Dynamic Analysis And Optimization Of Open-cylinder Pneumatic Ejection Device

The open cylinder pneumatic ejection device takes compressed air as the power source,whose interior ballistics process is simple,controllable.The power is output through the piston assembly,which has advantages of wide-range application,high utilization rate of the stroke,reuse and low cost.Therefore,the open cylinder pneumatic ejection device has good application prospects.In this paper,the scheme of open cylinder pneumatic ejection device is put forward,and the difficulties are studied.(1)Based on engineering thermodynamics and flow equation theory,the interior ballistic model of pneumatic ejection is established and veriflcated by a small cylinder type pneumatic ejection device,which provides a basis for optimization of internal ballistic.The interior ballistic optimization with the goal of the shortest effective ejection travel is established,and the combined optimization algorithm is used to optimize efficiently and accurately,which provides theoretical support for the optimization design of the open cylinder pneumatic ejection device.(2)Based on the surrogate model,the lightweight of the open cylinder ejection device is conducted.The sensitivity of the structure parameters to the device quality is analyzed by multiple regression method.Baesd on multi-island genetic algorithm,the optimization target of lightweight is reached,which is conducive to improve the maneuverability of the ejection device and saving the Production cost.(3)The comprehensive performance of the ejection device is studied.The interior ballistic index is satisfied by only adjusting pneumatic valve on extreme high,low temperature and high altitude environment.The loading method of complex dynamic loads is studied and the Vdload subroutine is writted to establish a more accurate dynamic model of open cylinder ejection device.The design and test of the high-speed buffer part is finished,and the piston assembly can be brake safely.(4)The open cylinder pneumatic ejection experiment system is established and conducted,which shows the feasibility of ejection decive,the high precision of dynamics model and the rationality of buffer part.By measuring the interior ballistic parameters,the datas show that the design indexs of open cylinder pneumatic ejection device are reached.