【作者】 高志强；

【导师】 李宝筏；

【作者基本信息】 沈阳农业大学 ， 农业机械化工程， 2008， 博士

【摘要】 我国齿轮行业近年来发展迅速,目前齿轮产品的年产值已突破7×10¹¹RMB,居世界第四位。在齿轮产品中车辆齿轮传动产品（包括汽车、工程机械和农机等）占到60%。我国生产齿轮的机床有5.3×10⁵台,役龄超过15年以上的机床约占40%,用这种装备加工出来的产品质量较差,工期难以保证,生产出的产品在国际市场上缺乏竞争力,因此为满足齿轮行业的生产需求必须从设备入手。首先是更新设备,我国近年来引进了大批国外设备,2006-2010年将新增设备1×10⁵台,每年用于新增设备投资约6×10¹⁰RMB。其次是对原有的设备进行改造,改造不仅能达到与购买新设备同样的效果,还能为企业节省大量的资金,通常只需花费不到原设备30%的费用.现在进口一台大型高档数控滚齿机的价格要1×10⁷RMB以上。此外,新购买的设备在使用了几年之后,仍然要遇到同样的诸如故障率高、功能落后和维修困难等问题,同样面临是淘汰或是改造的选择。机床数控化改造在发达国家已经成为新的经济增长点,这种方法在我国也已经得到了大多数企业的认可,非常适合我国的国情,有着广阔的前途。我国需要改造的机床很多,也有很多的公司在作改造,其中大部分机床是没有特殊工艺的通用型设备,如车床、铣床和加工中心等,从事特殊工艺机床改造的研究较少。数控滚齿机由于技术的原因起步较晚,上世纪八十年代国外才开始出现商品化的全功能数控滚齿机。本论文细致、深入地研究了西门子数控系统中齿轮加工部分的功能,掌握了滚齿机床的核心控制技术。同时对滚齿机的特殊工艺进行了深入的研究,并将其成功地应用于ZFWZ12型滚齿机数控化改造的实施中。完成了国内首例使用西门子Sinumerik840D系统的滚齿机改造,对今后齿轮机床的制造和数控化改造都具有重要的理论意义和应用价值。本文首先从理论上分析了数控滚齿机和普通滚齿机的加工原理,通过对比指出数控滚齿机无论在加工精度上还是在工作效率上都大大优于普通滚齿机。其次,以滚齿机的结构为基础,通过齐次坐标变换的方法建立了六轴数控滚齿机的数学模型。第三,论述了数控化改造的具体实施步骤,对关键技术作了详细说明:电子齿轮功能的目的是用数控系统直接驱动坐标轴,去掉机械传动链,它的实现是改造的核心内容;延迟停止和回退功能是避免在紧急情况下损坏工件和刀具,保证操作人员的安全所采取的必要措施。第四,根据滚齿加工工艺,设计加工工艺路线,编制加工程序。为了清晰明了,加工程序通常由若干主程序和子程序组成,此外还编制了一些固定循环。由于滚齿加工时所使用的工件参数、刀具参数和加工参数非常多,在加工不同类型的齿轮时调整起来非常繁琐,很容易出错.所以要使用另外的方法,把繁琐的工作进行简化。这就需要在滚齿机上开发专用的用户界面,把参数直观地反映到操作界面上,开发用户界面的软件可根据实际要求选定。重要的是加工程序要用参数化的方法来编,并一定要与用户界面参数相对应.在普通数控机床改造中是不需要另外编制用户界面的,加上有些数控系统的开放性不强,在数控系统中进行二次开发的应用不多,因此本文详细介绍了西门子数控系统下进行二次开发的具体方法。第五,齿轮的加工误差如齿形误差、齿向误差等虽然都是由齿坯、刀具和机床三方面引起的,但有些误差的产生可能不是单单来自某一个固定的方面,这给误差分析造成困难。考虑到本论文研究的改造项目只是针对机床本身,所以在分析原因时也以机床为主,分别从三个方面进行了探讨:刀架导轨相对于工作台回转轴线的不平行度、刀架导轨相对于工作台回转轴线的歪斜度和滚刀轴线的倾斜对误差的影响。分别计算得出改造后的理论精度值。经过研究与实施,ZFWZ12型滚齿机数控改造后的加工精度有了明显提高,并且与计算的结果是相符的。验收报告表明,工件加工精度达到国家六级。可靠性方面,从2006年4月交工到现在没有出现任何问题,说明改造是成功的。更多还原

【Abstract】 With the dramatic development of gear industry in China, its yearly production value has been up to 70 billion RMB, and ranked the forth in the world. Among the gear products, 60 percent was vehicle (automobile, engineering machinery and farming machinery) transmission gear. There are altogether 530 thousands gear cutting machines in China, however, 40 percent of them has been working for over 15 years, which leads to the quality inferiority, overdue delivery and less competitiveness in the world market .In order to meet the need of gear industry, manufacturing equipments must be improved. First of all, the replacement of equipment should be carried out. Numbers of foreign equipment have been introduced into China so far. It is predicted that 100 thousand pieces of equipment will be introduced with the yearly investment of 6 billion RMB from 2006 to 2010.Secondly, the renovation (retrofit, rebuild, remanufacture) of the old equipment needs to be initiated. After the renovation, the equipment will not only work as well as the new one, but it can also save the cost, 30 percent of the total initial purchase cost would be well enough. (Usually a sophisticated CNC Hobber costs at least 10 million RMB.) In addition, even the new-bought equipment, after having been used for several years would face the same problems as faults increasingly occur, functions outdate and difficult to maintain etc. Buying new one or renovating the old one will always be the problem.Retrofitting is becoming one of the new economic resources in the foreign countries. This method, has also been widely accepted in China because of its fitting for China, is going to have a promising future.Machine tools that need to be renovated are as many as the companies that are doing renovating, but most of them were universal machine tools like turning machine, milling machine and machining center, which has no special technics. And the study on the renovating with special technics is rarely carried out. CNC hobber was invented lately due to its technological difficulty. All-functions CNC hobber first appeared only in the 80’ of last century in abroad. This article is going to study the CNC retrofitting of hobber from the planning, implementing all the way to the result analysis with the method of combining theory and practice, trying to do some research of the machine with special technics. This is the first CNC Hobber retrofitting case that has ever been done with Siemens Sinumerik 840D CNC system in China.First of all, it studied the theory of CNC and non-CNC hobber, pointed out that the CNC type is more advanced than the non-CNC type in the aspect of machining precision and efficiency.Secondly, at the basis of hobber structure, used Homogeneous Transformation method to establish the math model of 6-axis CNC hobber.Thirdly, the procedures of retrofitting were introduced in detail, and the key technologies were specially discussed: Electric Gear is used to control motor so as to dismantle the mechanical transmission linkage; Extended stop and Retrace are the necessary methods to protect tools, parts, and person from any danger at time of emergency.Fourthly, based on the hobbing technics, the technics route was designed, and so did the gearing NC program. To make the program clear, the gearing program was separated in several main and sub programs. Fixed cycle programs are also designed in the NC program. Due to the large number of part parameters, tool parameters and gearing parameters, the program must be designed in a proper way, so as to reduce the once overload and detailed works with these parameters when gearing different kinds of products. Customer interface has to be designed to represent these parameters and connects the parameters to the NC program. The interface design software is decided according to the customer’s need.Fifthly, though the machining error of gear was caused by parts, tools and machine tool, but it is actually difficult to determine the exact causes of some errors. In order to clarify the problems, this article deals only with the causes by machine tool, due to the fact that only the machine tool itself has been ameliorated. The study is on 3 aspects: the errors caused by the unparallel degree of Z axis to the axial of C axis; the errors caused by the skewness of Z axis to the axial of C axis; the errors caused by the inclination of B axis.Finally, examine the retrofitted hobber with precision, efficiency and stability: the errors of gear are improved greatly compares to its previous values, turn out that the performance was obviously improved, meanwhile the hobber has been working normally since it was finished on April, 2006, which is to say the retrofitting is successful.更多还原