The Design And Application Of Electrically Closed Transmission Fatigue Life Test Platform Based On PLC

Transmission is one of the key parts of automobile driving system. Its main function is to change the torque and rotational speed from engine and to meet the various requirements of tractive force. Its working conditions will have a direct impact on the overall performance of the cars, transmission test is an important means to detect the quality, find the defects in the process of design and manufacture, provide scientific proof for design and quality evaluation, shorten the development cycle and improve the quality of products.This paper combines with Chongqing “121” commercial vehicle transmission technology support demonstration projects-“commercial vehicle transmissions collaborative innovation and key technology research”(cstc2012jcsf-jfzh X0027). Collecting advanced and widespread structures of mechanical transmissions test bed at home and abroad, combing the requirements of developer, this paper set up the hardware platform and supervisory software of electrically closed transmission fatigue life test bed. The main study contents are:① This paper first analyzed transmissions function, classifications, principle and failure mode, then analyzed the advantage and disadvantage of various test platform, put forward electrically closed test platform structural concept, explained the key DC bus technology in detail.② This paper designed the whole layout. The test-bed has the ability to test many types of gearboxes manually or automatically. The paper introduced the data gathering methods of rotational speed, torque, vibration, oil temperature by dividing the test bed into three parts: mechanical driving parts, DC bus parts, control and measurement parts, finished the hardware selection and introduced the relevant parameters.③ This paper designed the software structure. Operation interface was programed on Lab VIEW platform so that IPC can collect, process, display and store the real-time data of speed, torque, temperature and alarming for the fault. STEP7 and SCOUT were adopted to program and control the drive and load motor. Realization was made for the method of communication and control between PC and PLC by OPC on Lab VIEW platform.④ This paper confirmed the test conditions and specifications of S6-161 transmission, analyzed the results.Practical application showed this test bed was running with steady, reliable and good performance.