| 摘要 |
<p>The invention relates to a polygonal turning insert having a cutting edge, which includes three part edges, viz. a nose edge (12) situated in a corner and two main edges (13) converging toward the same, as well as chip-guiding flank surfaces for each one of the part edges, viz. a primary flank surface (21) situated behind the nose edge (12) along a bisector (B) between the main edges (13), as well as a pair of secondary flank surfaces situated inside the respective main edge. According to the invention, the primary flank surface (21) is convexly arched and delimited by an arched lower boundary line (22), which has an apex point (AP) facing the nose edge and being situated along the bisector (B) and includes two mirror-symmetrical arc part lines, which extend from the apex point to a pair of opposite end points situated along a straight reference line (RL) that intersects the bisector at a right angle in a middle point (MP) between the end points, the distance between the midpoint and the individual end point being greater than the distance between the midpoint and the apex point. In addition, the angle of inclination of the primary flank surface (21) in arbitrary vertical sections through the midpoint decreases from a greatest value in a section along the bisector (B) to a smallest value in a section along the reference line (RL).</p> |
