Systems and methods for automated sensing and machining for repairing airfoils of blades

• US 6,912,446 B2
• Filed: 10/23/2002
• Issued: 06/28/2005
• Est. Priority Date: 10/23/2002
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Wei, Bin, Wang, Weiping, Lee, Martin Kin-Fei
• Primary Examiner(s): PALADINI, ALBERT WILLIAM
• Application Number:
  US10/278,492
• Publication Number:
  US 20040083024A1
• Time in Patent Office: 979 Days
• Field of Search: 700/195, 700/98, 700/105, 700/118, 700/161, 700/163, 702/155, 72/162, 298/891
• US Class Current: 700/193
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/32 taking account of the properties of the material involved
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B23P 6/002 Repairing turbine components, e.g. moving or stationary blades, rotors, B23P6/045 takes precedence
• CPC Class Codes: B23P 6/007 using only additive methods, e.g. build-up welding
• CPC Class Codes: G05B 19/4083 Adapting programme, configuration
• CPC Class Codes: G05B 2219/32228 Repair, rework of manufactured article
• CPC Class Codes: G05B 2219/35128 Propeller blade
• CPC Class Codes: G05B 2219/45147 Machining blade, airfoil
• CPC Class Codes: Y10T 29/49318 Repairing or disassembling

Abstract

A method for repairing an airfoil comprising creating a nominal numerically-controlled tool path based on a nominal shape of the airfoil, measuring the airfoil using a displacement sensor, capturing differences in the airfoil shape as compared to the nominal shape, creating a three-dimensional map by synchronizing x, y and z coordinates and readings from the sensor, modifying the tool path based on the three-dimensional map, and machining the airfoil. A system for measuring and machining an airfoil comprising a computer operable for data acquisition and numerically-controlled tool path generation, a numerically-controlled machine, a cutting tool holder comprising a plurality of cutting tools, and a displacement-sensing probe.

Claims

1. A method for measuring and machining a blade having a weld-repaired region, the weld-repaired region being selected from the group consisting of a plate welded to a surface of the blade, a weld-filled crack repair volume, and combinations thereof, the method comprising:

measuring the blade having the weld-repaired region with a displacement-sensing probe to acquire a plurality of data corresponding to the actual shape of the blade having the weld-repaired region;

comparing the data to a nominal shape of the blade to determine a plurality of three-dimensional differences of the blade having the weld-repaired region with respect to the nominal shape;

generating a numerically-controlled tool path using the three dimensional differences, the numerically controlled tool path being customized to blend the weld-repaired region smoothly with its adjacent surfaces; and

blending the weld-repaired region using the numerically controlled tool path.

2. The method of claim 1, wherein the displacement-sensing probe is selected from the group consisting of:

a linear variable differential transformer (LVDT), a digital dial indicator, a laser distance sensor, and a laser triangulation sensor.

3. The method of claim 2, wherein the displacement-sensing probe is mounted on a computer-controlled multi-axis machine operable for moving in x, y and z directions with other rotational degrees of freedom as needed to scan the shape of the blade having the weld-repaired region.

4. The method of claim 3, wherein the data comprise displacement-sensing probe readings, which are recorded together with positions of axes of the computer-controlled multi-axis machine.

5. The method of claim 1, wherein a nominal numerically-controlled tool path is created based on the nominal shape of the blade and the blade'"'"'s position on a numerically-controlled machine.

6. The method of claim 1, wherein the measuring recognizes both blade deformation and blade misplacement on a numerically-controlled machine.

7. The method of claim 1, wherein the blending of the weld-repaired region is performed using a cutting tool of a numerically-controlled machine.

8. A system for measuring and machining a blade having a weld-repaired region, the weld-repaired region being selected from the group consisting of a plate welded to a surface of the blade, a weld-filled crack repair volume, and combinations thereof, the system comprising:

a displacement-sensing probe operable for measuring a plurality of dimensions of the blade in the weld-repaired region;

a computer-controlled multi-axis machine operable for moving the displacement-sensing probe in the x, y and Z directions as well as other rotational degrees of freedom to scan the shape of the blade in the weld-repaired region;

an adjustable platform operable for holding and positioning the blade having the weld-repaired region;

a tool holder comprising a plurality of cutting tools; and

a computer in connection with and operable for controlling the displacement-sensing probe, the multi-axis machine, the adjustable platform and the tool holder, wherein the computer is further operable for recognizing a deviation of the blade geometry from a nominal shape and creating a numerically-controlled tool path customized for machining the blade having the weld-repaired region, and wherein the computer is programmed to locate the weld-repair region on the blade for measuring the weld-repair region.

9. The system of claim 8, wherein the displacement-sensing probe is selected from the group consisting of:

a linear variable differential transformer (LVDT), a digital dial indicator, a laser distance sensor, and a laser triangulation sensor.

10. The system of claim 8, wherein the plurality of cutting tools are operable for blending the weld-repaired region.

11. The system of claim 8, wherein a plurality of displacement-sensing probe readings are recorded together with a plurality of positions of axes of the computer-controlled multi-axis machine.

12. The system of claim 8, wherein a nominal numerically-controlled tool path is created based on the nominal shape of the blade and the blade'"'"'s position on the adjustable platform.

13. The system of claim 8, wherein the nominal shape comprises the shape of the blade provided by a manufacturer before the blade is put into service.

14. The system of claim 8, wherein the nominal shape comprises an already distorted shape of the blade minus the weld-repaired region.

15. A method for repairing an airfoil having a weld-repaired region, the weld-repaired region being selected from the group consisting of a plate welded to a surface of the airfoil, a weld-filled crack repair volume, and combinations thereof, comprising:

providing the airfoil on a measurement and machining system;

creating a nominal numerically-controlled tool path based on a nominal shape of the airfoil and the airfoil'"'"'s position on the measuring and machining system;

measuring the airfoil in the weld-repair region using a sensor to acquire a plurality of readings from the sensor corresponding to the actual shape of the airfoil;

creating a three-dimensional map by synchronizing a plurality of x, y and z coordinates for the measurement and machining system and the readings from the sensor;

modifying the nominal numerically controlled (NC) tool path based on the three-dimensional map to generate a customized NC tool path; and

blending the weld-repair region on the airfoil using the customized NC tool path.

16. The method of claim 15, wherein the nominal shape comprises the shape of the airfoil provided by a manufacturer before the airfoil is put into service.

17. The method of claim 15, wherein the nominal shape comprises an already distorted shape of the airfoil minus the weld-repaired region.

18. The method of claim 17, wherein the sensor is mounted on a computer-controlled multi-axis machine operable for moving in x, y and z directions with other rotational degrees of freedom as needed to scan the shape of the airfoil having the weld-repaired region.

19. The method of claim 18, wherein the sensor readings are recorded together with a plurality of positions of axes of the computer-controlled multi-axis machine.

20. The method of claim 15, wherein the sensor is selected from the group consisting of:

a displacement-sensing probe, a linear variable differential transformer (LVDT), a digital dial indicator, a laser distance sensor, and a laser triangulation sensor.

21. A system for measuring and machining an airfoil having a weld-repaired region, the weld-repaired region being selected from the group consisting of a plate welded to a surface of the airfoil, a weld-filled crack repair volume, and combinations thereof, comprising:

a numerically-controlled machine;

a displacement-sensing probe mounted on the numerically-controlled machine and operable for acquiring a plurality of displacement-sensing probe readings corresponding to the actual shape of the airfoil in the weld-repair region;

a computer operable for acquiring the displacement-sensing probe readings from the displacement-sensing probe and for generating a numerically-controlled tool path for the numerically-controlled machine using the displacement-sensing probe readings, wherein the computer is programmed to locate the weld-repair region on the airfoil for measuring the weld-repair region; and

a cutting tool holder mounted on the numerically controlled machine and being equipped with a plurality of cutting tools, the cutting tools being adapted to blend the weld-repair region on the airfoil.

22. The system of claim 21, wherein the displacement-sensing probe is selected from the group consisting of:

a linear variable differential transformer (LVDT), a digital dial indicator, a laser distance sensor, and a laser triangulation sensor.

23. The system of claim 21, wherein the numerically-controlled machine is operable for moving in x, y and z directions with other rotational degrees of freedom as needed to scan the shape of the airfoil.

24. The system of claim 21, wherein the displacement-sensing probe readings are recorded together with a plurality of positions of axes of the numerically-controlled machine.

25. The system of claim 21, wherein a nominal numerically-controlled tool path is created based on a nominal shape of the airfoil and the airfoil'"'"'s position on the numerically-controlled machine.

26. The system of claim 21, wherein the computer is operable for recognizing both airfoil deformation and airfoil misplacement on the numerically-controlled machine.