Rotary tool and method for manufacturing machined product
A rotary tool may include a holder and a cutting insert. The cutting insert may include an upper surface including a first upper side, a lower surface including a first lower side, and a lateral surface. The lateral surface may include a first lateral surface, a second lateral surface, and a third lateral surface. The first upper side may include a first end. The first end may be located closer to the third lateral surface than the second lateral surface. The first lower side may include a second end. The second end may be located closer to the second lateral surface than the third lateral surface. In a front view of the upper surface, the first lateral surface may include a tip region surrounded by the first end and the second end, and the tip region may be recessed toward the rear end.
1. A rotary tool, extending along a rotation axis from a rear end to a front end, the rotary tool comprising:
a holder having a columnar shape extended along the rotation axis and comprising a pocket located on a side of the front end; and
a cutting insert located in the pocket,
the cutting insert comprising
an upper surface which is located ahead in a rotation direction of the rotation axis and comprises a first upper side located on a side of the front end,
a lower surface which is located on a side opposite to the upper surface and comprises a first lower side located on a side of the front end,
a lateral surface located between the upper surface and the lower surface,
an upper cutting edge located on the first upper side, and
a lower cutting edge located on the first lower side,
the lateral surface comprising
a first lateral surface located on a side of the front end,
a second lateral surface located on an outer peripheral side of the holder, and
a third lateral surface located on an inner peripheral side of the holder, wherein
the first upper side has a convex shape protruding toward the front end, and comprises a first end located on a side of the front end,
the first end is located closer to the third lateral surface than the second lateral surface,
the first lower side has a convex shape protruding toward the front end, and comprises a second end located on a side of the front end,
the second end is located closer to the second lateral surface than the third lateral surface, and
in a front view of the upper surface, the first lateral surface comprises a tip region extending from the first end to the second end, and an entirety of the tip region is recessed toward the rear end and located closer to the rear end than an imaginary straight line connecting the first end and the second end.
2. The rotary tool according to claim 1 , wherein
a cross section which passes through the first end and is orthogonal to the first upper side in the front view of the upper surface is a first cross section, and
the lateral surface has a recessed portion in the first cross section.
3. The rotary tool according to claim 1 , wherein
a cross section which passes through the second end and is orthogonal to the first lower side in the front view of the upper surface is a second cross section, and
the lateral surface has a recessed portion in the second cross section.
4. The rotary tool according to claim 1 , wherein, in a front view of the first lateral surface,
the first upper side has a convex shape protruding upward, and comprises a third end located most away from the lower surface, and
the third end is located immediately above the second end.
5. The rotary tool according to claim 1 , wherein, in a front view of the first lateral surface,
the first lower side has a convex shape protruding downward, and comprises a fourth end located most away from the upper surface, and
the fourth end is located immediately below the first end.
6. The rotary tool according to claim 1 , wherein
the upper surface comprises
an upper inclined surface which is located along the upper cutting edge and comes closer to the lower surface as getting further away from the upper cutting edge, and
an upper flat surface which is flat and located closer to a midportion of the upper surface than the upper inclined surface,
the upper flat surface comprises a fifth end located on a side of the front end, and
a distance between the fifth end and the third lateral surface is smaller than a distance between the fifth end and the second lateral surface.
7. The rotary tool according to claim 6 , wherein the third lateral surface is located closer to the fifth end than the first end.
8. The rotary tool according to claim 1 , wherein
the lower surface comprises
a lower inclined surface which is located along the lower cutting edge and comes closer to the upper surface as getting further away from the lower cutting edge, and
a lower flat surface which is flat and located closer to a midportion of the lower surface than the lower inclined surface,
the lower flat surface comprises a sixth end located on a side of the front end, and
the sixth end is located closer to the second lateral surface than the third lateral surface.
9. The rotary tool according to claim 8 , wherein the second lateral surface is located closer to the sixth end than the second end.
10. A method for manufacturing a machined product, comprising:
rotating the rotary tool according to claim 1 ;
bringing the rotary tool being rotated into contact with a workpiece; and
moving the rotary tool away from the workpiece.
11. The rotary tool according to claim 1 , wherein
the upper surface comprises
an upper inclined surface which is located along the upper cutting edge and comes closer to the lower surface as getting further away from the upper cutting edge, and
an upper flat surface which is flat and located closer to a midportion of the upper surface than the upper inclined surface,
the upper flat surface comprises a fifth end located on a side of the front end, and
the fifth end is located closest to the front end on the upper flat surface.
12. A rotary tool, extending along a rotation axis from a rear end to a front end, comprising:
a holder having a columnar shape extended along the rotation axis and comprising a pocket located on a side of the front end; and
a cutting insert located in the pocket,
the cutting insert comprising
an upper surface which is located ahead in a rotation direction of the rotation axis and comprises a first upper side located on a side of the front end,
a lower surface which is located on a side opposite to the upper surface and comprises a first lower side located on a side of the front end,
a lateral surface located between the upper surface and the lower surface,
an upper cutting edge located on the first upper side, and
a lower cutting edge located on the first lower side,
the lateral surface comprising
a first lateral surface located on a side of the front end,
a second lateral surface located on an outer peripheral side of the holder, and
a third lateral surface located on an inner peripheral side of the holder, wherein
the first upper side has a convex shape protruding toward the front end, and comprises a first end located on a side of the front end,
the first end is located closer to the third lateral surface than the second lateral surface,
the first lower side has a convex shape protruding toward the front end, and comprises a second end located on a side of the front end,
the second end is located closer to the second lateral surface than the third lateral surface, and
in a front view of the upper surface, the first lateral surface comprises a tip region extending from the first end to the second end, the tip region being recessed toward the rear end,
in a front view of the first lateral surface,
the first upper side has a convex shape protruding upward, and comprises a third end located most away from the lower surface, and
the third end is located immediately above the second end,
a cross section which passes through the second end and is orthogonal to the first lower side in the front view of the upper surface is a second cross section, and
the lateral surface has a recessed portion in the second cross section.
13. The rotary tool according to claim 12 , wherein
a cross section which passes through the first end and is orthogonal to the first upper side in the front view of the upper surface is a first cross section, and
the lateral surface has a recessed portion in the first cross section.
14. The rotary tool according to claim 12 , wherein, in a front view of the first lateral surface,
the first lower side has a convex shape protruding downward, and comprises a fourth end located most away from the upper surface, and
the fourth end is located immediately below the first end.
15. The rotary tool according to claim 12 , wherein
the upper surface comprises
an upper inclined surface which is located along the upper cutting edge and comes closer to the lower surface as getting further away from the upper cutting edge, and
an upper flat surface which is flat and located closer to a midportion of the upper surface than the upper inclined surface,
the upper flat surface comprises a fifth end located on a side of the front end, and
a distance between the fifth end and the third lateral surface is smaller than a distance between the fifth end and the second lateral surface.
16. The rotary tool according to claim 15 , wherein the third lateral surface is located closer to the fifth end than the first end.
17. The rotary tool according to claim 12 , wherein
the upper surface comprises
an upper inclined surface which is located along the upper cutting edge and comes closer to the lower surface as getting further away from the upper cutting edge, and
an upper flat surface which is flat and located closer to a midportion of the upper surface than the upper inclined surface,
the upper flat surface comprises a fifth end located on a side of the front end, and
the fifth end is located closest to the front end on the upper flat surface.
18. The rotary tool according to claim 12 , wherein
the lower surface comprises
a lower inclined surface which is located along the lower cutting edge and comes closer to the upper surface as getting further away from the lower cutting edge, and
a lower flat surface which is flat and located closer to a midportion of the lower surface than the lower inclined surface,
the lower flat surface comprises a sixth end located on a side of the front end, and
the sixth end is located closer to the second lateral surface than the third lateral surface.
19. The rotary tool according to claim 18 , wherein the second lateral surface is located closer to the sixth end than the second end.
20. A method for manufacturing a machined product, comprising:
rotating the rotary tool according to claim 12 ;
bringing the rotary tool being rotated into contact with a workpiece; and
moving the rotary tool away from the workpiece.
21. A rotary tool, extending along a rotation axis from a rear end to a front end, comprising:
a holder having a columnar shape extended along the rotation axis and comprising a pocket located on a side of the front end; and
a cutting insert located in the pocket,
the cutting insert comprising
an upper surface which is located ahead in a rotation direction of the rotation axis and comprises a first upper side located on a side of the front end,
a lower surface which is located on a side opposite to the upper surface and comprises a first lower side located on a side of the front end,
a lateral surface located between the upper surface and the lower surface,
an upper cutting edge located on the first upper side, and
a lower cutting edge located on the first lower side,
the lateral surface comprising
a first lateral surface located on a side of the front end,
a second lateral surface located on an outer peripheral side of the holder, and
a third lateral surface located on an inner peripheral side of the holder, wherein
the first upper side has a convex shape protruding toward the front end, and comprises a first end located on a side of the front end,
the first end is located closer to the third lateral surface than the second lateral surface,
the first lower side has a convex shape protruding toward the front end, and comprises a second end located on a side of the front end,
the second end is located closer to the second lateral surface than the third lateral surface, and
in a front view of the upper surface, the first lateral surface comprises a tip region extending from the first end to the second end, the tip region being recessed toward the rear end,
in a front view of the first lateral surface,
the first upper side has a convex shape protruding upward, and comprises a third end located most away from the lower surface, and
the third end is located immediately above the second end,
a cross section which passes through the first end and is orthogonal to the first upper side in the front view of the upper surface is a first cross section, and
the lateral surface has a recessed portion in the first cross section.