Process and device for restoring the tightness of connecting elements such as water boxes of alternators with a mixed water-hydrogen cooling system

• US 5,793,014 A
• Filed: 12/23/1996
• Issued: 08/11/1998
• Est. Priority Date: 12/27/1995
• Status: Expired due to Term

• Current Assignee: Electricitã© De France
• Original Assignee: Electricitã© De France
• Inventors: Adragna, Patrick, Sobkowiak, Lucien
• Primary Examiner(s): Mills, Gregory L.
• Application Number:
  US08/773,236
• Time in Patent Office: 596 Days
• Field of Search: 219/121.6, 219/121.63, 219/121.64, 219/121.65, 219/121.66, 219/121.68, 219/121.69, 219/121.73, 219/121.8, 219/121.84, 219/121.85, 228/261, 134/1, 134/22.11, 134/24, 29/81.01, 29/81.021, 29/888.021, 29/890.031, 29/402.06, 29/402.07
• US Class Current: 219/121.65
• CPC Class Codes: B08B 7/0042 by laser
• CPC Class Codes: B23K 1/0056 soldering by means of beams, e.g. lasers, E.B.
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/14 using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor B23K26/12 takes precedence
• CPC Class Codes: B23K 26/147 Features outside the nozzle for feeding the fluid stream towards the workpiece
• CPC Class Codes: B23K 26/60 Preliminary treatment
• CPC Class Codes: H02K 15/0093 Manufacturing or repairing cooling fluid boxes, i.e. terminals of fluid cooled windings ensuring both electrical and fluid connection
• CPC Class Codes: Y10T 29/49728 and by a metallurgical operation, e.g., welding, diffusion bonding, casting

Abstract

The process comprises separating the connecting element (3) from one of the pipes (4) which connects it to the circuit so as to open up an opening (6) of the connecting element and thereby gain access to the interior of the connecting element while leaving the latter in position in the circuit of the alternator, descaling at least a part of the interior surface of the connecting element by removal of an oxidized layer covering the interior surface (18) by use of a laser beam (16) introduced in the interior chamber (19) of the connecting element (3), cleaning the interior chamber (19) of the connecting element by suction of particles of matter resulting from the action of the laser beam (16), depositing a layer of brazing material on the surface (18) of the interior chamber (19) of the connecting element whose tightness must be restored, and melting the brazing material by means of the laser beam (16).

Claims

1. Process for restoring tightness of a connecting element of a circuit passed through by a fluid, said process comprising the following steps:

separating said element from a pipe connecting it to said circuit so as to form an opening of said connecting element and thereby provide access to an interior chamber of said connecting element while leaving said connecting element in position in said circuit, descaling at least a part of an interior surface of said interior chamber by removal of an oxidized layer covering said at least a part of said interior surface by means of a laser beam introduced in said interior chamber, cleaning said interior chamber by suction of particles of matter resulting from action of said laser beam, depositing a layer of brazing material on said at least a part of said interior surface of said interior chamber, and melting said brazing by means of said laser beam.

2. Process according to claim 1, comprising subjecting, in the course of said descaling and said melting of said brazing, material a focusing lens of said laser beam to movements which cause said laser beam to scan said at least a part of said interior surface.

3. Process according to claim 2, comprising effecting said suction of said particles of matter resulting from said action of said laser beam by means of a suction nozzle introduced through said opening of said connecting element, said nozzle being connected to a suction device.

4. Process according to claim 3, comprising, after the last operation for said suction of said particles of matter resulting from the action of said laser beam, injecting in said interior chamber a solvent for ensuring a final cleaning of said at least a part of said interior surface.

5. Process according to claim 2, comprising repeating said descaling and suction operations at least one.

6. Process according to claim 1, comprising effecting said suction of said particles of matter resulting from said action of said laser beam by means of a suction nozzle introduced through said opening of said connecting element, said nozzle being connected to a suction device.

7. Process according to claim 6, comprising repeating said descaling and suction operations at least one.

8. Process according to claim 6, comprising, after said suction of said particles of matter injecting in said interior chamber a solvent for ensuring a final cleaning of said at least a part of said interior surface.

9. Process according to claim 1, comprising effecting said deposition of said brazing material on said at least a part of said interior surface of said interior chamber by causing a spray gun to scan said at least a part of said interior surface of said interior chamber of said connecting element the tightness of which must be restored.

10. Process according to claim 1, comprising subjecting, between a descaling operation and a particle suction operation, between a particle suction operation and an operation for depositing a layer of brazing, material and after an operation for melting said brazing, material said at least a part of said interior surface to an inspection comprising observing the state of said at least a part of said interior surface by means of a video camera and a video system.

11. A device for treatment of at least a part of an interior surface of an interior chamber of a connecting element of a circuit passed through by a fluid, so as to restore tightness of said connecting element by a process comprising the following steps:

separating said connecting element from a pipe connecting it to said circuit so as to form an opening of said connecting element and thereby provide access to said interior chamber of said connecting element while leaving said connecting element in position in said circuit, descaling said at least a part of said interior surface of said interior chamber by removal of an oxidized layer covering said at least a part of said interior surface by means of a laser beam introduced in said interior chamber, cleaning said interior chamber by suction of particles of matter resulting from action of said laser beam, depositing a layer of brazing material on said at least a part of said interior surface of said interior chamber, and melting said brazing material by means of said laser beam,

said device comprising in combination;

a laser device including a lens for directing, in the course of said descaling and said melting of said brazing material, a laser beam onto said at least a part of said interior surface of said connecting element, a laser head, a fibre-optic cable connecting said laser head to said lens, an electronic inspection and power supply box connected to said laser head, displacing means carrying said lens for moving said lens and thereby causing said beam to scan said at least a part of said interior surface, means for the suction of the particles of the matter resulting from said descaling action of said laser beam, means for depositing a brazing material on said at least a part of said interior surface, said means for depositing said brazing material being capable of being substituted for said lens on said displacing means.

12. Device according to claim 11, further comprising means for inspecting said at least a part of said interior surface including a video system and a camera which may be substituted selectively for said lens and for said brazing material depositing means on said displacing means, and a bundle of fibre-optic cables connecting said video system to said camera.

13. Device according to claim 12, wherein said brazing material depositing means comprises a spray gun.

14. Device according to claim 13, wherein said displacing means for moving in turn said lens of said laser device, said brazing material depositing means and said video camera comprises a robot and a computer operatively connected to said robot for programming and remotely controlling said robot.

15. Device according to claim 12, wherein said displacing means for moving in turn said lens of said laser device, said brazing material depositing means and said video camera comprises a robot and a computer operatively connected to said robot for programming and remotely controlling said robot.

16. Device according to claim 11, wherein said brazing material depositing means comprises a spray gun.

17. Device according to claim 16, wherein said displacing means for moving in turn said lens of said laser device, said brazing material depositing means and said video camera comprises a robot and a computer operatively connected to said robot for programming and remotely controlling said robot.