Detect The Contact Between The Small Hole Of Connecting Rod And Bushing By Ultrasonic Testing

Ultrasonic testing is one of the most important techniques of non-destructing testing. Ultrasonic testing has been widely used in the field of industrial production, online quality control and medicine, because ultrasonic testing has these advantages such as comprehensive test range, high reliability and quick testing speed. With the rapid development of modern science and technology, ultrasonic testing development towards automation, intelligence, digital and visualization has been greatly promoted.Connecting rod is the critical component of mechanical system. The contact between the small hole of connecting rod and bushing constrain the performance of connecting rod. At present, the destructive spot-checking method is usually used to detect the contact, which has these disadvantages such as low reliability, inefficiency and workpiece wasted. We detect the contact by the method of ultrasonic testing in this subject.In this paper, I designed an ultrasonic testing system used to detection the contact between the small hole of connecting rod and bushing. This system is based on the principle of ultrasonic pulse reflection test, and for the purpose of engineering applications. MCU and data acquisition card are the hardware kernel of this system. The system's software-developing platform is based on virtual instrumentsAt first, this paper introduces the history and development of ultrasonic testing, illustrates the background and significance of this subject, and discusses the basic theory of ultrasonic testing. Then the mechanical control device is designed. The design of front-end analog circuit is especially introduced, which consist of transmitting circuit, limitr circuit, amplifying circuit filter circuit and data acquisition card. The communication between data acquisition card and host computer can be realized by calling dynamic link library. The development of human-computer interaction interface is based on LabVIEW programming environment. The process of the system and data acquisition is especially analyzed. The system can achieves these functions such as data acquisition, signal processing, real-time displaying and storage.In the end of this paper, the research work of the subject is summarized, and the author gives some technical prospects for further studies.