DMAIC方法在降低高压油泵泄压阀打开压强测试不良率方面的应用

DMAIC application in decreasing the defect rate of PRV open-pressure test for high-pressure pump

针对某款高压油泵泄压阀打开压强测试不良率高的问题,运用六西格玛的DMAIC方法进行系统性分析并提出了解决方案。首先定义输入和输出因子,并运用因果矩阵、潜在失效模式及后果分析对这些因子进行筛选。然后结合Minitab软件开展过程能力、多变异等一系列的分析锁定了两个关键输入因子,即泄压阀弹簧弹性系数测量不准确和出油阀组件压入力过大。再通过方差分析、实验设计等得到弹簧力参考值和出油阀组件润滑参数的最佳设置值。最后运用统计过程控制的方法对关键输入因子所涉及的制造过程进行趋势监控。现场实施结果表明,泄压阀打开压强测试的过程能力指数提高了85.2%,不良率降低了75.5%。该研究为后续类似的质量问题提供了一个高效的解决方案。

Aiming at decreasing the defect rate of PRV open-pressure test for high-pressure pump,it uses DMAIC of six Sigma to make a systematic analysis.It defines the input and output factors and screens out those important ones with Causal Matrix and FMEA,then it applies Minitab to analyze them gradually with PCA,MVA and obtains two root factors which are inaccurate measurement of PRV spring rate and high press-force of OCV sub-assembly.Based on ANOVA and DOE,it picks up the best parameters of spring reference force and OCV sub-assembly lubrication and monitors the related manufacturing processes with SPC.The field implementation results show that the CPK of PRV open-pressure test increases by 85.2%and defect rate decreases by 75.5%.This is a highly-effective solution for some similar quality problems.