As a transmission part, gear has very strict requirements for dimensional accuracy. However, under the forming condition, the die will undergo elastic deformation under the action of forming load, resulting in the change of die surface size, which will affect the accuracy of forgings. In order to ensure that the forgings meet the design dimensional accuracy and mechanical property requirements, the forging quality must be strictly controlled. The accuracy needs to be guaranteed in each production process from the selection of raw materials to post forging heat treatment to ensure the quality and consistency of products. In order to control the machining accuracy, the elastic deformation of the die in the forging process and the deformation caused by heat treatment can be studied and prevented, the elastic deformation law of the die and forging in the forming process can be mastered, and the dimensional accuracy of the forging can be accurately predicted and guaranteed; It can design reasonable forging process and die structure, optimize stress distribution and reduce forming load; In addition, the selection of die materials and equipment should also be considered.
Doege simulated the forging process of spur bevel gear, and extracted the axial and radial shrinkage data of forging tooth profile in the cooling process after forging. Yan changzuo% analyzed and pointed out that the heat treatment deformation of driven bevel gear mainly includes carburizing deformation and quenching deformation, in which quenching deformation is the main one, and put forward the method of reducing quenching deformation by isothermal step quenching. Wang Huosheng et al. Numerically simulated the quenching deformation of spiral bevel gear in the computational fluid dynamics software FLOW3D, measured the heat treatment deformation with the help of reverse engineering and digital analog comparison technology, and summarized the law of gear tooth deformation. Based on the elastic and rigid plastic finite element theory, an Hongping et al. Proposed a general and effective algorithm to calculate the elastic deformation of die, and developed the corresponding calculation module.
Hu Chengliang and others created an elastic-plastic elastic three-dimensional coupling model, synchronously calculated the elastic-plastic deformation of gear blank and the elastic deformation of die, and summarized the elastic expansion law of die cavity and the elastic recovery law of workpiece. Liu Li and others introduced the die cavity size compensation method for the die forging process of crankshaft parts. Luo Jing et al. M analyzed and optimized the forming process according to the structural characteristics of motorcycle gear, obtained reasonable product refined blank, draft angle and other parameters, and determined the preform size.