A high-efficiency generation method of integral impeller channel tool path based on parametric domain template trajectory mapping

Abstract

Integral impeller is a complex part commonly used in petroleum, chemical, shipbuilding, aerospace, and other industries. The manufacturing of the integral impeller involves the multi-axis machining of free-form surface, which is a time-consuming and error-prone process. Tool path planning is regarded as a key issue in this process, but there is still short of systematic solutions. In this paper, a parametric domain template trajectory mapping algorithm is presented to calculate the tool path of impeller channel machining. Through generating the template trajectory in the parametric domain, and mapping the template trajectory to the physical domain with the aid of the mapping model, and then the actual machining tool path can be obtained. The proposed method can realize the rapid acquisition and easy modification of the impeller machining tool path. Firstly, the trajectory mapping model from the parametric domain to the physical domain is established using the morphing technique, and the template trajectory mapping method in the parametric domain is given. Secondly, the clean-up boundary of the impeller channel is determined in the parametric domain, and the quasi-triangular and streamlined template trajectory of the impeller channel is defined. Finally, the template trajectory given in the parametric domain is mapped to the physical domain through the mapping model, and the streamlined and quasi-triangular tool paths of the impeller channel are calculated. An example analysis shows that the calculation difficulty of the tool path for impeller channel machining is greatly decreased, and the calculation efficiency is also improved. The simulation and actual machining are carried out. The result shows that the tool path generation method presented in this paper is effective and feasible, and it offers a new way for tool path planning of NC machining for impeller complex parts.