机零件图绘制。29 第2章 总体方案设计2 总体方案设计2.1 设计要求完成摆碾式液压铆接机的机械结构和电机传动系统设计。包括底座、立柱、电动机、铆接和液压缸等几个部分。电机可以带动旋转的铆接、铆接的压力，以减少阻力和提高铆钉头质量。2.2 方案设计2.2.1方案设计根据设计要求，提出如下设计方案：图 2-1 方案简图2.2.2工作原理电机通过联轴器与油缸杆连接，电机转动时可带动油缸杆旋转，油缸杆在液压油作用下可上下移动，铆接头有一定角度实现摆动辗压2.3 技术设计路线技术设计路线如下：调研摆动辗压铆接机的结构和工作原理根据设计要求确定设计方案设计主要零部件结构尺寸画出CAD装配图拆画各主要零部件的零件图。 第3章 主要零部件的设计3 主要零部件的设计3.1电机的选择电动机功率的确定由旋转电机，如果选择功率越大，能量消耗、浪费太低，使清洁头使用效果有限。3.2 轴及轴上零件的设计与校核3.2.1尺寸与结构设计计算，取故取2段的直径，长度。3.2.2强度校核计算首先，根据方案的决策树结构计算简图的确定轴承的旋转位置，教材中提取有价值的滚珠轴承式6206手册中，研究了= 17mm。【7】因此，范围支撑轴的L1 = 72mm。根据计算做图轴弯矩和扭矩图的树图结构板的弯曲和扭转的C部分是危险截面的轴。计算在C段MH，MV和M值如下表。载荷水平面H垂直面V支反力F，C截面弯矩M总弯矩扭矩3）按弯扭合成应力校核轴的强度根据式(15-5)及上表中的数据，以及轴单向旋转，扭转切应力，取，轴的计算应力已选定轴的材料为45Cr，调质处理。由表15-1查得。因此，故安全。3.2.3键的选择与校核键的工作长度，合适3.2.4轴承的选择与校核满足要求。3.3伸缩液压缸设计3.3.1确定主要参数（1）工作压力的确定3.3.2主要尺寸的设计与校核液压缸的工作压力主要还是依据设备的类型，以确定液压以及液压设备的不同用途，因为不同的操作条件下，通常使用的是压力范围，在设计的类比可以确定。同上，以提升液压缸为例进行设计。前述已经可以确定液压缸的工作压力，缸筒内径 D=125mm，活塞杆外径d=110mm。（1）液压缸壁厚和外径的计算 表3-5中的系列尺寸来选取标准值。无孔时： 有孔时： 式中 液压缸的最大行程。 液压缸的内径。为了保证最小导向长度时，如果过度增加，B是不合适的，可能有必要在气缸和活塞之间增加隔套增加K值。这套的长度的长度时所需的最小导向决定：在此设计中，液压缸本身的最大行程为50mm，液压缸自身的内径为125mm，所以应用公式的 =mm =15mm式中 F液压缸最大负载。 Z固定螺栓个数。 k螺纹拧紧系数，k = 1.121.5。根据上式求得 = =7.2mm（7）液压缸强度校核。 前面已经通过计算得：D =125mm， =12.5mm。则有10，所以为厚壁缸。=5mm=9.8mm可见缸筒壁厚满足强度要求。3.3.3液压缸的结构设计（1）缸体与缸盖的连接形式缸体与缸盖常见连接方式有法兰连接式（图3-1a）、半环连接式（图3-1b） 、螺纹连接式（图3-1c、f） 、拉杆连接式（图3-1d） 、焊接式连接（图3-1e）等。【8】图3-1常见的缸筒和缸盖结构头端部分和筒体的连接形式和工作压力，料筒和工作条件。考虑到，在这种结构中，端部与气缸筒法兰连接形成。（2）活塞杆与活塞的连接结构结构形式类的活塞和活塞杆有很多种，常见的综合型、锥销连接，外螺纹连接和半环式连接的各种形式，如图3-2（a）所示。半环连接结构复杂，装卸不便，而且可靠。图3-2 活塞杆与活塞的结构此外，活塞和活塞杆组成的整体结构，但他不能适应场合小综合考虑，在本设计中，活塞杆与活塞连接的螺纹连接形式，如图3-2（b）所示。（3）活塞杆导向部分的结构结构导向部包括活塞杆，活塞杆和端盖，结构，导向套和密封，灰尘和锁定装置等。结果导向套可与端盖直接的指导，也可以在端盖导套和单独的导向结构。导向套，便于更换后的磨损，所以更广泛的应用。本设计通过综合考虑，采取端盖直接引导。（4）密封装置液压缸中常见的密封间隙和摩擦密封装置，密封圈的密封圈，等。一个密封的空间依赖元素之间的空间运动的微笑，以防止泄漏的密封圈靠摩擦环，活塞上的摩擦（尼龙或其他材料）“O”形弹力作用下近壁圆柱环，防止泄漏；主要由密封圈、O形密封圈，V形形式式并结合大量居民的外币，橡胶材料油，尼龙，聚氨酯和结构简单，制造方便，磨损自动补偿能力之后，可靠，汽缸和活塞之间的活塞和活塞杆，气缸和气缸盖之间可以设计后，全面检查，O形圈密封。（5）缓冲装置液压缸驱动元件的质量在往复运动过程中会更快，由于移动元件具有较大的动能，使液压缸活塞运动到醉顶端，端盖与碰撞，产生冲击和机械冲击的噪声。不仅造成损坏的部分的液压缸，并造成损害的其他机器。为了避免这种风险，保证安全，需要采取措施来缓冲液压缸运动速度的控制。当活塞端移动，柱塞垫的末端插入气缸阻尼孔的活塞和气缸之间的端部形成封闭空间，仅剩余油腔中的液体挤压链从节流环之间的节流孔或缓冲柱塞和槽缝中挤出，使活塞运动的压力迫使制动减速度，实现缓冲区.缓冲装置的液压缸可调式节流孔（图3-3）类型的变化和节流孔（图3-4）。 图3-3 节流口可调式缓冲装置 图3-4 节流口变化式缓冲装置在本设计中，适当降低加工难度，决定改变节流孔式缓冲装置，缓冲装置可以调节。3.4铆接头的设计3.4.1铆接形式图3-5 铆接形状图3.4.2每转进给量的确定通过旋转在蚌设备吨位和发动机的功率和效率和铆接质量和影响很大，这么大，接触面积增加，需求大吨位，发动机的功率也相应增加；如果太低，生产率低，使用寿命短的变形不均匀，手锑，一般径向铆接1.52.2rad / r，跑道铆接1.21.8mm/ r。太多的选择供给量的劳动力，甚至小于0.8mm/ r，他是不可能满足铆接有效的批量生产。3.4.3摆角口的确定摆角大小直接影晌设备吨位、生产率和产品质量。若过大 虽然铆接力减小但变形不均匀，生产率低；而过小。则铆接力增加，设备吨位加大，一般取3.55.5为宜，本次取5.1。【9】3.4.4摆头转速的确定生产力转速摆头装置上的禁忌，不仅影响。肋也是一个大功率电机的效率高，但需要更多的发动机功率小；如果结果相位旋转。一般铆接机n取550850r/min大吨位铆接机选取较低的转速：小设备可选较高的转速。【10】3.4.5铆接头的结构尺寸确定通过上述分析经AutoCAD匹配设计得到如下图结构的铆接头：图3-6 铆接头的结构图3.5底座的设计结合其他零件采用AutoCAD匹配设计得到如下结构尺寸：图3-7 底座结构图3.6支架的设计在机械工件支撑或接收，机架支撑塔接收罐，如齿轮减速器壳体，机床床身集体机架等。3.6.1支架结构类型（1）按支架外形分类按支架外形分类：网架式、框架式、梁柱式、板块式和箱壳式。（2）按支架的制造方法和材料分类根据介质的制造方法，可分为铸造支架焊接，螺栓或铆接支架。根据支架材料可分为金属和非金属支架支撑。非金属载体可分为混凝土支撑，支撑件基础平台的混凝土，花岗岩和塑料支架。铸铁框架，钢和铝材料。小型设备（如仪器等）是由铜或塑料制造的支架。【11】3.6.2支架结构的选择选择形状的支撑结构是一个复杂的过程，在形式、结构构件截面结构和节点相结合的具体情况进行仔细的分析。对课程结构进行比较，技术对各种设备规格和要求不同，支撑结构的统一方法的选择更加困难。但机械结构，可以使用下列一般规则。这些规则，以节省材料的选择必须遵循的一般规律的形式。（1）内力分布结构和材料性能必须适应，以发挥优势轴力可以充分利用杆件的轴向力，截面上的分布是均匀的材料，所有材料都得到了充分的弯矩作用下的截面应力分布不均匀，使材料的应力分布是不经济的。【12】在机械结构方面的许多部件都是沿垂直方向的杆轴的弯矩。沿轴变化非常快。有竖向荷载的弯矩曲线，曲率，和整个地球曲率和负荷的比例。最大弯矩只短，长的部分的材料不能充分利用，这是另一个原因是受弯构件是不经济的。（2）结构的作用是基于由力作用点的最短距离的电荷传输材料，结构，使用更省。（3）结构的连续性，降低内力，节省材料。综合考虑机器的工作时所受的力，我选用机体材料HT200铸造支架，力学性能：=200MPa， =340MPa.适于制造箱体、底座类零件。 第4章 其他方面4 其他方面如下分析摆动辗压常见缺陷形式、产生原因及预防措施。4.1摆动辗压变形特征及其力学分析4.1.1摆辗变形的主要特征主要特征的旋转锻造变形时，有两个：（1）当高径比，即H0 /做0.5，产生一个“蘑菇”效应；当H0 /做0.5，变形相对均匀。工件和高径比较小，高度渗透变形整个房间。【12】（2）的摆动中心部分的拉应力。当工件较薄，旋转角度，如果每转进给量低，工件直径大，容易产生的现象表明，rupture.l中心计算，应力牵引范围在0.4区R0（R0为工件半径）。4.1.2摆辗件主要变形特征的分析（1）“蘑菇”效应【13】当工件较厚，进给量是低的，由于接触面积上下模和工件的不同（上面小，下面），测定知道附近的轴向压力在单元上模最在小房间，下模，使附近的金属上模容易满足塑性条件，以产生流动。在外边缘部分：R =1，工件上下表面接触到塑性状态下分别为：-z =-S和Z =SIGM美国从侧面去了解： |z在|），也由于磨损在上模，因此，（| | |上下|），可见一个房间工件在塑性状态下接触面容易满足，很容易形成“当工件的蘑菇状的厚，进给量是低的，由于接触面积上下模和工件的不同（上面小，下面），在轴向压力在单元上模最小的房间下模，在接触的表面，在工件塑性状态容易满足，产生流动，很容易形成“蘑菇头”。蘑菇状的：当工件较厚，进料量大，对模具的接触面积，接触压力，使摩擦力增大，这严重阻碍了地表径流和空白开始对轧制接触面积塑性变形，增大了接触面积对模具和空白空白，然后粘在上模，上模的延伸部分和接触部分空白区域的塑性变形下模，下模和部分空白的接触，摩擦力小，接触部分的空白，下模快速变形，容易形成蘑菇状。当毛坯变形形轮部分的高度和直径较小，当有不稳定现象发生时轧坯的轴向变形，使接触坯料与下模也部分，这部分提高金属表面的单位面积压力，达到材料的屈服极限，从而产生塑性变形，形成于下模对应的塑性变形区空白底两端，中间的快速变形，变形速度慢，形的滑车。图4-1 摆动辗压工件变形情况当工件较薄，测试知识，接触压力面上轴向相邻的单元上下模可同时满足的条件下，金属，塑料，金属可以同时沿径向和切向流和径向拉伸变形和变形细长的形状，比较均匀，不会产生“蘑菇头”。（2）薄件中心开裂在一个共同的旋转盘件锻造，中心区域在水平方向的正应力为拉应力，拉应力区比其他地区的工件，工件的变形模式的切向和径向、轴向缩短变形达到一定程度的凹陷，房间的中心，形成缺陷处理。由塑性条件：=（1 - 3=3可以确定，当S：1=s（1），由于= L 1.155时，10，即在中部的一部分存在拉应力（=z =，1 0）。结果表明，压力单元，单元中的中央部分的轴向压力很低，约14的流动应力S。计算中心压力P / 2K 1 0的结果，即在Y方向应力是由于存在拉应力区，使构件倾斜油缸中央变薄，常出现变。【13】图4-2 摆动辗压工件受拉力分析4.2摆辗件变形时产生的缺陷及防止方法4.2.1薄件中心开裂圆柱试件(铅件)墩粗和用响铜制锣摆辗时， 均发生了中心部分被拉裂现象，如图所示。图4-3 摆动辗压工件中心开裂情况旋转锻造工艺对工件的每一刻，只有部分与上模的接触面，房间周围不同部位的摆头交替地发生塑性变形，工件和由于应变状态相对稳定，持续的双向减少变形，使变形的积累，工件的心比其它部分更薄，这是该盘件锻造中心旋转的根本原因是薄的。件薄盘，当电源每个工件的旋转是低应力状态差，极易导致缺陷的减肥中心。【14】为了防止薄件中心裂纹，保持工件平面，不增加设备吨位，可采用局部增厚的中介，以增加截面系数，然后从加厚部分的空白增厚工件时，条件改进的应力，由于加厚部分和矩阵的限制下，工件的中间部分受拉应力的降低，各部分变形更均匀，心不发生凹陷，以避免缺陷的产生。轧制板材的碟形弹簧，从而增加供应量，使接触面积增加率，从而减少拉应力产生。然而，如果每转进给量太大，不仅工件翘曲，变形力的旋转锻造迅速增加。4.2.2大头件侧表面开裂旋转锻造变形时，如果样品（或工件）的侧表面裂纹，在相同的条件下，然后旋转锻造变形容易增加裂缝的发展方向。图4-4 摆动辗压工件纵向裂纹情况旋锻变形对纵向裂缝的趋势已经生产铁路车辆钩销件冷拉拔过程中，如果毛坯表面微裂纹或放电原因被意外地击中，旋锻头可能引起开裂。为了防止开裂纵向旋转锻造应选择原材料，注重质量，确保图纸，小心轻放，外表面保护。4.2.3高件失稳折迭在元件旋锻变形过程中，如果 L H / D，常常是必要的，以形成在变形过程中的滑轮，继续产生弯曲变形。【15】如果法兰倾斜的长茎（如轧制汽车半轴；钩舌销元件），由于经常接触端，旋转锻造生产的不稳定性，使工件弯曲、折叠，然后实践，运用“双重作用的蘑菇”加快形成头部，茎的部分可用于夹紧或选择合适的电除尘器ACE抑制纵向弯曲模具，为生产合格零件有国家生产的汽车半轴，杆部与夹紧机构，以缩短挂钩的自由端法兰；生产的长杆用销；限制杆插入空间下模和模壁的方法，以防止头部的杆件弯曲时的轧制。和一个空间是0.2毫米，旋锻头训练好，茎部弯曲。产生提高生产力和防止弯曲，可以增加每转进给量的增长率的接触面积。4.2.4高件锻不透 摆辗变形具有表面性质，摆辗变形首先在头部发生。当摆头与工件接触弧长aH时， 会发生锻不透的现象。摆辗成型适合于薄件，只有当高径比小于0.5，变形程度在20 % 左右时，可使变形渗透到整个工件。【16】 为了使深部的变形，在设备条件下摇动应尽可能地增加进给量。如果采用恒功率泵，在轧制开始，进给速度高，当温度降低，电阻增大，进给速度可自动减少，从而发挥省力滚摆的优点，并能减少弯曲防止折叠。4.2.5锻模中心易龟裂、塌陷 第5章 结论5 结 论本毕业设计使用中几乎所有我们专业的大学，这是我们大学所学专业知识的一次综合调查和评价。通过这次毕业设计，使我们对知识有一个通道，在理解和全球一体化的例子，我们需要材料力学的设计过程中，工程制图，材料，机械设计，机械工程，宽容的基础和CAD计算机辅助绘图和专业知识范围内的协调。在设计的过程中，我们不仅了解一点旧知识，使我们发现了许多以前没有注意到的细节，但正是这些细节问题凯利。如果我们可以机的关键技术人才。另外，我觉得毕业两个月的设计极大地丰富我们的知识，我学到了很多知识，不仅在更多的专业知识。在这一过程中，设计，由于需要运用知识，这要求我们在互联网或图书馆的访问，在设计方案，需要我们对工作环境的机械设计结构型材铆接机工作能力有了一定的了解的选择方案。没有问题，由于注意到，在这方面，我们必须认识到，通过实践和查阅资料，可以做的更好。 参考文献参考文献1 胡亚民，伍太宾，赵军华.摆动辗压工艺及模具设计M.重庆:重庆大学出版社，2008.2 李良福.精密毛坯的冷摆辗工艺研究J.金属成形工艺，1999(4):31-32.3 李良福.冷辗压伸缩式液压缸毛坯的工艺和设备J.金属成形工艺，1999(4):33-34.4 张如怀，付建华，梁秀春.摆辗机多轨迹摆头结构探索J.山西机械，1996(2):34-35.5 裴兴华，王广春，张辉，等.火车车轮摆辗成形模拟实验研究J.锻压技术，1995(3)6 王广春.环形件摆动辗压变形的三维刚塑性有限元分析.哈尔滨工业大学博士学位论文.1996， 957 王广春.环形件摆动辗压接触区域的压力分布.山东工业大学学报，1997(4)8 周德成.赵家昌;李春峰;勾舌销件冷拔摆辗成形塑性稳定性的研究J.机械工程师，1991(1)9 周德成;钱存济;裴兴华;侯华兴;杨伯纲.圆柱件摆辗变形的研究J.模具技术.1986(2)10 裴兴华;周德成;成美芳.圆柱形工件、环形工件摆辗变形特征及辗压力的测定J.锻压技术，1982(1)11 杨可桢 程光蕴 主编.机械设计基础.北京：高等教育出版社，200212 汝元功 唐照民 主编.机械设计手册. 北京：高等教育出版社，199513 唐照民等主编.机械设计.西安：西安交通大学出版社，199514 吴宗泽 主编.机械设计课程设计手册.北京：高等教育出版社，199915 杨黎明 主编.机械原理及机械零件.北京：高等教育出版社，1990 附录附 录 致谢致 谢大学生活即将结束，在这四年，我遇到了很多朋友热心帮助教授工作设计成功的完成不是他们的热情帮助和顾问的指导，教师和学生在这里都给予指导和帮助我的毕业这表示最诚挚的谢意。首先，设计指导，感谢你紧张的工作，试图引导时间，我们总是关心我们的进展状况，要求我们掌握帮助教师管理在整个设计过程中，从实际操作数据准备阶段，它提供了指导，我不仅学到了书本上的知识，更学会操作方法。其次，给予帮助教师设计的毕业生，与我的同学以诚挚的感谢，在设计的过程中，他们给了我很多的帮助和无私的关怀，更重要的是提供信息，在许多方面，我们的技术。此外，也给所有的学生我的帮助表示感谢。总之，本设计的结果是教师和学生，在一个月内，我们合作的非常愉快，教会我很多伟大的真理，是一种资产，我的生活，我在新教师和学生对我的帮助表示感谢！毕 业 设 计（论 文）任 务 书设计（论文）题目：型材铆接机机械结构设计 学生姓名： 学 号： 专 业： 所在学院： 指导教师： 职 称： 20xx年 2月 27日 任务书填写要求1毕业设计（论文）任务书由指导教师根据各课题的具体情况填写，经学生所在专业的负责人审查、系（院）领导签字后生效。此任务书应在毕业设计（论文）开始前一周内填好并发给学生。2任务书内容必须用黑墨水笔工整书写，不得涂改或潦草书写；或者按教务处统一设计的电子文档标准格式（可从教务处网页上下载）打印，要求正文小4号宋体，1.5倍行距，禁止打印在其它纸上剪贴。3任务书内填写的内容，必须和学生毕业设计（论文）完成的情况相一致，若有变更，应当经过所在专业及系（院）主管领导审批后方可重新填写。4任务书内有关“学院”、“专业”等名称的填写，应写中文全称，不能写数字代码。学生的“学号”要写全号，不能只写最后2位或1位数字。 5任务书内“主要参考文献”的填写，应按照金陵科技学院本科毕业设计（论文）撰写规范的要求书写。6有关年月日等日期的填写，应当按照国标GB/T 740894数据元和交换格式、信息交换、日期和时间表示法规定的要求，一律用阿拉伯数字书写。如“2002年4月2日”或“2002-04-02”。毕 业 设 计（论 文）任 务 书1本毕业设计（论文）课题应达到的目的： 培养学生综合运用所学知识，结合实际独立完成课题的工作能力。对学生的知识面，掌握知识的深度，运用理论结合实际去处理问题的能力，实验能力，外语水平，计算机运用水平，书面及口头表达能力进行考核。为以后走上工作岗位打下良好的基础。 2本毕业设计（论文）课题任务的内容和要求（包括原始数据、技术要求、工作要求等）： 型材铆接机是机械制造企业的一种常用重要设备，台式铆接机是用于链条、剪刀、电子器件和汽车摩托车零部件等铆接各种小直径铆钉的铆接设备，应用非常广泛。本题目的设计负责完成摆碾式液压铆接机的机械结构和电机传动系统设计。包括底座、立柱、电动机、铆头和液压缸等几个部分。用脚踏开关通过电气控制箱及电磁阀控制铆压液压缸动作,使铆头上下运动进行铆压。电机可带动铆头旋转,以降低铆压阻力和提高铆钉头的品质。 毕 业 设 计（论 文）任 务 书3对本毕业设计（论文）课题成果的要求包括图表、实物等硬件要求： 1、中英文翻译一份； 2、撰写开题报告一份； 3、方案的设计和拟定、主要参数和尺寸的确定 4、图纸设计和绘制（一套） 5、编写设计说明书。 4主要参考文献： 1 冯涓,王介民主编.工业产品艺术造型设计清华大学出版社，2004. 2 杨叔子主编.机械加工工艺师手册机械工业出版社，2002. 3 郑文纬,吴克坚主编.机械原理高等教育出版社，1997. 4 孟宪源主编.现代机构手册机械工业出版社，1994. 5 钟志华,周彦伟主编.现代设计方法武汉理工大学出版社，2001. 6 彭文生,李志明.黄华梁主编.机械设计高等教育出版社，2002. 7 朱喜林,张代治主编.机电一体化设计基础科学出版社，2004. 8 机械设计手册编委员.机械设计手册机械工业出版社，2004. 9 许林成主编.包装机械原理与设计上海科技出版社，1988. 10 于骏一,邹青主编.机械制造技术基础机械工业出版社，2005. 11 雷伏元主编.自动包装机械设计原理天津科技出版社，1986. 12 孙恒,陈作模主编.机械原理高等教育出版社，2001. 13 吴宗泽主编.机械设计师手册机械工业出版社，2002. 14 成大先主编.机械设计手册化学工业出版社，2002.1. 15 邹慧君.机械运动方案设计手册上海：上海交通大学出版社，1994. 16 吴圣庄.金属切削机床北京：机械工业出版社，1992. 毕 业 设 计（论 文）任 务 书5本毕业设计（论文）课题工作进度计划：20xx.12.16-20xx.1.10 领任务书、开题20xx.2.25-2.16.3.9 毕业实习调研，完成开题报告、中英文翻译、论文大纲20xx.3.19-20xx.4.25 提交论文草稿，4月中旬中期检查20xx.4.26-20xx.5.6 提交论文定稿20xx.5.6-20xx.5.13 准备答辩20xx.5.13-20xx.5.26 答辩，成绩评定，修改完成最终稿 所在专业审查意见：通过负责人： 年 月 日 毕 业 设 计（论 文）外 文 参 考 资 料 及 译 文译文题目：型材铆接机机械结构设计 学生姓名： 学 号： 专 业： 所在学院： 指导教师： 职 称： 20xx年 2月 27日英文原文Basic Machining Operations and Cutting TechnologyBasic Machining Operations Machine tools have evolved from the early foot-powered lathes of the Egyptians and John Wilkinsons boring mill. They are designed to provide rigid support for both the workpiece and the cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically, in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the form of a severely deformed chip. The chip is a waste product that is considerably shorter than the workpiece from which it came but with a corresponding increase in thickness of the uncut chip. The geometrical shape of workpiece depends on the shape of the tool and its path during the machining operation. Most machining operations produce parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and the tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is produced, and the operation is called turning. If a hollow tube is machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface uniformly varying diameter is called taper turning, if the tool point travels in a path of varying radius, a contoured surface like that of a bowling pin can be produced; or, if the piece is short enough and the support is sufficiently rigid, a contoured surface could be produced by feeding a shaped tool normal to the axis of rotation. Short tapered or cylindrical surfaces could also be contour formed. Flat or plane surfaces are frequently required. They can be generated by radial turning or facing, in which the tool point moves normal to the axis of rotation. In other cases, it is more convenient to hold the workpiece steady and reciprocate the tool across it in a series of straight-line cuts with a crosswise feed increment before each cutting stroke. This operation is called planning and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpiece under it as in planning. The tool is fed at each reciprocation. Contoured surfaces can be produced by using shaped tools. Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for holes with depths up to 5 to 10 times the drill diameter. Whether the drill turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary cutter with a number of cutting edges engages the workpiece. Which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter and the type of feed. Horizontal or vertical axes of rotation may be used, and the feed of the workpiece may be in any of the three coordinate directions. Basic Machine Tools Machine tools are used to produce a part of a specified geometrical shape and precise I size by removing metal from a ductile material in the form of chips. The latter are a waste product and vary from long continuous ribbons of a ductile material such as steel, which are undesirable from a disposal point of view, to easily handled well-broken chips resulting from cast iron. Machine tools perform five basic metal-removal processes: I turning, planning, drilling, milling, and grinding. All other metal-removal processes are modifications of these five basic processes. For example, boring is internal turning; reaming, tapping, and counter boring modify drilled holes and are related to drilling; bobbing and gear cutting are fundamentally milling operations; hack sawing and broaching are a form of planning and honing; lapping, super finishing. Polishing and buffing are variants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cutting tools of specific controllable geometry: 1. lathes, 2. planers, 3. drilling machines, and 4. milling machines. The grinding process forms chips, but the geometry of the abrasive grain is uncontrollable. The amount and rate of material removed by the various machining processes may be I large, as in heavy turning operations, or extremely small, as in lapping or super finishing operations where only the high spots of a surface are removed. A machine tool performs three major functions: 1. it rigidly supports the workpiece or its holder and the cutting tool; 2. it provides relative motion between the workpiece and the cutting tool; 3. it provides a range of feeds and speeds usually ranging from 4 to 32 choices in each case. Speed and Feeds in Machining Speeds, feeds, and depth of cut are the three major variables for economical machining. Other variables are the work and tool materials, coolant and geometry of the cutting tool. The rate of metal removal and power required for machining depend upon these variables. The depth of cut, feed, and cutting speed are machine settings that must be established in any metal-cutting operation. They all affect the forces, the power, and the rate of metal removal. They can be defined by comparing them to the needle and record of a phonograph. The cutting speed (V) is represented by the velocity of- the record surface relative to the needle in the tone arm at any instant. Feed is represented by the advance of the needle radially inward per revolution, or is the difference in position between two adjacent grooves. The depth of cut is the penetration of the needle into the record or the depth of the grooves. Turning on Lathe Centers The basic operations performed on an engine lathe are illustrated. Those operations performed on external surfaces with a single point cutting tool are called turning. Except for drilling, reaming, and lapping, the operations on internal surfaces are also performed by a single point cutting tool. All machining operations, including turning and boring, can be classified as roughing, finishing, or semi-finishing. The objective of a roughing operation is to remove the bulk of the material as rapidly and as efficiently as possible, while leaving a small amount of material on the work-piece for the finishing operation. Finishing operations are performed to obtain the final size, shape, and surface finish on the workpiece. Sometimes a semi-finishing operation will precede the finishing operation to leave a small predetermined and uniform amount of stock on the work-piece to be removed by the finishing operation. Generally, longer workpieces are turned while supported on one or two lathe centers. Cone shaped holes, called center holes, which fit the lathe centers are drilled in the ends of the workpiece-usually along the axis of the cylindrical part. The end of the workpiece adjacent to the tailstock is always supported by a tailstock center, while the end near the headstock may be supported by a headstock center or held in a chuck. The headstock end of the workpiece may be held in a four-jaw chuck, or in a type chuck. This method holds the workpiece firmly and transfers the power to the workpiece smoothly; the additional support to the workpiece provided by the chuck lessens the tendency for chatter to occur when cutting. Precise results can be obtained with this method if care is taken to hold the workpiece accurately in the chuck. Very precise results can be obtained by supporting the workpiece between two centers. A lathe dog is clamped to the workpiece; together they are driven by a driver plate mounted on the spindle nose. One end of the Workpiece is mecained;then the workpiece can be turned around in the lathe to machine the other end. The center holes in the workpiece serve as precise locating surfaces as well as bearing surfaces to carry the weight of the workpiece and to resist the cutting forces. After the workpiece has been removed from the lathe for any reason, the center holes will accurately align the workpiece back in the lathe or in another lathe, or in a cylindrical grinding machine. The workpiece must never be held at the headstock end by both a chuck and a lathe center. While at first thought this seems like a quick method of aligning the workpiece in the chuck, this must not be done because it is not possible to press evenly with the jaws against the workpiece while it is also supported by the center. The alignment provided by the center will not be maintained and the pressure of the jaws may damage the center hole, the lathe center, and perhaps even the lathe spindle. Compensating or floating jaw chucks used almost exclusively on high production work provide an exception to the statements made above. These chucks are really work drivers and cannot be used for the same purpose as ordinary three or four-jaw chucks. While very large diameter workpieces are sometimes mounted on two centers, they are preferably held at the headstock end by faceplate jaws to obtain the smooth power transmission; moreover, large lathe dogs that are adequate to transmit the power not generally available, although they can be made as a special. Faceplate jaws are like chuck jaws except that they are mounted on a faceplate, which has less overhang from the spindle bearings than a large chuck would have. Introduction of Machining Machining as a shape-producing method is the most universally used and the most important of all manufacturing processes. Machining is a shape-producing process in which a power-driven device causes material to be removed in chip form. Most machining is done with equipment that supports both the work piece and cutting tool although in some cases portable equipment is used with unsupported workpiece. Low setup cost for small Quantities. Machining has two applications in manufacturing. For casting, forging, and press working, each specific shape to be produced, even one part, nearly always has a high tooling cost. The shapes that may he produced by welding depend to a large degree on the shapes of raw material that are available. By making use of generally high cost equipment but without special tooling, it is possible, by machining; to start with nearly any form of raw material, so tong as the exterior dimensions are great enough, and produce any desired shape from any material. Therefore .machining is usually the preferred method for producing one or a few parts, even when the design of the part would logically lead to casting, forging or press working if a high quantity were to be produced. Close accuracies, good finishes. The second application for machining is based on the high accuracies and surface finishes possible. Many of the parts machined in low quantities would be produced with lower but acceptable tolerances if produced in high quantities by some other process. On the other hand, many parts are given their general shapes by some high quantity deformation process and machined only on selected surfaces where high accuracies are needed. Internal threads, for example, are seldom produced by any means other than machining and small holes in press worked parts may be machined following the press working operations. Primary Cutting Parameters The basic tool-work relationship in cutting is adequately described by means of four factors: tool geometry, cutting speed, feed, and depth of cut. The cutting tool must be made of an appropriate material; it must be strong, tough, hard, and wear resistant. The tool s geometry characterized by planes and angles, must be correct for each cutting operation. Cutting speed is the rate at which the work surface passes by the cutting edge. It may be expressed in feet per minute. For efficient machining the cutting speed must be of a magnitude appropriate to the particular work-tool combination. In general, the harder the work material, the slower the speed. Feed is the rate at which the cutting tool advances into the workpiece. Where the workpiece or the tool rotates, feed is measured in inches per revolution. When the tool or the work reciprocates, feed is measured in inches per stroke, Generally, feed varies inversely with cutting speed for otherwise similar conditions. The depth of cut, measured inches is the distance the tool is set into the work. It is the width of the chip in turning or the thickness of the chip in a rectilinear cut. In roughing operations, the depth of cut can be larger than for finishing operations. The Effect of Changes in Cutting Parameters on Cutting Temperatures In metal cutting operations heat is generated in the primary and secondary deformation zones and these results in a complex temperature distribution throughout the tool, workpiece and chip. A typical set of isotherms is shown in figure where it can be seen that, as could be expected, there is a very large temperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and there is a further large temperature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip. Since virtually all the work done in metal cutting is converted into heat, it could be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and the cutting temperatures will reduce. When considering increase in unreformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness tends to be a scale effect where the amounts of heat which pass to the workpiece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed; however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip m primary deformation. Further, the secondary deformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate it is appropriate to indicate how cutting temperatures can be assessed from cutting data. The most direct and accurate method for measuring temperatures in high -speed-steel cutting tools is that of Wright &. Trent which also yields detailed information on temperature distributions in high-speed-steel cutting tools. The technique is based on the metallographic examination of sectioned high-speed-steel tools which relates microstructure changes to thermal history. Trent has described measurements of cutting temperatures and temperature distributions for high-speed-steel tools when machining a wide range of workpiece materials. This technique has been further developed by using scanning electron microscopy to study fine-scale microstructure changes arising from over tempering of the tempered martens tic matrix of various high-speed-steels. This technique has also been used to study temperature distributions in both high-speed -steel single point turning tools and twist drills. Wears of Cutting Tool Discounting brittle fracture and edge chipping, which have already been dealt with, tool wear is basically of three types. Flank wear, crater wear, and notch wear. Flank wear occurs on both the major and the minor cutting edges. On the major cutting edge, which is responsible for bulk metal removal, these results in increased cutting forces and higher temperatures which if left unchecked can lead to vibration of the tool and workpiece and a condition where efficient cutting can no longer take place. On the minor cutting edge, which determines workpiece size and surface finish, flank wear can result in an oversized product which has poor surface finish. Under most practical cutting conditions, the tool will fail due to major flank wear before the minor flank wear is sufficiently large to result in the manufacture of an unacceptable component. Because of the stress distribution on the tool face, the frictional stress in the region of sliding contact between the chip and the face is at a maximum at the start of the sliding contact region and is zero at the end. Thus abrasive wear takes place in this region with more wear taking place adjacent to the seizure region than adjacent to the point at which the chip loses contact with the face. This result in localized pitting of the tool face some distance up the face which is usually referred to as catering and which normally has a section in the form of a circular arc. In many respects and for practical cutting conditions, crater wear is a less severe form of wear than flank wear and consequently flank wear is a more common tool failure criterion. However, since various authors have shown that the temperature on the face increases more rapidly with increasing cutting speed than the temperature on the flank, and since the rate of wear of any type is significantly affected by changes in temperature, crater wear usually occurs at high cutting speeds. At the end of the major flank wear land where the tool is in contact with the uncut workpiece surface it is common for the flank wear to be more pronounced than along the rest of the wear land. This is because of localised effects such as a hardened layer on the uncut surface caused by work hardening introduced by a previous cut, an oxide scale, and localised high temperatures resulting from the edge effect. This localised wear is usually referred to as notch wear and occasionally is very severe. Although the presence of the notch will not significantly affect the cutting properties of the tool, the notch is often relatively deep and if cutting were to continue there would be a good chance that the tool would fracture. If any form of progressive wear allowed to continue, dramatically and the tool would fail catastrophically, i. e. the tool would be no longer capable of cutting and, at best, the workpiece would be scrapped whilst, at worst, damage could be caused to the machine tool. For carbide cutting tools and for all types of wear, the tool is said to have reached the end of its useful life long before the onset of catastrophic failure. For high-speed-steel cutting tools, however, where the wear tends to be non-uniform it has been found that the most meaningful and reproducible results can be obtained when the wear is allowed to continue to the onset of catastrophic failure even though, of course, in practice a cutting time far less than that to failure would be used. The onset of catastrophic failure is characterized by one of several phenomena, the most common being a sudden increase in cutting force, the presence of burnished rings on the workpiece, and a significant increase in the noise level. Mechanism of Surface Finish Production There are basically five mechanisms which contribute to the production of a surface which have been machined. These are:(l) The basic geometry of the cutting process. In, for example, single point turning the tool will advance a constant distance axially per revolution of the workpiecc and the resultant surface will have on it, when viewed perpendicularly to the direction of tool feed motion, a series of cusps which will have a basic form which replicates the shape of the tool in cut. (2) The efficiency of the cutting operation. It has already been mentioned that cutting with unstable built-up-edges will produce a surface which contains hard built-up-edge fragments which will result in a degradation of the surface finish. It can also be demonstrated that cutting under adverse conditions such as apply when using large feeds small rake angles and low cutting speeds, besides producing conditions which lead to unstable built-up-edge production, the cutting process itself can become unstable and instead of continuous shear occurring in the shear zone, tearing takes place, discontinuous chips of uneven thickness are produced, and the resultant surface is poor. This situation is particularly noticeable when machining very ductile materials such as copper and aluminum. (3) The stability of the machine tool. Under some combinations of cutting conditions; workpiece size, method of clamping ,and cutting tool rigidity relative to the machine tool structure, instability can be set up in the tool which causes it to vibrate. Under some conditions this vibration will reach and maintain steady amplitude whilst under other conditions the vibration will built up and unless cutting is stopped considerable damage to both the cutting tool and workpiece may occur. This phenomenon is known as chatter and in axial turning is characterized by long pitch helical bands on the workpiece surface and short pitch undulations on the transient machined surface. (4)The effectiveness of removing swarf. In discontinuous chip production machining, such as milling or turning of brittle materials, it is expected that the chip (swarf) will leave the cutting zone either under gravity or with the assistance of a jet of cutting fluid and that they will not influence the cut surface in any way. However, when continuous chip production is evident, unless steps are taken to control the swarf it is likely that it will impinge on the cut surface and mark it. Inevitably, this marking besides looking. (5)The effective clearance angle on the cutting tool. For certain geometries of minor cutting edge relief and clearance angles it is possible to cut on the major cutting edge and burnish on the minor cutting edge. This can produce a good surface finish but, of course, it is strictly a combination of metal cutting and metal forming and is not to be recommended as a practical cutting method. However, due to cutting tool wear, these conditions occasionally arise and lead to a marked change in the surface characteristics. Limits and Tolerances Machine parts are manufactured so they are interchangeable. In other words, each part of a machine or mechanism is made to a certain size and shape so will fit into any other machine or mechanism of the same type. To make the part interchangeable, each individual part must be made to a size that will fit the mating part in the correct way. It is not only impossible, but also impractical to make many parts to an exact size. This is because machines are not perfect, and the tools become worn. A slight variation from the exact size is always allowed. The amount of this variation depends on the kind of part being manufactured. For examples part might be made 6 in. long with a variation allowed of 0.003 (three-thousandths) in. above and below this size. Therefore, the part could be 5.997 to 6.003 in. and still be the correct size. These are known as the limits. The difference between upper and lower limits is called the tolerance. A tolerance is the total permissible variation in the size of a part. The basic size is that size from which limits of size arc derived by the application of allowances and tolerances. Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance.Unilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is shown in only one direction from the nominal size. Unilateral tolerancing allow the changing of tolerance on a hole or shaft without seriously affecting the fit.When the tolerance is in both directions from the basic size it is known as a bilateral tolerance (plus and minus). Bilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is split and is shown on either side of the nominal size. Limit dimensioning is a system of dimensioning where only the maximum and minimum dimensions arc shown. Thus, the tolerance is the difference between these two dimensions. Surface Finishing and Dimensional Control Products that have been completed to their proper shape and size frequently require some type of surface finishing to enable them to satisfactorily fulfill their function. In some cases, it is necessary to improve the physical properties of the surface material for resistance to penetration or abrasion. In many manufacturing processes, the product surface is left with dirt .chips, grease, or other harmful material upon it. Assemblies that are made of different materials, or from the same materials processed in different manners, may require some special surface treatment to provide uniformity of appearance. Surface finishing may sometimes become an intermediate step processing. For instance, cleaning and polishing are usually essential before any kind of plating process. Some of the cleaning procedures are also used for improving surface smoothness on mating parts and for removing burrs and sharp corners, which might be harmful in later use. Another important need for surface finishing is for corrosion protection in a variety of: environments. The type of protection procedure will depend largely upon the anticipated exposure, with due consideration to the material being protected and the economic factors involved. Satisfying the above objectives necessitates the use of main surface-finishing methods that involve chemical change of the surface mechanical work affecting surface properties, cleaning by a variety of methods, and the application of protective coatings, organic and metallic. In the early days of engineering, the mating of parts was achieved by machining one part as nearly as possible to the required size, machining the mating part nearly to size, and then completing its machining, continually offering the other part to it, until the desired relationship was obtained. If it was inconvenient to offer one part to the other part during machining, the final work was done at the bench by a fitter, who scraped the mating parts until the desired fit was obtained, the fitter therefore being a fitter in the literal sense. J It is obvious that the two parts would have to remain together, and m the event of one having to be replaced, the fitting would have to be done all over again. In these days, we expect to be able to purchase a replacement for a broken part, and for it to function correctly without the need for scraping and other fitting operations.When one part can be used off the shelf to replace another of the same dimension and material specification, the parts are said to be interchangeable. A system of interchangeability usually lowers the production costs as there is no need for an expensive, fiddling operation, and it benefits the customer in the event of the need to replace worn parts. Automatic Fixture Design Traditional synchronous grippers for assembly equipment move parts to the gripper centre-line, assuring that the parts will be in a known position after they arc picked from a conveyor or nest. However, in some applications, forcing the part to the centre-line may damage cither the part or equipment. When the part is delicate and a small collision can result in scrap, when its location is fixed by a machine spindle or mould, or when tolerances are tight, it is preferable to make a gripper comply with the position of the part, rather than the other way around. For these tasks, Zaytran Inc. Of Elyria, Ohio, has created the GPN series of non- synchronous, compliant grippers. Because the force and synchronizations systems of the grippers are independent, the synchronization system can be replaced by a precision slide system without affecting gripper force. Gripper sizes range from 51b gripping force and 0.2 in. stroke to 40Glb gripping force and 6in stroke. Grippers Production is characterized by batch-size becoming smaller and smaller and greater variety of products. Assembly, being the last production step, is particularly vulnerable to changes in schedules, batch-sizes, and product design. This situation is forcing many companies to put more effort into extensive rationalization and automation of assembly that was previouslyextensive rationalization and automation of assembly that was previously the case. Although the development of flexible fixtures fell quickly behind the development of flexible handling systems such as industrial robots, there are, nonetheless promising attempts to increase the flexibility of fixtures. The fact that fixtures are the essential product - specific investment of a production system intensifies the economic necessity to make the fixture system more flexible. Fixtures can be divided according to their flexibility into special fixtures, group fixtures, modular fixtures and highly flexible fixtures. Flexible fixtures are characterized by their high adaptability to different workpieces, and by low change-over time and expenditure. There are several steps required to generate a fixture, in which a workpiece is fixed for a production task. The first step is to define the necessary position of the workpiece in the fixture, based on the unmachined or base pan, and the working features. Following this, a combination of stability planes must be selected. These stability planes constitute the fixture configuration in which the workpiece is fixed in the defined position, all the forces or torques are compensated, and the necessary access to the working features is ensured. Finally, the necessary positions of moveable or modular fixture elements must be calculated- adjusted, or assembled, so that the workpiece is firmly fixed in the fixture. Through such a procedure the planning and documentation of the configuration and assembly of fixture can be automated.The configuration task is to generate a combination of stability planes, such that fixture forces in these planes will result in workpiece and fixture stability. This task can be accomplished conventionally, interactively or in a nearly fully automated manner. The advantages of an interactive or automated configuration determination are a systematic fixture design process, a reduction of necessary designers, a shortening of lead time and better match to the working conditions. In short, a significant enhancement of fixture productivity and economy can be achieved.中文翻译基本加工工序和切削技术机床是从早期的埃及人的脚踏动力车和约翰威尔金森的镗床发展而来的。它们为工件和刀具提供刚性支撑并可以精确控制它们的相对位置和相对速度。基本上讲，金属切削是指一个磨尖的锲形工具从有韧性的工件表面上去除一条很窄的金属。切屑是被废弃的产品，与其它工件相比切屑较短，但对于未切削部分的厚度有一定的增加。工件表面的几何形状取决于刀具的形状以及加工操作过程中刀具的路径。大多数加工工序产生不同几何形状的零件。如果一个粗糙的工件在中心轴上转动并且刀具平行于旋转中心切入工件表面，一个旋转表面就产生了，这种操作称为车削。如果一个空心的管子以同样的方式在内表面加工，这种操作称为镗孔。当均匀地改变直径时便产生了一个圆锥形的外表面，这称为锥度车削。如果刀具接触点以改变半径的方式运动，那么一个外轮廓像球的工件便产生了；或者如果工件足够的短并且支撑是十分刚硬的，那么成型刀具相对于旋转轴正常进给的一个外表面便可产生，短锥形或圆柱形的表面也可形成。平坦的表面是经常需要的，它们可以由刀具接触点相对于旋转轴的径向车削产生。在刨削时对于较大的工件更容易将刀具固定并将工件置于刀具下面。刀具可以往复地进给。成形面可以通过成型刀具加工产生。多刃刀具也能使用。使用双刃槽钻钻深度是钻孔直径5-10倍的孔。不管是钻头旋转还是工件旋转，切削刃与工件之间的相对运动是一个重要因数。在铣削时一个带有许多切削刃的旋转刀具与工件接触，工件相对刀具慢慢运动。平的或成形面根据刀具的几何形状和进给方式可能产生。可以产生横向或纵向轴旋转并且可以在任何三个坐标方向上进给。基本机床机床通过从塑性材料上去除屑片来产生出具有特别几何形状和精确尺寸的零件。后者是废弃物，是由塑性材料如钢的长而不断的带状物变化而来，从处理的角度来看，那是没有用处的。很容易处理不好由铸铁产生的破裂的屑片。机床执行五种基本的去除金属的过程：车削，刨削，钻孔，铣削。所有其他的去除金属的过程都是由这五个基本程序修改而来的，举例来说，镗孔是内部车削；铰孔，攻丝和扩孔是进一步加工钻过的孔；齿轮加工是基于铣削操作的。抛光和打磨是磨削和去除磨料工序的变形。因此，只有四种基本类型的机床，使用特别可控制几何形状的切削工具1.车床，2.钻床，3.铣床，4.磨床。磨削过程形成了屑片，但磨粒的几何形状是不可控制的。通过各种加工工序去除材料的数量和速度是巨大的，正如在大型车削加工，或者是极小的如研磨和超精密加工中只有面的高点被除掉。一台机床履行三大职能：1.它支撑工件或夹具和刀具2.它为工件和刀具提供相对运动3.在每一种情况下提供一系列的进给量和一般可达4-32种的速度选择。加工速度和进给速度，进给量和切削深度是经济加工的三大变量。其他的量数是攻丝和刀具材料，冷却剂和刀具的几何形状，去除金属的速度和所需要的功率依赖于这些变量。切削深度，进给量和切削速度是任何一个金属加工工序中必须建立的机械参量。它们都影响去除金属的力，功率和速度。切削速度可以定义为在旋转一周时速度记录面相对任何瞬间呈辐射状扩散的针，或是两个相邻沟槽的距离。切削深度是进入的深度和沟槽的深度。在车床中心的车削在机动车床上完成的基本操作已被介绍了。那些用单点刀具在外表面的操作称为车削。除了钻孔，铰孔，研磨内部表面的操作也是由单点刀具完成的。所有的加工工序包括车削，镗孔可以被归类为粗加工，精加工或半精加工。精加工是尽可能快而有效的去除大量材料，而工件上留下的一小部分材料用于精加工。精加工为工件获得最后尺寸，形状和表面精度。有时，半精加工为精加工留下预定的一定量的材料，它是先于精加工的。一般来说，较长的工件同时被一个或两个车床中心支撑。锥形孔，所谓的中心孔，两端被钻的工件适于车床中心-通常沿着圆柱形工件的轴线。工件接近为架的那端通常由尾架中心支撑，在靠近主轴承的那端由主轴承中心支撑或由爪盘夹紧。这种方法可以牢固的加紧工件并且能顺利地将力传给工件；由卡盘对工件提供的辅助支撑减少切削时发生的颤振趋势，如果能小心准确地采用卡盘支撑工件的方法，则可以得到精确的结果。在两个中心之间支撑工件可以得到非常精确的结果。工件的一端已被加工，那么工件便可车削了。在车床上加工另一端，中心孔充当精确定位面和承载工件重量和抵制切削力的支撑面。当工件由于任何一原因从车床上移除后，中心孔将准确地使工件回到这个车床上或另一个车床上或一个圆柱磨床上。工件不允许被卡盘和车床中心夹在主轴承上。然而首先想到的是一个快速调整卡盘上工件的方法，但这是不允许的因为在由卡盘夹持的同时也由车床中心支撑是不可能的。由车床中心提供的调整将不能持续并且爪盘的压力会损坏中心孔和车床中心，甚至是车床主轴。浮动的爪盘为上述陈述提供了一个例外，它几乎完