采用电子散斑干涉法对车灯配光镜内部缺陷问题的研究

Interior Flaws Study of Car Light by Electronic Speckle Pattern Interferometry

在汽车车灯配光镜的生产过程中,由于用热压工艺而产生的热应力无法完全释放,积聚在其内部,产生不可见的细微缺陷。这些缺陷在一定的外界条件下扩展、生长,导致表面开裂、破碎,造成产品的报废。目前通常采用的有损检测方法虽然能够检测出缺陷的存在,但也破坏了车灯。为此,本文用采用电子散斑干涉法(ESPI)对车灯配光镜表面由于热应力而造成的变形以及细微裂纹缺陷的无损检测进行了实验研究,量化得到了配光镜表面在热载荷作用下的连续热变形分布。实验表明,用ESPI在热载荷的方式下可以成功地测量出配光镜缺陷的存在,并通过进一步研究,对同一型号但在残余应力分布上存在微小差异的两个车灯,我们给出了判别它们的定量标准。

During the production of car light, the thermal stress caused by heat-machining process could not be released fully, thus it induced flaw. The existing detecting method belongs to the Destructive Detect methods which could damage the light during the inspection. In this paper, the Electronic Speckle Pattern Interferometry (ESPI) technology was introduced into the study on the thermal deformation of car light surface and the feasibility on using it as the nondestructive detect technology (NDT) to detect the flaw of the light. According to the experimental work, the quantitative results on the thermal deformation of car light were got and it seems that the ESPI provide as a reliable method for the NDT on light surface. Furthermore, the quantitative standard was got to distinguish from two lights which they are the same style but imperceptible difference in the remnant stress.