A numerical controller includes a motion start point determination unit that calculates a cycle motion start point where the screw thread cutting cycle is to be started, an acceleration/deceleration control unit that moves the tool from the cycle motion start point to a screw thread cutting start point with motions of a plurality of axes overlapped, and a control unit that controls motions of a machining device based on control instructions received from an instruction analysis unit and the acceleration/deceleration control unit. The cycle motion start point is a point from which acceleration or deceleration of a first axis and a second axis orthogonal to the first axis is started so as to make a speed of the first axis reach a specified cutting feed speed and to make a speed of the second axis substantially become zero at time of arrival at the screw thread cutting start point.

A numerical controller includes a motion start point determination unit that calculates a cycle motion start point where the screw thread cutting cycle is to be started, an acceleration/deceleration control unit that moves the tool from the cycle motion start point to a screw thread cutting start point with motions of a plurality of axes overlapped, and a control unit that controls motions of a machining device based on control instructions received from an instruction analysis unit and the acceleration/deceleration control unit. The cycle motion start point is a point from which acceleration or deceleration of a first axis and a second axis orthogonal to the first axis is started so as to make a speed of the first axis reach a specified cutting feed speed and to make a speed of the second axis substantially become zero at time of arrival at the screw thread cutting start point.

An indexable cutting tool that allows for stable clamping of cutting inserts and prevents contact between head parts of fastening members and workpieces is provided. Recesses with a bottom are formed in an upper surface of the cutting insert. At least part of an inner wall surface of the recess is a curved surface bulged toward a center axis of the recess. When the recess is divided into four, first to fourth, regions by a first imaginary reference plane parallel to a rotation axis of a body and a second imaginary reference plane perpendicular to the rotation axis, the second region is located on a center side and on a proximal side of the body. A tapered surface of the fastening member makes contact with the curved surface within the second region. A center axis line of the fastening member is inclined such that the head part opposite from a distal end part is located closer to the center side and to the proximal side of the body than the distal end part.

An indexable cutting tool that allows for stable clamping of cutting inserts and prevents contact between head parts of fastening members and workpieces is provided. Recesses with a bottom are formed in an upper surface of the cutting insert. At least part of an inner wall surface of the recess is a curved surface bulged toward a center axis of the recess. When the recess is divided into four, first to fourth, regions by a first imaginary reference plane parallel to a rotation axis of a body and a second imaginary reference plane perpendicular to the rotation axis, the second region is located on a center side and on a proximal side of the body. A tapered surface of the fastening member makes contact with the curved surface within the second region. A center axis line of the fastening member is inclined such that the head part opposite from a distal end part is located closer to the center side and to the proximal side of the body than the distal end part.

The invention relates to a thread milling cutter for manufacturing an internal thread, wherein the thread milling cutter has at least one section with multiple teeth, wherein a pitch is arranged between every two adjacent teeth, wherein the predominant number of pitches corresponds to a desired pitch and there is at least one pitch that deviates from the desired pitch.

The invention further relates to a method for manufacturing an external thread on a component or an internal thread in a component, wherein, in one step, a thread milling cutter according to the invention is advanced into the wall of the component and in another step, the thread milling cutter is moved along the extent of the wall once and in this way is moved in the axial direction by one lead of a thread turn.

The invention relates to a thread milling cutter for manufacturing an internal thread, wherein the thread milling cutter has at least one section with multiple teeth, wherein a pitch is arranged between every two adjacent teeth, wherein the predominant number of pitches corresponds to a desired pitch and there is at least one pitch that deviates from the desired pitch.

The invention further relates to a method for manufacturing an external thread on a component or an internal thread in a component, wherein, in one step, a thread milling cutter according to the invention is advanced into the wall of the component and in another step, the thread milling cutter is moved along the extent of the wall once and in this way is moved in the axial direction by one lead of a thread turn.

A whirling tool for machining a workpiece, having: three or a multiple of three cutting plates, wherein each of the cutting plates comprises at least one cutting edge; a cutting plate holder having a plurality of cutting plate receptacles, wherein each of the cutting plate receptacles is configured to receive one of the cutting plates, wherein the cutting plate receptacles are disposed so as to be distributed in a circumferential direction across the cutting plate holder; and a plurality of fastening elements for releasably fastening the cutting plates in the cutting plate receptacles of the cutting plate holder; wherein the cutting plates comprise at least two different kinds of cutting plates, wherein at least one cutting plate of a first kind, and one cutting plate of a second kind are provided for each group of three cutting plates that are disposed beside one another on the cutting plate holder, wherein the cutting plate of the first kind differs from the cutting plate of the second kind by an overall geometry, by a dimension of the at least one cutting edge, and by a shape of the at least one cutting edge.

A whirling tool for machining a workpiece, having: three or a multiple of three cutting plates, wherein each of the cutting plates comprises at least one cutting edge; a cutting plate holder having a plurality of cutting plate receptacles, wherein each of the cutting plate receptacles is configured to receive one of the cutting plates, wherein the cutting plate receptacles are disposed so as to be distributed in a circumferential direction across the cutting plate holder; and a plurality of fastening elements for releasably fastening the cutting plates in the cutting plate receptacles of the cutting plate holder; wherein the cutting plates comprise at least two different kinds of cutting plates, wherein at least one cutting plate of a first kind, and one cutting plate of a second kind are provided for each group of three cutting plates that are disposed beside one another on the cutting plate holder, wherein the cutting plate of the first kind differs from the cutting plate of the second kind by an overall geometry, by a dimension of the at least one cutting edge, and by a shape of the at least one cutting edge.

A whirling tool for machining a workpiece, having: three or a multiple of three cutting plates, wherein each of the cutting plates comprises at least one cutting edge; a cutting plate holder having a plurality of cutting plate receptacles, wherein each of the cutting plate receptacles is configured to receive one of the cutting plates, wherein the cutting plate receptacles are disposed so as to be distributed in a circumferential direction across the cutting plate holder; and a plurality of fastening elements for releasably fastening the cutting plates in the cutting plate receptacles of the cutting plate holder; wherein the cutting plates comprise at least two different kinds of cutting plates, wherein at least one cutting plate of a first kind, and one cutting plate of a second kind are provided for each group of three cutting plates that are disposed beside one another on the cutting plate holder, wherein the cutting plate of the first kind differs from the cutting plate of the second kind by an overall geometry, by a dimension of the at least one cutting edge, and by a shape of the at least one cutting edge.

A whirling tool for machining a workpiece, having: three or a multiple of three cutting plates, wherein each of the cutting plates comprises at least one cutting edge; a cutting plate holder having a plurality of cutting plate receptacles, wherein each of the cutting plate receptacles is configured to receive one of the cutting plates, wherein the cutting plate receptacles are disposed so as to be distributed in a circumferential direction across the cutting plate holder; and a plurality of fastening elements for releasably fastening the cutting plates in the cutting plate receptacles of the cutting plate holder; wherein the cutting plates comprise at least two different kinds of cutting plates, wherein at least one cutting plate of a first kind, and one cutting plate of a second kind are provided for each group of three cutting plates that are disposed beside one another on the cutting plate holder, wherein the cutting plate of the first kind differs from the cutting plate of the second kind by an overall geometry, by a dimension of the at least one cutting edge, and by a shape of the at least one cutting edge.