Method of repairing a cracked head using an injector bore insert

{
  "publication_number": "US9370845B2",
  "country": "US",
  "kind": "B2",
  "title": "Method of repairing a cracked head using an injector bore insert",
  "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.",
  "claims": [
    "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."
  ],
  "description_excerpt": "The present invention relates to the sealing of a coolant passage from a fuel injector as well as to repair, manufacture and design of fuel injector bores, spark plug bores and pre-chamber bores.\n\nAn internal combustion engine having a multi-valve cylinder head with an injector or spark plug opening near the valve openings may experience damage by cracking when placed under high pressure or high thermal loads. Damage may include cracking between the injector/plug tip and the valve seats proximate thereto. Once the damage occurs, repair options to the cylinder head are limited, where if repair is possible, the efforts are often costly and time consuming.\n\nFIG. 1 sets forth a cylinder head 100 showing a cross section of an injector bore 120 above the valve seats in a cylinder head of an internal combustion engine. From FIG. 1, the injector body is positioned from above the top of the cylinder head, through the fuel-sealing region (as noted at the rectangular O-ring groove 145) just above 140 and the tapered portion of the injector located approximately adjacent to 150 near the combustion sealing cone 160. Further, the combustion face is set forth as 199. Cylinder heads may experience damage in certain situations by cracking. When cracking of the head occurs, often a crack may be observed near the thinner material area where the injector tip conical machining approaches the combustion face 199. Cracks which may initiate may often grow radially outward towards the valve seat bore area 170 and occasionally into the injector bore area at approximately 180.",
  "cpc": [
    "B23P 6/00",
    "B23P 6/04",
    "F02F 1/24",
    "F02F 1/242",
    "F02F 11/002",
    "F02F 2001/248",
    "F02F 2200/00",
    "F02M 61/14",
    "F02P 13/00",
    "Y10T 29/49233"
  ],
  "ipc": [
    "B23P 6/00",
    "F02F 1/24",
    "F02F 11/00",
    "B23P 6/04"
  ],
  "assignees": [
    "Cummins Inc"
  ],
  "inventors": [
    "Terrence M. Shaw"
  ],
  "filing_date": "2013-07-19",
  "publication_date": "2016-06-21",
  "grant_date": "2016-06-21",
  "priority_date": "2013-07-19",
  "application_number": "US-201313946953-A",
  "family_id": "52309928",
  "cited_by_count": 2,
  "citations": [
    "US4229867A",
    "US4967458A",
    "US4918805A",
    "US6212750B1",
    "US6474285B2",
    "US6668784B1",
    "US7047612B2",
    "US20080237304A1"
  ]
}