METHOD AND DEVICE FOR MEASURING A TOOTHING

Abstract

A method having the steps of measuring a geometry of a toothing using an optical measuring system, wherein a numerical aperture of the optical measuring system is adjustable and the numerical aperture of the optical measuring system is adapted depending on at least one geometric parameter of the toothing to be measured and/or is enlarged or reduced.

Claims

1. A method including the following steps: measuring a geometry of a toothing using an optical measuring system, wherein a numerical aperture of the optical measuring system is adjustable and is adapted, increased, or decreased, depending on at least one geometric parameter of the toothing to be measured.

2. The method according to claim 1, wherein the geometric parameter is a tooth pitch or a gap width of the toothing.

3. The method according to claim 1, wherein edge beams of the optical measuring system are not shadowed by a tooth of the toothing.

4. The method according to claim 1, wherein a first flank and/or profile section of the toothing is measured with a larger numerical aperture than a second flank and/or profile section of the toothing and/or the numerical aperture is adjusted during the measurement along a measurement path.

5. The method according to claim 1, wherein the numerical aperture for a measuring point is set on the basis of a light intensity detected using an image sensor, wherein the numerical aperture is set for which a maximum intensity is detected at constant illuminance of a light source and/or the numerical aperture is determined by calculation, on the basis of a predetermined nominal geometry of the toothing and a predetermined measuring angle.

6. The method according to claim 1, wherein the optical measuring system has a confocal sensor, wherein the geometry of the toothing is detected by confocal distance measurement and/or a measurement of a geometry of the toothing is carried out using a tactile measuring system.

7. The method including the following steps: measuring both a geometry of a first toothing and a geometry of a second toothing according to the method recited in claim 1; wherein the first toothing has a geometry different from the second toothing, and wherein the first toothing is measured with a first numerical aperture, wherein the second toothing is measured with a second numerical aperture and wherein the first numerical aperture is different from the second numerical aperture.

8. A device for measuring toothings comprising: an optical measuring system for measuring a geometry of a toothing; a receptacle for retaining a toothing to be measured and having a controller for controlling a measuring sequence, wherein the controller is arranged to perform a method according to claim 1.

9. The device according to claim 7, wherein the optical measuring system has a lens system with adjustable focal length, and/or the optical measuring system has a lens with adjustable focal length.

10. The device according to claim 7, wherein a tactile measuring system is provided for measuring a geometry of a toothing, and/or the optical measuring system has a confocal sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The disclosure is described in more detail below with reference to a drawing illustrating exemplary embodiments. The drawings each show schematically as follows:

[0041] FIG. 1 a device according to the disclosure for measuring a toothing;

[0042] FIG. 2 an optical measurement with a shading;

[0043] FIG. 3 an optical measurement without shading;

[0044] FIG. 4 an optical measuring system;

[0045] FIG. 5A the optical measuring system with an adaptive lens; and

[0046] FIG. 5B the optical measuring system with a lens system.

DETAILED DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1 shows a device 2 for measuring a toothing. The device 2 has an optical measuring system 4 for measuring a geometry of a toothing. The device 2 has a tactile measuring system 5 for measuring a geometry of a toothing. The device 2 has a receptacle 6 for retaining a toothing 8 to be measured and a controller 10 for controlling a measuring sequence.

[0048] The controller 10 is set up for carrying out a method according to the disclosure, having the method steps of: measuring a geometry of the toothing 8 by means of the optical measuring system 4, wherein a numerical aperture of the optical measuring system 4 can be set, and wherein the numerical aperture of the optical measuring system is adapted depending on at least one geometric parameter of the toothing 8 to be measured and/or is increased or decreased.

[0049] At least one nominal value of the at least one geometric parameter is stored in a data memory 11, which is part of the controller 10 or to which the controller 10 has access. The nominal value can, for example, be a nominal value known from a toothing design of the toothing to be measured.

[0050] The toothing can be rotated about an axis C. The optical measuring system 4 can be moved translationally in the x, y and z directions. The axis movements can be controlled by the controller 10.

[0051] FIG. 2 shows an optical measurement of the toothing 8 with the optical measuring system 4. Here, an edge beam 12 of a light cone 14 is shadowed by a tooth tip 16 of a tooth 18 of the toothing 8 and therefore does not contribute to the imaging of a measuring point 20. According to the disclosure, such shadowing is to be avoided in particular partially or completely.

[0052] The numerical aperture is therefore adapted to the geometry of the toothing 8 according to FIG. 3, in which e.g. a tooth pitch 15 and/or gap width 13 of the toothing 8 is taken into account. As can be seen from FIG. 3, the numerical aperture of the optical measuring system 4 has been reduced so that the edge beam 12 of the light cone 14 is no longer shadowed by the tooth tip 16 of the tooth 18.

[0053] The optical measuring system 4 is a device for confocal chromatic distance measurement.

[0054] The numerical aperture NA of the optical system 4 is defined in a known manner as the sine of half the object-side aperture angle 24 of the optical system 4 multiplied by a refractive index, which is 1 for air, for example (FIG. 4).

[0055] To reduce the numerical aperture, a distance 22 of a collimator lens 26 from an optical fiber 30 can be reduced to reduce the illumination of a focus lens 28. In order to still maximize the light output, the focus of the collimator lens 26 should be on a fiber output 32 of the optical fiber 30 coupled to a light source 34 and matched to the numerical aperture of the optical fiber 30.

[0056] To this end, the collimator lens 26 may be designed as an adaptive lens 26 with an adjustable focal length, as shown in FIG. 5A.

[0057] Alternatively or additionally, this can be accomplished by a variable focal length lens system 36, as shown in FIG. 5B.