Cutting insert for cutting and grooving tools

Abstract

The present invention relates to a turning insert that comprises a generally rectangularly shaped body having a front end surface with a main cutting edge at the intersection between the front end surface and an upper land area. A chipforming area is provided in the forward portion of the upper surface and is shaped in the form of a number of distinctly provided recesses and ridges in order to promote improved chip control and to obtain narrower chips in grooving operations.

What is claimed is:  
     
       1. A generally rectangularly shaped metal cutting insert for turning and grooving operations, comprising upper and lower front-to-rear extending  surfaces, two oppositely disposed side surfaces interconnecting said upper and lower front-to-rear extending  surfaces, and front and rear end surfaces each intersecting said upper and lower front-to-rear extending  surfaces and said side surfaces, a front portion of said upper surface including a main cutting edge formed by the intersection between said upper surface and said front surface, a chipforming area disposed inside of said main cutting edge and a chip breaking rear wall disposed inside of said chipforming area and extending upwardly therefrom, the chipforming area being formed by a plurality of first recesses centrally located on the upper surface, each of said recesses being located at a predetermined distance inside the  said cutting edge and having an elongated extension in a direction parallel with a longitudinal extension of the insert, second recesses shorter in length along the longitudinal extension of the insert being arranged on either side of said centrally provided  first recesses, a flat land area being provided between said main cutting edge and said first and second recesses, the chipforming area including a further recess which curves inwardly and downwardly from said flat land area at a smaller depth than the  a depth of said first and second recesses, said further recess curving upwardly to form said chip breaking rear wall the , lateral extension  edges of the  said further recess being confined  defined by two first ridge portions that converge rearwardly and merge at a rearward point  extend rearwardly in a converging manner toward each other, said two first ridge portions merging at rearward points thereof with respective integral second ridge portions, said second ridge portions extending essentially perpendicularly with respect to said main cutting edge. 
     
     
       2. An insert according to  claim 1 , wherein said first and second recesses are distinctly provided from each other, and a flat land area is provided between the main cutting edge and said first and second recesses . 
     
     
       3. An insert according to  claim 2 , wherein the rear  said chip breaking rear wall terminates rearwardly in a plateau located approximately at the same  a level as  of a neutral plane containing said flat land area. 
     
     
       4. An insert according to  claim 2 , wherein the  a width of the  said flat land area varies along the  said main cutting edge such that said width is smaller at a portion in front of the  a forward end of each of said first recesses than said width is at portions in front of intermediate rake surfaces located between adjacent ones of said first recesses. 
     
     
       5. An insert according to  claim 1 , wherein said first ridge portions extend from the  an outer periphery of said second recesses, and said second ridge portions extending  extend to the  a forward slope of a shoulder provided rearwardly of said chip breaking rear wall. 
     
     
       6. An insert according to  claim 5 , wherein said first ridge portions are each formed with a top surface inclined upwards to intersect with a top surface of said rear  second ridge portions. 
     
     
       7. An insert according to  claim 6 , wherein the a level of the top surface of the rear  said second ridge portions is located at a level above and generally parallel to the  a level of a neutral plane containing said flat land area. 
     
     
       8. An insert according to  claim 1 , wherein said first ridge portions are each formed with a top surface inclined upwards to intersect with a top surface of said rear  second ridge portions. 
     
     
       9. An insert according to  claim 8 , wherein the  a level of the top surface of the rear  said second ridge portions is located at a level above and generally parallel to the  a level of a neutral plane containing said flat land area. 
     
     
       10. An insert according to  claim 9 , wherein the rear  said chip breaking rear wall terminates rearwardly in a plateau located approximately at the same  a level as  of a neutral plane containing said flat land area. 
     
     
       11. An insert according to  claim 1 , wherein the lateral extension of the further recess is confined by first ridge portions that converge rearwardly and merge at a rearward point with integral second ridge portions, said second ridge portions extending essentially perpendicularly with respect to said main cutting edge. 
     
     
       12. An insert according to  claim 1 , wherein the insert is provided with side cutting edges extending from the forward end, which converge rearwardly to an intermediate position along the insert. 
     
     
       13. An insert according to  claim 1 , wherein the insert is provided with side cutting edges extending from the forward end, which converge rearwardly to an intermediate position along the insert. 
     
     
       14. A generally rectangularly shaped metal cutting insert for turning and grooving operations, comprising upper and lower surfaces, two oppositely disposed side surfaces interconnecting the upper and lower surfaces, and front and rear end surfaces each intersecting the upper and lower surfaces and the side surfaces, a front portion of the upper surface including a main cutting edge formed by the intersection between the upper surface and the from surface, a chipforming area disposed inside of the main cutting edge and a chip breaking rear wall disposed inside of the chipforming area and extending upwardly therefrom, the chipforming area being formed by a plurality of first recesses centrally located on the upper surface, each of the recesses being located at a predetermined distance inside the main cutting edge and having an elongated extension in a direction parallel with a longitudinal extension of the insert, a flat land area being provided between the main cutting edge and the first recesses, the chipforming area including a further recess which curves inwardly and downwardly from the flat land area at a smaller depth than a depth of the first recesses, the further recess curving upwardly to form the chip breaking rear wall, lateral edges of the further recess being defined by two first ridge portions that extend rearwardly in a converging manner toward each other, said two first ridge portions merging at rearward points thereof with respective integral second ridge portions, the second ridge portions extending essentially perpendicularly with respect to the main cutting edge. 
     
     
       15. An insert according to  claim 14 , wherein the chip breaking rear wall terminates rearwardly in a plateau located approximately at a level of a neutral plane containing the flat land area. 
     
     
       16. An insert according to  claim 14 , wherein a width of the flat land area varies along the main cutting edge such that the width is smaller at a portion in front of a forward end of each of the first recesses than the width is at portions of intermediate rake surfaces located between adjacent ones of the first recesses. 
     
     
       17. An insert according to  claim 14 , wherein the first ridge portions are each formed with a top surface inclined upwards to intersect with a top surface of the second ridge portions. 
     
     
       18. An insert according to  claim 17 , wherein a level of the top surface of the second ridge portions is located at a level above and generally parallel to a level of a neutral plane containing the flat land area. 
     
     
       19. An insert according to  claim 14 , wherein the chip breaking rear wall terminates rearwardly in a plateau located approximately at a level of a neutral plane containing the flat land area. 
     
     
       20. An insert according to  claim 14 , wherein the insert is provided with side cutting edges extending from the forward end, which converge rearwardly to an intermediate position along the insert.