针对基于人工检测的气门推杆质量控制方法存在效率低、容易漏检、不可靠等问题，提出了基于电磁感应原理的气门推杆涡流检测方法，设计了一套自动化检测系统。该系统包括机械结构、电气控制、检测装置等，能够实现气门推杆的自动上料、工位传输、仪器检测、自动分选等功能，从而完成气门推杆质量的自动判别。通过建立涡流响应信号的有限元模型，仿真研究了探头与推杆球头距离变化时涡流信号的变化规律，确定了推杆检测盲区。从现场人工检测合格的气门推杆中选择了100根进行测试，系统识别出了5根不合格气门推杆，并经复检确认。测试结果表明，设计的自动化检测系统可以显著提高检测效率和准确性。

Manual inspection is employed to identify defects in valve push rod for quality control, which has some unacceptable drawbacks such as inefficiency, susceptibility to undetected defect, and unreliability. In this work, eddy current testing based on electromagnetic induction principle is proposed to nondestructively evaluate the quality of valve push rods. The designed automated eddy current system consists of mechanical structure, electrical control and eddy current instrument. The valve push rods are able to be automatically loaded, transmitted, inspected and sorted in order through the developed system for quality examination. Subsequently, a finite element model is built to investigate the change of eddy current signals when the distance between the probe and the ball of a push rod increases. The signal analysis enables one to determine the non-detection zone of valve push rods. Finally, 100 valve push rods are selected randomly from the acceptable products through manual inspection, and five of them are identified to be defective. The results from the following manual inspection agree well with those from the developed automated eddy current system, which suggests that the developed system is superior in terms of efficiency and reliability.