Research On The Forming Process Method For A Cpmplex Half Tube Part

With the continuous development of aviation industry, catheter as an important component in various kinds of aircrafts is used more and more. Large and complex catheters are used in hydraulic, fuel and oxygen supply systems. As the torsion station of piping system pipe joint is the weakest link, where is prone to burst damage. The Safe hidden trouble can lead to the happening of the accident. So, pipe joint, as important in aircraft structures, the forming quality is very important to ensure the safety of aircraft.In this paper, a certain type aviation complex half tube part was studied. In a half tube forming, on the basis of detailed analysis of the part shape characteristics and forming process, putting forward three kinds of forming methods: half tube stamping, liquid deep drawing and cylinder flanging forming method.For half tube stamping method, the main idea is to increase a clamping piece method to eliminate the wrinkling. Clamping piece should be located in the most easily wrinkled area, punch with clamping piece first clamping part of the sheet wrinkle easily, punch downward again eventually stamping the thickness of homogeneous half tube. In addition, The initial position of clamping piece, the friction coefficient of mould and sheet and punch stamping speed also affect stamping forming quality. Due to the complexity of the half tube part shape, the pressure of the sheet metal is not balanced during the deep drawing, which will lead uneven material flow, the thickness distribution of the forming part is not uniform, and easily to appear at the same time wrinkling and rupture. In this article, under the influence of the blank-holder force and clamping force, which successfully solved the wrinkling and cracking problems, and stamping die structure is designed.For hydroforming, punch port process added surface was studied on the influence of hydroforming, designed the appropriate parabolic punch port process added surface structure. In addition, the process parameters such as the size of the die radius, blank holder force, friction coefficient also have a great influence for the half tube hydroforming. The greater the coefficient of friction, the smaller the die fillet radius and the smaller the blank-holder force, the better the part forming quality. The maximum liquid chamber pressure and liquid chamber pressure loading path are the important factors that influence the forming quality. When the maximum liquid chamber pressure is 17 MPa, the parts forming effect is best. In this paper, several kinds of loading paths are proposed, through the simulation results to select the optimal load curve.For cylinder flanging forming, the process is mainly forming the whole small branch on the mother tube. The factors to consider are: preformed hole size and shape, the structure of punch, punch stamping speed, etc.