大型凸轮轴孔柔性加工技术研究与实践

发布时间：2018-03-07 13:05

本文选题：大型柴油机　切入点：凸轮轴孔　出处：《湖南大学》2016年硕士论文　论文类型：学位论文

【摘要】：凸轮轴孔作为柴油机零部件的关键孔,承载着配气运动输出的作用,因此其加工精度对发动机性能有着重要影响。由于凸轮轴孔加工精度要求高,且孔较长,属于典型的高精度深孔加工。相比主轴孔,凸轮轴孔同样贯穿整个气缸体或气缸盖,但凸轮轴孔的直径更小,长径比更大,加工难度更高。而且在新品开发试制阶段,由于产量少,产品图纸尚未定型,在无法订购专用加工机床条件下,大型柴油机的凸轮轴孔柔性加工就成为新产品加工试制的重点难题。尤其是YC6K柴油机气缸盖的出现,更是将这一加工难题推上更高层级。本文通过对凸轮轴孔柔性加工系统误差理论分析,寻找提高凸轮轴孔加工质量关键要素,同时对玉柴现有的凸轮轴孔柔性加工工艺进行分析研究,寻找适合加工大型凸轮轴孔工艺方案。通过对6K柴油机气缸盖凸轮轴孔加工实践研究,掌握了大型凸轮轴孔柔性加工工艺技术:实践证明6K气缸盖凸轮轴孔在卧式加工中心上悬伸调头镗两端,再用专用镗杆,在卧式镗床上以两端已加工的凸轮轴孔作支撑导向,精镗中间档位的工艺方法是可行的。在实践过程中发现并解决相关问题:(1)可通过提高中间三档加工质量来提高凸轮轴加工的合格率;(2)针对摇臂滚轮与凸轮轴接触异常导致磨损现象,可结合夹具定位原理,在无配镗条件下拆盖后用凸轮轴孔作定位基准加工摇臂轴孔,以此提高摇臂轴对凸轮轴孔平行度,消除异常接触导致的严重磨损现象。(3)在实践过程中采用自主设计凸轮轴孔扩刀、精镗杆的技术方案,可有效地节约了新品试制阶段的刀具成本,同时极大缩短新产品交付周期,为玉柴YC6K柴油机抢占市场先机赢得宝贵时间。
[Abstract]:Camshaft hole, as the key hole of diesel engine parts, bears the function of valve distribution motion output, so its machining accuracy has an important effect on engine performance. The camshaft hole also runs through the whole cylinder block or cylinder head, but the diameter of the camshaft hole is smaller, the ratio of length to diameter is larger, and the processing is more difficult. Because the output is low and the product drawing has not yet been finalized, the flexible machining of camshaft hole of large diesel engine becomes the key problem in the new product manufacture, especially the appearance of cylinder head of YC6K diesel engine, under the condition that it is impossible to order special machining machine tool. By analyzing the error theory of camshaft hole flexible machining system, the key factors of improving camshaft hole machining quality are found. At the same time, the existing flexible machining technology of camshaft hole in Yuchai is analyzed and studied, and the suitable processing scheme for large camshaft hole is found. The practice of machining camshaft hole in cylinder head of 6K diesel engine is studied. Master the flexible machining technology of the large camshaft hole: the practice proves that the 6K cylinder head camshaft hole is boring the two ends of the overhanging turning head on the horizontal machining center, and then using a special boring bar to support and guide the camshaft hole which has been machined at both ends in the horizontal boring machine. The process method of fine boring middle gear is feasible. In the process of practice, we find and solve the related problem: 1) the qualified rate of camshaft machining can be improved by improving the quality of middle three gear machining. (2) aiming at the contact between rock arm roller and camshaft, we can improve the qualified rate of camshaft machining by improving the machining quality of middle third gear. Abnormal wear and tear, Combined with the principle of fixture positioning, the camshaft hole can be used as the positioning reference after removing the cover under the condition of no matching boring, so as to improve the parallelism between the rocker shaft and camshaft hole. Eliminating the serious wear phenomenon caused by abnormal contact. (3) in the process of practice, adopting the technical scheme of designing camshaft hole reaming cutter independently and fine boring bar can effectively save the cutting tool cost in the trial production stage of the new product, and at the same time greatly shorten the delivery period of the new product. For Yuchai YC6K diesel engine to seize the market to win valuable time.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK426

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