Milling insert and a milling tool

Patent metadata

Field	Value
Publication number	US-10512975-B2
Application number	US-201615546750-A
Country	US
Kind code	B2
Filing date	Jan 15, 2016
Priority date	Jan 30, 2015
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

A milling insert for shoulder milling having s a positive basic shape and includes an upper side having a rake surface, a lower side including a planar bottom surface, a side surface extending around the periphery of the milling insert, and a cutting edge formed between the side surface and the rake surface. The cutting edge has at least a major cutting edge portion, a corner radius cutting edge portion, a ramping cutting edge portion, and a surface wiping cutting edge portion. The side surface includes an upper set of primary clearance surfaces and a lower set of secondary clearance surfaces having a plurality of planar secondary clearance surfaces, wherein the upper set of primary clearance surfaces forms an overhang protruding with respect to the secondary clearance surfaces and extending around the entire upper periphery of the milling insert.

First claim

The invention claimed is:

1. A milling insert for mounting in a shoulder milling tool, the milling insert having a positive basic shape and comprising:
an upper side having a rake surface;
a lower side opposite the upper side, the lower side including a planar bottom surface;
a side surface extending between the upper side and the lower side and around a periphery of the milling insert; and
a cutting edge formed between the side surface and the rake surface, the cutting edge including at least a major cutting edge portion, a corner radius cutting edge portion, a ramping cutting edge portion, and a surface wiping cutting edge portion positioned between the corner radius cutting edge portion and the ramping cutting edge portion and forming an angle with the ramping cutting edge portion, the side surface including an upper set of primary clearance surfaces and a lower set of secondary clearance surfaces including a plurality of planar support surfaces, wherein the upper set of primary clearance surfaces forms an overhang protruding with respect to an entirety of the secondary clearance surfaces, so that extension planes in which the planar secondary clearance surfaces extend are located inside the associated primary clearance surfaces with respect to a central axis of the milling insert, and wherein the protruding overhang extends around the entire upper periphery of the milling insert.

2. The milling insert according to claim 1 , wherein the cutting edge extends in parallel with the bottom surface.

3. The milling insert according to claim 1 , wherein the upper side includes a planar central region extending in parallel with the bottom surface, wherein the planar central region is recessed with respect to the cutting edge.

4. The milling insert according to claim 1 , wherein the major cutting edge portion is convex as seen in a plane parallel with the bottom surface.

5. The milling insert according to claim 1 , wherein the milling insert has a thickness t tot in a direction perpendicular to the bottom surface, and wherein the lower set of secondary clearance surfaces extends along at least 50% of the thickness.

6. The milling insert according to claim 1 , wherein the overhang has a thickness t oh within the range 0.20 mm≤t oh ≤0.5 mm in a direction perpendicular to the bottom surface.

7. The milling insert according to claim 1 , wherein, when the milling insert is mounted in a tool body, at least one of the planar support surfaces is configured to form an axial support surface and at least another one of the planar support surfaces is configured to form a radial support surface, the radial support surface and the axial support surface forming an acute angle with each other as seen in a plane parallel with the bottom surface.

8. The milling insert according to claim 1 , wherein the secondary clearance surfaces are formed at acute seating angles with respect to an upper extension plane parallel with the bottom surface and extending at the level of the cutting edge.

9. The milling insert according to claim 1 , wherein the cutting edge includes an additional cutting edge portion positioned between, and forming an angle with, the surface wiping cutting edge portion and the ramping cutting edge portion.

10. The milling insert according to claim 1 , wherein the primary clearance surface below the major cutting edge is formed at an overhang angle β major with respect to an upper extension plane parallel with the bottom surface and extending at the level of the cutting edge, the overhang angle β major decreasing from the corner radius cutting edge portion and along the major cutting edge portion, so that an effective clearance angle along the major cutting edge portion is constant when the milling insert is mounted in a tool body.

11. The milling insert according to claim 10 , wherein the secondary clearance surface below the major cutting edge portion is formed at a seating angle η major with respect to the upper extension plane, the seating angle η major being constant along the major cutting edge portion.

12. The milling insert according to claim 1 , wherein the primary clearance surface below the ramping cutting edge portion is formed at an acute overhang angle β ramp with respect to an upper extension plane parallel with the bottom surface and extending at the level of the cutting edge, the secondary clearance surface below the ramping cutting edge portion being formed at an acute seating angle η ramp with respect to said upper extension plane, and wherein β ramp <η ramp .

13. The milling insert according to claim 1 , wherein below each of the major cutting edge portion, the corner radius cutting edge portion, and the surface wiping cutting edge portion, the secondary clearance surface associated with the respective cutting edge portion is formed at an acute seating angle with respect to an upper extension plane parallel with the bottom surface and extending at the level of the cutting edge, and the primary clearance surface associated with the respective cutting edge portion is formed at an acute overhang angle with respect to said upper extension plane, wherein the seating angle is smaller than the overhang angle.

14. The milling insert according to claim 1 , wherein the milling insert is indexable with two index positions.

15. A milling tool comprising:
a tool body; and
at least one milling insert detachably mounted in an insert seat of the tool body, the at least one milling insert including an upper side having a rake surface; a lower side opposite the upper side, the lower side including a planar bottom surface; a side surface extending between the upper side and the lower side and around a periphery of the milling insert; and a cutting edge formed between the side surface and the rake surface, the cutting edge including at least a major cutting edge portion a corner radius cutting edge portion, a ramping cutting edge portion, and a surface wiping cutting edge portion positioned between the corner radius cutting edge portion and the ramping cutting edge portion and forming an angle with the ramping cutting edge, the side surface including an upper set of primary clearance surfaces, and a lower set of secondary clearance surfaces including a plurality of planar support surfaces, wherein the upper set of primary clearance surfaces forms an overhang protruding with respect to an entirety of the secondary clearance surfaces, so that extension planes in which the planar secondary clearance surfaces extend are located inside the associated primary clearance surfaces with respect to a central axis of the milling insert, and wherein the protruding overhang extends around the entire upper periphery of the milling insert.

Assignees

• Sandvik Intellectual Property
• Sandvik Intellectual Property

Inventors

• Roman Stefan

Classifications

• B23C5/109 Primary

  with removable cutting inserts · CPC title

• B23C2200/243

  bevelled or chamfered · CPC title

• B23C2200/126

  stepped · CPC title

• B23C2210/045

  axial rake angle · CPC title

• B23C2200/0494

  Rectangular · CPC title