Theoretical Research On Process Of Spline Cold Rolling

With the rapid growth in synthetic national-power of China, a speedily development phase with mechanical manufacturing has arrived. The quantity- demanded of high-strength and high-precision shaft-part is gradually increasing in aviation, astronavigation and mechanical industry. Because there are many advantages such as high productivity, good continuity of metal wool in tooth face, high strength and better wear resisting property of tooth face, the non-cutting forming technology by cold rolling is more and more regarded and widely used in production of high-strength and high-precision spline. The denformation mechanism of spline cold rolling is complexity. So the research of the theory and mechanics analysis on process of spline cold rolling is few in the world. The existing forming technology and the production often depend on experience. The systemic theory instructing the production is lack.The processing mechanics of spline cold rolling is analyzed. The slip-line field of plastically deforming area in process of spline cold rolling is founded combined with the methods of the analysis-inference and the graphics. Different friction-conditions are used in different contact areas in order to realistically reflect the factual situation. The unit pressure on contact surface of the rolling process was solved according to the stress filed theory of the slip-line. According to theory of the conjugate curves and the envelope curve, the mathematic model of roller-tooth-curve and workpiece-tooth-curve was established. And according to the mathematic models, the calculation-program of entire contact area in rolling process is compiled.Based on the solving of unit pressure and contact area, the calculation-program of rolling-force and rolling-moment is compiled. The influencing causes of module, pressure angle, decrement, number of roller teeth and workpiece have been studied, and the rolling parameters may be obtained. The mathematic models have been simplified and the instructing formulae of rolling-force and rolling-moment are established.The model of finite element is setted up. Forming process of spline cold rolling is simulated by DEFORM. The theoretical results of unit pressure are consistent with the finite element analysis. The theoretical result of rolling-force which is calculated by modified model that considered successor yield is consistent with the result of numerical simulation, and the error percentage is less than 1.5%.In this paper, the elementary theory is established. The result of research provides the theory-basis for developing the special cold rolling machine in spline and industrial process. It is significant to use and to improve the new technology of the cold rolling and it is also significant to research and to develop the equipments of the cold rolling.