毕业论文题目数控机床加工专业数控加工与维护工程班级大专数控（一）班学生小学生指导教师李老师西安工业大学函授部摘要分析了锅炉安全阀阀门漏泄、阀体结合面渗漏、冲量安全阀动作后主安全阀不动作、冲量安全阀回座后主安全阀延迟回座时间过长以及安全阀的回座压力低、频跳和颤振等常见的故障原因，并针对故障原因提出了解决方法。数控加工刀具必须适应数控机床高速、高效和自动化程度高的特点，一般应包括通用刀具、通用连接刀柄及少量专用刀柄。刀柄要联接刀具并装在机床动力头上，因此已逐渐标准化和系列化。数控刀具的分类有多种方法。根据刀具结构可分为：①整体式；②镶嵌式，采用焊接或机夹式连接，机夹式又可分为不转位和可转位两种；③特殊型式，如复合式刀具，减震式刀具等。根据制造刀具所用的材料可分为：①高速钢刀具；②硬质合金刀具；③金刚石刀具；④其他材料刀具，如立方氮化硼刀具，陶瓷刀具等。从切削工艺上可分为：①车削刀具，分外圆、内孔、螺纹、切割刀具等多种；②钻削刀具，包括钻头、铰刀、丝锥等；③镗削刀具；④铣削刀具等。为了适应数控机床对刀具耐用、稳定、易调、可换等的要求，近几年机夹式可转位刀具得到广泛的应用，在数量上达到整个数控刀具的30%～40%，金属切除量占总数的80%～90%。我国数控机床制造业在８０年代曾有过高速发展的阶段，许多机床厂从传统产品实现向数控化产品的转型。但总的来说，技术水平不高，质量不佳，所以在９０年代初期面临国家经济由计划性经济向市场经济转移调整，经历了几年最困难的萧条时期，那时生产能力降到５０％，库存超过４个月。从１９９５年“九五”以后国家从扩大内需启动机床市场，加强限制进口数控设备的审批，投资重点支持关键数控系统、设备、技术攻关，对数控设备生产起到了很大的促进作用，尤其是在１９９９年以后，国家向国防工业及关键民用工业部门投入大量技改资金，使数控设备制造市场一派繁荣。从２０００年８月份的上海数控机床展览会和２００１年４月北京国际机床展览会上，也可以看到多品种产品的繁荣景象。关键词：阀体机床刀具机架式目录第一章数控加工的概念第二章数控机床的特点第三章数控机床在使用中的注意事项第四章国内外数控发展的趋势4.1数控加工常用刀具的种类及特点······································································84.2数控加工刀具的选择·····················································································10第五章阀体的数控加工实例5.1限流装置结构及原理·····················································································125.2灶前阀的规格······························································································135.3阀门形式的选择···························································································135.4结构、尺寸及外观························································································145.5阀体的加工程序···························································································16结论致谢参考文献第一章数控加工的概念数控机床的工作原理就是将加工过程所需的各种操作（如主轴变速、工件的松开与夹紧、进刀与退刀、开车与停车、自动关...
