Study Of High-Speed Precise Forming With Cold Roll-Beating Technique

High-speed precise cold roll-beating technique is the net forming processing method that the characteristic of metal plastic forming is used, top revolving roller is applied to roll and beat blank shaft, then force metal to flow and form component profile. Cold roll-beating forming technique of involute spline is non-scrap and complex plastic forming technique, whose basic principle is that rollers beat spline shaft rapidly with simple points in order to make partial plastic deformation of spline shaft and form involute spline when the motion of rollers and spline shaft conforms to certain specification. Cold roll-beating forming process of involute spline is studied in this thesis, and some common key technology of high-speed precise cold roll-beating is revealed. Consequently, a non-cutting, high-efficiency, high-quality manufacturing technique comes into being.Based on in-depth analysis of basic principle of involute spline cold roll-beating technique, the cold roll-beating process of involute spline is analyzed, using the method of combining theoretical analysis and experiments, which focus on cold roll-beating motion system and mathematical model of involute spline, the dynamic response and stress wave of the process of involute spline cold roll-beating. Metal flowing and deforming mechanism during the process of involute spline cold roll-beating is revealed. On the basis of analyzing the design and manufacturing technology of rolling wheel, the CAD system of rolling wheel and the simulation system of roller grinding are developed. The study results are tested and validated.The principle and motion relation of involute spline cold roll-beating is analyzed deeply, and the transmission equations between rolling roller and workpiece are set up, when continuously indexing cold roll-beating of involute spline. The method of adjusting stagger angle and relating equation of rollers are put forward, and the analytic model of stagger angle is built, thereby the unavoidable interference of cold roll-beating process is solved when indexing spline continuously. The effect of spline precision by stagger angle is discussed, and an optimizing selection method of stagger angle is put forward.Coordinate system of involute spline cold roll-beating continuously is established. Based on the theory of space engagement, motion model of continously indexing cold roll-beating is built, and an analytic method of cold roll-beating involute spline tooth profile error is put forward, spline forming principle is analyzed from the aspect of motion relation, engagement principle, tooth profile forming motion, and engagement function. It reveals that the forming method of involute spline cold roll-beating is generation method. Based on the analysis of forming principle of involute spline, the mathematical model of roller designing is built.3D solid model of involute spline cold roll-beating motion system is built. Based on the stress wave theory, stress wave model and its transfer rule of spline cold roll-beating is built, the speed of stress wave is calculated, and the effect mechanism of spline cold roll-beating by stress wave is revealed through simulation. Based on the dynamic response theory of elastic-plastic linear hardening system, the system dynamic response mathematic model of elastic-plastic linear hardening is built, dynamic response during involute spline cold roll-beating is analyzed using the model, and the stress response change and deformation is analyzed at the condition of different cold roll-beating speed and different strain rate.The large deformation dynamic constitutive model of spline cold roll-beating is built. Through the finite element method and the effect of spline cold roll-beating forming by spline forming process, stress distribution at different moments, stress change process with time, strain distribution at different moments, plastic strain change process with time, profile error, forming size, elastic deformation and friction. The forming mechanism of involute spline cold roll-beating is revealed. The experimental results testify the validity of the analysis model and method.The design and manufacturing of rollers is studied. The design principle, the elastic modification of mathematical model, the optimization of material and the heat treatment for rollers are analyzed. The CAD and grinding simulation algorithm of roller are put forward. The whole frame of involute spline roller CAD system is built, involute spline roller CAD system is developed, and the parameterization of roller design is realized. The equations of grinding wheel profile and its center motion track of grinding roller are built, and the grinding simulation system of involute spline roller is developed, which can solve the problem that involute spline roller is difficult to grind because of its complex profile and high precision. Application indicates that the design and manufacturing of roller are correct.