PROCESS FOR REPAIRING A CYLINDER RUNNING SURFACE BY MEANS OF PLASMA SPRAYING PROCESSES

• US 20130129939A1
• Filed: 11/20/2012
• Published: 05/23/2013
• Est. Priority Date: 11/22/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Silk, Mark Robert, Verpoort, Clemens Maria, Schramm, Leander, Puetz, Wolfgang
• Granted Patent: US 8,877,285 B2
• Time in Patent Office: Days
• US Class Current: 427/569
• CPC Class Codes: B05D 5/005 Repairing damaged coatings
• CPC Class Codes: B23P 6/02 Pistons or cylinders
• CPC Class Codes: C23C 4/02 Pretreatment of the material to be coated, e.g. for coating on selected surface areas
• CPC Class Codes: C23C 4/12 characterised by the method of spraying
• CPC Class Codes: C23C 4/131 Wire arc spraying
• CPC Class Codes: C23C 4/134 Plasma spraying
• CPC Class Codes: C23C 4/18 After-treatment

Abstract

A method of repairing an inner surface of a cylinder liner housed in an engine block. Material is removed from the inner surface to produce a reduced-thickness region, the reduced-thickness region extending axially relative to the cylinder and stopping short of an end of the liner to leave a region of original diameter between the reduced thickness region and the end of the liner. The surface the reduced-thickness region is then roughened, for example by hammer brushing. A plasma coating is applied to the reduced-thickness region and to at least a portion of the region of original diameter. The coating is then finish-machined to produce a uniform internal diameter equal to an original internal diameter of the region of original diameter prior to the application of the coating.

Claims

1. A method of repairing a damaged region of a cylinder liner comprising:

machining the damaged region to produce a reduced-thickness region;

roughening a surface of the reduced-thickness region;

applying a coating to the reduced-thickness region and to an un-roughened region adjacent to the reduced-thickness region; and

finish-machining the coating to produce a desired internal diameter, the coating being substantially completely removed from the un-roughened surface.

2. The method of claim 1, wherein the step of applying the coating comprises a plasma spraying process.

3. The method of claim 2, wherein the plasma spraying process comprises a plasma transfer wire arc coating process.

4. The method of claim 1, wherein the machining step produces a transition between the reduced-thickness region and the un-machined region.

5. The method of claim 4, wherein the transition is an inclined plane.

6. The method of claim 1, wherein the roughening step comprises a hammer brushing process.

7. The method of claim 1, wherein the finish-machining step comprises honing.

8. The method of claim 1, wherein the coating is applied so as to extend onto a lip of an engine block immediately adjacent to the liner.

9. A method of repairing a damaged region of a cylinder liner housed in an engine block comprising:

machining the damaged region to produce a reduced-thickness region, the reduced-thickness region stopping short of an axial end of the liner and leaving an un-machined region of the liner adjacent to the axial end;

roughening a surface the reduced-thickness region;

applying a coating to the reduced-thickness region, the coating extending onto the un-machined region of the liner adjacent to the reduced-thickness region; and

finish-machining the coating to produce a desired internal diameter equal to a diameter of the un-machined region prior to the application of the coating.

10. The method of claim 9, wherein the coating further extends axially onto a lip of the engine block immediately adjacent to the axial end of the liner.

11. The method of claim 9, wherein the coating is applied by a plasma transfer wire arc coating process.

12. The method of claim 9, wherein the machining step produces a transition between the reduced-thickness region and the un-machined region.

13. The method of claim 12, wherein the transition is an internal chamfer.

14. The method of claim 9, wherein the roughening step comprises a hammer brushing process.

15. The method of claim 9, wherein the finish-machining step comprises honing.

16. A method of repairing an inner surface of a cylinder liner housed in an engine block comprising:

removing material from the inner surface to produce a reduced-thickness region, the reduced-thickness region extending axially relative to the cylinder and stopping short of an end of the liner to leave a region of original diameter between the reduced thickness region and the end of the liner;

roughening a surface of the reduced-thickness region;

applying a coating to the reduced-thickness region and to at least a portion of the region of original diameter; and

finish-machining the coating to produce a uniform internal diameter equal to an original internal diameter of the region of original diameter prior to the application of the coating.

17. The method of claim 16, wherein the coating further extends axially onto a lip of the engine block immediately adjacent to the end of the liner.

18. The method of claim 16, wherein the coating is applied by a plasma transfer wire arc coating process.

19. The method of claim 16, wherein the roughening step comprises a hammer brushing process.

20. The method of claim 16, wherein the finish-machining step comprises honing.