Research Of A Bend Forming Technology For A Fuel Inlet Tube Of An Aero-engine

Tube is an important part of the aero-engine,and the assembly parts are distributed inside and outside the engine.The tube is in a harsh environment when the aircraft engine is working.The tubes in the combustion chamber must withstand high temperatures of nearly 1,000 degrees,some external tubes must withstand an internal pressure of up to 30 MPa.There are as many as two hundred tubes assembled in an aero-engine.Due to the position of the external accessories of the engine,some tubes have complicated shapes.In order to ensure the performance of aero-engines,the manufacture of tubes must have a high accuracy of shape and position tolerance and forming quality.In this thesis,taking the intake pipe of the afterburner fuel manifold in an aeroengine as an example,the research on the bending process of the tube is carried out.First,the professional metal sheet forming finite element simulation analysis software PAM-STAMP is used to perform numerical simulation analysis on its bending forming process,and the forming process is determined according to the analysis results.Secondly,design and manufacture the special-shaped mold for special tube bending,and optimize the structure of the molds.Finally,the process parameters are optimized by studying the spring back after bending and its compensation,a set of effective process plan is worked out.The main contents are as follows:(1)Build a finite element model of bending pipe that conforms to the processing conditions,and use the finite element software PAM-STAMP to compare and analyze the compression bending method and the traction rotary bending method to select the optimal forming method.(2)According to the characteristics of the forming process of this type of catheter,formulate the corresponding forming mold and optimize the mold design.To shorten the preparation time before the treatment,use UG GRIP secondary development language to complete parametric modeling of the mold.(3)Use the combination of finite element simulation analysis and experiment to obtain the results,such as roundness,wall thickness reduction,stress distribution status after forming.Use these results to predict the rebound situation and find the relationship between the rebound angle and the bending center angle by third-order polynomial fitting.(4)According to the post-processing results of finite element simulation analysis,process parameters are formulated.Through the process trial production,the feasibility of the process plan is verified,and the process specification for batch production is finally formed.Process trial showed that the conduit forming process has studied forming accuracy and the good surface quality of the tube,high yield,etc.,of the engine to meet the production requirements.