A method for manufacturing a piston of an internal combustion engine from a piston upper part and a piston lower part may include producing at least the piston lower part as a forged steel part. A partial cross section of a cooling duct may be provided in the piston lower part. A closed supply inlet funnel may be forged within the piston lower part. The closed supply inlet funnel may be bored into the piston lower part from the cooling duct. A borehole may be introduced into the piston lower part obliquely to a piston axis. The piston lower part and the piston upper part may be welded to one another.

A method of producing a piston blank, comprising producing an intermediate blank of a piston for an axial piston machine by extrusion wherein the intermediate blank includes a shaft portion, a ball head portion, and a sealing portion, wherein the shaft portion connects the ball head portion to the sealing portion. The method also includes producing a piston blank of the piston from the intermediate blank and machining a through-opening in the intermediate blank, wherein the through-opening extends within the piston blank in the longitudinal direction.

A piston for an internal combustion engine including a cooling gallery and a complex combustion surface is provided. The piston includes an upper crown member joined to a lower member, for example by hybrid induction welding. A complex combustion bowl is formed in the upper crown member by forging. The combustion bowl includes at least one protrusion, and typically a plurality of protrusions spaced from one another. After the forging step and before the joining step, portions of an undercrown surface located opposite the spaces between the protrusions are machined, and portions located directly opposite the protrusions are left as-forged. The crown member is joined to the lower member, for example by hybrid induction welding.

A piston for an internal combustion engine is provided. The piston includes a lower part joined to an upper part, for example by friction welding with inertia. The upper part presents a combustion surface and an undercrown surface. The piston also includes a cooling gallery surface provided by the upper part and the lower part. The cooling gallery surface surrounds a volume of space for containing a cooling media. The piston can include serrations in the cooling gallery surface and/or undercrown surface to increase surface area and thus reduce the temperature of the piston. The piston can also include shaped weld curls, instead of or in addition to the serrations, which also increase surface area and reduce the temperature of the piston.

A piston for an internal combustion engine is provided. The piston includes a lower part joined to an upper part, for example by friction welding with inertia. The upper part presents a combustion surface and an undercrown surface. The piston also includes a cooling gallery surface provided by the upper part and the lower part. The cooling gallery surface surrounds a volume of space for containing a cooling media. The piston can include serrations in the cooling gallery surface and/or undercrown surface to increase surface area and thus reduce the temperature of the piston. The piston can also include shaped weld curls, instead of or in addition to the serrations, which also increase surface area and reduce the temperature of the piston.

The invention discloses a method for producing an internal combustion engine piston having at least one cavity which is filled with an alkali metal cooling medium and is subsequently closed. The at least one cavity longitudinally extends from a central point into the piston body toward the piston circumference. The invention further discloses a piston produced according to the method.

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.

A piston for an internal combustion engine includes a piston upper part and a piston lower part having a cooling channel including at least one inlet opening. A dam-type elevation is formed in the region of the at least one inlet opening through forging of the dam elevation in the cooling channel portion in the piston lower part. In one example, a funnel-shaped inlet contour is formed in the inlet opening by pre-forging. In one example, a V-shaped element is formed in the piston upper part cooling chamber portion in alignment with the inlet opening and used as a coolant jet splitter.

A method for producing a piston for an internal combustion engine may include the steps of: producing a first blank corresponding to a piston main body via a deformation process; producing a second blank corresponding to a piston ring part via at least one of a deformation process and a casting process; pre-machining the first blank and the second blank, and finishing a welding surface of the first blank and a welding surface of the second blank via machining; connecting the first blank and the second blank via welding the welding surface of the first blank to the welding surface of the second blank to form a piston body; and performing at least one of a secondary machining process and a finish machining process on the piston body to produce the piston.

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.