【作者】 赵斌；

【导师】 苏强； 张国钧；

【作者基本信息】 上海交通大学 ， 项目管理， 2008， 硕士

【摘要】 电热水器的加热管结垢与内胆漏水问题一直是困扰热水器生产厂家的主要难题。本文采用试验设计(Design of Experiment,DOE)方法,结合失效模式及效果分析(FMEA),对一种新型的低结垢、低镁棒消耗量的电热水器氟碳涂层加热管在研发过程中的质量控制方法进行了深入研究。本文首先介绍了电热水器的基本原理、市场上出现的主要问题以及现有解决方案的局限性,并提出了具体的解决方案——一种新型的低结垢、低镁棒消耗量的氟碳涂层电热水器加热管。以DOE技术为指导,对该新型加热管在产品研发过程中所涉及的主要参数,如加热管基材、涂料以及加工工艺,针对电热水器寿命测试后的镁棒消耗量与加热管结垢量这两个指标,进行优化设计,试验结束后再利用极差分析法,结合实际成本、交货期等因素得出最佳方案。同时,还应用正交试验方法对具体加工工艺进行进一步的优化分析,试验结束后应用综合评分法计算最佳的工艺参数。在两次DOE优化设计的基础上制作的氟碳涂层加热管与现有的普通加热管相比,热水器的镁棒消耗量下降为原来的二分之一,同时加热管结垢量下降为原来的三分之一。针对该氟碳涂层加热管的新物流过程,应用失效模式及效果分析(FMEA)进行质量控制分析,找出潜在过程失效模式并提出改进方案,计算措施实施前后的风险顺序数RPN并汇总至分析表中。通过FMEA的应用,将物流过程的总预测风险顺序数降为应用前的五分之一,效果较明显。在上述质量措施实施的基础上,通过与使用普通加热管的电热水器的市场质量问题反馈发现,使用新型加热管的电热水器中,一年期市场退机比例为千分之二,而同期内使用普通加热管的相同型号的电热水器中,市场退机比例则高达千分之十三。应用DOE与FMEA就新型氟碳涂层加热管的参数与物流过程进行优化与改善,使电热水器的产品质量得到了提高与保证。从实际的市场退机率比较来看,市场退机率得到明显降低,客观上验证了DOE与FMEA方法对新产品研发质量质量控制的有效性。更多还原

【Abstract】 The problems of heating element scaling and inner tank water leakage are the two main quality problems disturbing the manufacturers of electric water heater. On the basis of DOE (Design of Experiment) and FMEA (Failure Mode and Effects Analysis), this paper conducts the quality control method analysis for the new type low-scaling and low-magnesium-consumption heating element of electric water heater during research and development phase.Firstly, this paper introduced the basic theory of electric water heater, the main quality problems happening in the market and imitations of existing solutions, and then put forward a specific technical solution as a new type low-scaling and low-magnesium- consumption heating element of electric water heater.On the basis of DOE technology, this paper conducted the optimization design towards the main parameters such as heating element metal material, painting material and technical process during the research and development phase of this kind of new type heating element. After the test finished, with the analysis method of maximum variance and the consideration of actual cost and delivery timing, the best parameters combination was decided. Furthermore, on the basis of above, the technical process of new heating element was continually optimizing using orthogonal experiment method. After this test finished, the best process parameters was got by implementing the comprehensive evaluation method.Then, the new logistic process of this kind of new type heating element was analyzed with FMEA method to figure out the potential failure mode, raise the new solution for continual improvement, calculate the RPN before and after implementation of quality solution and fill up in the analysis table.Finally, on the basis of implementation of above mentioned quality control methods, certain quantity of electric water heaters assembled with new type heating element were sold to certain place together with other electric water heater assembled with old type heating element. And after one year usage, it’s found that the market rejection rate of electric water heaters with new type heating element was only 2‰, while for which with old type heating element, the rate is as high as 13‰.In a conclusion, the usage of new type heating element and the implementation of relative quality control methods will obviously lengthen the expected life of electric water heaters, decrease the market rejection cost and improve customer satisfaction.更多还原