"畸变工程":从系统的角度探讨零件的畸变现象

在产品的最终加工过程中用精磨去除零件中的畸变是一个既费钱又费时的事情。例如，仅在(车辆)传动技术领域，1995年德国用于最后精磨以消除工件的畸变而增加的成本已达8．5亿欧元。迄今为止，行业人士认为在最后的产品加工过程中导致零件产生畸变的主要原因在于淬火过程，而今大家普遍认为这个观点不是很对，认为淬火过程只是释放了在各个加工环节中积累在工件中的畸变潜能，如铸造、车削加工、铣削、淬火、磨削。由不来梅大学创立及Deutsche Forschungsgemeinschaft资助的合作研究中心SFB570“畸变工程”的研究方针是从系统导向着手，分析零件的畸变。合作研究中心由12个子项目组成，涉及20多位来自材料科学、制造技术、数学及过程控制工程的研究人员。根据系统导向的方法，合作研究中心SFB570“畸变工程”认为，与优化零件整个生产过程(工序链)相比，对零件生产过程中的单个过程的优化是第二位的。为了推广系统导向的方法，保证SFB570“畸变工程”中集中在不同工序和技术的这12个子项目问的一个连续、协调的知识和信息交换，已成立了一个系统模式工作组。这个工作组的焦点在于详细阐述和进一步发展系统导向的方法以及协调应用于这些子项目中的工序和方法。和其它方法相比较，整体方法包括了零件的生命周期分析、因果分析、失效模式和效果分析(FMEA)以及试验设计(DOE)。除畸变潜能这个新概念外，同时还发展了生产过程补偿潜能这一概念。文中讨论并描述了整体步骤(包括相关方法和手段)，以及迄今为止取得的结果。

"Distortion Engineering":A System-Oriented View on the Distortion of Component-Parts

The removal of component-part distortion by a final grinding operation as the last step of a production process is a cost and time consuming strategy.Only in the area of transmission technology, for example,the costs for the removal of component-part distortion by a final grinding operation added up to EUR 850m in Germany in 1995[1]. So far, in industry the main cause for the component-part distortion at the end of the production process was seen in the hardening process.However,today it is commonly known that this is not fundamentally right and that the hardening process only sets the distortion potential free,which was accumulated in the workpiece during the production process along the various process steps such as casting,turning,milling,hardening and grinding.The superordinate approach of the Collaborative Research Center SFB 570 "Distortion Engineering",which has been established at the University of Bremen and which is funded by the Deutsche Forschungsgemeinschaft,is a system-oriented analysis of the distortion of component-parts.The Collaborative Research Center comprises some 12 subprojects and involves more than 20 researchers from materials science,manufacturing technology,mathematics and process control engineering.According to the system-oriented approach,within the Collaborative Research Center SFB 570 the optimization of a single step of the production process is considered being of secondary importance in comparison with the optimization of the whole production process (process chain) of a component-part.In order to promote the system-oriented approach and to guarantee a continuous and harmonized exchange of knowledge and information between the 12 subprojects focusing on the various process steps and technologies within the SFB 570,a working group on systems modeling has been established.The focus of this working group is to elaborate and further develop on the system-oriented approach and to harmonize the procedures and methodologies being applied in the subprojects.Beside others the overall approach includes measures like life-cycle analysis of component-parts,Cause and Effect Analysis, FMEA (Failure Mode and Effect Analysis),DOE (Design of Experiments). In addition to a new concept for a distortion potential,also a concept for a compensation potential of production processes has been developed.The overall approach, including related methods and tools as well as results achieved so far, will be discussed and demonstra-ted.