Abstract: Telescopic hydraulic cylinder is widely used in large erecting devices. Telescopic cylinder can provide longer stroke compared to single stage cylinder. However, its structure is complex. In order to get the characteristics of telescopic cylinder, a motion model is established based on the cavity node method. The LuGre friction model is improved by considering the lubricant film. The contact force model is improved using the equivalent damping model of the hysteresis factor. The process of erection driven by telescopic cylinder is simulated. The action area mutates when the telescopic cylinder converts one stage to other stage, which leads to the sudden change in pressure and velocity, and excessive impact. In order to reduce the impact, many buffer holes are arranged on the cylinder barrel. The simulated results show that the cylinders synchronously move in the replacement of stage after the buffer structure is used. The sudden change in pressure is transferred into slow change. The pressure is raised to the next working pressure in advance, thus greatly reducing the fluctuations of velocity and acceleration.

Key words: ordnance science and technology, telescopic hydraulic cylinder, erection, inter-stage contact, inter-stage buffer