Development Of Special Spot Welding Device For 5 M Class Tank Of Launch Vehicle

At present,China’s aerospace industry is in a period of rapid development.A new generation of launch vehicles has been developed,and the diameter of the core launch vehicle has increased from 3.35 m to 5 M,which poses many technical difficulties.In particular,in the spot welding process of the large diameter aluminum alloy workpiece of the arrow body,the active spot welding device can no longer meet the process requirements,and at the same time it faces strict confidentiality and restrictions on foreign military technology.The design and manufacture of spot welding device suitable for the bottom of large diameter tank and the tube section has become one of the bottlenecks in the development of the aerospace manufacturing industry in China.Therefore,a special non-standard bottom and tube spot welding device is designed,and several structural parts are welded on the inner wall and bottom of the tank to meet the requirements of arrow-body spot welding technology.The research and development of this spot welding device has very important theoretical and practical significance for the manufacture and assembly of 5m carrier rocket tanks and the development of domestic spot welding technology.Based on a thorough study of the special spot welding equipment at the bottom of the 3.35 M box body of an active launch vehicle,this paper analyzes the structure parameters and process characteristics of the bottom of the tank and the barrel of the 5M carrier rocket,according to the technical requirements of the new spot welding device.The overall design scheme of the spot welding device is determined.In the scheme,the forward / backward,azimuth / pitch,ascending / descending movements of the welded workpiece are realized mainly through the azimuth axis system,pitch axis system,vertical and horizontal lifting system and clamping mechanism.The connection between the two welding guns of the spot welding machine is always in the direction of the normal shape of the outer wall of the workpiece through the linkage of each axis,and the technical requirements for welding the workpiece at a dead angle of 360 ° are reached.In this paper,the load torque of each transmission system is calculated under the maximum load,and the output power and torque of the required motor are obtained,and the type and specific model are determined.By selecting a reasonable structure of telescopic arm,bent arm,and inner support component,the support stiffness of the spot welding device is improved,and the detailed structural design of the pitch push rod,telescopic push rod,and azimuth axis is carried out.The finite element software is used to simulate and analyze the stress and deformation of the above parts under different working conditions.The simulation results prove that the above parts meet the design requirements.Finally,according to the design parameters and inspection standards of the spot welding device,the actual measurement of the spot welding device is carried out.By comparing the actual measured data with the design parameters,it is proved that the design of the 5M launch vehicle bottom and barrel spot welding device is reasonable and feasible,and fully meets the requirements of the design parameters.