EP-4737040-A1 - MACHINING METHOD FOR GEAR COMPONENT, PROGRAM THEREFOR, AND MACHINING DEVICE

EP4737040A1EP 4737040 A1EP4737040 A1EP 4737040A1EP-4737040-A1

Abstract

The present invention provides a gear part machining method, a program, and a machining apparatus that accurately machine a non-toothed part. The machining method according to the present invention includes: causing a workpiece spindle to hold one end portion of a cylindrical workpiece with an axis of the cylindrical workpiece aligned with a rotation machining axis. The cylindrical workpiece includes a toothed part formed by performing tooth forming on a part of a circumferential surface of the cylindrical workpiece. The part of the circumferential surface extends along a direction of the axis of the cylindrical workpiece. The toothed part is measured to calculate a misalignment between a center axis of the toothed part and the rotation machining axis. Another end portion of the cylindrical workpiece is machined eccentrically relative to the rotation machining axis based on the misalignment. The program causes the workpiece spindle to hold the one end portion of the cylindrical workpiece with the axis of the cylindrical workpiece aligned with the rotation machining axis, the cylindrical workpiece including the toothed part formed by performing the tooth forming on the part of the circumferential surface of the cylindrical workpiece, the part of the circumferential surface extending along the direction of the axis of the cylindrical workpiece; causes the toothed part to be measured; causes the misalignment between the center axis of the toothed part and the rotation machining axis to be calculated based on the measured measurement value; and causes the other end portion of the cylindrical workpiece to be machined eccentrically relative to the rotation machining axis based on the calculated misalignment. The machining apparatus includes a first workpiece spindle, a tool holder, a mover and a controller configured to control operations of these elements. The machining apparatus follows the above-described machining program.

Inventors

HAYASHI TOSHIKI
TAJIMA JUN
Mishina Masahiro
YAMAMOTO YUKI

Assignees

Yamazaki Mazak Corporation

Dates

Publication Date: 20260506
Application Date: 20240426

Claims (14)

A gear part machining method comprising: causing a workpiece spindle to hold one end portion of a cylindrical workpiece with an axis of the cylindrical workpiece aligned with a rotation machining axis, the cylindrical workpiece including a toothed part formed by performing tooth forming on a part of a circumferential surface of the cylindrical workpiece, the part of the circumferential surface extending along the axis of the cylindrical workpiece; measuring the toothed part to calculate a misalignment between a center axis of the toothed part and the rotation machining axis; and machining another end portion of the cylindrical workpiece eccentrically relative to the rotation machining axis based on the misalignment.
The gear part machining method according to claim 1, wherein the measuring of the toothed part includes measuring a pitch of a tooth portion of the toothed part while rotating the workpiece about the rotation machining axis.
The gear part machining method according to claim 2, wherein based on a rotation phase difference of the tooth portion of the toothed part, the misalignment is calculated as an eccentricity amount and an eccentricity direction of the center axis relative to the rotation machining axis.
The gear part machining method according to any one of claims 1 to 3, wherein the eccentric machining is performed while rotating the workpiece about the rotation machining axis.
The gear part machining method according to any one of claims 1 to 3, wherein the eccentric machining is performed using a rotatable rotation tool.
The gear part machining method according to any one of claims 1 to 3, wherein the toothed part is formed by performing the tooth forming on an outer circumferential surface of the workpiece.
The gear part machining method according to any one of claims 1 to 3, wherein the workpiece is formed by machining a cylindrical material by: causing the workpiece spindle to hold the cylindrical material; and turning a portion of the cylindrical material corresponding to the one end portion of the workpiece and performing the tooth forming to form the toothed part.
A gear-part machining program that: causes a workpiece spindle to hold one end portion of a cylindrical workpiece with an axis of the cylindrical workpiece aligned with a rotation machining axis, the cylindrical workpiece including a toothed part formed by performing tooth forming on a part of a circumferential surface of the cylindrical workpiece, the part of the circumferential surface extending along the axis of the cylindrical workpiece; causes the toothed part to be measured; causes a misalignment between a center axis of the toothed part and the rotation machining axis to be calculated based on the measured measurement value; and causes another end portion of the cylindrical workpiece to be machined eccentrically relative to the rotation machining axis based on the calculated misalignment.
The gear-part machining program according to claim 8, wherein the toothed part is measured by measuring a pitch of a tooth portion of the toothed part while rotating the workpiece about the rotation machining axis.
The gear-part machining program according to claim 9, wherein based on a rotation phase difference of the tooth portion of the toothed part, the misalignment is calculated as an eccentricity amount and an eccentricity direction of the center axis relative to the rotation machining axis.
The gear part machining program according to any of claims 8 to 10, wherein the workpiece is formed by machining a cylindrical material by: causing the workpiece spindle to hold the cylindrical material; and turning a portion of the cylindrical material corresponding to the one end portion of the workpiece and performing the tooth forming to form the toothed part.
A machining apparatus comprising: a first workpiece spindle configured to hold a workpiece so as to be rotatable; a tool holder configured to hold a measurement instrument or a tool; a mover configured to move the first workpiece spindle and the tool holder relative to each other; and a controller configured to control an operation of the first workpiece spindle, an operation of the tool holder, and an operation of the mover, based on a machining program, the machining apparatus being configured to: cause the first workpiece spindle to hold one end portion of the workpiece that has a cylindrical shape with an axis of the cylindrical workpiece aligned with a rotation machining axis, the cylindrical workpiece including a toothed part formed by performing tooth forming on a part of a circumferential surface of the cylindrical workpiece, the part of the circumferential surface extending along the axis of the cylindrical workpiece; measure the toothed part using the measurement instrument held by the tool holder; calculate a misalignment between a center axis of the toothed part and the rotation machining axis based on the measured measurement value; and using the tool held by the tool holder, machine another end portion of the cylindrical workpiece eccentrically relative to the rotation machining axis based on the calculated misalignment.
The machining apparatus according to claim 12, further comprising a second workpiece spindle configured to hold the workpiece so as to be rotatable, wherein the workpiece is formed by machining a cylindrical material by: causing the second workpiece spindle to hold the cylindrical material; and turning a portion of the cylindrical material corresponding to the one end portion of the workpiece and performing the tooth forming to form the toothed part.
The machining apparatus according to claim 12 or 13, further comprising a changer configured to change the tool and the measurement instrument held by the tool holder.

Description

Technical Field The present invention relates to a gear part machining method, a program thereof, and a machining apparatus. In particular, the present invention relates to a gear part machining method for machining a non-toothed part, a program for machining a non-toothed part, and a machining apparatus that machines a non-toothed part. Background Art A tooth forming method is known in which a hobbing cutter is rotated and pressed against a rotating workpiece to cut the rotating workpiece into a gear part. If a rotation axis of a rotation table is not aligned with an axis of the workpiece, gear teeth on the gear part are formed eccentrically. For example, Patent Literature 1 discloses such a machining method that in tooth forming using a hobbing machine, a rotation phase of the rotation table and a cutting depth of the hobbing cutter are corrected to cancel the eccentricity amount between the rotation axis of the rotation table and the axis of the workpiece. According to Patent Literature 1, even if the workpiece is attached to the rotation table eccentrically, the workpiece can be machined into a gear highly accurately. Citation List Patent Literature PTL1: WO/2011/129008. Summary of Invention Technical Problem Incidentally, when a multitasking machine is used, it is possible to: attach a hobbing cutter to the multitasking machine to perform gear-forming machining on, for example, a circumferential surface of the workpiece, thereby forming a toothed part; and change the tool to subsequently perform cutting on another part of the workpiece. In this respect, there may be a case that after tooth forming of the workpiece, the workpiece is temporarily removed from a workpiece spindle, and then attached again to subject the workpiece to rotation cutting. In this case, a rotation axis of the workpiece spindle can not be aligned with a center axis of the toothed part of the attached workpiece, with the result that rotation cutting can not be performed accurately. The same applies in a case that a tooth-formed part is attached to a machining apparatus to subject the tooth-formed part to rotation cutting. It is an object of the present invention to provide a gear part machining method for accurately machining a part of a workpiece other than a toothed part, a program for accurately machining a part of a workpiece other than a toothed part, and a machining apparatus that accurately machines a part of a workpiece other than a toothed part. Solution to Problem A gear part machining method according to the present invention includes causing a workpiece spindle to hold one end portion of a cylindrical workpiece with an axis of the cylindrical workpiece aligned with a rotation machining axis. The cylindrical workpiece includes a toothed part formed by performing tooth forming on a part of a circumferential surface of the cylindrical workpiece. The part of the circumferential surface extends along the axis of the cylindrical workpiece. The toothed part is measured to calculate a misalignment between a center axis of the toothed part and the rotation machining axis. Another end portion of the cylindrical workpiece is machined eccentrically relative to the rotation machining axis based on the misalignment. A machining program according to the present invention causes a workpiece spindle to hold one end portion of a cylindrical workpiece with an axis of the cylindrical workpiece aligned with a rotation machining axis. The cylindrical workpiece includes a toothed part formed by performing tooth forming on a part of a circumferential surface of the cylindrical workpiece. The part of the circumferential surface extends along the axis of the cylindrical workpiece. The gear-part machining program causes the toothed part to be measured. The gear-part machining program causes a misalignment between a center axis of the toothed part and the rotation machining axis to be calculated based on the measured measurement value. The gear-part machining program causes another end portion of the cylindrical workpiece to be machined eccentrically relative to the rotation machining axis based on the calculated misalignment. A machining apparatus according to the present invention includes a first workpiece spindle, a tool holder, a mover, and a controller. The first workpiece spindle is configured to hold a workpiece so as to be rotatable. The tool holder is configured to hold a measurement instrument or a tool. The mover is configured to move the first workpiece spindle and the tool holder relative to each other. The controller is configured to control an operation of the first workpiece spindle, an operation of the tool holder, and an operation of the mover. Based on a machining program, the machining apparatus is configured to cause the first workpiece spindle to hold one end portion of the workpiece that has a cylindrical shape with an axis of the cylindrical workpiece aligned with a rotation machining axis. The cylindrical workpiece includ