Method of manufacture using autonomous adaptive machining

Patent metadata

Field	Value
Publication number	US-10955815-B2
Application number	US-201816185378-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Nov 9, 2018
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A method of removing features from a cast workpiece includes generating a nominal toolpath for machining the cast workpiece. The cast workpiece is mounted onto a platform of a computer numeric control machine. The cast workpiece is inspected with a probe to generate probe data. Features to be removed are identified based upon the probe data generated during the inspection. Any expected features of the cast workpiece that are missing from the cast workpiece are identified. A transformation matrix is applied to the nominal toolpath with a controller of the computer numeric control machine, wherein the transformation matrix is based upon the probe data. Alignment of the cast workpiece is adjusted relative to the computer numeric control machine based on the transformation matrix with the computer numeric control machine. Features are removed from the cast workpiece that were identified during inspection.

First claim

The invention claimed is:

1. A method of removing features from a cast workpiece, the method comprising:
generating a nominal toolpath for machining the cast workpiece;
mounting the cast workpiece onto a platform of a computer numeric control machine;
inspecting the cast workpiece with a probe to generate probe data, wherein inspecting the cast workpiece comprises identifying at least one of a pin bump, a gating, and an encapsulation of a trailing edge of an airfoil;
identifying features to be removed based upon the probe data generated during the inspection;
identifying any expected features of the cast workpiece that are missing from the cast workpiece;
applying a transformation matrix to the nominal toolpath with a controller of the computer numeric control machine, wherein the transformation matrix is based upon the probe data;
adjusting, with the computer numeric control machine, alignment of the cast workpiece relative to the computer numeric control machine based on the transformation matrix; and
removing features from the cast workpiece that were identified during inspection.

2. The method of claim 1 , wherein removing features of the cast workpiece comprises machining the cast workpiece to remove material so as to form an airfoil fillet or round a trailing edge of an airfoil.

3. The method of claim 1 , wherein inspecting the cast workpiece comprises probing the cast workpiece with at least one of touching and optical scanning of surfaces of the cast workpiece.

4. The method of claim 3 , wherein inspecting the cast workpiece further comprises probing the cast workpiece for an initial registration.

5. The method of claim 1 , wherein generating the nominal toolpath for machining the cast workpiece comprises:
importing a nominal net-state model of the cast workpiece to a three dimensional scanning system;
creating, with the three dimensional scanning system, a three dimensional scan of an example cast workpiece;
creating, with the three dimensional scanning system, an index of at least one feature to identify and machine;
identifying, with the three dimensional scanning system, a surface profile reference by feature; and
generating, with a computer aided design utility, the nominal toolpath for each feature.

6. The method of claim 1 , wherein generating the nominal toolpath for machining the cast workpiece comprises:
importing a nominal net-state model of the cast workpiece to a three dimensional scanning system;
importing a computer aided design file of an example cast workpiece to a computer aided design utility;
creating, with the computer aided design utility, an index of at least one feature to identify and machine;
identifying, with the computer aided design utility, a surface profile reference by feature; and
generating, with the computer aided design utility, the nominal toolpath for each feature.

7. The method of claim 1 , wherein the probe comprises a tactile, optical, X-ray, or infrared probe.

8. The method of claim 1 , wherein the transformation matrix comprises a series of entries as instructions for transforming the nominal toolpath to account for dimensional differences between a nominal net state model of the cast workpiece and the cast workpiece as-built.

9. The method of claim 8 , wherein the series of entries in the transformation matrix are based on the probe data.

10. The method of claim 8 , wherein the series of entries represent changes to the nominal toolpath needed to adjust for the differences between the nominal net state and actual measurements of the cast workpiece as recorded in the probe data.

11. A method of manufacturing a cast workpiece, the method comprising:
a first phase comprising:
i. importing, to a three dimensional scanning system, a nominal net-state model of the cast workpiece;
ii. creating, with the three dimensional scanning system, a three dimensional scan of an example cast workpiece;
iii. creating, with the three dimensional scanning system, an index of at least one feature to identify and machine;
iv. identifying, with the three dimensional scanning system, a surface profile reference by feature; and
v. generating, with a computer aided design utility, a nominal toolpath for each feature; and

a second phase comprising:
vi. mounting the cast workpiece onto a platform of a computer numeric control machine;
vii. probing, with a sensor, the cast workpiece for an initial registration;
viii. looping, with the computer numeric control machine, through an index of features;
ix. probing, with the sensor, a location and a contour that is surrounding a positive feature;
x. determining, with a controller of the computer numeric control machine, whether a feature is identified within limits;
xi. calculating, with the controller of the computer numeric control machine, a transformation matrix of the computer numeric control machine based on probe data from the sensor;
xii. applying, with the controller of the computer numeric control machine, the transformation matrix to the nominal toolpath;
xiii. machining the feature with the computer numeric control machine;
xiv. determining, with the controller of the computer numeric control machine, whether the feature is a last feature of the cast workpiece; and
xv. completing, with the computer numeric control machine, the machining of the cast workpiece.

12. The method of claim 11 , wherein calculating the toolpath of the computer numeric control machine comprises calculating local translations and rotations versus a nominal feature location and a surface contour.

13. The method of claim 11 , further wherein:
if the feature is not identified within limits in step x, then repeat step viii; or
if the feature is identified within limits in step x, then go to step xi.

14. The method of claim 11 , further wherein:
if the feature is not the last feature in step xiv, then repeat step viii; or
if the feature is the last feature in step xiv, then go to step xv.

15. The method of claim 11 , wherein the sensor comprises a tactile, optical, X-ray, or infrared probe.

16. The method of claim 11 , wherein the transformation matrix comprises a series of entries as instructions for transforming the nominal toolpath to account for dimensional differences between a nominal net state model of the cast workpiece and the cast workpiece as-built.

17. The method of claim 16 , wherein the series of entries in the transformation matrix are based on the probe data.

18. The method of claim 16 , wherein the series of entries represent changes to the nominal toolpath needed to adjust for the differences between the nominal net state and actual measurements of the cast workpiece as recorded in the probe data.

Assignees

• United Technologies Corp
• Raytheon Tech Corp

Inventors

• Auxier James Tilsley
• Barron Alan C
• Cofalka Norman W

Classifications

• F01D5/141

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title

• F05D2230/10

  by removing material · CPC title

• F01D5/12 Primary

  Blades ({specially adapted for radial flow machines or engines F01D5/04}; blade roots F01D5/30; rotors with blades adjustable in operation F01D7/00; stator blades F01D9/02) · CPC title

• G05B19/402 Primary

  characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position (G05B19/19 takes precedence) · CPC title

• G05B19/406

  characterised by monitoring or safety (G05B19/19 takes precedence) · CPC title