Papers by Keyword: Flank

Abstract: Micro-drilling become more widely used from precision mechanics to electronics. Nowadays, the main commercial tools are planar point micro-drills. However, that geometry often causes a high thrust force, high temperature, and rapid wear during micro-drilling. Furthermore, it is difficult to adjust the four flank surfaces to accurately intersect at one point, particularly when the drill diameter becomes smaller. To solve this problem, non-coaxial helical drills points have been proposed by some researchers, and is characterized by a continuous helical flank instead of the piecewise planar flank. Its drilling performance is improved compared with planar drill point. This study presents a 5-axis coordinated CNC grinding method of the non-coaxial helical drill flank. Mathematical models of the drill flank and its engagement line between cylinder grinding wheel and drill tool are established, and then the path of the grinding wheel with respect to the drill tool is obtained. In order to verify the availability of the proposed methods, three dimension (3D) grinding simulation of non-coaxial helical drills with diameter 0.5mm was carried out using the CAD software, and then were fabricated on a 6-axis Makino CNC tool grinder. The ground micro-drills examined by 3D laser scanning microscope show good identity with the simulated result. These indicate that the manufacturing model presented in this paper provides a practical and efficient method to grind the flank of a non-coaxial helical micro-drill.

Abstract: Application of petroleum based cutting fluids in machining operation may cause many problems such as eye burn and skin inflation etc. Vegetables oils are good alternative to overcome such issues. In this work, experiments were carried out to study the influence of coconut oil on the performance of single point cutting tool insert in turning operation. Three cutting conditions viz. dry, wet and coconut oil were considered to evaluate the tool wear. Results obtained from the experiments highlighted the advantages of coconut oil, a considerable reduction in flank wear, crater wear and auxiliary wear was observed in the turning operation.