Method for calibrating a measuring probe in a gear cutting machine

Patent metadata

Field	Value
Publication number	US-11268800-B2
Application number	US-202016802461-A
Country	US
Kind code	B2
Filing date	Feb 26, 2020
Priority date	Feb 26, 2019
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

The present application discloses a method for calibrating a measuring probe in a gear cutting machine by using a workpiece received in a workpiece holder of the gear cutting machine, wherein the measuring probe includes a measuring probe tip which is movably arranged on a measuring probe base, wherein the deflection of the measuring probe tip relative the measuring probe base can be determined via at least one sensor of the measuring probe, and wherein the measuring probe is traversable relative to the workpiece holder via at least two axes of movement of the gear cutting machine. The method comprises rotating the workpiece via an axis of rotation of the workpiece holder and traversing the measuring probe via the at least two axes of movement of the gear cutting machine such that in the case of a perfect calibration the touch point of the measuring probe tip on the tooth flank would remain unchanged.

First claim

The invention claimed is:

1. A method for calibrating a measuring probe in a gear cutting machine by using a workpiece received in a workpiece holder of the gear cutting machine, wherein the measuring probe includes a measuring probe tip which is movably arranged on a measuring probe base, wherein the deflection of the measuring probe tip relative the measuring probe base can be determined via at least one sensor of the measuring probe, and wherein the measuring probe is traversable relative to the workpiece holder via at least two axes of movement of the gear cutting machine, the method comprising the following steps:
traversing measuring probe and/or workpiece into a relative position in which the measuring probe tip touches a tooth flank of the workpiece;
rotating the workpiece via an axis of rotation of the workpiece holder and simultaneously traversing the measuring probe via the at least two axes of movement of the gear cutting machine such that, in the case of a perfect calibration, during the rotation of the workpiece and traversing of the measuring probe:
the touch point of the measuring probe tip on the tooth flank remains unchanged, and
the deflection or the amount of the deflection of the measuring probe tip maintains a specified value;

determining a deviation of the deflection of the measuring probe tip from the at least one specified value at at least one measurement point; and
determining at least one correction value of the calibration on the basis of the deviation.

2. The method according to claim 1 , wherein the deviation is determined for a plurality of measurement points and the at least one correction value is determined on the basis of the plurality of deviations, and wherein a curve of the deviations is determined over the plurality of measurement points.

3. The method according to claim 1 , wherein the deviation and/or the curve of the deviations is compared with a plurality of theoretical deviations determined for different calibration errors and/or theoretical curves of the deviations in order to determine at least one correction value of the calibration.

4. The method according to claim 1 , wherein in at least one first measurement run a deviation in contact with a first flank of the workpiece and in at least one second measurement run a deviation in contact with a second, preferably opposite flank of the workpiece is determined.

5. The method according to claim 1 , wherein correction values are determined for at least two directions of movement and/or axes of movement, wherein the directions of movement and/or axes of movement preferably allow a movement in a plane perpendicular to the axis of rotation of the workpiece holder.

6. The method according to claim 1 , wherein rotating the workpiece is effected via the axis of rotation of the workpiece holder, and traversing the measuring probe is effected via the at least two axes of movement of the gear cutting machine at the same time and/or continuously.

7. The method according to claim 1 , wherein rotating the workpiece is effected via the axis of rotation of the workpiece holder, and traversing the measuring probe is effected via the at least two axes of movement of the gear cutting machine alternately and/or intermittently.

8. The method according to claim 1 , wherein in dependence on a profile of the workpiece and/or constraints of the gear cutting machine and/or the measuring probe a radius on which the touch point is located and/or a range of angles of rotation of the axis of rotation of the workpiece holder, which is traced, is determined.

9. The method according to claim 1 , wherein the measuring probe tip has the shape of a sphere.

10. The method according to claim 1 , wherein the gear cutting machine includes a machining head which is traversable relative to the workpiece holder via the at least two axes of movement, wherein the measuring probe and a tool holder are arranged on the machining head.

11. The method according to claim 1 , wherein the at least two axes of movement are linear axes.

12. A gear cutting machine with a workpiece holder for receiving a workpiece and with a measuring probe, wherein the measuring probe includes a measuring probe tip which is movably arranged on a measuring probe base, wherein the deflection of the measuring probe tip relative the measuring probe base and/or the achievement of a deflection of the measuring probe tip relative to the measuring probe base can be determined via at least one sensor of the measuring probe, and wherein the measuring probe is traversable relative to the workpiece holder via at least two axes of movement of the gear cutting machine,
wherein the gear cutting machine includes a control unit which is configured to calibrate the measuring probe by a method according to claim 1 .

13. The gear cutting machine according to claim 12 , wherein the control unit is configured such that the method is executed fully automatically as part of a production cycle.

14. A method for calibrating a measuring probe in a gear cutting machine by using a workpiece received in a workpiece holder of the gear cutting machine, wherein the measuring probe includes a measuring probe tip which is movably arranged on a measuring probe base, wherein the deflection of the measuring probe tip relative the measuring probe base and/or the achievement of a deflection of the measuring probe tip relative to the measuring probe base can be determined via at least one sensor of the measuring probe, and wherein the measuring probe is traversable relative to the workpiece holder via at least two axes of movement of the gear cutting machine, the method comprising the following steps:
traversing measuring probe and/or workpiece into a relative position in which the measuring probe tip touches the tooth flank of the workpiece;
rotating the workpiece via an axis of rotation of the workpiece holder and simultaneously traversing the measuring probe via the at least two axes of movement of the gear cutting machine such that, in the case of a perfect calibration, during the rotation of the workpiece and traversing of the measuring probe:
the touch point of the measuring probe tip on the tooth flank remains unchanged, and
the deflection or the amount of the deflection of the measuring probe tip maintains a specified value;

determining a deviation between the actual position of the axis of rotation of the workpiece holder and/or the at least two axes of movement of the gear cutting machine from a position which the same would have in the case of a perfect calibration, at at least one measurement point; and
determining at least one correction value of the calibration on the basis of the deviation.

15. A method for calibrating a measuring probe in a gear cutting machine by using a workpiece received in a workpiece holder of the gear cutting machine, wherein the measuring probe includes a measuring probe tip which is movably arranged on a measuring probe base, wherein the deflection of the measuring probe tip relative the measuring probe base can be determined via at least one sensor of the measuring probe, and wherein the measuring probe is traversable relative to the workpiece holder via at least two axes of movement of the gear cutting machine, the method comprising the following steps:
traversing measuring probe and/or workpiece into a relative position in which the measuring probe tip touches a tooth flank of the workpiece;
rotating the workpiece via an axis of rotation of the workpiece holder and traversing the measuring probe via the at least two axes of movement of the gear cutting machine such that:
the touch point

Assignees

• Liebherr Verzahntech Gmbh

Inventors

• Van Hauth Johannes

Classifications

• G01M13/021

  Gearings · CPC title

• G01B21/042 Primary

  Calibration or calibration artifacts (G01B3/30, G01B9/02072 take precedence) · CPC title

• G01B5/202 Primary

  of gears · CPC title

• B24B49/02

  according to the instantaneous size and required size of the workpiece acted upon, the measuring or gauging being continuous or intermittent (B24B49/12 takes precedence) · CPC title

• B24B19/009

  for grinding profiled workpieces using a profiled grinding tool · CPC title