Real Time Monitoring of Friction Variation in Stamping Process Using Die-Embedded Sensing System
摘要
A die-embedded sensing system by embedding a 3-axis piezo sensor in the die was developed to measure the dynamic characteristics of sliding friction between materials and dies during stamping process. A hat-bending of steel sheets of high-strength steels was performed using the developed monitoring system. The influence of material strength, slide speed, cushion pressure, etc. on the dynamic characteristics of friction was evaluated. It is found that the friction coefficient changes dynamically depending on the processing conditions and material strength and the mixed lubricating state lasted for a certain duration time, and the duration time was theoretically calculated based on the squeeze effect theory. A pulse motion was adapted to the hat-bending process based on the calculation and the effect of the friction reduction was verified.