Wheel Orientation Calculation for Helical Rake Flank Sharpening of Broaching Tool

To achieve accuracy of rake angle and ensure the grinding quality of the rake flanks of broaching tools, a novel wheel orientation and position calculating method is proposed, the contact curve is identified following the enveloping theory, and its distribution constraints are obtained. Defining the rake angle by two contact points, the wheel orientation evaluation is transformed into a nonlinear equation, which is further resolved as two single-variable searching problems obeying the principle that the swing angle of the grinding wheel ought to depart away the helix angle. Thus this equation can be easily solved by Newton-Raphson method. The results indicate that either larger radius or larger swing angle of the wheel corresponds with a larger tilt angle, and a swing angle close to the helix angle of rake flank is suggested to avoid the interference between the grinding wheel and front cutting teeth. A VERCUT based simulation verifies that the wheel orientation and position from this proposed method can ensure grinding precision of the helical rake flank of broaching tool.