数控切割钢材的工艺过程及所遇到的问题

新疆工业高等专科学校毕业设计（论文）课题名称：数控切割钢板的工艺过程及所遇到的切割问题系别：机械工程系专业班级：计算机辅助设计与制造学号：091895学生姓名：余刚指导教师：陆义工2012年3月28日数控切割钢材的工艺过程及所遇到的问题i新疆工业高等专科学校机械工程系毕业设计（论文）任务书学生姓名余刚专业班级机械制造及自动化设计(论文)题目数控切割钢材的工艺过程及所遇到的问题接受任务日期年月日完成任务日期年月日指导教师唐克生指导教师单位设计(论文)内容目标设计(论文)要求论文指导记录参考资料注：此表发给学生后由指导教师填写，学生按此表要求开展毕业设计（论文）工作。数控切割钢材的工艺过程及所遇到的问题ii新疆工业高等专科学校机械工程系毕业设计（论文）成绩表学生姓名余刚专业班级机械制造及自动化设计(论文)题目数控切割钢材的工艺过程及所遇到的问题指导教师（签名）唐克生指导教师单位指导教师评语评阅成绩：评阅教师签字：年月日答辩记录成绩：提问教师签字：年月日答辩小组意见答辩成绩：答辩小组组长签字：年月日数控切割钢材的工艺过程及所遇到的问题3摘要随着国家二十一世纪狠抓冶金科技进步，提高我国钢铁工业的技术水平和装配水平，到2020年前后我国有望成为世界的钢铁强国。“十五”期间建筑钢结构的发展目标，是争取达到每年建筑钢结构用钢材占全国钢材总产量的3％。由此可见，我国建筑钢结构的发展将上一个新台阶。随着现代机械加工业地发展，对切割的质量、精度要求的不断提高，对提高生产效率、降低生产成本、具有高智能化的自动切割功能的要求也在提升。数控切割机的发展必须要适应现代机械加工业发展的要求。各种数控火焰机和其他切割机，为钢结构高效制作和生产高质量产品创造了良好条件。钢材的切割量非常大；随着现代机械工业的发展，对板材切割加工的工作效率和产品质量的要求也同时提高。在一次下料中影响切割的诸多因素中,能否做好下料件的编程工艺,将直接影响切割尺寸精度,影响组件使用.在此,结合实际工作经验,总结了数控火焰切割机的下料工艺方法，及其切割问题。关键词:机械加工；下料；数控火焰机；高效制作；编程切割；尺寸精度工艺方法；目录摘要·······························································································iii第一章数控切割种类和发展·······························································11.1数控火焰切割技术简介······························································11.2数控切割机的特点····································································21.3国内外数控火焰切割技术的发展··················································2第二章数控火焰切割的工艺·····························································32.1火焰切割的工艺要点·································································32.1.1气割前的准备工作····························································32.1.2火焰调整········································································42.1.3操作技术········································································52.2气割工艺参数··········································································62.2.1预热火焰的选择·······························································62.2.2切割氧压力的选定····························································72.2.3切割速度········································································72.2.4割嘴到工件表面的距离······················································8第三章提高火焰切割的精度质量······················································103.1影响钢板火焰切割质量·····································································103.1.1气体·············································································103.1.2切割速度·······································································103.1.3割嘴与被切工件表面的高度······················································103.2提高数控火焰切割机的切割质量·················································113.2.1各种厚度板切割质量的控制···············································113.2.2带孔零件切割质量的控制··················································113.2.3细长件切割质量的控制·····················································113.3影响数控火焰切割机的精度·······················································123.4出现切割尺寸不准现象·····························································12第四章切割所遇到的问题及解决方案···············································134.1数控火焰切割缺陷与原因分析····················································134.1.1上边缘切割质量缺陷························································144.2切割断面凹凸不平，即平面度差·················································144.3切割断面的粗糙度缺陷·····························································164.4挂渣在切割断面上或下边缘产生难以清除的挂渣··························164.5裂纹·····················································································174.6火焰切割问题产生的原因及解决措施列表····································17结束语······················································································20致谢·························································································21参考文献···················································································22数控切割钢材的工艺过程及所遇到的问题1第一章数控切割种类和发展经过几十年的发展，数控切割机在切割能源和数控控制系统两方面取得了长足的发展，切割能源已由单一的火焰能源切割发展为目前的多种能源(火焰、等离子、激光、高压水射流)切割方式；数控切割机控制系统已由当初的简单功能、复杂编程和输入方式、自动化程度不高发展到具有功能完善、智能化、图形化、网络化的控制方式；驱动系统也从的步进驱动、模拟伺服驱动到今天的全数字式伺服驱动；数控火焰切割机，切割具有大厚度碳钢切割能力，切割费用较低，但存在切割变形大，切割精度不高，而且切割速度较低，切割预热时间、穿孔时间长，较难适应全自动化操作的需要。它的应用场合主要限于碳钢、大厚度板材切割，在中、薄碳钢板材切割上逐渐会被等离子切割代替。数控火焰切割机是一种将电脑控制、精密机械传动、氧、燃气切割三者技术相结合的高效率、高精度、高可靠的热切割设备。它适用于造船工业，重型机械，化工设备，锅炉制造，机车车辆等制造行业的高精度钢板热.切割的新型自动化设备。气体火焰切割是热切割中最早被采用和最重用的工艺方法，这种切割方法设备简单、操作方便灵活、投资费用少、切割质量好等特点。尤其是能够切割各种含曲线形状的零件和大厚度工件等一系列特点使得它进入工业领域以来一直作为工业生产中碳钢的基本方法而被广泛采用。1.1数控火焰切割技术简介火焰切割是利用气体火焰的热能讲工件切割出金属预热到一定温度后喷出高速切割氧气流使预热处的金属燃烧并放出热量实现切割的方法。最常见的气体火焰切割是氧-乙炔火焰切割。数控火焰切割机是应用计算机数字程序控制的全自动化切割设备，人们借助计算机辅助设计程序，吧所要切割零件的形状、尺寸。切割顺序及切割过程中的各项辅助功能按一定的语言程序规则进行编程，然后输入控制机，经运算发出功能指令，再有伺服行走系统和切割执行机构协调动作，从而完成零件的切割。数控切割钢材的工艺过程及所遇到的问题21.2数控切割机的特点功能齐全，自动化程度高，具有割炬自动升降、自动点火、自动穿孔、自动切割、割缝自动补偿、动态图形跟踪显示等功能，实现了切割全过程的自动控制。（1）可配置多个割炬工作，省去了制作样板和划线的工时，生产效率高，采用套料程序，提高钢板利用率。（2）能合理选定切割工艺参数和切割路径，可减小热变形，加工精度高，切割质量好，能够减少后续打磨和装焊工时。（3）切割信息易于准备，修改和报春。（4）机器运行稳定可靠，操作方便。1.3国内外数控火焰切割技术的发展国外发达国家切割行业90%为数控切割机下料，仅10%为手工下料，而我国用数控切割机下料仅占下料总量的10%以下，其中数控等离子切割比例更小。绝大多数仍采用手工或半自动切割，笨重落后，劳动强度大，生产效率低，而且材料浪费严重，因此十分有必要发展并普及数控等离子切割机以改变这一落后现状。关于国产数控切割机与国外产品的差距，就数控火焰切割机而言，已无大的差距，性能也比较稳定，只是国产切割机为保证质量，一些主要部件如电磁气阀、减压阀、交流伺服系统等均采用进口件，目前国