Research On The Key Technique Of Rapid Manufacture For Rough Moulds Cavity Based On Group-Welding

Rapidly manufacture technologies for large-scaled moulds are bottlenecks to the development of new models of cars, and more attention is paid to this subject in recent years. In this dissertation, a group-welding based rapidly manufacture system for moulds cavity is proposed, which is featured with screw mandrils and discrete configuration. The key techniques for this manufacture system are also discussed.By uses of this system, rough moulds are produced as follows without traditional casting: forming heated thick steel plate into mould cavity by the Discrete Cavity Mould (DCM), then welding the formed mould cavity onto mould bracket. DCM is a key equipment in this manufacture system, which is used to the forming of rough mould cavity. DCM consists of a base and mandrils mounted on the base closely and evenly, and DCM includes die DCM and punch DCM. The cavity of DCM is changed when adjusting the height of screw mandrils.Calculating and adjusting the height of screw mandrils are necessary to practice this technique. The object of this dissertation is to calculate the height of screw mandrils from CAD data and develop a mechanical hand to adjust screw mandrils' height automatically.A method based on discrete sphere center surface is proposed to calculate screw mandrils' height, when compared to analytical equation, there is no need the searching for contact points between screw mandrils and plate to be formed, and this method is more concise and general. A mechanical hand with four adjusting heads mounted on it has been designed, which performs the adjusting process precisely and quickly. Forming experiments prove the practicability and advantage of this technology.