A Study Of Valve Push Rod Radial Runout Measuring Instrument

Valve push rod is one of the important components of the engine, it transmits the force from the cam wheel to the rocker arm. Since the precision of valve push rod would affect engine movement, its quality may have great influence on the engine performance and life.Traditional measurement methods rely on a lot of manual work, which result in high production cost and low efficiency, and the human eyes is easy to fatigue, that would increase product error rate. For the limitations of detection accuracy, efficiency, automation and information technology traditional inspection method cannot meet the requirements of production and testing.Because of the high efficiency and uninterrupted working of machine vision, Now more and more factories use machine Vision to take place of human being. According to the valve push rod specific requirements on the radial runout, we designed an automation measuring instrument based on machine vision.Valve push rod measuring instrument use industrial camera to detect regional push rod image, and the design of the rotary mechanism to drive around the reference axis of rotation of the push rod, calculate the rotation after a circle that push rod radial runout, according to the measurement results of the push rod then classified the rods.Before measuring we need to calibrate the Industrial camera. A calibration method was designed based on the product itself. Analysis of the rod body need to extract the edges of objects, we analyzes several classical edge detection algorithm, finally using extraction method lookup straight edge, improve the measurement accuracy and precision.The valve push rod radial measuring instrument was used for a long time to test repeatability and accuracy test, the test results show that the instrument can meet the actual requirements of detection.