Design Of General Automotive Ball Joint Test Equipment And Research On Its Key Technologies

Automotive ball joints decide the sensitivity and accuracy and driving stability of a car's steering. They are important parts that related to safety driving and agile operating and they must undergo a rigorous performance and durability testing. For the domestic areas especially in Taizhou region, automobile and motorcycle industry are advanced. There are many ball joints factories, but most of them lack of general test equipments. This paper combines the research and development of Yuhuan projects:development of universal automotive ball and socket assembly test equipment, the systematic design of universal automotive ball and socket assembly test bench, and one of the key technologies is mainly launched. The study mainly includes the following aspects:Design of universal automotive ball and socket assembly test bench:on the basis of related national standards as well as factory standards in Taizhou areas, we analysis the testing type and implementation of ball joints, establish the functional objectives of the test equipment, functional decomposition and structure mapping and establish the program of the free control of three degrees as well as combined loading test method.The mechanical structure design of test equipment and the optimal research of key structure:Based on the test bed for the establishment of the overall program, detailed design of mechanical structures are tested. The equipment use a series fixtures, so that it can match the multi-class ball joints and broad the application ranges of the test bed; three degrees load are independent which avoids mutual interference; Using finite element method to do mechanical analysis and material optimization and structural optimization of key mechanical components which improves the life of the test equipment.The electrical control system design of test equipment:The test equipment Uses PC as the core part of the electrical control system and uses multi-function PCI card with the PLC module to expand the system capacity. NI Labview software is used to programming and algorithm. The software supports different kinds of programs of durability and performance and supports report generation. Considering the complexity of the test, we have designed error monitoring functions and troubleshooting tips to improve the safety performance of the test equipment.Design of electro-hydraulic loading system and control algorithms:Analyze the electro-hydraulic loading system. In order to solve the problem of Inefficiency of the system, constant pressure variable pumps are used as a hydraulic source to load the system which reduces the energy consumption of durability test effectively. Meanwhile, we have built the theoretical model of valve-regulated symmetrical cylinder, modified and optimized the model with testing methods to improve the model accuracy. For many valve controlled cylinder and loaded ball joints are different and the System interference are large, Fuzzy-PID control algorithm combined with disturbance observer were used to control the loading of different characteristics of high-frequency precise force load.Finally, a variety of tests have improved that the designed test equipment are able to complete different kinds of different tests and meet the requirements of design features.