Piston ring-belt structural reinforcement via additive machining

A piston for an internal combustion engine, comprising:

• a body formed of a first material, said first material being selected from a steel material, an aluminum-based material, and cast iron;
• said body including an upper combustion surface surrounding a center axis for exposure to a combustion chamber, said upper combustion surface including a combustion bowl surrounded by an outer rim;
• said body including an undercrown surface facing opposite said upper combustion surface;
• said body including a ring belt extending from said outer rim of said upper combustion surface and longitudinally relative to said center axis, said ring belt having a plurality of ring grooves facing away from said center axis;
• said body being free of a closed cooling gallery located along said undercrown surface or said ring belt;
• said body including a pair of pin bosses disposed diametrically opposite one another, said pin bosses extending from said undercrown surface and longitudinal relative to said center axis, each of said pin bosses including a pin bore surrounding a pin bore axis;
• an intermediate piece extending radially from an inner surface of said ring belt to said undercrown surface or one of said pin bosses, said intermediate piece being mechanically attached to said inner surface of said ring belt, and said intermediate piece being mechanically attached to said undercrown surface or one of said pin bosses;
• at least one pair of inserts for supporting said ring belt, said inserts being formed of a second material, and said second material being selected from a steel material, a nickel-chrome alloy, and a titanium alloy;
• said inserts being diametrically opposite one another, and each of said inserts extending radially and continuously from an inner surface of said ring belt to said undercrown surface or radially and continuously from an inner surface of said ring belt to one of said pin bosses, and one of said inserts being formed on said intermediate piece;
• said insert being formed by an additive machining process, and the additive machining process being selected from direct depositing, laser cladding, laser sintering, arc welding, additive welding, laser sintering, arc welding, additive welding, plasma transferred arc spraying, plasma welding, arc welding, selective laser sintering, and high velocity oxygen fuel spraying, plasma spraying said second material.

A method of manufacturing a piston, comprising the steps of:

• providing a body formed of a metal material, the body including an upper combustion surface and an oppositely facing undercrown surface, the body including a ring belt having a plurality of ring grooves and extending from the upper combustion surface, and the body include a pair of pin bosses extending from the undercrown surface;
• mechanically attaching an intermediate piece to the body, the intermediate piece extending radially from the inner surface of the ring belt to the undercrown surface or radially from the inner surface of the ring belt to one of the pin bosses;
• forming an insert extending radially from an inner surface of the ring belt to the undercrown surface or radially from the inner surface of the ring belt to one of the pin bosses for supporting the ring belt;
• and
• the step of forming the insert including applying the insert to the intermediate piece by an additive machining process.