Numerical Simulation and Analysis of Forging Process for Automotive Starter Motor Ring Gear
DEFORM-3D software is a powerful simulation tool that uses the Finite Element Method to analyze the three dimensional complex forging process, It provides a virtual testing environment in which engineers can study the influence of geometric parameters, process parameters and other factors on forging process performance. This paper aims at the forging process of automotive starter motor ring gear, and suitable technology parameters have been determined, which is combined with the numerical simulation by FEM method. The variation of metal flow, stress and strain were obtained. And an experiment was employed to prove that he simulation result and the experimental result tallies well. This research plays a guiding role on the optimal design of the forging processes and dies structure for similar parts.
A Study on the Extrusion by a two-step process for manufacturing helical gear
Much research has been carried out in the manufacturing of helical gears by cold forging or by extrusion. Although cold forging is applied to some bevel, spur, and helical gears, problems in connection with the reduction forming load and tool life still make it difficult for these methods to be commercialized. In this study, focusing on reducing a load in forming helical gears, the extrusion of helical gears by two-step process is proposed. This process is composed primarily of extruding a billet to a spur gear and then twisting the previous spur gear extruded to a helical gear. Cylindrical billets of Cr-Mo steel(SCM 415) and aluminium alloy(Al60 series) were used as specimen materials for the experiments. The maximum loads obtained by upper-bound analysis and FEM are compared with the results of experiments. The loads of the analysis have good agreements with those of the experiment. The newly proposed method can be used as an advanced technique that remarkably reduces the forming load and replaces the conventional forming.
Improvement of tool life in cold forging of complex automotive parts
Abstract In cold forging of outer races for constant velocity joints tool loads during the backward extrusion operation lead to very high loading conditions in the tool inserts. Fatigue cracking is the common failure mode that ends the service life of the tooling. This paper analyzes the stress states that exist in the inserts during the forming operation and determines the causes of the fatigue failures. Advanced tooling design concepts using a profiled, strip-wound stress container are investigated in order to change the loading conditions in the dies in a way that crack initiation can be avoided. The design concept is verified by a specially designed laboratory forging test. The test results show that the stress state in a die can be reduced with the new tooling concept and that the fatigue failure can be avoided.