Research On High Pressure Hot Gas Forming Process And Equipment Design Of Alloy Tube Based On Gasoline Combustion

In recent years,with the increasingly prominent problems of air pollution and energy shortage,people are demanding more and more about energy conservation and environmental protection.Thus,the lightweight has become one of the important research directions in the fields of automobile and aerospace.The high pressure hot gas forming parts usually have hollow structure,variable cross section and closed section instead of solid structure,equal section and welding section respectively.It can not only greatly reduce the weight,but also increase the stiffness and fatigue strength of the parts.It is widely used in lightweight design to save fuels,reduce exhaust emission and improve overall safety performance.Aiming at the problems for the high pressure hot gas forming process,such as high pressure requirement,complex structure of forming equipment and high input cost,a new method of high pressure hot gas forming for tubes was proposed.Then,the equipment about the new forming method was designed and the process test was conducted.The main research contents are as follows:(1)A new high pressure hot gas forming method based on gasoline combustion for tubes was proposed.It can not only slow down the reduction of temperature,but also reduce the internal pressure and load required for forming.Besides,the forming process does not require the ultra-high pressure device,and it has the characteristics of simple structure and low input cost.(2)Aiming at the new high pressure hot gas forming method,a set of test equipments were designed.The structure of the equipment mainly includes forming mold,seal and axial feeding device,gas supply system,gasoline supply system and pulse ignition system.And then,the design of main parts and the selection of standard parts were carried out.(3)In the structural design of the main parts,the structure of the seal punch was optimized.A new seal punch with elastic structure was designed,which combined with the advantages of cone table seal and ring tip edge seal.And on the basis of this,an elastic feeding mechanism was designed.It can ensure the static sealing effect and improve the dynamic sealing quality of the tubes in the forming process.(4)There were some work about processing,assembling and debugging for the designed forming equipment.And the forming equipment can meet the expected design requirements to achieve a series of actions,such as mold closing,sealing,gasoline injection,gas supply,ignition and so on.(5)Finally,the process test was conducted with the debugged test equipment.Under the condition of 0.7MPa air pressure in the laboratory,the forming parts were obtained by using the designed forming method and equipment.The maximum section diameter of the part was 48.62 mm,and the bulging rate was 1.29%.The results show that it is feasible to use the new forming method and equipment for high pressure hot gas forming of tubes.