Double-sided cutting insert having diagonally opposed raised corners and diagonally opposed lowered corners, and rotary cutting tool

Patent metadata

Field	Value
Publication number	US-11027342-B2
Application number	US-201916366088-A
Country	US
Kind code	B2
Filing date	Mar 27, 2019
Priority date	Mar 27, 2019
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A cutting insert has two opposing end surfaces interconnected by a peripheral side surface, the peripheral side surface having two major side surfaces and two minor side surfaces. Major edges are formed at the intersection of the major side surfaces and the end surfaces. Each end surface has two diagonally opposed raised corners and two diagonally opposed lowered corners with respect to a median plane, each raised corner adjoining one of the major edges at a first major point and each lowered corner adjoining one of the major edges at a third major point. In a major side view, each major edge has an associated first imaginary straight line containing its first and third major points, and an elevated edge portion located on one side of the first imaginary straight line. The cutting insert is removably secured in a rotary cutting tool.

First claim

What is claimed is:

1. A cutting insert ( 20 ), comprising:
two opposing end surfaces ( 22 a , 22 b ) interconnected by a peripheral side surface ( 24 ) and an insert axis (A 1 ) passing through the opposing end surfaces ( 22 a , 22 b ),
each end surface ( 22 a , 22 b ) having a recessed central surface ( 58 ),
the peripheral side surface ( 24 ) having two opposing major side surfaces ( 26 a , 26 b ), two minor side surfaces ( 28 a , 28 b ), and four convexly curved corner surfaces ( 42 ) alternating with the two major side surfaces ( 26 a , 26 b ) and the two minor side surfaces ( 28 a , 28 b ),
a major edge ( 30 ) formed at the intersection of each major side surface ( 26 a , 26 b ) and each end surface ( 22 a , 22 b ), and a major cutting edge ( 34 ) formed along at least a portion of each major edge ( 30 ),
a minor edge ( 32 ) formed at the intersection of each minor side surface ( 28 a , 28 b ) and each end surface ( 22 a , 22 b ), and a minor cutting edge ( 36 ) formed along at least a portion of each minor edge ( 32 ),

a median plane (M) perpendicular to the first insert axis (A 1 ) and intersecting the peripheral side surface ( 24 ) to form an insert boundary line (BL), and
each end surface ( 22 a , 22 b ) having two diagonally opposed raised corners (RC) and two diagonally opposed lowered corners (LC) with respect to the median plane (M),
each raised corner (RC) having a convexly curved raised corner edge ( 46 ) formed at the intersection of one of said four convexly curved corner surfaces ( 42 ) and its associated end surface ( 22 a , 22 b ), each raised corner edge ( 46 ) adjoining one of the major edges ( 30 ) at a first major point (NJ 1 ), each raised corner (RC) further having a raised corner cutting edge ( 50 ) formed along at least a portion of each raised corner edge ( 46 ),
each lowered corner (LC) having a convexly curved lowered corner edge ( 48 ) formed at the intersection of one of said four convexly curved corner surfaces ( 42 ) and its associated end surface ( 22 a , 22 b ), each lowered corner edge ( 48 ) adjoining one of the major edges ( 30 ) at a third major point (NJ 3 ), each lowered corner edge ( 48 ) being entirely located closer to the median plane (M) than its associated central recessed surface ( 58 ), each lowered corner (LC) further having a lowered corner cutting edge ( 52 ) formed along at least a portion of each lowered corner edge ( 48 ),

wherein in a major side view of the cutting insert ( 20 ):
the first and third major points (NJ 1 , NJ 3 ) of each major edge ( 30 ) define a major side length (SL) measured parallel to the median plane (M), the major side length (SL) being divided into equal first, second and third length portions (L 1 , L 2 , L 3 ), in which the first length portion (L 1 ) is delimited by the first major point (NJ 1 ) and the third length portion (L 3 ) is delimited by the third major point (NJ 3 ),
each major edge ( 30 ) has an associated first imaginary straight line (LM 1 ) containing its first and third major points (NJ 1 , NJ 3 ) and an elevated edge portion ( 62 ), the elevated edge portion ( 62 ) being located on one side of the first imaginary straight line (LM 1 ) and the insert boundary line (BL) being located on the other side of the first imaginary straight line (LM 1 ), and
each elevated edge portion ( 62 ) has a second major point (NJ 2 ) located: (i) furthest from its associated first imaginary straight line (LM 1 ), and (ii) in the third length portion (L 3 ) of its associated major side length (SL).

2. The cutting insert ( 20 ) according to claim 1 , wherein in a major side view of the cutting insert ( 20 ):
each major edge ( 30 ) has an associated second imaginary straight line (LM 2 ) containing its first and second major points (NJ 1 , NJ 2 ) and intersecting one of the minor cutting edges ( 36 ) at a projected intersection point (NI), and
each projected intersection point (NI) is located further from the median plane (M) than its adjacent third major point (NJ 3 ).

3. The cutting insert ( 20 ) according to claim 2 , wherein:
each end surface ( 22 a , 22 b ) includes a minor land surface ( 40 ) immediately adjacent each of its associated minor cutting edges ( 36 ), and
in a cross-section taken in a second plane (P 2 ) located in-between the two major side surfaces ( 26 a , 26 b ) and containing one of the projected intersection points (NI), the adjacent minor land surface ( 40 ) forms an internal minor cutting angle (α 1 ) with an adjacent minor side surface ( 28 a , 28 b ), and the minor cutting angle (α 1 ) is at least 65 degrees and at most 115 degrees.

4. The cutting insert ( 20 ) according to claim 2 , wherein:
each projected intersection point (NI) is located a first height (H 1 ) from the median plane (M),
each third major point (NJ 3 ) is located a second height (H 2 ) from the median plane (M), and
the first height (H 1 ) is at least 120 percent of the second height (H 2 ).

5. The cutting insert ( 20 ) according to claim 4 , wherein:
the first height (H 1 ) is no more than 220 percent of the second height (H 2 ).

6. The cutting insert ( 20 ) according to claim 1 , wherein:
each end surface ( 22 a , 22 b ) includes a minor land surface ( 40 ) immediately adjacent each of its associated minor cutting edges ( 36 ), and
in a cross-section taken in any plane located in-between the two major side surfaces ( 26 a , 26 b ) and intersecting one of the minor cutting edges ( 36 ), the adjacent minor land surface ( 40 ) forms an internal minor cutting angle (α 1 ) with an adjacent minor side surface ( 28 a , 28 b ), and the minor cutting angle (α 1 ) is at least 65 degrees and at most 115 degrees.

7. The cutting insert ( 20 ) according to claim 1 , wherein in an end view of the cutting insert ( 20 ), each minor edge ( 32 ) is either coincident with the insert boundary line (BL) or located outside the insert boundary line (BL).

8. The cutting insert ( 20 ) according to claim 1 , wherein each minor cutting edge ( 36 ) extends the entire length of its associated minor edge ( 32 ).

9. The cutting insert ( 20 ) according to claim 1 , wherein in a cross-section taken in the median plane (M) and intersecting the four corner surfaces ( 42 ):
the four corner surfaces ( 42 ) adjoin the two minor side surfaces ( 28 a , 28 b ) at four corner points (NC),
the four corner points (NC) define an imaginary parallelogram (PL) having first and second pairs of imaginary parallel sides (S 1 , S 2 ), and
the first pair of imaginary parallel sides (S 1 ) are perpendicular to the major side length (SL) of each major edge ( 30 ).

10. The cutting insert ( 20 ) according to claim 1 , wherein in a minor side view of the cutting insert ( 20 ), each minor cutting edge ( 36 ) includes:
a wiping edge portion ( 66 ) adjoining its associated raised corner edge ( 30 ),
a ramping edge portion ( 68 ) adjoining its associated lowered corner edge ( 34 ), and
a convexly shaped joining edge portion ( 70 ) extending between the wiping edge portion ( 66 ) and the ramping edge portion ( 68 ).

11. The cutting insert ( 20 ) according to claim 10 , wherein in a minor side view of the cutting insert ( 20 ), each ramping edge portion ( 68 ) includes:
a first ramping edge sub-portion ( 68 a ) adjoining its associated lowered corner edge ( 48 ),
a third ramping sub-portion ( 68 c ) adjoining its associated joining edge portion ( 70 ), and
a concavely shaped second ramping edge sub-portion ( 68 b ) extending between the first and third ramping edge sub-portions ( 68 a , 68 c ).

12. The cutting

Assignees

• Iscar Ltd

Inventors

• Atar Osama

Classifications

• B23C5/202 Primary

  Plate-like cutting inserts with special form (special form related to securing of the insert B23C5/22) · CPC title

• B23C5/109 Primary

  with removable cutting inserts · CPC title

• B23C2200/284

  Negative clearance angles · CPC title

• B23C2210/168

  Seats for cutting inserts, supports for replacable cutting bits · CPC title

• B23C2210/045

  axial rake angle · CPC title