Cutting insert
The present disclosure relates to a cutting insert. The cutting insert according to the exemplary embodiment of the present disclosure has a dot formed between a main cutting edge and a chip breaker, and the dot has a bridge formed between the main cutting edges. Therefore, a chip, which is produced during a cutting process, may come into contact with three points on a main cutting edge land portion, the bridge, and the dot. The chip may discharge heat generated from the cutting insert while the chip comes into contact with the three points.
1. A cutting insert comprising:
main cutting edges 20 which are formed at edge portions of a polygonal shape in a top plan view in which an upper surface 11 is directly viewed;
corner cutting edges 30 which are formed at vertex portions of the polygonal shape so as to extend from the main cutting edges 20 ;
chip breakers 70 which are formed between the upper surface 11 and the main cutting edges 20 and break a chip;
main bottom portions 72 which are concavely formed between the main cutting edges 20 and the chip breakers 70 ;
first dots 40 which are convexly formed on the chip breakers 70 ;
first bridges 42 which are formed between the main cutting edges 20 and the first dots 40 so as to be lower than the main cutting edges 20 and the first dots 40 ;
second dots 50 which are convexly formed on the chip breakers 70 so as to be spaced apart from the first dots 40 with respect to a machining direction; and
second bridges 52 which are formed between the main cutting edges 20 and the second dots 50 so as to be lower than the main cutting edges 20 and the second dots 50 .
2. The cutting insert of claim 1 , wherein a first highest point T 1 of the first dot 40 is lower than the main cutting edge 20 .
3. The cutting insert of claim 1 , wherein a second highest point T 2 of the second dot 50 is lower than the main cutting edge 20 .
4. The cutting insert of claim 1 , wherein when a first highest point T 1 of the first dot 40 and a second highest point T 2 of the second dot 50 are connected by an imaginary line, a first angle a 1 is formed between the imaginary line and the main cutting edge 20 , and the first angle a 1 is an acute angle.
5. The cutting insert of claim 4 , wherein the first angle a 1 is 5 degrees to 10 degrees.
6. The cutting insert of claim 1 , wherein a distance from a vertex of the corner cutting edge 30 to a first highest point T 1 of the first dot 40 is 0.5 mm to 2.0 mm.
7. The cutting insert of claim 1 , wherein a distance from a vertex of the corner cutting edge 30 to a second highest point T 2 of the second dot 50 is 1.0 mm to 3.5 mm.
8. The cutting insert of claim 1 , wherein a separation distance between the first dot 40 and the second dot 50 is 0.5 mm to 2.5 mm.
9. The cutting insert of claim 1 , wherein a main cutting edge land portion 22 is formed on the main cutting edge 20 , a corner land portion 32 is formed on the corner cutting edge 30 , and a width w 1 of the corner land portion 32 is smaller than a width w 2 of the main cutting edge land portion 22 .
10. The cutting insert of claim 9 , further comprising:
corner bottom portions 34 which are concavely formed between the corner cutting edges 30 and the chip breakers 70 ,
wherein said cutting insert is adapted to contact a produced chip sequentially at a first point at an end of the corner land portion 32 , a second point on the corner bottom portion 34 , and a third point on the chip breaker 70 .
11. The cutting insert of claim 1 , wherein a longitudinal direction of the first dot 40 forms a second angle a 2 with respect to the main cutting edge 20 , and
the second angle a 2 is an acute angle.
12. The cutting insert of claim 11 , wherein the second angle a 2 is equal to or larger than 85 degrees and smaller than 90 degrees.
13. The cutting insert of claim 1 , wherein a longitudinal direction of the second dot 50 forms a third angle a 3 with respect to the main cutting edge 20 , and the third angle a 3 is an acute angle.
14. The cutting insert of claim 13 , wherein the third angle a 3 is equal to or larger than 85 degrees and smaller than 90 degrees.
15. The cutting insert of claim 1 , which is adapted to contact a produced chip sequentially at a first point p 1 at an end of the cutting edge land portion 22 , a second point p 2 on the first bridge 42 , and a third point p 3 on the first dot 40 .
16. The cutting insert of claim 1 , which is intended to machine a workpiece made of forged steel for a vehicle component.