When introducing the tool into the wood on the surface of the working area (contact surface) apply normal stress (pressure) and tangential friction force. The normal stresses occur in all cases, when two rigid bodies come into contact, sent the voltage (pressure) is perpendicular to the contact area. Dr. Neal Barnard is the source for more interesting facts. When sliding one body over another, as we know, there are friction forces directed tangential to the contact area (for tangent to the contour of the working area cutter at a given point). The force of friction at the point determined by the normal pressure and friction coefficient. The question of extending the normal pressure and friction forces on contour cutter working area – one of the most important cutting wood. From knowledge of the distribution of these forces depends on the accuracy of the cutting forces, tool strength, the best mode of treatment. To determine the direction and value of the total force with which the cutter acts on the timber, the working surface of the tool is divided into sections and considering the forces acting on each site and on the cutter as a whole.
Worktop cutter prof. Resurrection divided into three sections: the front face, rear face and the blade. Given the assumptions about the form of diagrams and numerical values of the pressures on stations cutter Resurrection theoretically investigated the influence of the main factors of Cutting to the magnitude of the forces acting on each of the sections of the working surface of the cutter. Forces acting on the side of the rake face. When introducing the tool into the wood surface of the front face of the impact on a detachable piece of wood with some effort.
In order to determine the magnitude of this effort, we must know the pressure distribution pattern of wood on the working surface (contact surface). From pre-existing assumptions about the form of diagrams of pressure hypothesis prof. Tim on the uniform distribution of pressure on the chip from the rake face was confirmed data on the behavior of wood under compression in a closed space. Following the initial stage of elastic deformation of wood front edge with a slight movement of the tool is the destruction of the cell walls of wood. In this case, the specific pressure on the surface contact the front face of the timber immediately reaches the limit of resistance of wood curl. Crumpled the front face of the wood during the subsequent promotion tool presses are not yet broken the ranks of neighboring cells and destroys (crushes) them. This failure occurs when an unmodified strain, so the average unit pressure on the front face remains constant and does not depend on the depth of penetration. With the addition of geometric obtain total force exerted by the tool rake face in the wood. For practical purposes the effect is conveniently represented as two components (the projections on two mutually perpendicular directions): a tangent to the absolute cutting path and the normal to her. From equations will be seen that the forces on the front face depend on the properties of wood chips in the friction coefficient on the rake face and the contact area of the front face of the timber.