Research On The Accurate Rolling Round Process Of Four Roller

Four-roller plate bending machine is widely used because of its multifuntional and automatic properties. With the development of economy of our society, products of manufacture industry has been required for higher precision and efficiency. However, in order to get good formed parts, workers just rely on their working experience to operate the plate bending machine now, resulting in low production efficiency. Therefore it is of great importance to study on the technology of the four-roller bending machine.Engineers from home and abroad research more on the design and craft of three-roller plate roll than on the theory of technology of four roller coiler and two rollers plate bending roll, besides, they often adopt the method of analyzng geometrical relationship of plate and working rollers and determine the bending radius before springback with the empirical formula. Well, rolling round technological process has already been obtained during the daily producing.In this paper, concrete content of round-rolling is studied based on the technological process. According to the theory of elastic and plastic forming of metal, the two main forming steps, prebending and rolling, are established after the proposing of the fixed end hypothesis assumption, the springback theory of small curvature plane bending which is propounded by our team is employed to calculate the springback of pipes, by these means,the relationships of the bending roller’s location and the pipes’ radius get acquired. Due to the similarity of working conditions of four-roller plate bending machine and the asymmetrical three roller plate roll, the latter machine’s position amendment way has been adopted to compensate the former’s. The Visual C++ programming calculation is introduced to calculate the established prebending and rolling theory, with the known material, device, craft, pipe parameters, the roller’s forming location and force will be received. The large scale nonlinear finite element software ABAQUS is used to simulate the rolling round process and analyze the forming modeling, the simulation results of theorical and simulational bending radius, deflections, forming forces are contrasted to verify the correction of the established theories and offer the amendment equation. In theend, a testing device is designed for the theory’s physicial verification, and the experimental consequences are studied, the value of the theories’ applyment has been proved through the approaches of numerical simulation and experiment.The achievements of this paper are able to provide theoretic craft parameters and technical support for the industries which use four roller coilers to fabricate pipes, predict the power of the bending device, improve the qualities and precisions of the formed parts and the producing efficiency, reduce the production cycle, and lighten the work strength of the operators.