Gear machining apparatus and gear machining method

Patent metadata

Field	Value
Publication number	US-11077508-B2
Application number	US-201916571397-A
Country	US
Kind code	B2
Filing date	Sep 16, 2019
Priority date	Sep 18, 2018
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A gear machining apparatus performs cutting work for a workpiece and generates a gear by performing a feed operation of a gear cutter relative to the workpiece along a direction of an axis of the workpiece while synchronously rotating the gear cutter and the workpiece in a state in which an axis of the gear cutter is inclined with respect to a line parallel to the axis of the workpiece. The gear machining apparatus continuously performs cutting work for a first tooth flank and cutting work for a second tooth flank during a single feed operation, and changes a correction angle between the cutting work for the first tooth flank and the cutting work for the second tooth flank.

First claim

What is claimed is:

1. A gear machining apparatus configured to perform cutting work for a workpiece and generate a gear by performing a feed operation of a gear cutter relative to the workpiece along a direction of an axis of the workpiece while synchronously rotating the gear cutter and the workpiece in a state in which an axis of the gear cutter is inclined with respect to a line parallel to the axis of the workpiece,
the gear having a plurality of teeth each having a face provided with a gear slip preventing portion including:
a first tooth flank; and
a second tooth flank formed continuous with the first tooth flank and having a helix angle different from a helix angle of the first tooth flank,

the gear machining apparatus comprising a machining control unit configured to control rotation of the workpiece and rotation of the gear cutter, and control the feed operation of the gear cutter relative to the workpiece, wherein
a position where the gear cutter cuts the face is defined as a cutting point, the cutting point when the cutting work is started is defined as a start point, and the cutting point when the gear cutter is fed by a predetermined feed amount from the start point is defined as a movement point,
the cutting point when the gear cutter is fed by the predetermined feed amount from the start point while the workpiece and the gear cutter rotate in a predetermined reference synchronous rotation state is defined as a reference movement point,
a phase shift angle to one side in a circumferential direction of the workpiece, which is set to shift a phase of the movement point from a phase of the reference movement point when the gear cutter is fed by the predetermined feed amount from the start point, is defined as a correction angle, and
the machining control unit is configured to continuously perform the cutting work for the first tooth flank and the cutting work for the second tooth flank during the feed operation performed on a single occasion, and change the correction angle between the cutting work for the first tooth flank and the cutting work for the second tooth flank.

2. The gear machining apparatus according to claim 1 , wherein the machining control unit is configured to temporarily stop the feed operation during a period from a finish of the cutting work for the first tooth flank to a start of the cutting work for the second tooth flank.

3. The gear machining apparatus according to claim 1 , wherein the machining control unit is configured to perform the feed operation while decelerating the feed operation during a period from a finish of the cutting work for the first tooth flank to a start of the cutting work for the second tooth flank.

4. The gear machining apparatus according to claim 1 , wherein the machining control unit is configured to perform the feed operation at a constant speed during a period from a start of the cutting work for the first tooth flank to a finish of the cutting work for the second tooth flank.

5. The gear machining apparatus according to claim 2 , wherein the machining control unit is configured to set the correction angle to 0° during the period from the finish of the cutting work for the first tooth flank to the start of the cutting work for the second tooth flank.

6. The gear machining apparatus according to claim 1 , wherein the machining control unit is configured to set the correction angle to a positive angle in one of the cutting work for the first tooth flank and the cutting work for the second tooth flank, and set the correction angle to a negative angle in the other one of the cutting work for the first tooth flank and the cutting work for the second tooth flank.

7. The gear machining apparatus according to claim 1 , wherein the machining control unit is configured to change a rotation speed ratio of the workpiece to the gear cutter between the cutting work for the first tooth flank and the cutting work for the second tooth flank.

8. The gear machining apparatus according to claim 7 , wherein the machining control unit is configured to keep a rotation speed of one of the workpiece and the gear cutter at a constant rotation speed and change a rotation speed of the other one of the workpiece and the gear cutter in the cutting work for the first tooth flank and in the cutting work for the second tooth flank.

9. A gear machining method for performing cutting work for a workpiece and generating a gear by performing a feed operation of a gear cutter relative to the workpiece along a direction of an axis of the workpiece while synchronously rotating the gear cutter and the workpiece in a state in which an axis of the gear cutter is inclined with respect to a line parallel to the axis of the workpiece, wherein
the gear has a plurality of teeth each having a face provided with a gear slip preventing portion including:
a first tooth flank; and
a second tooth flank formed continuous with the first tooth flank and having a helix angle different from a helix angle of the first tooth flank,

a position where the gear cutter cuts the face is defined as a cutting point, the cutting point when the cutting work is started is defined as a start point, and the cutting point when the gear cutter is fed by a predetermined feed amount from the start point is defined as a movement point,
the cutting point when the gear cutter is fed by the predetermined feed amount from the start point while the workpiece and the gear cutter rotate in a predetermined reference synchronous rotation state is defined as a reference movement point, and
a phase shill angle to one side in a circumferential direction of the workpiece, which is set to shift a phase of the movement point from a phase of the reference movement point when the gear cutter is fed by the predetermined feed amount from the start point, is defined as a correction angle,
the gear machining method comprising continuously performing the cutting work for the first tooth flank and the cutting work for the second tooth flank during the feed operation performed on a single occasion, and changing the correction angle between the cutting work for the first tooth flank and the cutting work for the second tooth flank.

10. The gear machining method according to claim 9 , further comprising:
cutting the first tooth flank in a state in which the correction angle is set to a first angle;
changing the correction angle from the first angle to a second angle while rotating the workpiece and the gear cutter; and
cutting the second tooth flank in a state in which the correction angle is set to the second angle.

11. The gear machining method according to claim 10 , wherein the changing the correction angle is performed in a state in which the feed operation is stopped.

12. The gear machining method according to claim 10 , wherein the changing the correction angle is performed while decelerating the feed operation.

13. The gear machining method according to claim 10 , wherein the changing the correction angle is performed in a state in which a speed of the feed operation is set to the same speed between the cutting the first tooth flank and the cutting the second tooth flank.

14. The gear machining method according to claim 11 , wherein the changing the correction angle is performed in a state in which the correction angle is set to 0°.

Assignees

• Jtekt Corp

Inventors

• Nakano Hiroyuki
• Otani Hisashi
• Takasu Shuntaro

Classifications

• B23F5/12 Primary

  by planing or slotting · CPC title

• B23F15/00 Primary

  Methods or machines for making gear wheels of special kinds not covered by groups B23F7/00 - B23F13/00 · CPC title

• B23F5/163 Primary

  the tool and workpiece being in crossed axis arrangement, e.g. skiving, i.e. "Waelzschaelen" · CPC title