Structure Design And Simulation Of 20mm Sniper Rifle Buffer Device

In this thesis,based on a detailed analysis of the current situation and development prospects of recoil reduction technology for artillery and large-caliber firearms at home and abroad,the overall scheme and buffering requirements of the 20 mm sniper rifle are proposed,and the overall scheme of using the combined action of the buffer device and the rifling brakes to reduce recoil is proposed.According to the working principle of sniper rifle and buffer requirements,the whole gun is modeled in 3D by using UG.The buffer device adopts the throttle lever hydraulic buffer device,and the buffer scheme adopts the free recoil of the barrel before the projectile comes out of the chamber,and the body barrel bulge hits the piston rod of the buffer device when the projectile flies out of the chamber,and the buffer device starts to work in order to achieve the purpose of effectively reducing the recoil resistance and the perceptible shock wave strength of the shooter without affecting the shooting accuracy.The forces on the recoil portion of the 20 mm sniper rifle during firing were clarified,and an internal ballistic model was developed to solve it,and the parameters of the internal ballistic period and after-effect period were derived.The recoil braking diagram was developed based on the data obtained by analyzing and calculating the recoil motion elements under the conditions of the proposed braking efficiency.According to the recoil braking diagram and the general scheme of the cushion device,the detailed dimensional design of each component such as piston,piston rod and throttle rod was carried out to provide an effective model for the internal flow field simulation.Numerical simulations of the fluid flow inside the buffer device were carried out using FLUENT.The update techniques of Profile file-driven motion boundary,spring-light-smooth method plus mesh reconstruction technique together to form the mesh were used.The laws and characteristics of the fluid flow inside this buffer device are revealed.Hydraulic resistance coefficients and hydraulic resistance curves are calculated from the simulation results.The model in UG is imported into ADAMS,and the virtual prototype simulation model is established by adding constraints and loads.The hydraulic resistance curve obtained from the flow field simulation is imported into ADAMS,and the forces acting on the body tube during recoil are loaded onto the body tube model for dynamics simulation.The displacement and velocity curves of the free recoil and braking recoil phases of the body tube were obtained by the simulation.To determine whether the recoil part can reduce the velocity to 0m/s within the finite recoil stroke,as a substitute for the traditional Longo-Kuta inverse calculation link,it was verified that the buffer device design of this thesis is reasonable and can effectively reduce the recoil impulse.Based on the established analytical model and the design requirements of the cushioning device,a roulette wheel genetic algorithm was selected as the optimization algorithm,the maximum and minimum limit diameters of the throttle bar were taken as constraints,and the peak hydraulic resistance was taken as the optimization target,and a genetic algorithm was written in MATLAB to optimize the throttle bar form factor.The optimized solution reduces the peak hydraulic resistance by 10.4% and makes the buffering process smoother.The throttle lever hydraulic buffer device designed in this thesis effectively reduces the recoil resistance without affecting the shooting accuracy,smoothing the recoil process and achieving the purpose of making the 20 mm sniper rifle shoot against the shoulder,which has reference value for the research of recoil reduction technology for large caliber sniper rifles.