Краткий справочник по резанию материалов на металлообрабатывающих станках TECHNICAL DATA

Краткий справочник по резанию материалов на металлообрабатывающих станках TECHNICAL DATA

Краткий справочник по резанию материалов на металлообрабатывающих станках TECHNICAL DATA _ APPROACH ANGLE AND THE TOOL LIFE Approach Angle and Chip Thickness When the depth of cut and feed per tooth, fe, are fixed, the smaller the corner angle (KAPR) is, then the thinner the chip thickness (h) becomes (for a 45° KAPR, it is approx. 75% that of a 90° KAPR). This can be seen in below. Therefore as the KAPR increases, the cutting resistance decreases resulting in longer tool life. Note however, if the chip thickness is too large then the cutting resistance can increase leading to vibrations and shortened tool life. KAPR:90’ KAPR: 75’ KAPR:45° Effects on chip thickness due to the variation of lead angles Approach Angle and Face Wear Below shows wear patterns for different lead angles. When comparing crater wear for 90° and 45° lead angles, it can be clearly seen that the ctater wear for 90° lead angle is larger. Lead Angle 90° Lead Angle 75° Lead Angle 45° vc=100m/min Wl V 6,:SS Tc=69min 1 \ jj m vc=125m/min Tc=55min \mmmi \ vc=160m/min Tc=31min Workpiece SNCM439 287HB Tools DC=125mm Insert: M20Cemented Carbide Cutting Conditions: ap=3.0mm ae=110mm fz=0.2mm/t. Dry Cutting UP AND DOWN CUT (CLIMB) MILLING When choosing a method to machine, up cutting or down cut milling (climb milling) is decided by the conditions of the machine tool, the milling cutter and the application. However, it is said that in terms of tool life, down cut (climb) milling is more advantageous. Up Cut Down Cut Tool rotation Workpiece movement direction Milling cutter inserts Portion machined Portion machined y00 rotation Workpiece movement Milling cutter inserts Mitsubishi Materials 1989 TECHNICAL DATA