Research On Key Technologies Of Warm Forging For Spur Gear

Gears are applied in the automobile and other mechanical industries widely as parts to transfer movement and power, it will produce large economic efficiency to gear manufacturing industry that improving the processing technology of gear, because it is huge in quantity and application. The process of precision forging have its advantages of giving greater utilization of raw material, improved strength and surface finish and other virtues than traditional cutting. Warm precision forging is developed on the basis of cold precision forging, which have the advantages and avoid of the drawbacks that belong to cold precision forging and hot precision forging. So it is gaining recognition gradually that warm precision forging is applied to form gear recent years, and getting rapid development. Therefore, it is important significant to study the technology of warm precision forging of gears.Put forward a structure of floating position to the hole of blank, which combine of the principle of hole divided flow of mandrel constraint and the technology of floating-die, integrated a kind of mould structure for warm precision forging of spur gear together; Generalized a calculating formula for the volume of spur gear utilizing the CAD technology for the first time, and contrast the result of adopting Pro/E to calculate the volume of spur gear, enhance the calculation accuracy of blanks volume in the warm precision forging of gear; Adopted 3D finite element simulation software DEFORM-3D, the numerical analysis was employed to examine the warm precision forging process in spur gears in view of different blanks that possess different dimensions. The effective stress distribution, the effective strain distribution, the load curve of the whole process and the diagram of bottom die's radial force were got through the analysis. At last, utilized the module of die stress analysis of software DEFORM-3D, calculated stress of the floating die in the process of warm precision forging.The structure of floating position to the hole of blank that were provided in this paper, which can locate the blanks use it's center bore, so that unbalance loading of forming force and the unsimultaneous forming of gear teeth can be avoided, in this way, the warm precision forging can be achieved smoothly; The result of numerical analysis show that the corner of gear was filled fully and registered gear can be obtained; In the process of gear's warm forging, the working condition of bottom die is very poor, which show hearing high contact pressure and fierce attrition, cyclical variation of stress, strain and temperature that induced by repeated loading, all condition that induce large influence to the life of die. From the result of stress simulation for bottom die, we can get the conclusion that the stress of mould cavity that form gear teeth top is the maximal radial force, secondly, is the mould cavity that form involute and gear root. In order to research the influence that blanks that possess different dimensions will produce the different radial force of bottom die in the process. Taken a specific gear for example, sixteen numerical analysises of warm precision forging were performed in view of sixteen kinds of programs, from the diagram of bottom die's radial force, contrasted analysis the different dimensions of gear blanks that cause different bottom die's radial force, got the best dimensions of blank. Above works provide some theory basis for the bottom die's designing in the warm precision forging of spur gear, and have certain referential value.