Gear Billet Hot-closed Forging Numerical Simulation Analysis

The technology of closed-die forging on metal plastic forming is complexity. There willproduce all kinds of defects in forming process, which affected the quality of forging, andcaused a lot of materials and energy waste. In the process of forgings, how to control andeliminate the forging defects, improve the quality of forging production, reduce unnecessaryenergy waste, becomes the important research topics in the field of metal plastic formingprocess.Now，gear as an important component about balance drive system，its quality is the mostimportant standard that a reliable transmission system or not. Gear forging stock is the basisstep on the gear forming. With the rapidly development of machinery industry, thetraditional methods of forging gear have been unable to meet the high standard requirement,now in the industry how to improve the traditional production methods is imperative. Hightemperature factors in the process of the metal plastic forming can improve the formingenvironment, but will be accompanied by the damage and oxidation decarburizationphenomenon in the process of heating. The volume of billet can’t accurate in forging process,and prone to forging defects in the process of finish forging, such as insufficient filling andlongitudinal burr problem. According to the above problems, this paper introduceshot-closed die forging process on the gear, the main content is to design the reasonablestructure parameters about peel, effectively to control the metal flow, to lead the excessmetal into the warehouse department, and to realize the precision of stock forming.During forming process, using DEFORM3D forming analysis system softwareanalyzed the whole forging forming process. The study found that when changes thestructure size h, b, r, in the area of the reasonable, each size of gear forging has certaineffects on the shoulder longitudinal burr，Specific as follows：1.Within a reasonable range of h size, the greater the metal flowing into the peel, thesmaller resistance to deformation. At this point, the more excess metal can easily into thepeel warehouse department, rather than out by the closing gaps. Also reduced the mold loadand prolong the service life of the mold.2.Within a reasonable range size b, extended the metal flows into the storehouse ofdistance. As the amount of metal into the peel bridge department increased, the metal inbridge area can contact fully with upper and lower die convex platform, the metal in the bridge department is greater resistance, the metal flow ability is reduced, so as to prevent themetal further into the warehouse, lead to overmuch metal in mold, form longitudinal burrdefects.3.within a reasonable range r size increases, the resistance being changed to smaller inmetal forming process. So metal is easier to change the original flow to continue movement,to achieve better filling, and effectively control the burr.To sum up, in order to control the longitudinal burr defect, peel structure size should bepaid more attention. When choosing the appropriate temperature environment, and under thepremise of the forging shape structure, if three influence parameters about peel structurehave a reasonable configuration, then hot-closed forging process without longitudinal burrdefects is easy to implement.