基于UG的上盖的数控加工

黑龙江农业经济职业学院毕业论文基于UG的上盖的数控加工姓名：王振作指导教师：孔庆玲专业：数控技术班级：1212014年10月23日黑龙江农业经济职业学院机电工程系毕业论文Ⅰ目录摘要···················································································································1前言···················································································································21零件分析·············································································································31.1零件分析·····································································································61.2毛坯、余量分析····························································································61.2.1毛坯形状和尺寸的选择················································································61.2.2加工余量的选择·························································································62加工准备及工艺路线选择························································································62.1基准的选择··································································································62.2刀具选择·····································································································72.3确定进给路线·······························································································72.4加工工序卡··································································································83UG造型仿真·········································································································83.1加工并生成程序····························································································83.2工艺参数设定·······························································································83.3零件的加工过程····························································································9结论··················································································································13参考文献···············································································································14致谢··················································································································15黑龙江农业经济职业学院机电工程系毕业论文1基于UG的上盖的数控加工摘要：本文主要通过对复杂零件的数控自动加工与仿真加工，利用UGCAM加工模块进行自动数控编程，优化了加工路线、刀具轨迹、切削方式等工艺参数，并通过虚拟加工过程仿真检查刀具过切、刀具与工件之间的碰撞和干涉，考虑可能影响铣削的因素，设计其加工工艺和加工，完成要求。在机械加工领域来说，要完成零件的加工就必须熟悉以上内容，这样才能更好、更快的完成工作。关键词：铣削，pro/E，UG，数控加工黑龙江农业经济职业学院机电工程系毕业论文2前言在现代制造业中，大到飞机、火箭，小到烟灰缸，都需要模具生产。模具生产好比“效益放大器”，模具行业是“朝阳行业”。一个地区的工业化进程由模具的生产水平决定。现在模具的要求越来越高，加工周期越来越度短，加工模具的风险也越来越大。为确保模具一次加工成功，必须采用先进的UG设计工具，最多限度地减少设计过程带来的失误。UG具有强大的建模和加工功能，对于从事机械加工的工艺人员来说，要掌握好是加工复杂模具一次成功的有效工具。由于UG的应用多集中在数控铣、加工中心等方面，并且相关铣削方面的学习资料较少，对于UG铣削加工应该更多地与实际铣床相结合。本论文以一个上盖零件的铣削加工为例，介绍了基于UG的上盖的数控加工的方法，在数控铣床上完成该零件的铣削加工，UG的自动编程可以提高NC程序的正确性个安全性，同时还能提高工作效率。数控机床的编程方法分为手工编程和自动编程，自动编程工具分为语词式自动编程工具和图形交互式自动编程工具，当今主流的自动编程工具是图形交互式自动编程工具，本论文主要是用自动编程来进行数控加工，UG的数控铣模块包含钻孔、铰孔、内孔、倒圆角等操作，用UG的铣削模块可自动生成数控铣床的NC程序，UG产生NC程序的步骤为：零件建模—创建程序—创建刀具—创建几何体—创建操作—生成刀具轨迹—生成NC程序。黑龙江农业经济职业学院机电工程系毕业论文31.零件分析与毛坯选择及UG造型1.1零件分析在数控铣削加工中，对零件图进行工艺分析的主要内容包括零件结构工艺性分析、选择数控铣削的加工内容、零件毛坯的工艺性分析和加工方案分析。图1A面两视图黑龙江农业经济职业学院机电工程系毕业论文4图2B面三视图黑龙江农业经济职业学院机电工程系毕业论文5图3A，B面三维建模黑龙江农业经济职业学院机电工程系毕业论文6首先要认真分析与研究产品的用途、性能和工作条件，了解零件在产品中的位置、装配关系以及作用，弄清各项技能要求对装配质量和使用性能的影响，找出主要的和关键的技术要求，然后对零件图样进行分析。该零件视图表达完整、清晰，尺寸及有关技术要求齐全、明确。1.2毛坯、余量分析1.2.1毛坯形状和尺寸的选择选择毛坯形状和尺寸总的要求是：减少“肥头大耳”，实现少屑或无屑加工。因此，毛坯形状要求接近成品形状，以减少机械加工的劳动量。但也有以下四种情况。（1）采用锻件，铸造毛坯时，因锻模时的欠压量与允许的错模量不等，铸造时也会因砂型误差、收缩量及金属液体的流动性差不能充满型腔等造成余量的不等，此外，铸造、锻造后，毛坯的挠曲变形量的不同也会造成加工余量不充分、不稳定，所以，除板料外，不论是锻件、铸件还是型材，只要准备采用数控加工，其加工表面均应有较充分的余量。（2）尺寸小或薄的零件，为便于装夹并减少夹头，可将多个工件连在一起，由一个毛坯制出。（3）装配后形成同一工作表面的两个相关零件，为保证加工质量并使加工方便，常把两件合为一个整体毛坯，加工到一定阶段后再切开。（4）对于不便装夹的毛坯，可考虑在毛坯上另外增加装夹余量或工艺凸台、工艺凸耳等辅助基准。1.2.2加工余量的选择加工余量是指加工过程中所切去的金属层厚度，加工余量有工序余量和加工总余量之分。由于毛坯制造和各个工序尺寸都存在着误差，加工余量也是个变动值。加工总余量也是个变动值，其值及公差一般可从有关手册中查的或凭经验确定。加工余量的大小，直接影响零件的加工质量和生产率。加工余量过大，不仅增加机械加工劳动量，降低生产率，而且增加材料、工具和电力的消耗，增加成本。但若加工余量过小，又不能消除前工序的各种误差和表面缺陷，甚至产品作废。因为该零件的加工余量如下：粗加工外表面的加工余量选择0.5mm，半精加工的加工余量0.1mm，接着做完精加工。粗加工凹槽余量0.1mm，精加工0.05mm。2.加工准备及工艺路线选择在对零件进行加工前要对零件进行许多分析，如装夹方式、基准选择、确定坐标零点、刀具选择及机床选择等。2.1基准的选择定位基准的选择基准就是确定生产对象上的某些点、线、面的位置所依据的那些点、线、面。正确选择定位基准是定制机械加工工艺规程和进行夹具设计的关键。定位基准分为精基准和粗基准。2.1.1夹具的选择机床夹具的种类很多，按使用的机床类型分为车床夹具、铣床夹具、钻床夹具、镗床夹具、加工中心夹具等。而按专门化程度划分来说，该零件使用的是立式加工中心。零件又属于平面类零件，应使用通用夹具，通用夹具是已经标准化、无需调整或稍加调整就可以用来装夹不同工具的夹具。黑龙江农业经济职业学院机电工程系毕业论文72.2刀具选择铣刀种类繁多，在使用时要根据加工部位、表面粗糙度、精度等来选用，根据图形的精度和加工部位来说，所选刀具卡见附录。Φ12整体合金刀具为精加工用刀具，一般情况下不做粗加工，如果加工中出现尖叫，或者是连续冲击声，这种现象表明切削参数选用不合理，充分冷却在整个过程中是必不可少的。Φ32的立铣刀应采用侧固刀柄；Φ25内螺纹孔单刃镗刀应采用侧固刀柄或强力弹簧夹套刀柄；Φ20的立铣刀应采用强力弹簧夹套刀柄；Φ16H的铰刀应采用弹簧夹套刀柄；Φ8整体硬质合金立铣刀和Φ8球头刀课采用热装刀柄。对于刀具使用，可兼顾粗、精加工分开原则，防止加工刀具尽早磨损。整体应合金刀侧刃直线性好，精度高，适合精加工使用，精加工阶段，应尽可能不用Φ12的整体硬质合金铣刀，以备精加工使用。Φ32立铣刀，用于平面粗、精加工，外轮廓粗加工。Φ20立铣刀，用于内外轮廓、腔槽半精加工。Φ8球头刀，用于圆弧面加工。Φ8整体硬质合金立铣刀，用于内外轮廓精加工。2.3确定进给路线在数控加工中，刀具刀位点相对于工件运动的轨迹称为进给路线。进给路线不仅包括切削加工时的进给路线，还包括刀具到位、对刀、退刀和换刀等一系列过程的刀具运动路线。进给路线不仅反映了几个内容，也说明了加工顺序。确定进给路线。主要是确定粗加工及空行程的进给路线，因为精加工的进给路线基本上是按零件的轮廓进行的。在确定时还要注意一些问题：（1）选择工件刚性破坏小的路线，以减少加工变形对加工精度的影响。（2）寻求最短的进给路线，以提高加工效率。（3）切入和切出的路线应考虑外延，以保证加工的表面质量。（4）完工时的最后一刀应一次走刀连续加工，以免产生刀痕等缺陷。此外，确定进给路线时，