Study On The Hydraulic System And Key Parts Of Advanced Hydraulic Support

The development of coal mining technology plays an important role in constructing high output and high efficiency mine. As a piece of major security supporting equipment in a coal face, the hydraulic support especially high-end hydraulic support becomes a research hot spot in enterprises. For lacking of scientific theory, the cycle of development and production is too long, the design of hydraulic supports is proved to be reasonable and economic only in field application. As the frontier topics, the theoretical study of mechatronics and hydraulics for high-end hydraulic supports is useful in optimization design.From the viewpoint of system engineering, dynamic models for the large flow pipelines, valves of high-end hydraulic supports are firstly established and corresponding simulation, analysis and experimental verification are then made in this dissertation. The emphasis is on the establishment of mechanical model and simulation model for the Macro relief valve, pilot operated check valve, electro-hydraulic valve which are used in the high-end hydraulic supports. Based on AMESim, the simulation analyses of the above-mentioned valves are made according to MT419-1995 and EN1804-3, the main factors which affect the working performance of large flow valves are then identified and corresponding improvement suggestions are put forward. Simulation model for the large flow hydraulic pipelines are also established and systematic experimental verification for the complete appliance are carried out. With regard to the fast moving properties of the high-end hydraulic support, the corresponding strength and deflection calculations of the hydraulic legs are done, and the equations of the descending speed controlled by pressure of the hydraulic legs are derived and analyzed. The influence of the external diameter of the hydraulic leg on its descending speed and advancing speed of the support is pointed out, and the workflow of designing and checking strength of double-telescopic legs is also introduced. Furthermore, in order to verify the theoretical model and the simulation results of the above hydraulic valves and hydraulic legs, the measuring and control test devices of mechatronic system and the hydraulic legs were developed, the experimental data and action curves were collected and the corresponding test results have been obtained. This dissertation analyzes the dynamic performance of hydraulic system for hydraulic supports systematically through the establishment of the model, the research of the simulation, the verification of the test results, it has theoretical significance and practical value to the design of high-end hydraulic supports.