Study on wheel cover safety for grinding machines:

prediction of cover material safety based on tensile test

Abstract

The grinding wheel cover is one of the most important safety parts that protect the machine tool operator from abrasive fragments. The wheel cover material and thickness are defined in ISO 16089 and JIS B 6033, which are specifications for grinding machine safety. There have been few studies regarding collision using brittle projectiles, so the related phenomena have not been clarified. Especially, the relations between collision safety and mechanical properties of cover material have not been evaluated quantitatively. This study involved collision experiments of an abrasive projectile (WA46O8V) against four types of wheel cover material with different tensile strengths (SS400, SUS304, C2801, and A5052) to determine the effects of the stress-strain curve on collision safety. The experimental results indicated that the collision safety can be predicted by yield ratio and the integral value of the stress-strain curve of the cover material. In addition, the applicable conditions of the derived prediction equation for collision safety were clarified using FEM analysis.