Abstract:Aiming at the hydraulic cylinder used for driving the hydraulic fire pump, using of the throttling slots composed of two segments, the section's area of first segment was rectangle constant and the second was variable as the buffer structure of cylinder, was pointed out. The mathematical model of the buffer structure was analyzed, the working process of buffer cylinder was simulated by AMESim software, and the influence of buffering effect by throttling slot's parameters was analyzed. The result shows that the smaller the width, depth and the number of slots, the lower is the final velocity of buffer, but the higher is the peak value of buffering pressure. On the contrary, the lower the peak value of buffering pressure, the longer the time is to establish buffering pressure, even the greater is the final velocity. So suitable choosing of parameters of buffer structure of cylinder is required.