Research On A New Medium-caliber Police Automatic Riot Gun Technology

Automatic shot gun is a new kind of shot gun that can launch shotshells continuously,which can conduct successive fire strike on targets.Under serious current domestic anti-terrorist situation,the traditional single-fire pump shot gun with poor fire-sustainability can not meet the operation requirement to maintain regional stability and deal with emergent events.There have been many cases that foreign countries massively equipped with automatic shot gun,but the large-scale equipment of related products didn't occur domestically.In this dissertation,on the basis of adequate investigation,a new kind of automatic shot gun was developed,and the main contributions are as fellows:(1)The design of overall plan was conducted.The design concept of this project was proposed,and the tactical and technical specifications that this automatic shot gun should realize were determined.The overall plan was proposed,and the auto-cyclic chart was designed.(2)Engineering design,prototype manufacturing and test were carried out.The structural design of every part of the automatic shot gun was conducted with three-dimensional modeling software SolidWorks,and the engineering drawings conforming to the national drawing standard for this project were accomplished.Then,the prototype was manufactured and the live firing test was conducted successfully,which verified the feasibility of the overall plan and structure design and the reliability of the working cycle.(3)Dynamics and kinematics analyses of the automat were fulfilled.The 3D model was imported into the multi-body dynamics simulation software ADAMS,and the virtual prototype of this new automatic shot gun was established.The dynamic simulation of the automatic working cycle and the analysis of the simulation result were carried out.Through the comparison of the post-processing curve to the structure design,the collisions throughout the auto-cyclic process of on the automat were analyzed emphatically.In addition,for the work characteristics of automat under different working conditions,four major factors were selected,and four groups of simulation analyses were carried out by single variable method.The influence of the four factors on the arrival velocity of recoil and counter-recoil of the bolt carrier,and the theoretical firing rate was figured out,which pointed out the direction for the test and improvement design on subsequent prototypes,and provided important technical support.(4)The finite element analyses on key parts were finished.For two groups of key parts of this shot gun-the locking mechanism and the fit of cartridge case and chamber,the finite element analyses of their subjected stress under the load of chamber pressure was carried out.The magnitude and distribution of stress were obtained.According to related theories,the strength of these key parts was checked,and the stress was not beyond the yield limit.Therefore,the work of locking mechanism was determined to be reliable,and the design with partial case outside the barrel chamber was safe and feasible.Besides,the timing of the extracting was proper.This dissertation not only provides the basis for the prototype improvement and parameters optimization of this automatic shot gun,but also offers useful guidance for the design and research of these kinds of small arms,which will have big reference value.