【作者】 孙岳；

【导师】 左铁钏；

【作者基本信息】 北京工业大学 ， 光学工程， 2006， 硕士

【摘要】 激光焊接由于其准确性高,能量密度高,变形和热影响区小,高生产效率和加工范围灵活多样等众多优点,而在现在加工技术中得到了越来越广泛的应用。如今,在工业上,激光焊接大量被应用在汽车车身和传动部件的大批量生产。齿轮的激光焊接有着比传统的加工法更多的优点。汽车工业中汽车变速箱齿轮的大量应用,使激光焊接齿轮更需要一种高度灵活的激光焊接系统。首先,本论文在分析汽车变速箱复合齿轮结构的基础上,简要介绍了汽车变速箱复合齿轮激光焊接的主要原理及特性。其次,本文设计了一套应用于汽车变速箱齿轮的激光焊接系统。在这一系统中,两工件在6.3吨液动压力机上进行压装后,工件组被人为运送到气动卡盘上,卡盘由电气控制柜控制,靠内孔夹紧工件。在焊接过程中,工件由数控加工中心的一个旋转轴带动旋转并实现控制。焊接的准确性由工作台上的机械结构设计和卡盘的准确性共同决定。本文中概括了激光焊接汽车变速箱齿轮生产中从清洁,组装到装卡的工艺要点。最后,本文进行了汽车齿轮的激光焊接实验研究,由于两齿轮间装配方式采用过盈配合,齿轮组在激光焊接中并不需要填充材料。本文选择了合理的工艺参数,对材料为20CrMo及20CrNiMo的变速箱齿轮进行了激光焊接。对主要工艺参数如:激光功率、焊接速度、离焦量、辅助气体等,进行了系统地研究,并得到非常理想的效果。实验表明,合理的焊接工艺参数是取得良好焊接效果的一个重要因素。同时,对焊接后的样品进行了金相组织分析和超声波探伤。激光焊接汽车变速箱齿轮获得了满意的焊接效果。更多还原

【Abstract】 Laser welding has increased its role in the modern technology due to the precision, high-intensity ,low distortion, small heat influenced zone ,high production rate and process flexibility capabilities . Today laser welding is mainly applied in industrial mass production of components for automobile engines and transmissions.Laser welding gears have shown many advantages over conventional methods. High volume manufacture of transmission gear has been well established world-wide in the automotive industry. The widely used of laser welding gears requires the use of highly flexible welding systems.Firstly, on the basis of analyzing the double-linked gear in the automobile’s gearbox, this paper introduces briefly the principle and characteristics of laser welding. Secondly, the system of laser welding transmission gear is designed. In the system, the parts are pressed in a 6.3 ton hydraulic press station. The pressed parts are loaded manually into the clamping device(Air chunk) .The chunk controlled by the electrical control cabinet will clamp the part on the inner diameter. For welding the clamped part is now rotating. The rotational movement is a CNC axis and therefore adjustable. Here the welds are mostly linear while the accuracy is obtained by the design of the machine and the clamping tools. Some attentions about processes are summarized from cleaning, assembling as well as fixing the workpiece. Finally, the transmission gears have been welded in the experiments. Laser welding can be performed without filler material, due to the interference between the two gears. The main technological parameters of laser welding transmission gear made of 20CrMo and 20CrNiMo are studied systemically for example: welding power、speed、defocusing parameter and flow parameter . The excellent welding profile can be got in the experiments. As the result of the experiment, technical parameter is a key to obtain the good welding result. Meanwhile, after analyzing the microstructure of welding workpieces and the ultrasonic flaw detecting , Welding seam of laser welding transmission gear has got a satisfying effect .更多还原