Design and Key Process Simulation of a New Type of Pipe Bending Unit

The pipe bending mechanism was analysed and a new unit was designed to solve problems of low efficiency and high incidence of defects in large-diameter products. Subsequently, the workflow of the unit was formed, and the finite element model of elbow formation was established. A pipe with D = 60.3 mm and t = 3.05 mm was used as an example to simulate the effects of key parameters on the forming quality and determine the optimization parameters. Results show that as clearance increases within in a small range, the flowability of the pipe and the forming quality of the elbow improve. As the surface friction and push-bending speed increase, the quality gradually deteriorates and more defects appear. The mandrel helps enhance the forming quality of the elbow. The wall is thinner in the extrados near the push head but thicker in the intrados near the push head. The obtained conclusions provide a basis for establishing a quantitative relationship between the process parameters of bending machines and forming quality and the comprehensive optimization of the bending machine process.