A Two-degree-of-freedom Tool-holder Mechanism for Real-time Adjustment of Tool Angles in Turning Process

Tool geometry has a significant impact on cutting mechanics and key machining parameters such as tool life, workpiece surface quality, specific cutting energy, and dynamic stability of the cutting process. In the turning process, where the cutting tool remains in a fixed position, it is possible to develop a mechanism to adjust the tool angles during machining. This research introduces a new tool-holder mechanism for the lathe that can adjust the side inclination and front inclination angles. The simultaneous control of these angles allows for precise adjustment of the normal rake and clearance angles of the tool. Since these angles greatly affect all machining parameters, this mechanism can enhance the quality of the machining process. By implementing an active chatter control system using the proposed mechanism, the controller can reduce the tool’s clearance angle to increase process damping and prevent chatter. The mechanism enables adjustment of the normal rake and clearance angles by up to 8 degrees. Test results demonstrate that utilizing this mechanism and the provided chatter suppression/control technique can effectively prevent chatter at higher machining speeds and improve machining stability. The proposed mechanism has potential applications in advanced CNC lathes with open architecture for precise and optimal adjustment of machining parameters.