Development of the Single-setup Milling Process Model of the Shaft Support Necks and Cams

Three-dimensional geometrical modeling of the processes of allowance removal and shaping of support necks and cams of camshafts when milling with crossed axes of the tool and part is proposed. Single-setup milling of camshafts, which are widely used in automotive, tractor, shipbuilding and other industries, is carried out by a cutter with crossed axes of it and the part. The rotation angle of the cutter is selected from the condition of providing the required roughness of the treated surface and is regulated by the feed. At the same time, high processing productivity is provided by an increase in camshaft speed. A method of milling support necks and cams is developed, where the processing is carried out by a cutter, the height of which is less than the lengths of the processed surfaces. When processing the passage, the main allowance is removed by the end face of the quadrangular roughing carbide plate, and the finishing is carried out by the unloaded periphery of the cermet finishing plate. This allowance distribution increases the productivity and accuracy of processing, and the ability to rotate the roughing plate saves material and reduces the cost of processing. In the process of milling the curved surface of the camshaft cam, the depth of cut along the machined profile is always greater than the value of the removed allowance. This causes a decrease in the accuracy and productivity of processing. In order to eliminate this problem, it is proposed to stabilize the depth of cut and feed along the contour with uneven rotation of the part. The uniformity of the depth of cut and feed along the curved contour of the cam is achieved by simultaneous vertical and transverse movements of the cutter and uneven rotation of the camshaft. When milling the curved surface of the cam, the center of which does not coincide with the camshaft center, there is an uneven rotation of the latter and synchronous vertical and transverse movement of the cutter. When machining the cam section, the center of which coincides with the camshaft center, the cutter is given only rotatio

Research of the Milling Process of A Cylindrical Surface by an Oriented Instrument

The object of research is the milling process with the crossed axes of the cylindrical surface and the tool. During the research, general modular three-dimensional models of the tool surface, the processes of removing the allowance and the shaping of the cylindrical surface are used on the basis of three unified modules: tool, shaping and orientation. Computer simulation is also used to build a three-dimensional model of the milling process of a cylindrical surface with an oriented tool. A graphic scheme of milling a cylindrical surface with an oriented tool has been created. The developed cylindrical module for shaping the tool surface, which is described by the product of the displacement matrices along the corresponding axes and the surface of the machined part, is represented by the product of the radius of the tool vector and its orientation module in the shaft coordinate system. The resulting graph of the distribution of the specific productivity of the milling process along the tooth profile of the tool during processing with crossed axes of the cutter and part. An analysis of this graph shows that the milling method with an oriented tool makes it possible to increase the accuracy of the shaping process due to uniform wear of the tool. The intersection angle of the cylindrical surface and the tool is also determined, the value of which is taken from the condition of ensuring the maximum removal of the material layer with uniform loading of the end part of the cutter. For this, a three-dimensional model of the process of milling a cylindrical surface with crossed axes of the tool and the part is developed, in which rough milling is carried out by the end part of the tool, and the finish – by the peripheral. In the course of the research, it is found that when finishing milling, the value of the rotation angle of the cutter is taken from the condition that the peripheral part of the cutter is fully loaded. Improving the processing efficiency is achieved by crossing the axes of the tool and the part, which allows to program the intersection point, and uniform wear of the cutter, which improves the quality of the machined surface. It is also possible to use high-speed milling to provide increased processing productivity