Study on forming condition and tool of flywheel by using flow forming process

Abstract

Many plastic forming methods, such as cold and hot forging, hydroforming, deep drawing, extrusion, rolling and spinning have been researched to develop metal plastic forming techniques. Still, no appropriate tool exists for the process and for the required geometry in manufacturing, especially in the forming fields. Thus, through this study we examined exhaustively flow forming and an appropriate material for extreme plastic deformation and flow stress. To this end, we focused on volume increase per unit length against the spinning process, a flow forming method, where the most important consideration is probably to sustain the metal flow as well as to prevent metal fold in the forming process. We chose a gear part of the flywheel of an automotive engine for the study model which consists of a separate plate and gear with different thicknesses, welded for assembling two parts. The rim of the squared section, thickened for gear machining on the plate edge, was manufactured through the flow forming method. Because this method does not allow the required geometry when forming, incremental forming was applied for flow forming. In addition, the geometry and process conditions of the forming tool based on the forming features were investigated in each step. As results of the present study, the optimised forming conditions for gear machining considering the thickness of the outer edge of the flywheel were evaluated using comparable tests, with various groove depths, angles and process conditions in each step of the manufacture of the forming roller.

Keywords:

• Flow stress
• Flow forming
• Incremental forming
• Forming roller
• Flywheel
• Extreme plastic deformation
• Edge thickening

This work was supported by the Inha University.