VIRTUAL POLE METHOD - ALTERNATIVE METHOD FOR PROFILING RACK TOOLS

This paper presents a variant for determining the enwrapping condition, in the case of rack gear type tools. This variant was called the “virtual pole method”. The position of the virtual pole Pv is defined by the movement angle of the blank together with the centrode associated with the generated profile. The virtual pole method allows translating in the centrodes’ absolute movements, a point on the generated profile, on to the rack tool profile, thus determining the geometric locus representing the generating tool profile. The new method is easier to apply, while remaining scientifically rigorous. By applying the proposed algorithm, it is no longer necessary to write explicitly the relative movements between the tool and the piece, which simplifies the calculation process and eliminates some of the possibilities for errors.