Automatic Kinematics Analysis Of A New Semi - Automatic Shotgun

A semi-automatic shotgun with a new clearance-rotating bolt system was studied in this paper and how the automatic mechanism works and how the major parameters influence the movement of the automatic mechanism have been summarized from the research. The main contents are as follows:The principle of the automatic mechanisms was introduced. The movement process of the automatic mechanisms was analyzed based on dynamics of automatic weapons and the key factors influencing the automaton movement were confirmed. Based on the theory of classical internal ballistics and finite element analysis method, the internal ballistic process and the simulation of the interaction between shell and chamber were calculated.The virtual prototype model of the shotgun was established by three-dimensional modeling software and the ADAMS. The simulations about how the factor, such as stiffness and preloading of the return spring, clearance after the bolt and the coefficient of friction between the shell and the chamber influences the kinematic characteristics were calculated. The advantages and disadvantages about the clearance-rotating bolt system and inertia driven system were analyzed.The result shows that:the stiffness and preloading of the return spring has a very minimal impact on the recoil motion, but there is a marked impact on the return motion; the clearance after the bolt is the key factors influencing the energy of the automatic mechanisms after unlock from the barrel, the energy increases with the increase of clearance, but the growth rate gradually decreased; the coefficient of friction between the shell and the chamber also have a very strong effect, especially in case of large clearance; the size of the clearance has a small influence on automatic mechanisms’movement with higher friction coefficient.