Study on effect of lead and tilt angle of tool on cutting force and tool wear in turn milling

摘要

Turn milling method is one of the key technic to achieve high efficiency machining and improvement of tool life for difficult-to-cut materials. It is because the depth of cut can be increased compared with common turning method. In addition, tool wear distributes on the several cutting edges of milling tool. However, a contact condition between rotating tool and cylindrical workpiece varies significantly depending on the tool posture such as tool lead angle and tilt angle. Then, it is important to evaluate the effect of lead angle and tilt angle of tool on cutting force and tool wear in turn-milling in order to estimate the optimal tool posture. In this report, a simulation model which can calculate the removal area and contact area geometrically for 5-axis controlled turn milling is proposed to estimate cutting force and behaviour of contact area between tool and workpiece regarding tool posture. The workpiece was modelled as a point-group model and the points were removed when tool edge passed the workpiece surface. Cutting force was obtained as a function of the removal area in this simulation. The simulated cutting forces are experimentally verified for round insert cutter. Furthermore, the tool wear on each tool posture was also tested, and the relationship between tool wear and tool posture was evaluated by using the simulation. It was found that the experimental cutting force increased with an increase of tilt angle, and it was also verified that the simulation showed same tendency. Moreover, from the results of the simulation, it was clarified that the experimental tool wear, especially boundary wear, changed depending on tool posture, because boundary shape and length between tool edge and workpiece surface changed with tool lead angle and tilt angle.