Study On The Influence Factors Of Hydroforming Of 5A02 Aluminum Alloy Reducer Tee

In recent years,a great deal of researches have been done on the development of hydroforming process and its technology at home and abroad,and in the field of aviation and automobile,reducer tee is widely used.In this paper,through the analysis of forming theory and influencing factors,using the method of combining experiment and simulation to study and optimize a 5A02 aluminum alloy reducer tee(OD=45 mm,ID=42 mm,BD= 28mm).A new type of pipe cutting method is proposed to reduce the thickening of the thickness of the wall.The contents of the study are as follows:First,the forming principle and process of reducer tee were briefly introduced,and its failure form was described.Several typical influencing factors of the reducer tee hydroforming were curt introduced,and the forming expert control system and material database were establish by the C++ language.Secondly,the 1/4 finite element model of the reducer tee was established.Then the stress and thickness difference of equal and different diameter T-shaped tube during the hydroforming process were compared,and the influence factors the feed speed,the transition fillet and the friction coefficient in the hydroforming process,which contained were simulated and analyzed.The optimum forming process parameters were obtained.When the feeding speed was 1500mm/s,the transition fillet was 4mm and the friction coefficient was 0.06,the internal pressure and feed were matched with each other,it was easiest to simulate the forming of parts that meet the requirements.Thirdly,the forming equipment and die were introduced,as well as the pre-preparation of experimental forming.Through the comparison of the equal and different diameter forming,it was found that the thickening of the wall of the reducer tee is more obvious.Then the loading path of the forming part and the transition angle are analyzed.The whole lubrication of PE film would lead to wrinkling of the forming parts.However,the local friction control principle could effectively control the wrinkling phenomenon,and the wrinkling phenomenon appeared easily in the contact parts between the mixed lubricant parts and the punch head.At last,aiming at the uneven wall thickness of the original flat blanking method on the reducer tee(OD=45mm,BD=28mm)hydroforming,the shape of the original tube embryo of the formed part was obtained by dividing the model of the forming part with 1.5 mm wall thickness,The cutting angle is 49.768°.A new method of cutting material for pipe material was put forward to used-inclined angle cutting.According to the degree of actual tube embryo cutting,simulate three type of the tube blanking mode,the inclined angle was 30°,45°and 60°,respectively.And analyze the wall thickness of different parts under different angles,get the best blanking way for 45°cutting,its forming effect is the best,the thickness uniformity also is the best,and the thickness of the wall thickness of the straight tube is not quite different from the original wall thickness.The design of new forming die,improved the push,used the O-type sealing ring,the original material and new materials of wall thickness are compared,which is more easily to get the thickness of the thickness of the forming of the forming parts.Finally,it is proved that the new type of tube inclined angle down material under 45° can effectively control the wall thickness of 45mm×28mm reducer tee.