Analysis of the influence of instrumental and regime factors on the quality of wood grinding

Abstract

The grinding tool does not have a solid cutting edge, in most cases the front angles for abrasive grains are negative, the grains have rounded vertices and an irregular geometric shape. Grinding should be considered as a process of cutting-scratching the surface layer of wood with a large number of abrasive grains of the grinding tool. The main purpose of the grinding process is to prepare the surface for finishing by eliminating irregularities and defects of the previous processing. The effectiveness of grinding to a greater extent depends on the processing conditions, characteristics and properties of the grinding tool. Theoretical studies and analysis of the derived equations for determining the critical values of the rake angle, cut thickness and cutting speed show that all of the above parameters have a significant effect on the amount of lifting of the processed material by abrasive grain and the intensity of the appearance of contact fractures. An increase in the critical thickness of the slice leads to an increase in the deformation of the surface layers of the processed material, and, consequently, to an increase in the depth and number of contact fractures. The increase in the absolute value of the rake angle leads to the need to increase the critical cutting speed to ensure the conditions of chip formation. In general, an increase in cutting speed always has a positive effect on chip formation conditions and on the quality of the machined surface. An increase in the modulus of the rake angle leads to a deterioration in the conditions of chip formation and surface quality. An increase in the radius of curvature of the cutting edge of the grain leads to an increase in the critical thickness of the slice, which entails an increase in contact deformations and fractures.