A one-piece piston blank of near-net shape wherein the piston blank has a flange disposed opposite a skirt, the flange being spin-bendable to form a cooling channel with reduced preliminary removal of material relative to conventional forged piston blanks.

A forging device for producing a piston blank has a forging mold that has an essentially cylindrical cavity matching the radial outer surface of the piston blank, a forging base delimiting the cavity, and a central die consisting of a mandrel that has a conically tapering extension which is mounted on the mandrel and the shape of which matches the inner surface of the piston blank. In order to form the radially outer surfaces of the piston slipper walls and a peripheral cooling pocket located radially outside the slipper walls in the piston head, the forging device has two lateral jaws which are mounted in the forging device so as to be movable at an angle to the longitudinal axis of the forging device.

A steel piston with an oil gallery, and process for forming a steel piston oil gallery channel, which corresponds to the complex shape of the combustion bowl in the piston crown. The oil gallery channel is first forged to the basic shape that corresponds to the shape of the walls of the combustion bowl. Machine-turning surfaces in the oil gallery channel can be machine-finished as desired. Surfaces in the oil gallery which cannot be machined with conventional turning operations, such as recesses and protrusions into the channel, are left in the original forged condition.

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.

Exemplary pistons and methods of making the same are disclosed. An exemplary piston may include a crown defining a combustion bowl and a ring land extending circumferentially around the combustion bowl. Exemplary pistons may further include a skirt supporting the crown. The skirt may include a pair of pin bosses defining a pin bore configured to receive a piston pin, and two opposing skirt supports defining surfaces configured to slide along a cylinder bore surface. The skirt supports each define a different radial stiffness.

A one-piece piston blank of near-net shape wherein the piston blank has a flange disposed opposite a skirt, the flange being spin-bendable to form a cooling channel with reduced preliminary removal of material relative to conventional forged piston blanks.

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.

Methods for forging a piston blank are disclosed such that the forged piston blank is in a near-net shape and size of a final piston. Bending a flange to form a cooling channel can be done with reduced or no preliminary machining away of core material relative prior to bending the flange.

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 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.