Abstract: A cutting insert includes a cylindrical body portion, a cutting portion, a first fitting portion, a second fitting portion, and a third fitting portion. The cutting portion includes a rake face and a flank face. A ridgeline between the rake face and the flank face constitutes a cutting edge. When viewed in the axial direction, the cutting portion is provided opposite to the third fitting portion relative to the insertion hole. When viewed in the axial direction, a straight line extending through an outer circumferential end of the cutting edge and a center of the insertion hole overlaps with the third fitting portion and is located between the first fitting portion and the second fitting portion. A third central angle is smaller than a first central angle and is smaller than a second central angle.

Abstract: A cutting insert according to the present disclosure includes a first surface, a second surface, a side surface, and a cutting edge. The first surface has a rake face continuous to the cutting edge. The cutting edge has a corner cutting edge, a flat cutting edge, and a main cutting edge. The rake face has a first rake face portion, a second rake face portion, and a third rake face portion, the first rake face portion being continuous to the flat cutting edge, the second rake face portion being continuous to the main cutting edge, the third rake face portion being continuous to the corner cutting edge and being located between the first rake face portion and the second rake face portion. The rake face is provided with a level difference portion.

Abstract: A manufacturing method, a manufacturing apparatus, a computer readable recording medium, and a program for manufacturing a machine component having a rotation symmetry plane are provided.

Abstract: A cutting insert includes a cylindrical body portion, a cutting portion, a first fitting portion, a second fitting portion, and a third fitting portion. The cutting portion includes a rake face and a flank face. A ridgeline between the rake face and the flank face constitutes a cutting edge. When viewed in the axial direction, the cutting portion is provided opposite to the third fitting portion relative to the insertion hole. When viewed in the axial direction, a straight line extending through an outer circumferential end of the cutting edge and a center of the insertion hole overlaps with the third fitting portion and is located between the first fitting portion and the second fitting portion. A third central angle is smaller than a first central angle and is smaller than a second central angle.

Abstract: A method for manufacturing a machine component includes determining a track of a cutting edge and feeding the cutting edge along the track. The determining a track includes calculating a coordinate (X(t), Y(t), Z(t)) of a first end portion of the cutting edge in accordance with X(t)=(Rsh(t)cos ?(t)?Xchip(t)), Y(t)=(Rsh(t)sin ?(t)?Ychip(t)), and Z(t)=(Zsh(t)?Zchip(t)), where a variable t assumes (N+1) values not smaller than 0 and not greater than 1. ?(t) represents an angle formed by a straight line connecting a point of cutting projected on an XY plane and an origin of the XY plane to each other with respect to an X axis, and ?(t) satisfies a condition tan ? ? ? ? ( t ) = tan ? ? ? · tan ? ? ? s - tan ? ? ? · tan 2 ? ? + tan 2 ? ? - tan 2 ? ? s tan ? ? ? · tan ? ? ? s + tan ? ? ? · tan 2 ? ? + tan 2 ? ? - tan 2 ? ? s .

Abstract: A method of correcting a track of a cutting edge is provided. With movement of the cutting edge, a point on the cutting edge in contact with the rotation symmetry plane is moved along the cutting edge from a first end portion of the cutting edge to a second end portion of the cutting edge opposite to the first end portion. The correction method includes measuring, by a measurement unit, a shape of the cut and machined rotation symmetry plane, calculating, by an operation unit, an error of the measured shape of the rotation symmetry plane from a target shape of the rotation symmetry plane in a direction of the axial line of rotation, and correcting, by the operation unit, a component in the direction of the axial line of rotation of a track of a point of cutting based on the error.

Abstract: A cutting edge has a corner cutting edge, a flat drag, and a main cutting edge. The rake surface has a first rake surface portion, a second rake surface portion, and a third rake surface portion. The first rake surface portion has a first inclined surface inclined at a first angle. The second rake surface portion has a second inclined surface inclined at a second angle greater than the first angle. The first end portion and the second end portion are higher than the reference surface in a direction perpendicular to the reference surface, and the main cutting edge extends so as to intersect the reference surface when viewed in a direction parallel to the reference surface. A first step portion rising from the third rake surface portion and continuous with the first rake surface portion is provided on the rake surface.

Abstract: The cutting edge has: a corner cutting edge; a flat cutting edge continuous to a first end portion of the corner cutting edge; and a main cutting edge continuous to a second end portion of the corner cutting edge opposite to the first end portion of the corner cutting edge. The rake face has: a first rising surface portion; and a first rake face portion continuous to the first rising surface portion and located opposite to the corner cutting edge when viewed from the first rising surface portion. When viewed in a direction perpendicular to the reference surface, the first boundary includes a first line segment extending, from one of the flat cutting edge and the corner cutting edge, in a direction crossing a straight line extending along the main cutting edge.

Abstract: The edge portion includes an upper surface, a side surface, and a land surface. The side surface has a front side surface and a pair of lateral side surfaces. An intersection between the land surface and the front side surface forms a front cutting edge. An intersection between the land surface and each of the pair of lateral side surfaces form a corresponding one of a pair of lateral cutting edges. The edge portion contains 80 vol % or more of diamond. A chip breaker recess is provided between the upper surface and the land surface. The surfaces forming the chip breaker recess include a rake face and a breaker wall surface. The upper surface has a front edge portion opposite to the front cutting edge from the chip breaker recess. A pair of protruding portions are provided to extend from the front edge portion toward the front cutting edge.

Abstract: A method for manufacturing a machine component having a rotation symmetry plane includes machining a rotation symmetry plane. The machining a rotation symmetry plane includes determining a track of the cutting. The determining a track determines the track in accordance with a condition that (1) a first end portion of the cutting edge is positioned at a cutting start position of the rotation symmetry plane, (2) N regions defined by division of the cutting edge successively come in contact with the rotation symmetry plane, (3) an inclination of a tangent line at a point of cutting of each of the N regions is equal to a target inclination of a tangent line which passes through the point of cutting and comes in contact with the rotation symmetry plane in a cut plane of the rotation symmetry plane, and (4) a second end of the cutting edge is positioned at a cutting end position of the rotation symmetry plane.

Abstract: There is provided a rotary tool including a rotary tool body and a blade provided to the rotary tool body and having a cutting edge, the blade containing 80% by volume or more of diamond, and the blade including a land surface extending along the cutting edge, and a chip breaker having a recess located opposite to the cutting edge with the land surface therebetween.

Abstract: A method for manufacturing a machine component includes determining a track of a cutting edge and feeding the cutting edge along the track. The determining a track includes calculating a coordinate (X(t), Y(t), Z(t)) of a first end portion of the cutting edge in accordance with X(t)=(Rsh(t)cos ?(t)?Xchip(t)), Y(t)=(Rsh(t)sin ?(t)?Ychip(t)), and Z(t)=(Zsh(t)?Zchip(t)), where a variable t assumes (N+1) values not smaller than 0 and not greater than 1. ?(t) represents an angle formed by a straight line connecting a point of cutting projected on an XY plane and an origin of the XY plane to each other with respect to an X axis, and ?(t) satisfies a condition tan ? ? ? ? ( t ) = tan ? ? ? · tan ? ? ? s - tan ? ? ? · tan 2 ? ? + tan 2 ? ? - tan 2 ? ? s tan ? ? ? · tan ? ? ? s + tan ? ? ? · tan 2 ? ? + tan 2 ? ? - tan 2 ? ? s .

Abstract: A cutting insert according to the present disclosure includes a first surface, a second surface, a side surface, and a cutting edge. The first surface has a rake face continuous to the cutting edge. The cutting edge has a corner cutting edge, a flat cutting edge, and a main cutting edge. The rake face has a first rake face portion, a second rake face portion, and a third rake face portion, the first rake face portion being continuous to the flat cutting edge, the second rake face portion being continuous to the main cutting edge, the third rake face portion being continuous to the corner cutting edge and being located between the first rake face portion and the second rake face portion. The rake face is provided with a level difference portion.

Abstract: A manufacturing method, a manufacturing apparatus, a computer readable recording medium, and a program for manufacturing a machine component having a rotation symmetry plane are provided.

Abstract: A cutting edge has a corner cutting edge, a flat drag, and a main cutting edge. The rake surface has a first rake surface portion, a second rake surface portion, and a third rake surface portion. The first rake surface portion has a first inclined surface inclined at a first angle. The second rake surface portion has a second inclined surface inclined at a second angle greater than the first angle. The first end portion and the second end portion are higher than the reference surface in a direction perpendicular to the reference surface, and the main cutting edge extends so as to intersect the reference surface when viewed in a direction parallel to the reference surface. A first step portion rising from the third rake surface portion and continuous with the first rake surface portion is provided on the rake surface.

Abstract: A method includes positioning a linear cutting edge inclined at an angle greater than 0° and smaller than 90° with respect to a Z axis at a cutting start position displaced from a position on an X axis along a direction of a Y axis in a three-dimensional orthogonal coordinate system in which an axial line of rotation of a rotation symmetry plane is defined as the Z axis, an axis in a radial direction of the rotation symmetry plane is defined as the X axis, and an axis orthogonal to both of the Z axis and the X axis is defined as the Y axis and machining the rotation symmetry plane by feeding the cutting edge from the cutting start position along a track having an X axis component, a Y axis component, and a Z axis component while the cutting edge is in contact with a rotating machine component.