Effect of Insert Angles on Cutting Tool Geometry

An analysis of publications has shown that mechanically clamped indexable inserts are predominantly used in modern tool manufacturing. Each insert has its shape and geometry in the tool coordinate system. The static system’s required geometry is achieved by the tilting of the insert pocket in the radial and axial directions. Therefore, it is of great importance in the tool design to know the relationships between the insert’s geometry parameters in the tool coordinate system where the geometry paraments of the insert are defined and working geometry parameters of the tool defined in the static coordinate system. The paper presents the developed methodology for determining the insert pocket base surface position to ensure the required values of the tool geometry parameters of the selected indexable insert in the static coordinate system. The graphs of the dependence of each of the angles of the insert geometry on the angles of rotation of this insert in the front and profile planes are presented as the level lines for practical use. Using these graphs, one can optimize all geometric insertion parameters in the static coordinate system. The model of the calculations of the mechanism of the insert clamping by a screw is developed. The basic size and tolerance of the output link determine the distance from the intersection line of the base surfaces to the thread axis on the pocket and the minimum amount of the screw stroke on the insert clamping in the pocket. Keywords: indexable insert, cutting tool, coordinate system, base surfaces, geometric parameters.

Study of Gear Profile Curve Equation for Less-Teeth Gear Transmission

Due to the shortage of complete design material and mature manufacturing method, less teeth gear (1-7 teeth) transmission has many restrictions in practice nowadays. In this paper, applying the principles of using rack cutter to cut involute gear by using generating methods, we established the dynamic coordinate system and the static coordinate system. By using coordinate transformation method, we derived the equations of gear profile involute and dedendum transition curve. After using Pro/E to plot the end profile of less-teeth gears, we did the 3D modeling and the simulation of the less teeth gear. We also improved a general hobber machine and manufactured less teeth gears successfully. The derivation method of gear profile curve in this paper has lucid concepts which make it quite clear and easy to understand, therefore, it provides theoretical basis to the design, the manufacturing and detection of the less teeth gear.