Development Of Test Rig And Its Key Components Of Valves For Coal Mining Shield Support

The reliability of coal mining shield support is very important for the safety in the coal production. The valves for shield support are the core control components of shield support, so stricter requirement is needed for their performance. The types of valves mainly include relief valve, pilot-controlled check valve, reversing valve and shut-off valve. A kind of CAT hydraulic test rig has been developed in this dissertation. It is used for the experiment and test of valves for coal mining shield support for Zhengzhou Coal Mining Machinery Group. The characteristic of this test rig is high pressure (more than 50MPa), mass flow (more than 500 liters per minute), adequate for the emulsion medium and computer aided testing system is used. This article mainly does some research on the hydraulic system of the test rig and its key water hydraulic components. The main research work is as follows:According to the technology requirements brought forward by Zhengzhou Coal Mining Machinery Group, and the standard drafted by the fore Coal Department, this dissertation makes the general plan of the test rig, then designed the schematic diagram of hydraulic system. Modularization idea is adopted in designing this system, and the whole test rig is divided into six modules. What's more, the possible hydraulic strike and pressure loss in this system are also analyzed and calculated, and the corresponding measures are taken.The article does some research on the water relief valve by static calculation and dynamic simulation, and then accomplishes the structure design based on it. The water flow restrictive valves are designed as the back pressure valve and flow adjusting valve. For the demand of higher pressure (as high as 75MPa), the bidirectional pressure charging system is designed. The automatic switching device is designed to satisfy the request of age experiment for reversing valve. Since age experiment should be taken for more than 6,000 times, this device can greatly enhance the efficiency. Finally, the operation platforms for model test rig and intensity test rig are designed.At present, the developing direction of valves for shield support is high pressure and mass flow. With the test rig being successfully developed, it can provide an effective testing facility for the valves for shield support and can greatly hasten their quality elevation.