Abstract:
The rake face geometry of rectangular slot progressive broaches employed in turbine disk machining represents a critical cutting surface that directly determines the cutting performance and operational longevity of broaching tools. Due to the fact that interference is prone to occur between the grinding wheel and the rake face during grinding, and it is difficult to consistently machine the chip groove by being tangent to the groove bottom, shape errors are thus generated. Meanwhile, the structural characteristic of a broach having multiple teeth and cutting edges leads to problems such as low automation level and frequent human-machine interaction in generating the trajectory of the rake face. In response to the aforementioned issues, coordinate systems for the broach and the grinding wheel are established. The motion equation of the grinding wheel is described via coordinate transformation matrices, and the parameter constraints during grinding are analyzed. Ultimately, the position and orientation of the grinding wheel are calculated. A feature recognition method based on boundary representation utilizing grinding wheel pose is employed to analyze the topological relationships of the rake face in the broach model, and identify the rake face machining features that meet the requirements by matching spatial geometric relationships. Finally, by integrating the grinding wheel pose and the identified rake face machining features, an automatic generation system for rake face grinding trajectories was developed on the UG/NX platform through secondary development. The correctness of the grinding wheel pose and the applicability of the grinding trajectories were validated through grinding simulation.