Investigation of the effect of abrasive belt constant force grinding based on mechanical decoupling tool system

Abstract

In the abrasive belt grinding process, there are factors affecting the machining stability, efficiency, and quality. Based on the analysis of the grinding process, the normal force in the contact area between the abrasive belt and the workpiece is a major factor. By comparing constant force and non-constant force grinding, the results imply that keeping the grinding force constant will achieve desired material removal and better surface quality. The phenomenon of over- and under-cutting of the workpieces can also be avoided by a constant normal force. In this article, a controllable and flexible belt grinding mechanism accompanied with a mechanical decoupling control strategy is built and tested. Afterward, a detailed comparison is made between the traditional force-position coupling system and the proposed decoupling control system. The proposed control system suppresses the interference between the position and force control systems. The contact force is directly measured and controlled without detecting the position of other components in the tool system. The complexity of the control system is thereby reduced. Finally, several grinding experiments are carried out. The standard deviation and coefficient of variation of the measured normal force are kept within 0.25 and 0.02, respectively. The experiment results reveal that the mechanical decoupling system performs well in force control compared with the traditional force-position coupling system. In addition, the surface roughness Ra < 0.4 μm, the surface quality of the workpiece is improved significantly with the constant force controller.