Research And Simulation On Precision Forging Of Driven Spiral Bevel Gears

Spiral bevel gear has strong bearing capacity and high transmission stability,which can well meet the requirements of high-speed and heavy-duty transmission.It is an important transmission part of the rear axle reducer of the automobile.With the rapid development of automobile industry,the demand for spiral bevel gear is increasing,and the requirements for its performance,life,cost,manufacturing efficiency and other aspects are gradually improved.The traditional gear processing technology has the problems of low production efficiency,damaging the streamline organization of the material,high production cost and low performance.Precision forging technology of spiral bevel gear is an effective way to solve the above problems.Precision forging technology is applied to the forming and manufacturing of large driven spiral bevel gears,which can not only save materials and improve processing efficiency,but also improve the internal microstructure of materials and mechanical properties of gears.It is an advanced technology method for the manufacturing of high-performance spiral bevel gears.However,there are still many problems to be solved in the precision forging process of spiral bevel gears,such as preforming optimization and tooth profile precision control.Therefore,the precision forging process of driven spiral bevel gears is studied to effectively improve the performance,life and manufacturing efficiency of spiral bevel gears.It can enhance the innovation ability and competitiveness of China's auto parts industry and promote the development of China's auto industryIn this study,the precision forging process of automotive rear axle driven spiral bevel gear is studied.Through the method of thermal simulation,theoretical analysis and numerical simulation,the thermal deformation behavior of the material,preforming optimization,material flow law and the inhomogeneous elastic deformation of the die are systematically studied.The precision forging process plan of spiral bevel gears has been optimized in many aspects.The main research work of this paper is as follows:(1)The isothermal hot compression test of 22CrMoH gear steel was carried out by Gleeble-3800 thermal simulation experimental machine.The thermal deformation law of the material was analyzed,and the effects of deformation temperature and strain rate on the flow stress and internal microstructure of the material during the hot compression process were studied.Based on the Arrhenius constitutive equation,the constitutive model and the hot working map of the material were established,which provided a reference for the numerical simulation and the selection of forging process parameters.(2)Optimized the pre-forming process parameters.The precision forging process of driven spiral bevel gear,which includes blanking,upsetting-punching compounding,rolling preforming and final forging,is put forward.A thermodynamic coupling finite element model for radial rolling of ring parts based on radial ring mill was established on the Deform platform,and the distribution and variation of physical field parameters such as deformation velocity,stress and strain,and temperature during the preforming process of gear blank were analyzed.Through theoretical analysis and experimental verification,the influences of feed speed,rotational speed,roll size and other factors on the wide spread phenomenon of ring parts and the fish tail defect were studied.Through orthogonal experiment,the influence laws of the above factors on the wide spread phenomenon and the fish tail defect were studied.(3)The neural network optimization system of gear billet preforming process parameters based on ant colony algorithm was established.Neural network was used to establish a nonlinear model of ring rolling process parameters,width coefficient and fishtail coefficient.Ant colony optimization algorithm was used to search and decide the optimal combination of process parameters.The optimized parameter combination was as follows:When the feed speed is 5 mm/s,the rotation speed is 15.10 rad/s,the driving roller radius is 500 mm,and the core roller radius is 36.75 mm,the comprehensive goal of small width coefficient and moderate fishtail coefficient of the ring can be achieved,and the good forming of the preformed billet can be achieved(4)The final forging process of spiral bevel gear was numerically simulated,and the material flow and filling laws,the distribution and evolution laws of stress and strain field,temperature field and forming load during the forming process were studied.The rationality of the forging technology proposed was analyzed.In order to improve the precision of forging and guide the design and modification of die tooth profile,the die stress during forging and the elastic deformation of die tooth profile were numerically simulated,and the distribution and variation law of die stress and deformation were studied,and the non-uniform elastic deformation law of die tooth profile was obtained.Aiming at the problems of large forming load and complex stress distribution of forgings in the final forging process,a design scheme of preformed billet was proposed.Taking the forming load and equivalent stress of forgings as the optimization objective,a response surface optimization design model of preformed billet was established,and the optimization of preformed billet was realized.