Flexible thickness control of hydroforming by forced lubrication method in arbitrary region and time

Abstract

The elastic and plastic properties of metal can be used in various applications. Junior Associate Professor Hiroaki Kubota is working to improve manufacturing design through the application of elasto-plastic mechanics. He is particularly interested in hydroforming; a process in which steel tubes are inflated by water pressure. This can be used to produce hollow, lightweight automobile parts. Kubota previously worked in the body design and advanced development department of a car manufacturing company, learning of the importance of thickness distribution of vehicle components. It was this that inspired his current work. At the Department of Mechanical Engineering, School of Engineering, Tokai University, Japan, where Kubota is based, he is conducting research on hydroforming technology and applied research on the optimisation of plastic working using finite element analysis (FEM) and artificial intelligence (AI). Through their research on lubrication hydroforming, the team developed a forced lubrication technology that supplies high-pressure lubricant between a die and a tube during tube hydroforming, leading to even distribution and uniform wall thickness. The researchers want to expand the application of high-strength steel tubes to contribute to more lightweight and rigid cars. In their work the team confirmed that when a high-pressure lubricant was injected between the die and the steel tube, uniform wall thickness was achieved and cracking prevented. This was the very first time that forced lubrication was found to be effective in hydroforming. The team also discovered that by managing the forced lubrication, the thickness of parts can be freely controlled.