PROFILING OF THE HOB MILL TOOL FOR GENERATING A PROFILE KNOWN IN DISCRETE FORM

Abstract

In industrial practice, is sometimes needed to manufacture specific parts without blueprints. This part of engineering process is known as reverse engineering. Usually, this assumes that an existing piece is measured or scanned and based on this result is made a new part. If the part can be machined with universal cutting tools the manufacturing process don’t rise problems, but in case of parts which needs specific tools, these must be designed to be suitable for machining the piece. In this paper, a tool profiling algorithm is proposed, which is based on the capacity to measure and represent some surfaces in a methodical cloud of points form. The proposed profiling algorithm is based on the “virtual pole” method. This method is used together with the intermediate surface theorem for profiling tools characterized by a helical primary peripheral surface. This article will represent a continuation of a research which was been published in 2021, in Bulletin of Polytechnic Institute from Jassy. In that published article, the profiling of the hob mill tool was presented in a theoretical way and the ”virtual pole” theorem was applied for an any type of profiles. The proposed algorithm allowed the determination of the tool’s profile reciprocally enveloping with a piece’s profile known in discrete form. Now, in this paper, the discrete form profile will represent exactly a cycloidal disk from a cycloidal reducer whose coordinates were determined using specific reverse engineering processes. Considering that the determination of the relative movements between the tool and the part, as well as the determination of the enveloping condition are relatively complicated and can be a source of errors, the purpose of this work is to highlight the advantages of the ”virtual pole” method compared to the other specific methods of tool profiling that generate by enwrapping. At the same time, it is investigated if the ”virtual pole” method can provide a support for the identification of the intermediate surface, with the help of graphic design environments, for profiling, in this case, the worm tools, since the ”virtual pole” method cannot be applied as such in the case of disk-type tools, worm tools and cylindrical-frontal tools, due to the fact that the theorem is intended for the study of planar gearing. The advantages of using the ”virtual pole” method are obvious compared to the classical tool profiling methods. The results demonstrated the accuracy of the method, by the fact that, using the ”virtual pole” method, the calculation time for profiling the hob mill tool for generating a profile known in discrete form, namely the profile of the cycloidal disk, is significantly reduced.