An improved piston forging for use in an internal combustion engine is disclosed. The piston forging comprises a crown, a pair of pin towers extending generally axially away from the crown, and a skirt extending generally axially away from the crown. The improved piston forging further comprises a plurality of grains flowing across the piston forging. The plurality of grains are reoriented during the forging operation into a configuration that follows the surfaces and features of the piston forging. More specifically, the plurality of grains are reoriented in a manner that is most beneficial to resist combustion and inertial forces that are enacted upon a machined piston during operation.

A piston unit for coupling to a crosshead piston rod with a crosshead piston pin includes a piston crown member and an integrated crosshead pin support and skirt member. The piston crown member consists essentially of forged steel. An integrated crosshead pin support and skirt member consists essentially of forged steel. The integrated pin support and skirt member is affixed to the piston crown member and is configured to support the crosshead piston pin. In a method of making a crosshead piston, a piston crown member is forged from steel. An integrated crosshead pin support and skirt member is forged from steel. The piston crown member is welded to the integrated crosshead pin support and skirt member.

A piston for an internal combustion engine and method of construction is provided. The piston has a robust, lightweight monolithic piston body including an upper wall forming a combustion bowl depending radially inwardly from an annular, uppermost combustion surface. An undercrown surface is formed on an underside of the combustion bowl, with at least a portion of the undercrown surface being bounded by diametrically opposite skirt portions, pin bosses and strut portions connecting the skirt portions to the pin bosses. The bounded undercrown surface has an openly exposed surface area, as viewed looking along a central longitudinal axis along which the piston reciprocates, providing an expansive area against which oil being splashed or sprayed can come into direct contact with to enhance cooling the piston while in use. Through channels extending over upper regions of the pin bosses can be provided to further reduce weight and facilitate cooling.

A piston for an internal combustion engine and method of construction is provided. The piston has a robust, lightweight monolithic piston body including an upper wall forming a combustion bowl depending radially inwardly from an annular, uppermost combustion surface. An undercrown surface is formed on an underside of the combustion bowl, with at least a portion of the undercrown surface being bounded by diametrically opposite skirt portions, pin bosses and strut portions connecting the skirt portions to the pin bosses. The bounded undercrown surface has an openly exposed surface area, as viewed looking along a central longitudinal axis along which the piston reciprocates, providing an expansive area against which oil being splashed or sprayed can come into direct contact with to enhance cooling the piston while in use. Through channels extending over upper regions of the pin bosses can be provided to further reduce weight and facilitate cooling.

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.

The invention relates to a method for producing a sintered part with a high radial precision. The sintered part is made of at least one first joining part to be sintered and a second joining part to be sintered, and the method has at least the following steps: joining the first joining part with the second joining part, and bringing about the high radial precision, having a step of deforming at least one radial deformation element which is preferably positioned so as to adjoin a joint contact zone, wherein the deformation of the radial deformation element is caused at least by means of a calibration tool and is carried out at least substantially as a plastic deformation of the radial deformation element. The invention further relates to a set of parts for joining the joining parts to be sintered into a sintered part with a high radial precision.

The invention relates to a method for producing a sintered part with a high radial precision. The sintered part is made of at least one first joining part to be sintered and a second joining part to be sintered, and the method has at least the following steps: joining the first joining part with the second joining part, and bringing about the high radial precision, having a step of deforming at least one radial deformation element which is preferably positioned so as to adjoin a joint contact zone, wherein the deformation of the radial deformation element is caused at least by means of a calibration tool and is carried out at least substantially as a plastic deformation of the radial deformation element. The invention further relates to a set of parts for joining the joining parts to be sintered into a sintered part with a high radial precision.