| Electron beam welding technology is becoming more and more important in aviation industry,military,national defense and other fields,especially high-pressure level of electron beam welding,welding large thickness,large volume workpieces,with very excellent welding performance.However,due to the fixed welding gun structure in the high-voltage electron beam welder,there are problems such as limited welding length and insufficient utilization of welding space,which can not meet the welding requirements of large volume and deep long weld workpieces.Therefore,this paper proposes to design a high-voltage electron beam welding machine outdoor gun structure,the structure can be in the vacuum chamber volume unchanged premise,increase the length of the workpiece welding,but also in the large volume of workpiece welding,through the movement of the electronic gun to complete welding,increase the processing range of the welding machine,improve the utilization rate of vacuum welding space.In this thesis,the outdoor gun structure and sealing design of the high-voltage electron beam welder are completed,the structural parameters of the vacuum chamber wall thickness and reinforced ribs of the welding machine are calculated,and the change law of deformation,modality and bending of the vacuum chamber under the effect of load is obtained by finite element analysis method.The calculation and analysis show that under the vacuum pressure 0.1MPa,the maximum deformation of the vacuum chamber when the welder is running is 0.7mm,the maximum iso-effect force is 102.9MPa,the first-order natural frequency 86.774 Hz and the first-order critical unstable external pressure 115.05 MPa,indicating that the vacuum chamber is designed to meet the stability and reliability requirements.In addition,three rubber materials,butyl rubber,polyurethane and fluoride elastomer,were selected for stretching test,and the second-order material constants C10 and C01 of the MooneyRivlin model of the above three materials were obtained.Based on elastic mechanics theory and Archard friction wear principle,a mathematical model of seal contact pressure and wear life is established.The results show that the predicted working life of the sealing structure of the outdoor gun is 42 days,which meets the requirements of use.The outdoor gun seal structure of the high-voltage electron beam welder is simulated and analyzed.In the static sealing state,the effects of the compression volume,material and wear ring thickness of the O-type sealing ring on the sealing structure sealing performance were studied by using finite element analysis methods,and the contact pressure and Miss stress distribution on the main seal contact surface were obtained,and the static sealing performance of the outdoor gun seal structure under different operating conditions was discussed,which laid a theoretical foundation for the design of the seal structure.On the basis of static simulation,a dynamic simulation model of sealing structure is constructed,which analyzes the contact pressure and Misses stress distribution of such factors as the velocity of the gun’s reciprocating movement,discusses the dynamic sealing performance of the outdoor gun seal structure under different operating conditions,and provides a reference for the optimization of the sealing structure and the selection of operating conditions.An experimental platform for proportional sealing,such as outdoor moving guns,was set up,and the sealing performance of the sealing structure was carried out under static and dynamic conditions respectively,and the vacuum degree changed with time.Experiments show that the vacuum degree in the vacuum cavity is 9.9×10-3Pa at 3355 s under static conditions,and the vacuum degree× remains basically stable with the change of time;The sealing structure is designed to meet the outdoor gun sealing requirements of high-voltage electron beam welders. |
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