Design And Research On The Testing Equipment Of Automative Cab’s Lifting Hydrocylinder

In this paper, the development status of the oil cylinder detecting technology is analyzed and the basic theory and technology of the oil cylinder detecting technology, equipment designing, manufacturing, assembly, detection control, debugging and so on are researched. The automatic detecting equipment is developed which is used to detect the lifting oil cylinder in the cab of heavy duty truck. Through the control software, the cylinder internal pressure and piston rod displacement parameters were detected. The transformation of cylinder factory testing is accomplished from manual detection to automatic and intelligent detection by comparing the detection test with factory standard, which solves the problem of the hydraulic cylinder production enterprises detection technology backward, low detection efficiency and detection accuracy.According to the technical requirements, the functional division of the detection equipment is accomplished. This includes seven parts which are the base device, loading device, fixture device, protection device, cooling device, electrical system and hydraulic system. Every part of the body is preliminary designed and the 3D entity model of detection equipment mechanical component is created by 3D drawing software Solid Works. Through the assembly module of Solid Works, the virtual assembly of the mechanical structure of the detecting device is carried on. Through the finite element analysis software ANSYS Workbench, the statics computation analysis of the overall structure and frock clamp and other key parts of the equipment is carried on. By a comparison of mechanical properties of the obtained analysis data and the material itself properties, the mechanical structure design of the detection equipment meet the strength, stiffness and stability requirements. By using the 3D drawing software and the finite element analysis software, the design and analysis of mechanical structure of the testing equipment is accomplished, which greatly reduces the product design cycle and solves the problems of low efficiency, long design time and so on.The factory inspection of the oil cylinder is whether the testing process to meet the factory standard by checking the internal pressure and the displacement of the piston rod. the corresponding hydraulic principle diagram is designed according to the motion mode of the testing equipment. Furthermore, control system is devised with PLC as controller, man-machine interface as host computer to achieve the required functions of testing equipment. The hardware configuration is carried out by PLC. Reasonable PLC input and output ports are allocated to determine the main hardware connection scheme. What’s more, the operation interface of HMI human machine interface is developed. The programs of main menu interface of touch screen and testing process interface are also designed. Taking advantage of the LAD, PLC program is conducted with edit mode calling subroutine in main program. A database variable link is adopted in touch screen program design to realize the communication between each interface control element and PLC. In order to improve the detection efficiency and detection accuracy, visual operation and automatic detection are taken in test equipment.To verify the five test items standard of hydro-cylinder, assembly debugging and experimental research have been conducted in test equipment. According to the efficient and accurate test results production beat and detection project, design of the whole test equipment is rational and feasible.