ANALYSIS OF THE FORCE INTERACTION OF A DISC KNIFE WITH WOOD IN CHIP-FREE DIVISION

Abstract

The interaction of a circular knife with wood is a simple but interesting topic. The article will analyze the interaction of a knife with wood. A program is described that allows determining the preliminary deformation force for various disk shapes: rings, prisms, spheres, according to a given penetration area. Two periods of pressing are considered, both continuous and hollow, with sharply different pressure changes. Talk about the process of deformation of wood during compression along the fibers. Conclusions are drawn to reduce the cutting force. To establish the relationship between the degree of pressing and the axial stress (division force), a series of experiments were carried out on a testing machine using standard samples of pine and poplar wood. An experimental curve is constructed in a system of rectangular coordinates. With the help of a mechanical dynamometer, the total force of the division of softwood was determined. Theoretical substantiation of the obtained force of cutting with a disk knife is carried out. It has been established that the total effort of cutting soft wood is on average less than when sawing with round saws by 20-30%. It was also found that the smallest contact spot of the cutting disc with wood up to a contact angle with wood of 90 ° changes insignificantly and the total cutting force decreases with a decrease in the contact angle.