Study On Precision Forging Of Vehicle Differential Gear

Die forging gear technology has advantages of high frequency, high materialutilization and good forgings performance. The differential gears were mainlymanufactured by die forging process. At present, the short service life of the planetarygear forging die and the low precision of forgings can not meet the requirements ofrapid industrial development. In order to improve the service life of the gear forging dieand forging precision, the early failure forms and causes of planetary gear mold, theproject design of new die forging, and the structure design of precision forging die werestudied.First of all, the mold failure was analyzed. According to the working process andstructure characteristics of planetary gear, the early failure forms of mold were analyzed.Using the principal stress method, the forging deformation force were solved andanalyzed. The analysis of two aspects was that the main reason to cause the plasticdeformation of mold and severe wear of guiding device is that the inaccuratepositioning of roughcast, the main reason for fatigue failure of tooth shape mouldsurface is that the contact time of tooth shape mould and hot blank is too long.Secondly, the new scheme of planetary gear forging was put forward. The model ofmould parts were built by UG software. The simulation of the design scheme was putforword by DEFORM-3D. The forming speed was optimized with the analysis ofvelocity field, temperature field, strain field, stress field and the load-stroke curve.Determine the new die forging scheme of planetary gear precision forging forming isfeasible. The rough forging die and forging die structure of planetary gear were putforward.Finally, the process test was studied. The results show that the precision ofplanetary gear, which forged by the new die forging structure, is high, tooth shaped full,the metal transition of the small corner is smooth, and the mold run well. The blankpositioning inaccuracy and the early plastic deformation and wear of the original moldwere solved successfully.