A cutting insert of an embodiment includes an upper surface including a first upper cutting edge and a second upper cutting edge, a lower surface including a first lower cutting edge and a second lower cutting edge, and a side surface. The side surface includes a first surface extending from the second upper cutting edge, a second surface extending from the first lower cutting edge, a third surface extending from the first upper cutting edge, and a fourth surface extending from the second lower cutting edge. The first surface and the fourth surface are parallel to a central axis. The second surface is inclined so as to depart from the central axis as going from the lower surface toward the upper surface. The third surface is inclined so as to depart from the central axis as going from the upper surface toward the lower surface.

A cutting insert includes a polygonal plate-shaped insert main body having two polygonal surfaces, a side surface having a flank, and a cutting edge to be formed in an intersection ridgeline portion between a rake face and the flank. The insert main body has a rotationally symmetrical shape with respect to an insert center line, and has a front-rear reversely symmetrical shape with respect to the polygonal surface. The cutting edge includes a corner cutting edge, a major cutting edge extending from an one end of the corner cutting edge, and a wiper cutting edge extending from an one end of the major cutting edge in a direction intersecting the major cutting edge at an obtuse angle. A first region is disposed where a clearance angle of the flank gradually decreases to a negative angle after continuously passing through 0 from a positive angle.

A detachable cutting insert for an indexable rotary cutting tool, has a cutting edge portion that includes a major cutting edge continuous with a first end of a first corner edge near a short-side-direction side surface, which is formed into a straight line. The cutting insert has a first minor cutting edge that is continuous with a second end of the major cutting edge, which is formed into a circular arc. The cutting insert has a second minor cutting edge that is continuous with a third end of the first minor cutting edge, which is formed into a straight line. In a cross-sectional view of a rake face of the second minor cutting edge, perpendicular to the second minor cutting edge, a cross-sectional ridgeline of the rake face of the second minor cutting edge is formed into a convex shape protruding above a cross-sectional ridgeline of a reference plane.

Cutting inserts are disclosed having four cutting edges and milling tools comprising the cutting inserts installed in pockets on a rotatable cutting tool holder. The cutting inserts comprise a front face, a rear face and four side faces extending between the front and rear faces. A cutting edge is provided at the intersection of the front face and each side face. Each cutting edge comprises a plurality of cutting edge segments, including a facet cutting edge that forms the flat surface of a workpiece being milled, and a straight lead cutting edge that extends at an angle away from the facet cutting edge. The lead cutting edge angle is selected to provide effective milling of the workpiece at entry. The cutting inserts have side seating surfaces that allow the inserts to be more stably supported in cutting insert pockets.

A minor cutting edge has a first minor cutting edge and a second minor cutting edge that extends inward of the insert in a direction of an insert short side face axial line, as the second minor cutting edge extends from the first minor cutting edge in a direction of an insert major face axial line. A flank face of the second minor cutting edge is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from the second minor cutting edge in the direction of an insert long side face axial line, and is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from a major face adjacent to the flank face in the direction of the insert major face axial line.

A cutting insert of an embodiment includes an upper surface including a first upper cutting edge and a second upper cutting edge, a lower surface including a first lower cutting edge and a second lower cutting edge, and a side surface. The side surface includes a first surface extending from the second upper cutting edge, a second surface extending from the first lower cutting edge, a third surface extending from the first upper cutting edge, and a fourth surface extending from the second lower cutting edge. The first surface and the fourth surface are parallel to a central axis. The second surface is inclined so as to depart from the central axis as going from the lower surface toward the upper surface. The third surface is inclined so as to depart from the central axis as going from the upper surface toward the lower surface.

A cutting insert has opposing first and second end surfaces, and a peripheral side surface (connecting the end surfaces. A central axis penetrates the two end surfaces. The peripheral sure surface includes an outwardly inclined first side surface part related to a major cutting edge and a second side surface part related to a minor cutting edge. The outwardly inclined first side surface part gradually extends outward from the cutting insert, heading from the first end surface to the second end surface. When a second virtual plane, which is substantially perpendicular to the central axis and passes through the major cutting edge, is defined, an inwardly inclined part, on a back side of the cutting edge, of the second end surface is inclined so as to become more distant from the second virtual plane, heading from the outwardly inclined first side surface part to the central axis.

A cutting insert includes a cutting edge portion, and the cutting edge portion includes a bottom cutting edge forming an arc shape that protrudes toward a front end side in a central axis direction, an outer peripheral cutting edge forming an arc shape that protrudes toward an outside in a radial direction, and a cutting edge of corner that connects an outer end of the bottom cutting edge in the radial direction and a front end of the outer peripheral cutting edge in the central axis direction and forms an arc shape that protrudes toward a front end outer circumferential side. The bottom cutting edge and the outer peripheral cutting edge are formed so as to form a linearly symmetric shape together with respect to an imaginary straight line that passes through an arc central point of the cutting edge of corner and intersects the central axis.

The present invention relates to a cutting device and a chamfering machine comprising the same, and according to one aspect of the present invention, a cutting device for use in a chamfering process of a film laminate is provided, in which the cutting device comprises a rotating wheel having a rotation center; and a cutting bite comprising a main body mounted on the rotating wheel and a cutting tip provided on the main body and provided to perform chamfering of the film laminate by rotating the rotating wheel, wherein the cutting bite is mounted on the rotating wheel such that the central axis of the cutting tip is inclined at a first angle with respect to the tangential direction of a rotation locus of the cutting bite formed by rotating the rotating wheel.

A cutting insert includes first and second polygonal surfaces and a plurality of side surfaces. A corner edge that has a corner rake surface on the first polygonal surface is formed at a first corner portion, and a main cutting edge is formed from the corner edge to a second corner portion. The main cutting edge includes, at least on a corner edge side, a rake angle gradual increase region where a rake angle of a main rake surface gradually increases to a positive angle side as going from a first end portion of the corner edge toward a second corner portion side.