Method of repairing a cracked head using an injector bore insert
AssigneeCummins Inc.
InventorTerrence M. SHAW
Life of this patent
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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.
Claims25
A method for repairing a multi-valve cylinder head having an active opening near the valve openings, comprising:
- placing a first bore pilot bushing above a top of the head and central to the active 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 head to a predetermined depth;
- cutting a conical surface around the outer diameter of the second bore pilot hole;
- completing a tapped hole;
- sealing one or more predetermined sealing locations before inserting an injector bore insert;
- re-boring one or more valve seats' receiving details' interior chamfers and cylindrical surfaces;
- and,
- facing off flush the insert with a combustion face.
An injector bore insert for insertion in a cylinder head of an internal combustion engine, comprising:
- 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 gasses.
An internal combustion engine having a multi-valve cylinder head with an active opening near the valve openings, comprising:
- an injector bore insert repaired by placing a first bore pilot bushing above a top of the head and central to the injector bore;
- 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 head to a predetermined depth;
- cutting a conical surface around the outer diameter of the second pilot hole bore;
- completing a tapped hole;
- sealing one or more predetermined sealing locations before inserting an injector bore insert;
- re-boring one or more valve seats interior chamfers and cylindrical surfaces;
- and,
- facing off flush the insert with a combustion face.
Dependencies are inferred from the claim text.