Research On Control System Of Fatigue Machine For Flat Scroll Spring

The depth and extent of fatigue test researching is increasing at present, the working of fatigue project is on process in a lot of domestic graduate school and university. As an important test facility, spring fatigue testing machine plays a key role in studying the life of spring, which is widely used in related laboratories of aerospace, automobile, higher education institutions and research institutes. Spring fatigue testing machine helps us to study the spring strip, improve manufacturing process, raise the quality of spring, lower manufacturing costs, and to ensure the reliability of spring products. There are many kinds of spring fatigue testing machine, however, few of them are specially designed for the flat scroll spring fatigue test. In this thesis, the main task is to study the control system of the flat scroll spring fatigue testing machine, the technical indexes of this thesis are built upon the technical contract signed with a spring plant in Chengdu.The control system is an important part of the testing machine, which is the key factor to decide the performance of the testing machine. The control system is required to ensure the stability, accuracy and rapidity of motion control, and also required to be able to judge the fatigue fracture of the specimen accurately and record the times of the fatigue torsion. In response to these circumstances, this paper has conducted a special study.Firstly the paper introduce the mechanical properties of the flat scroll spring and the mechanical structure of the testing machine, and analyze the relationship of variables in the fatigue test process, and these provide theoretical basis for the design of the fatigue testing machine’s control system.Secondly, the paper introduces the hardware and software design of the control system. In terms of hardware, A4series servo motor unit produced by Panasonic is the executing agency of system, the MT4000series HMI produced by Kinco company is made as the operation panel, the Siemens S7-200series PLC is taken as the control core unit.In terms of software, the PLC control program is developed in the STEP7-Micro Software development environment, the operator interface is designed in the EV5000configure software. Through the test, the control system of the flat scroll spring fatigue testing machine has met the design requirements of high reliability, accurate positioning and fast response, and filled up the blank of this kind of control system in China.