Elastic-contact-based tool-path planning for free-form surface in belt grinding

Abstract

As for the fact that the majority of current researches take the technology of tool-path planning for free-form surface only as a geometrical problem, which is not suitable for belt grinding because of the elastic deformation of the grinding belt that leads to a variable contact, in this article, the tool-path planning method for belt grinding is developed from the elastic contact point of view. Based on the Hertzian contact theory and taking the grinding force into consideration, a calculation method of the contact area between the belt and the workpiece is presented. Then, a tool-path planning model is presented based on the real contact area to meet the full coverage. In addition, an optimization model based on the constant scallop-height is further developed to meet the high form accuracy of the workpiece. First, a modified model for the material removal depth is developed based on the Preston equation. Then, according to the curvature of the contact surface, three situations are analyzed and the calculation methods of the tool-path interval are given. Finally, experiments on the simulation blade are conducted, and the experimental results show the effectiveness of the method in this article.

A material removal model for nonconstant-contact flexible grinding

“…However, the fitting expressions have no physical sense, and they will fail once the situation changes. By comparison, theoretical models can give explanations by using Preston equation or the Archard wear equation [4][5][6], which show a similar connection between the MR and processing parameters. Nevertheless, the micro interactions are not considered in detail but treated comprehensively as a coefficient in the models.…”

Calibration and error compensation of scanner-based robotic belt grinding system

“…Taking the steam turbine blade as an example, most of the operations are done in the machining center from a minimum envelope stainless steel blank except for the finishing of airfoil surfaces. Successful belt grinding involves many aspects such as coordinate system calibration, 1 grinding process modeling, 2 trajectory planning, 3–5 grinding force adaptive control, 6 error analysis, and compensation. 7,8 In order to achieve the practical application of the belt grinding system, the first step is to establish an efficient, accurate, and practical coordinate system calibration method.…”