| With the rapid development of the mechanical industry, the hydraulic transmission system is developing in the direction of high speed, high pressure, high precision and heavy load. When the hydraulic cylinder dragging a heavy load at high speed run to the end, if there is no suitable buffer device, often make a dramatic pressure shock and vibration associated with harsh noise, even lead to loose fasteners and damage hydraulic transmission parts. It is very dangerous. This paper studied a new cushioning structurewedge-shaped thorough theoretical and experimental research. Its main research contents are as follows:(1) The flow equations were stablished by dividing cushioning process into three stages, which are local pressure loss, sharp edged throttling and variable gap throttling. And the mathematical model of cushioning process of about wedge-shaped cushioning hydraulic cylinder was established. The mathematical model was simulated and analyzed by using MATLAB.(2) The flow field of three-dimensional model about the rodless chamber, buffer chamber and the oil discharge hole in wedge-shaped cushioning hydraulic cylinder was built. Setting the piston and other objects as a rigid body coupling with the flow field, use FLUENT to achieve dynamic simulation of the cushioning process through the user defined function and dynamic mesh. The results of numerical simulation were analyzed, and it is proved that describing the cushioning process by the phase method is correct.(3) A wedge-shaped cushioning hydraulic cylinder cushion experimental platform was built. According to the experimental data corrected the mathematical model and simulation parameters. Verify the mathematical model of the accuracy and reliability by compared the experimental results and the mathematical model calculation results.(4) Using the mathematical model to research the effect of pressure in rod chamber and piston speed by different structure parameters such as: wedge angle, the length of wedge angle, inlet chamfer, the length of chamfer and different operating conditions like external load and supply pressure.Using the obtained mathematical model can quickly and easily to obtain the wedged buffer hydraulic cylinder cushioning curves,which can provide theoretical guidance for the buffer structure design, optimization and improvement of hydraulic cylinder of the reliability. At the same time the research methods of this paper can also be a reference for other structure of buffer device. It has the practical engineering significance. |
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