活塞燃烧室的涡流阵列检测

Eddy current array testing of piston combustion chamber

根据发动机活塞的铸造工艺,分析了活塞燃烧室表面可能产生缺陷的类型,提出了基于涡流阵列的检测方法。研制了活塞燃烧室表面涡流阵列C扫描检测系统,采用自主设计的两种对比试块,研究了激励频率、高通滤波、检测速度等参数对涡流信号的影响。开展了检测工艺研究,根据检测速度、深度、灵敏度以及信噪比等因素选定检测工艺参数,根据选定的工艺参数调整阻抗增益和相位,在检测速度小于24s/件的情况下,有效实现了活塞燃烧室表面规格为5 mm×0.12mm×0.2mm(长×宽×深)的人工裂纹的检出。

According to the casting process of the engine piston,the types of defects that may occur on the surface of the piston combustion chamber are analyzed,and a detection method based on eddy current array technology is proposed.An eddy current array C-scan detection system for the piston combustion chamber was developed.Using two independently designed comparative test blocks,the effects of excitation frequency,high-pass filtering,detection speed and other parameters of the eddy current signal were studied.Then the inspection process was researched,and the process parameters were selected by comprehensively considering the factors such as inspection speed,depth,sensitivity and signal-tc-noise ratio.Finally,the selected process parameters are used to adjust the impedance gain and phase.Under the condition that the detection velocity is less than 24 seconds per piece,the detection of artificial cracks of 5 mm×0.12 mm×0.2 mm(length X width X depth) on the surface of the piston combustion chamber is effectively achieved.