Key Technologies In Hot Forging And Cold Extrusion Of Slot Claw Pole For Hybrid Excitation Generator

With the continuous improvement of power consumption and energy conservation emission reduction requirements in car,high-output,efficient,small-size and light-weight hybrid excitation generators are the focus of R&D in the industry.Fortunately,it can be solved by installing permanent magnets on the claw poles instead of increasing the volume and weight of the winding coils before.However,the conventional claw pole structure has the disadvantages of unstable installing position for permanent magnets.There is even no position to reference.So,the development of slotted claw poles,which are key components of hybrid excitation generators,has become an imperative for the industrialization of hybrid excitation generators.The existing slot claw slot machining uses four-axis milling machine and special milling cutter.This process has the outstanding problem of expensive and easily worn and easily damaged milling cutter,low processing efficiency,large equipment investment and high production cost.Therefore,the purpose of this paper is to develop a technology to replace the milling of slot-type claw hot-pole forging and cold extrusion forming parts to achieve low-cost,high-efficiency high-volume industrial production goal.Because of the complex size in slotted claw slot,there are many problems in the cold extrusion process,such as inhomogeneous metal flow,die cracking,difficulty in filling the slot size,etc.Precise shape and size of the hot forged billet is firstly required.While in hot forging,there are also many key problems,such as high temperature flow,thermal multi-field coupling,high-temperature friction and wear and low life for dies.Based on the above problems,this paper systematically focuses on the key theory and technical issues of slot claw electrode material,such as high temperature deformation behavior of material,numerical simulation of hot forging and cold extrusion,preforming process's optimization and die life prediction,to provide a new set of slotted claws for hot forging-cold extrusion technology.The main workandthe results obtained in this dissertation are as follows:?1?Research on the high-temperature deformation behavior and constitutive equation of QD08 steel with Gleeble thermal simulation tester.Temperatures were set at 1000?,1100?,1150?,and 1200?;strain rates were set at0.1 s^-1,1 s^-1,5 s^-1,and 10 s^-1.Based on the high-temperature deformation behavior and constitutive equations,the thermal processing map of QD08steel was established.The microstructure evolution was also observed.?2?Constructing the mathematical model of slot hot claw forging homogeneity based on high temperature deformation behavior of QD08 steel.Based on the rigid-plastic thermo-mechanical coupling finite element method and the high-temperature constitutive equation of QD08 steel,the distribution law of material flow and the influencing factors of forming defects in forging process were studied.The die's structure was optimized.?3?Establishing a modified particle swarm optimization algorithm IPSO?Supported Particle Optimized Aotn,IPSO?supporting vector machine SVM hot forging and cold extrusion preform optimization model.By analyzing the stress-strain distribution,material flow law and forming load in the process of hot forging and cold extrusion of slotted claws,a machine learning method based on SVM was proposed to construct the corresponding process of hot forging and cold extrusion slot.The multiple nonlinear regression function model between the parameters?such as cold extrusion with groove fillet,claw height,groove inside,jaw width,and groove height?and the objective function?coupled with mass,force and load?was proposed.By optimizing the kernel function parameters of SVM with particle swarm optimization algorithm,the quantitative relationship between the process parameters and the target parameters was obtained.It can be used to optimize the size of the hot-forging and cold-extruded preforms for slotted jaws,form a new and practical hot-forging and cold-extrusion process,laying the foundation for the optimization of volume forming preforming technology and its engineering application.?4?Reaearch on the high temperature friction and wear test of H13 die steel,modified Archard wear model and life prediction of hot forging and cold extrusion die.The friction and wear properties of H13 steel were studied at room temperature,200?,350?,500?,and 650?;Load was set to 50 N,100N,150 N;Speed was at 1 m/s.Combining with finite element technology,the numerical simulation of the wear of the slotted hot-forging and cold-extrusion die was carried out.Based on the forming cycles,the wear life's prediction model of dies was obtained.The expected results have been successfully applied to the new process of slotted jaw hot-hot forging and extrusion,which will significantly reduce the production cost and greatly increase the economic benefits.The forging-cold extrusion theory and technology for a new way for the large-volume,low-cost manufacturing of hybrid excitation generator slot claws,which also provide theoretical basis and technical support for volume forming preform optimization and die life prediction.