МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ ТЕПЛОНАПРЯЖЕННОСТИ ПРОЦЕССА ПЛОСКОГО ШЛИФОВАНИЯ ЗАГОТОВОК КОМПОЗИЦИОННЫМИ КРУГАМИ

Abstract

Currently, the most significant reserve for improvement of grinding technological efficiency involves the application of the composite grinding wheels (CGW). However, the CGW is more complicated body comparing with the intermittent (IGW) and standard (SGW) grinding wheels due to the presence of lubricating elements (LE) filled with the solid lubricating material (SLM) with a density different from the density of the material of the wheel abrasive part. The problems and issues of IGW and SGW application when grinding are thoroughly studied, however, the CGW design features make it more difficult or impossible to apply the techniques and mathematical models developed for the SGW and the IGW to describe grinding process. In this regard, it is necessary to pay special attention to the problem of mathematical modeling of thermal physics of the grinding process using the CGW. The paper suggests the mathematical model of thermal stress of flat pendulum grinding by the periphery of CGW with the structural elements in the form of radial slits filled with the solid lubricant. This model allows estimating the temperature field on the surface and inside the workpiece throughout the full working three-stage cycle of flat pendulum grinding including the forward motion of grinding wheel to touch with the workpiece and grinding with inward movement and sparkling-out. The developed mathematical model is based on the calculation of the P z tangential component of grinding force of each travel of grinding and sparkling-out. This will allow determining the density of heat flow emitted in the contact zone, and the average contact temperature of each travel of GW. The combination of the results of calculation of average contact temperature of all travels of grinding and sparkling-out will allow assessing the temperature field of the full cycle of grinding and predicting the occurrence of grinding defects.