Research On The Theory And Process Of Spinning/Rolling Mechanical Forming Of Medium-caliber Metal Corrugated Hose

Metal bellows is a kind of cylindrical thin-walled elastic shell with transverse ripple,which has good bending characteristics,and has been widely used in petrochemical,automobile,steel,refrigeration and temperature control,aerospace and other related industries.According to the production and manufacture of metal corrugated with different diameter and length,there are mainly hydraulic bulging,mechanical bulging,rubber bulging and mechanical forming.Among them,spinning / rolling continuous mechanical forming technology has attracted the attention of scholars at home and abroad because of its advantages of high molding efficiency,good quality and large length.However,it is not possible to realize continuous forming of high quality bellows with diameter greater than20 mm in China.The relevant forming equipment and mould of small diameter bellows are mainly imported,and the technology theory is not yet mastered.In order to realize the independent spinning / rolling forming technology of corrugated pipe with medium diameter and above,it is urgent to find out the influence rule of equipment structure,mold and forming process parameters on the forming process of bellows.Therefore,the following research work is carried out by combining theoretical analysis,numerical simulation and experiment.Firstly,based on the production line of bellows in a domestic factory,the process flow,forming principle and the evolution law of corrugated pipe wall thickness are analyzed.The relationship between mold parameters and the stress of bellows is established.Then,based on ABAQUS finite element software,the finite element analysis model of spinning and rolling independent forming process is established to reproduce the actual forming process.The influence of die size parameters,forming process parameters and tube blank structure parameters on the wall thickness,springback and stress change of bellows after forming are analyzed,and the optimal dimension parameters of the die are explored.Then,the finite element model of combined spinning / rolling forming is established,which can simulate and verify the feasibility of three times spinning and one roll forming,optimize the process parameters and matching relationship of each pass,and analyze the mutual influence and genetic characteristics of tube blank in each pass molding process,and provide the expected guidance for the quality change of the medium diameter corrugated pipe after forming.Finally,on the basis of the above research,the spinning forming experimental device is designed and verified by comparing the experimental results with the finite element simulation.The research content can provide technical support for the design of the forming die and equipment,forming process analysis,and the matching relationship of the passes.