COMPARATIVE ASSESSMENT OF WOOD SAWING TRAJECTORIES WITH CIRCULAR SAWS

During the technological regime calculation of the wood processing, in particular the trunk crossing with circular disc saws, there is important to simplify the sawing trajectory and replace it with a fragment of a circular arc. The sawing and feeding movements, as well as the diameter of the saw, are among the factors that determine the shape of the flat curved line described by the tooth of the cutting tool. The mathematical description of the trajectory of sawing by a woodworking tool with a rotary motion is performed in many scientific works. However, some issues require further research. A comparative evaluation of the trajectories of sawing wood with circular saws during trunk crossing is performed in the article. The evaluation was carried out using the methodology for calculating the length of fragments of second-order plane curves, developed and implemented in the form of a computer program in the MathCad. The methodology is based on the principles of discreteness and approximation regarding the approximate determination of geometric parameters. The results of numerical experiments for six variants of transverse sawing technological regimes are presented and analyzed. Dependencies between the kinematic parameters of a wood-cutting tool with different number of teeth and the length of arcs of cutting trajectories were established. It is determined under which conditions it is possible to replace the arc of a curve of the second order of the general form with a corresponding fragment of the same curve of the canonical form, in particular circles and cycloids, which will allow rational design of the power of the drives of the cutting and feeding mechanisms of specialized woodworking equipment. A recommendation was submitted regarding the introduction of the proposed methodology to the educational process of forestry complex equipment specialties, in particular regarding the teaching of the discipline «Theory and construction of woodworking equipment».