Hot forming of cooling galleries in steel pistons
AssigneeOhio State Innovation Foundation
InventorRajiv Shivpuri
Life of this patent
Estimating the term…
Abstract
A piston, particularly a piston for use in a diesel engine, particularly a heavy duty diesel engine, is formed from a billet of metal, such that the finished piston has a mass that is at least 50%, and, more preferably, up to about 62%, of the mass of the billet. Other than finishing steps, the piston is formed with a closed gallery, without loss of mass through machining processes.
Claims14
A method for forging a piston blank to a near-net shape, the method comprising:
- heating a billet;
- while heated, shaping the billet by at least one hit in a die;
- allowing cooling of the shaped billet;
- heating a pre-flange portion of the shaped billet while maintaining a skirt portion at a temperature sufficiently cool to retain its shape;
- and upsetting the pre-flange portion of the billet to form a flange, thereby forming a near-net shape piston blank.
A method for forging a piston blank to a near-net shape, the method comprising:
- heating a steel billet;
- while heated, shaping the billet to form a pre-flange portion and a skirt portion;
- cooling the shaped billet;
- heating the pre-flange portion to temperatures permitting deformation while maintaining the skirt portion at a temperature substantially resisting deformation;
- upsetting the pre-flange portion of the billet to form a flange spaced apart from the skirt, thereby forming a near-net shape piston blank, wherein the flange spaced apart from the skirt comprises a steel core between the flange and the skirt, and the flange being spin-bendable to form a cooling channel without preliminary removal of material from the steel core.
A method for forging a one-piece piston blank to a near-net shape, the method comprising:
- heating an entirety of a steel billet;
- shaping the billet to form (a) a pre-flange portion wherein at least a region of such portion has a conical-like shape and (b) a hollow skirt portion;
- cooling the shaped billet;
- heating the pre-flange portion to temperatures permitting deformation while maintaining the skirt portion at a temperature preventing substantial deformation;
- and upsetting the pre-flange portion of the billet to form a flange spaced apart from the hollow skirt with a steel core between the flange and the hollow skirt while the hollow skirt retains its shape, thereby forming a near-net shape piston blank.
Dependencies are inferred from the claim text.