Design and optimization of a novel throttling-inside-piston multi-stage hydraulic cylinder

In order to improve the performance of multi-stage cylinder to achieve rapid and steady extension, a novel throttlinginside-piston multi-stage hydraulic cylinder is proposed without changing physical size and piston working strokes of the traditional sequential multi-stage hydraulic cylinder. Based on internal structure optimal design and basic size parameter calculation, the mathematical model of the proposed throttling-inside-piston multi-stage hydraulic cylinder is studied using multi-rigid-body and impact-recovery dynamic theory. Then, the diameters of the orifices within the pistons are optimized using constraint optimization technique. Comparative simulation results show that the new type of throttlinginside-piston multi-stage hydraulic cylinder can significantly enhance the rapidity and steadiness for the erecting system.