Improvement in Machining Efficiency of Complex Profiles using 5-Axes Simultaneous Machining Approach
| Autor: | Junaid Ali Abbasi, Sarwar Ali Abbasi, Mukhtar Hussain Sahir |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Mehran University Research Journal of Engineering and Technology, Vol 31, Iss 3, Pp 421-430 (2012) |
| Druh dokumentu: | article |
| ISSN: | 0254-7821 2413-7219 |
| Popis: | This research paper focuses on the process of machining complex and varying contour aerofoil parts used in aerospace industry like wings, blades of turbine and diffusers, etc. The main theme is to enhance productivity and on the other hand achieving accurate machining results for complex profile parts. The research consists of three main parts viz. Accurate and optimized tool path generation of complex profile, understanding and conversion of a 5-axes machine kinematics into mathematical relationships and developing a post processor which converts cutter location file into machine readable file, and finally a time and accuracy study has been made and compared with techniques used previously for machining of such components. Tool path is generated on CAM software from where CL (Cutter Location) file is generated, then by use of mathematical calculations post processor is developed and used for the conversion of that CL file into machine readable file. Time and accuracy analysis has been made in the end on an impeller blade machining. Tool paths generated in CAM software requires to be very closely analyzed in order to ensure collision free tool paths as movement in all 5-axes increases the chances of collision of head to work piece or with the table. For the study of 5-axes machine kinematics and calculations, a general 5-axes machine having 3 linear axes and two axes in rotary/tilting table has been used. By applying mathematical relationships using rotational matrix theorem and dot product of two vector quantities, equations were derived for rotary and tilting axes and then written in programming language (Visual C++) for line to line conversion of CL file into machine readable file. For the generation of CL file three different tool paths were generated. First process was the roughing of the area between every two adjacent blades then the next step was to finish the surface of the blades and the leading/trailing edge and the last process was to finish the hub surface of the impeller. The cutting parameters like feed, speed, axial depth of cut, radial depth of cut are dependent on the spindle power of the machine and the type of the material of part to be machined and that of the cutter itself. The selection of the size of the cutting tool used for the machining of each process is also dependant on the minimum area between two adjacent surfaces of the blades of impeller and maximum curvature of the blade from shroud surface to hub surface in order to avoid collision of the cutting tool with the blade surfaces. In the end, how the new approach has benefited is analyzed. The need for research on new approach was very demanding as to manufacture complex profile parts mostly used in aerospace industry with traditional machining approaches causes unpredictable delays due to manual calculations, inaccurate machining results like poor surface finish, tool breakage, etc, as well as requirement of various jigs/fixtures and skilled workers for accomplishing the task all the time. Now by adopting the approach as explored in this research gives a lot of advantages over traditional manufacturing approach. Some important features compared are presented in the tabular form. |
| Databáze: | Directory of Open Access Journals |
| Externí odkaz: |
|