Double-sided, polygonal cutting inserts with alternating concave and convex cutting edged

Abstract

A double-sided, polygonal cutting insert includes a first surface and a second surface opposite the first surface. A plurality of side surfaces extend between the first surface and the second surface. A plurality of primary concave cutting edges are formed at an intersection between the plurality of side surfaces and the first and second surfaces, and a plurality of convex wiper edges are formed at an intersection between the plurality of side surfaces and the first and second surfaces. Each wiper edge has a step extending radially outward from a respective side surface. The cutting insert is mounted in a cutting tool such that the primary cutting edge and a wiper edge contact a workpiece to produce a high-quality surface finish on the workpiece.

1 . A double-sided, polygonal cutting insert, comprising:
 a first surface;   a second surface opposite the first surface;   a plurality of side surfaces extending between the first surface and the second surface, each side surface is perpendicular to the first surface and the second surface;   a plurality of primary cutting edges formed at an intersection between the plurality of side surfaces and the first surface; and   a plurality of wiper edges formed at an intersection between the plurality of side surfaces and the first surface, each wiper edge having a step protruding radially outward from a respective side surface and formed with a substantially planar outer surface.   
     
     
         2 . The cutting insert of  claim 1 , wherein each primary cutting edge is concave along a central longitudinal axis of the cutting insert and a top edge of the step of each wiper edge is convex along the central longitudinal axis of the cutting insert. 
     
     
         3 . The cutting insert of  claim 2 , wherein the convex wiper edge has a radius, R W , of from 10 to 100 millimeters. 
     
     
         4 . The cutting insert of  claim 1 , wherein the plurality of primary cutting edges and the plurality of wiper edges are arranged in an alternating fashion. 
     
     
         5 . The cutting insert of  claim 1 , wherein each primary cutting edge and each adjacent wiper edge form a compound curve. 
     
     
         6 . The cutting insert of  claim 1 , wherein the second surface is identical to the first surface. 
     
     
         7 . The cutting insert of  claim 1 , further comprising a plurality of corner radiuses extending between the first and second surfaces and each of the plurality of side surfaces. 
     
     
         8 . The cutting insert of  claim 7 , wherein each of the plurality of corner radiuses are identical to each other. 
     
     
         9 . The cutting insert of  claim 7 , wherein the plurality of corner radiuses extend between each of the plurality of primary cutting edges and each of the plurality of wiper edges. 
     
     
         10 . The cutting insert of  claim 1 , wherein a length, CL, of each primary cutting edge and each wiper edge is described by the following equation:
   CL=IC tan(22.5)−CR,
   where,
 IC is a diameter of an inscribed circle of the cutting insert, and 
 CR is equal to a magnitude of the corner radius. 
   
     
     
         11 . A double-sided, polygonal cutting insert, comprising:
 a first surface;   a second surface opposite the first surface;   a plurality of side surfaces extending between the first surface and the second surface;   a plurality of primary cutting edges formed at an intersection between the plurality of side surfaces and the first surface, and a plurality of primary cutting edges formed at an intersection between the plurality of side surfaces and the second surface; and   a plurality of wiper edges formed at an intersection between the plurality of side surfaces and the first surface and a plurality of wiper edges formed at an intersection between the plurality of side surfaces and the second surface, each wiper edge having a step extending radially outward from a respective side surface and formed with a substantially planar outer surface.   
     
     
         12 . The cutting insert of  claim 11 , wherein each primary cutting edge is concave along a central longitudinal axis of the cutting insert and top edge of the step of each wiper edge is convex along the central longitudinal axis of the cutting insert. 
     
     
         13 . The cutting insert of  claim 12 , wherein the convex wiper edge has a radius, R W , of from 10 to 100 millimeters. 
     
     
         14 . The cutting insert of  claim 11 , wherein the plurality of primary cutting edges and the plurality of wiper edges are arranged in an alternating fashion. 
     
     
         15 . The cutting insert of  claim 11 , wherein each primary cutting edge and each adjacent wiper edge form a compound curve. 
     
     
         16 . The cutting insert of  claim 11 , wherein the second surface is identical to the first surface. 
     
     
         17 . The cutting insert of  claim 11 , further comprising a plurality of corner radiuses extending between the first and second surfaces and each of the plurality of side surfaces. 
     
     
         18 . The cutting insert of  claim 17 , wherein each of the plurality of corner radiuses are identical to each other. 
     
     
         19 . The cutting insert of  claim 11 , wherein a length, CL, of each primary cutting edge and each wiper edge is described by the following equation:
   CL=IC tan(22.5)−CR,
   where,
 IC is a diameter of an inscribed circle of the cutting insert, and 
 CR is equal to a magnitude of the corner radius. 
   
     
     
         20 . A cutting tool comprising a tool body having a plurality of pockets for mounting a cutting insert as recited in  claim 1 , wherein at least one primary cutting edge of a first cutting insert mounted in a first pocket and at least one wiper edge of a second cutting insert mounted in a second pocket contact a workpiece during a cutting operation, thereby producing a high-quality surface finish on the workpiece.