Negative finish turning insert with chip forming arrangement
A turning insert for machining both Inconel and Titanium workpieces. The insert includes a chip forming arrangement including only a single v-shaped groove. The groove includes a specific depth and position to improve machining of both Inconel and Titanium work pieces.
1. A cemented carbide turning insert comprising:
opposite first and second surfaces;
a peripherally extending peripheral surface connecting and extending perpendicular to the first and second surfaces;
a peripheral edge formed at an intersection of the peripheral surface and the first surface, the peripheral edge having at least one corner comprising a corner radius;
a cutting edge formed along at least a portion of the peripheral edge, and extending along the corner radius as well as first and second edge portions connected to and extending from different sides of the corner;
a bisector plane P 1 perpendicular to the first and second surfaces and bisecting the corner radius;
a bisector point P defined at an intersection of the cutting edge and the bisector plane;
a horizontal plane perpendicular to the peripheral surface and intersecting the bisector point;
a downward direction directed perpendicularly from the horizontal plane towards the second surface;
an upward direction opposite to the downward direction;
an inward direction directed into the insert from an intersection of the bisector plane and the peripheral surface; and
a chip forming arrangement formed at the first surface, adjacent to the cutting edge, the chip forming arrangement being devoid of a land and consisting of a single, continuous v-shaped groove extending on both sides of the corner radius, in a top view;
the groove comprising:
a curved groove portion adjacent the corner radius, and two straight extension portions connected to either side of the curved groove portion;
a descending surface extending directly from the cutting edge in a downward-inward direction to a lowest point of the groove; and
an ascending surface extending from the lowest point in an upward-inward direction to a highest point;
wherein along the bisector plane:
the lowest point is a first horizontal distance D 1 from the bisector point, fulfilling the condition 0.50 mm≤D 1 ≤1.20 mm;
the lowest point is a first vertical distance H 1 downward from the horizontal plane, fulfilling the condition 0.15 mm≤H 1 ≤0.30 mm; and
the highest point is a second horizontal distance D 2 from the bisector point, fulfilling the condition 1.10 mm≤D 2 ≤1.70 mm.
2. The insert according to claim 1 , wherein the first horizontal distance D 1 fulfills the condition 0.70 mm≤D 1 ≤1.10 mm.
3. The insert according to claim 1 , wherein the vertical distance H 1 fulfills the condition 0.20 mm≤H 1 ≤0.30 mm.
4. The insert according to claim 1 , wherein the second horizontal distance D 2 fulfills the condition 1.20 mm≤D 2 ≤1.60 mm.
5. The insert according to claim 1 , wherein the chip forming arrangement is symmetric about the bisector plane.
6. The insert according to claim 1 , wherein the ascending surface, along the bisector plane, extends in a smooth concave manner.
7. The insert according to claim 1 , wherein a majority of the descending surface, along the bisector plane, extends in a straight manner.
8. The insert according to claim 1 , wherein the highest point is located upward of the horizontal plane.
9. The insert according to claim 1 , wherein the highest point is a second vertical distance H 2 from the lowest point, fulfilling the condition H 2 =H 1 ±0.05 mm.
10. The insert according to claim 9 , wherein the highest point is within 0.1 mm of the horizontal plane.
11. The insert according to claim 1 , wherein the second horizontal distance D 2 is the largest distance compared to comparative distances taken along planes other than the bisector plane.
12. The insert according to claim 11 , wherein the v-shaped groove is widest along the bisector plane (P 1 ), and becomes progressively narrower along at least a portion of the groove's straight extension portions, in a direction away from the curved groove portion.
13. The insert according to claim 1 , wherein the cutting edge has a circular radius.
14. The insert according to claim 1 , further comprising an additional chip forming arrangement having the same features but formed at the second surface.
15. The insert according to claim 1 , comprising a chip forming arrangement at each corner of the first and second surfaces having the same features as the chip forming arrangement defined in claim 1 .
16. The insert according to claim 1 , wherein the cutting edge adjacent the chip forming arrangement extends parallel to the horizontal plane.
17. The insert according to claim 1 , wherein the first vertical distance H 1 is the largest distance compared to comparative distances taken along planes other than the bisector plane.
18. The insert according to claim 17 , wherein the v-shaped groove is deepest along the bisector plane (P 1 ), and becomes progressively shallower along at least a portion of the groove's straight extension portions, in a direction away from the curved groove portion.
19. The insert according to claim 18 , wherein the v-shaped groove is widest along the bisector plane (P 1 ), and becomes progressively narrower along at least a portion of the groove's straight extension portions, in a direction away from the curved groove portion.
20. The insert according to claim 1 , wherein a ratio D 1 /D 2 is at least 0.5.