Gear machining apparatus and gear machining method

Patent metadata

Field	Value
Publication number	US-11033974-B2
Application number	US-201916571410-A
Country	US
Kind code	B2
Filing date	Sep 16, 2019
Priority date	Sep 18, 2018
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A gear machining apparatus and a gear machining method are provided. The 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 sets a correction angle to a first angle when cutting work for a second tooth flank is started after cutting work for a first tooth flank is finished, and moves the gear cutter from a first finish position to a second start position while rotating the workpiece and the gear cutter.

First claim

What is claimed is:

1. A gear machining apparatus configured to perform cutting work for 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 one face including:
a first tooth flank; and
a second tooth flank 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 start position of the feed operation when the first tooth flank is formed is defined as a first start position, a finish position of the feed operation when the first tooth flank is formed is defined as a first finish position, and a start position of the feed operation when the second tooth flank is formed is defined as a second start position,
a position where the gear cutter cuts the one 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,
a phase shift angle of the second start position from the first finish position to the one side in the circumferential direction of the workpiece is defined as a first angle, and
the machining control unit is configured to set the correction angle to the first angle when the cutting work for the second tooth flank is started after the cutting work for the first tooth flank is finished, and move the gear cutter from the first finish position to the second start position while rotating the workpiece and the gear cutter.

2. The gear machining apparatus according to claim 1 , wherein the machining control unit is configured to shift the phase of the movement point from the phase of the reference movement point by feeding the gear cutter by the predetermined feed amount from the start point while rotating the workpiece and the gear cutter at a rotation speed ratio different from a rotation speed ratio in a reference synchronous rotation state in which the workpiece and the gear cutter rotate synchronously.

3. The gear machining apparatus according to claim 2 , wherein the machining control unit is configured to compute the rotation speed ratio between the workpiece and the gear cutter when the gear cutter is fed by the predetermined feed amount from the start point based on a distance between the first finish position and the second start position in the direction of the axis of the workpiece and based on the correction angle.

4. The gear machining apparatus according to claim 1 , wherein
a phase shift angle of the first finish position from the first start position to the one side in the circumferential direction of the workpiece is defined as a second angle, and a phase shift angle of the second start position from the first start position to the one side in the circumferential direction of the workpiece is defined as a third angle, and
the machining control unit is configured to set, as the first angle, an angle obtained by subtracting the second angle from the third angle.

5. The gear machining apparatus according to claim 1 , wherein
the other face of each of the plurality of teeth includes:
a third tooth flank having a helix angle different from the helix angle of the first tooth flank; and
a fourth tooth flank having a helix angle different from the helix angle of the third tooth flank,

a start position of the feed operation when the third tooth flank is formed is defined as a third start position, a finish position of the feed operation when the third tooth flank is formed is defined as a third finish position, and a start position of the feed operation when the fourth tooth flank is formed is defined as a fourth start position,
a phase shift angle of the fourth start position from the third finish position to the other side in the circumferential direction of the workpiece is defined as a fourth angle, and
the machining control unit is configured to:
set a rotation direction of the workpiece and a rotation direction of the gear cutter to be identical between the cutting work for the first tooth flank and the cutting work for the second is sobs flank, and set, after the cutting work for the second tooth flank is finished, the rotation direction of the workpiece and the rotation direction of the gear cutter to be opposite to the rotation direction of the workpiece and the rotation direction of the gear cutter in the cutting work for the first tooth flank; and
set the correction angle to the fourth angle when the cutting work for the fourth tooth flank is started after the cutting work for the third tooth flank is finished, and move the gear cutter from the third finish position to the fourth start position while rotating the workpiece and the gear cutter.

6. 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 one face including:
a first tooth flank; and
a second tooth flank having a helix angle different from a helix angle of the first tooth flank,

a start position of the feed operation when the first tooth flank is formed is defined as a first start position, a finish position of the feed operation when the first tooth flank is formed is defined as a first finish position, and a start position of the feed operation when the second tooth flank is formed is defined as a second start position,
a position where the gear critter cuts the one 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
a phase shift angle of the second start position from the first finish position to the one side in the circumferential direction of the workpiece is defined as a first angle,
the gear machining method comprising setting the correction angle to the first angle when the cutting w

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