Study of tool nose change and its relation with workpiece roughness and turning process vibration

• Grant number: 05/02949-1
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2006
• End date: August 31, 2008
• Field of knowledge: Engineering - Mechanical Engineering - Manufacturing Processes
• Principal Investigator: Amauri Hassui
• Grantee: Amauri Hassui
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

There are several papers related to the turning process. This is due to the fact that the turning process, among all the other machining processes, is the easiest to understand, since the cut is continuous, done with a single cutting edge, whose geometry is defined. It is known that the tool wear influences the cutting forces, that in its turn tend to change the process vibration and these factors are reproduced in the workpiece quality. Besides, this tool wear tends to change the tool nose geometry and therefore, its printed profilede on the workpiece, in other words the workpiece roughness. The most common studied tool wear are the flank and crater wear and both present continuous growth throug the tool life. On the other hand, the workpiece roughness presents high dispersion, in other words, there is a tendency of growing through the tool life, but the measured values are far from the mean line. This work is an attempt to investigate a possible reason of this high dispersion, namely, the shape deviation of the tool nose. The flank and notch wear tend to change the tool nose shape. This change can happen in a regular way, increasing the effective tool nose radius or irregular, turning this radius in a random profile. Besides, in this work, it will be studied the influency of this tool nose shape deviation on the process vibration. To reach these goals, it will be carried out several turning tests where the roughness profile, tool images and vibration signal will be acquired. The vibrations signal processing and images analysis will try to establish correlations between these phenomena and the workpiece roughness. (AU)