Method of repairing a cracked head using an injector bore insert

Patent metadata

Field	Value
Publication number	US-9370845-B2
Application number	US-201313946953-A
Country	US
Kind code	B2
Filing date	Jul 19, 2013
Priority date	Jul 19, 2013
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

A method for repairing a multi-valve cylinder head, having a fuel injector or spark plug, or pre-chamber opening near the valve openings, that provides an insert with structural integrity that is capable of providing for both a repair for the crack and injector sleeve functionality in the finish-machined cylinder head. The present invention overcomes the consequences and structural limitations typically confronting larger diameter configurations while providing for a reliable sealing approach.

First claim

What is claimed is:

1. A method for repairing a multi-valve cylinder head having a plurality of valve openings, comprising, for one opening of the plurality of valve openings:
placing a first bore pilot bushing above a top of the cylinder head and central to the one opening;
drilling a first bore pilot hole at a first bore pilot diameter through the pilot bushing;
drilling a second bore pilot hole from a bottom side of the cylinder head to a predetermined depth;
cutting a conical surface around an outer diameter of the second bore pilot hole;
completing a tapped hole;
sealing one or more predetermined sealing locations;
installing an injector bore insert into the first and second bore pilot holes;
re-boring interior chamfers and cylindrical surfaces of a valve seat bore of the one opening; and,
facing off flush the insert with a combustion face of the cylinder head.

2. The method of claim 1 , further comprising scalloping the combustion face of the cylinder head, including the insert, and the valve seat bore, to reduce head and insert stresses.

3. The method of claim 1 , wherein the one opening is one of a fuel injector opening, a spark plug opening, or a pre-chamber.

4. The method of claim 3 , wherein the cylinder head is in an internal combustion engine.

5. The method of claim 4 , wherein the engine is a diesel engine having an injector tip-to-valve bridge failure.

6. The method of claim 1 , wherein the one opening of the cylinder head is repaired and includes a structural injector sleeve.

7. The method of claim 6 , wherein the structural injector sleeve provides axial and radial structural integrity to a central region of the cylinder head which is greater than an axial and radial structural integrity as originally cast.

8. The method of claim 7 , wherein the structural injector sleeve includes an injector tip opening.

9. The method of claim 8 , wherein the cylinder head includes one or more of compacted graphite iron and alloyed gray iron or ductile iron or other ferrous materials.

10. The method of claim 6 , wherein the structural injector sleeve is positioned partially within the valve seat bore and is free from rotation during engine operation.

11. The method of claim 1 , wherein the insert includes a generally full circumferential groove at the combustion face.

12. The method of claim 1 , wherein the insert includes a generally non-circumferential groove at the combustion face in relation to one or more individual valve seat loads.

13. The method of claim 1 , wherein sealing one or more predetermined sealing locations includes applying a sealant to the insert, and wherein the insert is installed with a hex drive lug still attached.

14. The method of claim 1 , further comprising installing an O-ring onto the insert before installation.

15. The method of claim 1 , wherein the insert provides for both a repair for a crack and injector sleeve functionality for the cylinder head, thereby providing an injector tip/injector bore opening with axial and radial compliance.

16. The method of claim 1 , wherein the cylinder head comprises an aluminum cylinder head.

17. The method of claim 1 , wherein the insert comprises:
a proximate portion adjacent to a combustion face and a distal portion including an upper threaded outer diameter;
an angled conical collar;
a remote threaded portion along an upper bore portion for improved axial compliance and bolted joint robustness;
a circumferential slot extending distally from approximately the combustion face for providing enhanced radial compliance; and,
one or more sealed regions for sealing following installation to prevent against one or more of fuel and coolant and combustion gases.

18. The method of claim 17 , wherein the insert further comprises a removable hex portion positioned at the proximate portion.

19. The method of claim 17 , wherein the angled conical collar is angled obtusely or acutely.

20. The method of claim 17 , wherein the insert is further comprised of a steel material.

21. The method of claim 20 , wherein the insert further comprises an inner dimension at the distal portion being approximately equal to an original injector sleeve width and a cylinder head bore width.

22. The method of claim 20 , wherein the insert further comprises an inner dimension at the proximate portion being approximately equal to an installed/machined dimension of an original injector sleeve.

Assignees

• Cummins Inc

Inventors

• Shaw Terrence M

Classifications

• B23P6/04

  Repairing fractures or cracked metal parts or products, e.g. castings · CPC title

• F02M61/14 Primary

  Arrangements of injectors with respect to engines; Mounting of injectors · CPC title

• F02F2200/00

  Manufacturing · CPC title

• B23P6/00 Primary

  Restoring or reconditioning objects (straightening or restoring form of sheet metal, metal rods, metal tubes, metal profiles, or specific articles made therefrom B21D1/00, B21D3/00; repairing defective or damaged objects by casting techniques B22D19/10) · CPC title

• Y10T29/49233

  Repairing, converting, servicing or salvaging · CPC title