Electrochemical machining system and method of machining a conductive work piece

Patent metadata

Field	Value
Publication number	US-9943921-B2
Application number	US-201514814259-A
Country	US
Kind code	B2
Filing date	Jul 30, 2015
Priority date	Jul 30, 2015
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

An electrochemical machining system for machining a conductive work piece is provided. The system includes a drilling tool configured to remove material from the conductive work piece. The drilling tool is configured to advance within the conductive work piece along a tool path to form a bore hole having a variable geometry that extends through the conductive work piece when the material is removed therefrom. The system further includes an inspection device configured to determine a position of the drilling tool along the tool path, and a controller configured to communicate with the inspection device. The controller is further configured to compare the tool path to a nominal tool path, and determine a position error of said drilling tool, the position error defined by a difference between the tool path and the nominal tool path.

First claim

What is claimed is:

1. An electrochemical machining system for machining a conductive work piece, said system comprising:
a drilling tool configured to remove material from the conductive work piece, wherein said drilling tool is configured to advance within the conductive work piece along a tool path to form a bore hole having a variable geometry that extends through the conductive work piece when the material is removed therefrom;
an inspection device configured to determine a position of said drilling tool along the tool path; and
a controller configured to communicate with said inspection device, wherein said controller is further configured to:
compare the tool path to a nominal tool path; and
determine a position error of said drilling tool, the position error defined by a difference between the tool path and the nominal tool path.

2. The system in accordance with claim 1 , wherein said inspection device is configured to perform a pre-drilling inspection of the conductive work piece to determine dimensions thereof, said controller further configured to determine a modified nominal tool path based on variations in the dimensions of the conductive work piece when compared to dimensions of a virtual conductive work piece.

3. The system in accordance with claim 1 , wherein said inspection device comprises at least one of an ultrasonic testing device or an X-ray testing device.

4. The system in accordance with claim 1 further comprising a flow controller configured to channel a flow of electrolytic fluid through a central flushing channel extending through said drilling tool, such that the flow of electrolytic fluid is discharged towards the conductive work piece in the bore hole.

5. The system in accordance with claim 4 further comprising an ion sensor configured to measure an ion concentration in the electrolytic fluid discharged from the bore hole.

6. The system in accordance with claim 1 further comprising a robotic device coupled to said drilling tool, wherein said robotic device is configured to advance said drilling tool along the tool path.

7. The system in accordance with claim 6 , wherein said robotic device is configured to communicate with said controller, said robotic device further configured to modify an orientation of said drilling tool within the bore hole based on the position error of said drilling tool.

8. A method of machining a conductive work piece, said method comprising:
advancing a drilling tool within the conductive work piece along a tool path to form a bore hole having a variable geometry that extends through the conductive work piece when the material is removed therefrom, the drilling tool including a plurality of electrode patches;
conducting an inspection of the conductive work piece to determine a position of the drilling tool along the tool path; and
determining a position error of the drilling tool, the position error defined by a difference between the position of the drilling tool when compared to a theoretical position of the drilling tool along a nominal tool path.

9. The method in accordance with claim 8 further comprising:
conducting a pre-drilling inspection of the conductive work piece;
determining variations in dimensions of the conductive work piece when compared to dimensions of a virtual conductive work piece; and
modifying the nominal tool path based on the variations in the conductive work piece.

10. The method in accordance with claim 8 further comprising executing a corrective action to reduce the position error when the position error is greater than a first predetermined threshold.

11. The method in accordance with claim 10 , wherein executing a corrective action comprises modifying at least one drilling parameter that comprises at least one of an amount of electric current supplied to the plurality of electrode patches, an orientation of the drilling tool within the bore hole, a flushing pressure of electrolytic fluid channeled through the drilling tool, or a feed rate of the drilling tool advancing within the bore hole.

12. The method in accordance with claim 10 further comprising executing a low-level corrective action when the position error is greater than the first predetermined threshold, and less than a second predetermined threshold greater than the first predetermined threshold.

13. The method in accordance with claim 12 further comprising executing a mid-level corrective action when the position error is greater than the second predetermined threshold, and less than a third predetermined threshold greater than the second predetermined threshold.

14. The method in accordance with claim 13 further comprising terminating operation of the drilling tool when the position error is greater than a fourth predetermined threshold greater than the third predetermined threshold.

15. The method in accordance with claim 8 further comprising:
discharging a flow of electrolytic fluid towards the conductive work piece within the bore hole, the flow of electrolytic fluid channeled through a central flushing channel extending through the drilling tool;
measuring an ion concentration in the electrolytic fluid discharged from the bore hole; and
determining a chemical composition of the electrolytic fluid based on the ion concentration in the electrolytic fluid.

16. One or more non-transitory computer-readable storage media having computer-executable instructions embodied thereon for use in machining a conductive work piece, wherein when executed by a controller, the computer-executable instructions cause the controller to:
direct a robotic device to advance a drilling tool within the conductive work piece along a tool path to form a bore hole having a variable geometry that extends through the conductive work piece when the material is removed therefrom, the drilling tool including a plurality of electrode patches;
direct an inspection device to conduct an inspection of the conductive work piece to determine a position of the drilling tool along the tool path; and
determine a position error of the drilling tool, the position error defined by a difference between the position of the drilling tool when compared to a theoretical position of the drilling tool along a nominal tool path.

17. The one or more non-transitory computer-readable storage media in accordance with claim 16 , wherein the computer-executable instructions further cause the controller to:
direct the inspection device to conduct a pre-drilling inspection of the conductive work piece;
determine variations in dimensions of the conductive work piece when compared to dimensions of a virtual conductive work piece; and
modify the nominal tool path based on the variations in the conductive work piece.

18. The one or more non-transitory computer-readable storage media in accordance with claim 17 , wherein the computer-executable instructions further cause the controller to execute a low-level corrective action when the position error is greater than the first predetermined threshold, and less than a second predetermined threshold greater than the first predetermined threshold.

19. The one or more non-transitory computer-readable storage media in accordance with claim 18 , wherein the computer-executable instructions further cause the controller to execute a mid-level corrective action when the position error is greater than the second predetermined threshold, and less than a third predetermined threshold greater than the second predetermined threshold.

20. The one or more non-transitory comp

Assignees

• Gen Electric

Inventors

• Trimmer Andrew Lee
• Hayashi Steven Robert
• Nieters Edward James
• Mcnamara Jeremy Gordon

Classifications

• B23H3/00

  Electrochemical machining, i.e. removing metal by passing current between an electrode and a workpiece in the presence of an electrolyte · CPC title

• B23Q17/2233

  for adjusting the tool relative to the workpiece · CPC title

• B23H9/16

  using an electrolytic jet · CPC title

• B23H9/10

  Working turbine blades or nozzles · CPC title

• B23H3/04

  Electrodes specially adapted therefor or their manufacture (B23H9/00 takes precedence) · CPC title