Cutting insert and cutting tool for a peeling operation

A cutting insert for bar peeling comprising a multi-cornered polygonal body of wear resistant material, said body including top and bottom surfaces and a peripheral edge surface extending therebetween, said peripheral edge surface including corner clearance faces disposed at respective corners of said body, said corner clearance faces intersecting said top surface to form corner cutting edges, each corner cutting edge being convexly curved as said top surface is viewed in plan, said top surface defining a chip face and including chipbreaker recesses located adjacent respective ones of said corner cutting edges, each recess being spaced from its respective corner cutting edge in a direction toward a center of said insert, each of said recesses being curved and comprised of a near wall and a far wall, said near wall located closer to said corner cutting edge than said far wall, each of said near and far walls intersecting said top surface along an intersection line which is of concave-convex curvature as viewed in plan, each of said intersection lines having its convex side facing generally toward said corner cutting edge, each of said corner clearance faces extending at an acute angle relative to said top surface, said clearance angle becoming progressively larger as a respective corner is approached.

A cutting insert for bar peeling comprising a multi-cornered polygonal body of wear resistant material, said body including top and bottom surfaces and a peripheral edge surface extending therebetween, said peripheral edge surface including corner clearance faces disposed at respective corners of said body, said corner clearance faces intersecting said top surface to form corner cutting edges, each corner cutting edge being convexly curved as said top surface is viewed in plan, said top surface defining a chip face and including chipbreaker recesses located adjacent respective ones of said corner cutting edges, each recess being spaced from its respective corner cutting edge in a direction toward a center of said insert, each of said recesses being curved and comprised of a near wall and a far wall, said near wall located closer to said corner cutting edge than said far wall, each of said near and far walls intersecting said top surface along an intersection line which is of concave-convex curvature as viewed in plan, each of said intersection lines having its convex side facing generally toward said corner cutting edge, wherein said curvature of said corner cutting edge varies so that the degree of curvature increases toward said corner.

A cutting insert for bar peeling comprising a multi-cornered polygonal body of wear resistant material, said body including top and bottom surfaces and a peripheral edge surface extending therebetween, said peripheral edge surface including corner clearance faces disposed at respective corners of said body, said corner clearance faces intersecting said top surface to form corner cutting edges, each corner cutting edge being convexly curved as said top surface is viewed in plan, said top surface defining a chip face and including chipbreaker recesses located adjacent respective ones of said corner cutting edges, each recess being spaced from its respective corner cutting edge in a direction toward a center of said insert, each of said recesses being curved and comprised of a near wall and a far wall, said near wall located closer to said corner cutting edge than said far wall, each of said near and far walls intersecting said top surface along an intersection line which is of concave-convex curvature as viewed in plan, each of said intersection lines having its convex side facing generally toward said corner cutting edge, wherein said top face includes a land disposed between each of corner cutting edges and its respective recess, said land becoming wider as said corner is approached.

A cutting insert for bar peeling comprising a multi-cornered polygonal body of wear resistant material, said body including top and bottom surfaces and a peripheral edge surface extending therebetween, said peripheral edge surface including corner clearance faces disposed at respective corners of said body, said corner clearance faces intersecting said top surface to form corner cutting edges, each corner cutting edge being convexly curved as said top surface is viewed in plan, said top surface defining a chip face and including chipbreaker recesses located adjacent respective ones of said corner cutting edges, each recess being spaced from its respective corner cutting edge in a direction toward a center of said insert, each of said recesses being curved and comprised of a near wall and a far wall, said near wall located closer to said corner cutting edge than said far wall, each of said near and far walls intersecting said top surface along an intersection line which is of concave-convex curvature as viewed in plan, each of said intersection lines having its convex side facing generally toward said corner cutting edge, wherein each of said corner clearance faces includes a bevel intersecting a respective corner cutting edge at an angle in the range of 10 to 20 degrees.

A tool for bar peeling comprising a toolholder on which are removably disposed a circular roughing insert and a finishing insert, said finishing insert being substantially triangular shaped with a curved corner cutting edge in each corner thereof, said finishing insert including a top face and a peripheral edge face which includes a side clearance face and a corner clearance face which intersect said top face to form a side cutting edge and a corner cutting edge, respectively;

• said corner clearance face, at a junction with said side clearance face, forming a zero degree clearance angle relative to a plane extending perpendicular to said top face, said clearance angle progressively increasing from said junction to a respective corner of said insert.