Process and apparatus for locating coated cooling holes on turbine vanes

• US 7,388,980 B2
• Filed: 07/19/2004
• Issued: 06/17/2008
• Est. Priority Date: 12/15/2000
• Status: Expired due to Term

• Current Assignee: Raytheon Technologies Corporation d/b/a RTX
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Vaidyanathan, Janakiraman
• Primary Examiner(s): Mehta; Bhavesh
• Assistant Examiner(s): Strege; John B
• Application Number:
  US10/893,832
• Publication Number:
  US 20040253105A1
• Time in Patent Office: 1,429 Days
• Field of Search: 382/152, 382/141
• US Class Current: 382/152
• CPC Class Codes: B23P 2700/06 Cooling passages of turbine components, e.g. unblocking or preventing blocking of cooling passages of turbine components
• CPC Class Codes: B23P 6/002 Repairing turbine components, e.g. moving or stationary blades, rotors, B23P6/045 takes precedence
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: F01D 5/288 Protective coatings for blades
• CPC Class Codes: G06T 2207/30136 Metal
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

The present invention relates to processes and systems for locating coated cooling holes on parts such as turbine vanes. In a first embodiment of the present invention, a thermal imaging technique is utilized to obtain the locations of the cooling holes on a turbine vane. In a second embodiment of the present invention, a laser scanning technique is utilized to obtain the locations of the cooling holes on a turbine vane.

Claims

1. A process for locating coated cooling holes on a part comprising the steps of:

providing a scanning system with a laser and a laser spot sensor;

scanning a surface of said part in a region containing said cooling holes with said laser and said laser spot sensor and storing information about said region in the form of point cloud data representing points on said surface;

said scanning step comprising programming said laser spot sensor to scan in a two dimensional plane over said region containing said cooling holes and outputting from said laser spot sensor depth information about said part surface as said laser spot sensor scans in said two dimensional plane and recording position information about said sensor as said sensor scans said surface using the servo mechanisms which drive the sensor; and

processing said point cloud data to determine a center point for each cooling hole in said region.

2. A process according to claim 1, further comprising calculating a scanning orientation for maximum hole/part intersection area exposure prior to initiating said scanning step.

3. A process according to claim 1, wherein said processing step comprises digitally creating said surface of said part from said point cloud data and digitally subtracting said created surface from said point cloud data to create subtracted data which corresponds to laser scan points where the laser spot intercepts part and hole interface regions.

4. A process according to claim 3, further comprising segregating said subtracted data to create isolated point clouds which represent individual points on a hole profile corresponding to the surface of said part and hole cylinder interface area and creating a form representing each cooling hole from said segregated point cloud data.

5. A process according to claim 4, wherein said processing step further comprises calculating the size of each cooling hole and the orientation of each cooling hole from said form.

8. A process according to claim 1, wherein said scanning step comprises scanning a surface of a turbine engine component containing said cooling holes.

9. A process according to claim 1, wherein said scanning step comprises scanning a surface of a turbine vane containing said cooling holes.

6. A system for locating coated cooling holes in parts which comprises:

a laser for generating a beam of light onto a surface of a part containing a plurality of cooling holes;

a laser spot sensor for receiving light reflected from said surface of said part;

said laser spot sensor being programmed to scan in a two dimensional plane over said region containing said cooling holes and for outputting from said laser spot sensor calibrated depth information about said part surface as said laser spot sensor scans in said two dimensional plane;

means for recording position information about said sensor as said sensor scans said surface using the servo mechanisms which drive the sensor;

a computer having a memory device, said computer being connected to said laser spot sensor for receiving information in the form of point cloud data; and

means within said computer for processing said point cloud data to determine the location of each cooling hole in said scanned surface.

7. A system according to claim 6, wherein said processing means within said computer comprises means for generating a form representing the cooling holes and means for calculating the size of each cooling hole and its axial orientation from said form.

10. A process for locating coated cooling holes on a part comprising the steps of:

providing a scanning system with a laser and a laser spot sensor;

scanning a surface of said part in a region containing said cooling holes with said laser and said laser spot sensor and storing information about said region in the form of point cloud data representing points on said surface;

processing said point cloud data to determine a center point for each cooling hole in said region; and

said processing step comprising digitally creating said surface of said part from said point cloud data and digitally subtracting said created surface from said point cloud data to create subtracted data which corresponds to laser scan points where the laser spot intercepts part and hole interface regions.