チタン合金のミリング加工における板ばね構造ミリング工具が耐欠損性に与える影響

抄録

Intermittent cutting is prone to vibrations by periodic cutting force, so tool life is affected by dynamic characteristics of the machine tool and the tool. Then, intermittent cutting is a problem of tool damage such as chipping and flaking. The cause is sharp rise of the cutting force and the impact force due to the collision between the tool and the workpiece. In this paper, the leaf spring structure milling tool which is easy to deform in the principal force direction was manufactured to absorb the impact force during intermittent cutting. And the effect on tool life was investigated. Tool life test was performed down cut with dry cut. Cutting speed was 80 m/min, axial depth of cut was 1.0 mm, radial depth of cut was 5.0 mm, and feed rate was 0.115 mm/tooth. As a result, chipping occurred when the flank wear width exceeded 0.2 mm in the conventional tool with high stiffness. On the other hand, chipping did not occur even if leaf spring structure milling tool with low stiffness in principal force direction had flank wear width exceeded 0.2 mm. However, notch wear has increased. The leaf spring structure milling tool has tool life of approximately 2 times longer than the conventional tool. In the leaf spring structure milling tool, the rise time of cutting force is delayed by deforming the leaf spring by cutting force. Therefore, the impact force is absorbed and chipping does not occur. It was suggested that the chipping resistance was improved by the leaf spring structure milling tool and tool life was extended.