Study On Tooth Profile Precision Forging Technology Of Spiral Bevel Gear

The spiral bevel gear is named for the curve of the tooth surface,which has the advantages of the local instantaneous point contact,the high degree of meshing coincidence and the steady transmission.The traditional processing method of spiral bevel gear is gear milling,processing efficiency is low,serious waste of materials,and the precision forging process for the development of efficient,green,lightweight design,is of great significance to solve the problem of quality and cost control in the process of mass production.Based on the net cold extrusion forming process of spiral bevel gear tooth surface,research content as follows:1 According to the local conjugate principle,tooth contact simulation and pre control technology,ensure the tooth surface meshing gear pair with nice performance,get a set of gear and pinion's tooth surface data size,construct the tooth patch.Then get the blank model by the basic geometric parameters,and obtained the gear model by the difference command in the software modeling environment,on this account,to establish the mold model.Reasonable pre forging die with gear tooth surface modification will directly affect the tooth surface of cold extrusion forging precision.By changing the diameter of the gear milling cutter disc,on the premise of guarantee the constant of the geometric parameters,the change of tooth surface gear long radius of curvature,thus can get a set of pre forging drum cavity die,in preparation for the finite element method to simulate the forming process.2 This paper intends to adopt a combination of processing: The tooth surface of spiral bevel gear is formed by hot forging pre forming and cold extrusion forming two times,the tooth surface of the pinion generating method using conventional paired milling forming process.According to the particularity of spiral bevel gear structure,the feasible scheme is discussed,mainly for filling and forming of metal material after the smooth mold research.Based on the principle of closed die forging,the shape and volume of the blank and the structure of the die are optimized.3 The simulation analysis of the cold forging process of spiral bevel gears by DEFORM-3D software.In this paper,the simulation environment,material properties and kinematic relations are set up,and the feasibility of the model and the interference points are analyzed under the condition that the tooth surface is in the form of rebound deformation.On the basis of ensuring that the surface of the metal is filled with the mold cavity,through the modification of the pre forging tooth surface,the direction of the metal streamline is changed,the cold extrusion pressure is reduced,and the smoothness of the tooth surface is improved.4 The forming process and die modification scheme are verified by the actual hot forging forming process,Discusses the modification of hot forging die cavity,change of metal flow,to solve the superiority of spiral bevel gear tooth surface precision cold extrusion forming of the net.According to the structural characteristics of the concave die,the paper puts forward the technological scheme of the tooth root fillet modification.By getting the sample appearance and accuracy of detection results can be seen,forging gear full,accurate shape,good surface smoothness,without obvious defects.In this paper,the theoretical research and experimental research are carried out on the cold extrusion forming process of the spiral bevel gear.The research of this paper lays the foundation for the theory and practice of the spiral bevel gear.