A method for producing a piston may include forming a piston blank in a first forming tool such that the piston blank surrounds a ring carrier configured to receive a piston ring via positive engagement after producing the ring carrier by a sintering process. The piston blank, at least in a circumferential region disposed at a piston head, may be composed of a light metal alloy suitable for forging. The method may also include removing the piston blank from the first forming tool and placing the piston blank in a second forming tool, and inserting a holding-down tool into the second forming tool to hold the ring carrier down. The method may further include pressing a final forming punch into the second forming tool to deform the piston blank and form a piston.

A method for the production of a piston made of steel, for an internal combustion engine, in which the upper piston part is produced using the forging method, and the lower piston part is produced using the forging or casting method, and they are subsequently welded to one another. To simplify the production method and make it cheaper, the upper piston part is forged using the method of hot forming and of cold calibration, to finish it to such an extent that further processing of the combustion bowl and of the upper cooling channel regions can be eliminated.

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.

Disclosed is a monoblock or cooling channel piston and a method for producing a monoblock piston for use in an internal combustion engine. A piston blank includes a circumferential collar protruding radially in the region of the piston crown is first produced and the collar is then shaped. A contact region on a top region of the piston skirts and the collar is shaped such that the outer circumferential edge thereof points at a distance to the contact region and forms a defined gap. The gap is then sealed by a closure element in order to form a closed cooling channel.

Disclosed is a monoblock or cooling channel piston and a method for producing a monoblock piston for use in an internal combustion engine. A piston blank includes a circumferential collar protruding radially in the region of the piston crown is first produced and the collar is then shaped. A contact region on a top region of the piston skirts and the collar is shaped such that the outer circumferential edge thereof points at a distance to the contact region and forms a defined gap. The gap is then sealed by a closure element in order to form a closed cooling channel.

A piston includes an upper member having a crown and a combustion surface extending radially inward from the crown. The upper member includes concentrically oriented first and second upper connecting surfaces integrally formed on the bottom side of the upper member. At least one of the upper connecting surfaces includes a curvilinear and/or multi-arcuate cross-sectional profile. The piston also includes a lower member having a pair of opposing skirts, each skirt defining a bore. The lower member also includes concentrically oriented first and second lower connecting surfaces integrally formed on a top side of the lower member. The lower member is integrally connected to the upper member by friction welding. The curvilinear and/or multi-arcuate profile enables a shortened distance between the top surface of the crown and the bore centerline of the bore. Methods of manufacturing the piston are also disclosed.

A piston includes an upper member having a crown and a combustion surface extending radially inward from the crown. The upper member includes concentrically oriented first and second upper connecting surfaces integrally formed on the bottom side of the upper member. At least one of the upper connecting surfaces includes a curvilinear and/or multi-arcuate cross-sectional profile. The piston also includes a lower member having a pair of opposing skirts, each skirt defining a bore. The lower member also includes concentrically oriented first and second lower connecting surfaces integrally formed on a top side of the lower member. The lower member is integrally connected to the upper member by friction welding. The curvilinear and/or multi-arcuate profile enables a shortened distance between the top surface of the crown and the bore centerline of the bore. Methods of manufacturing the piston are also disclosed.

Disclosed herein are an aluminum alloy for an insert ring, an aluminum insert ring using the same, and a piston manufacturing method using the same, and, particularly, are an insert ring manufactured to have high strength and abrasion resistance and reduce its weight by adjusting aluminum alloy components, and a method of manufacturing a piston having high bonding properties to the insert ring through the same.

Disclosed herein are an aluminum alloy for an insert ring, an aluminum insert ring using the same, and a piston manufacturing method using the same, and, particularly, are an insert ring manufactured to have high strength and abrasion resistance and reduce its weight by adjusting aluminum alloy components, and a method of manufacturing a piston having high bonding properties to the insert ring through the same.

A plunger member 3 used for a belt type continuously variable transmission is configured by cold press molding a blank material 32 according to deep-drawing molding, and closed forging, compression molding or a combined molding thereof, where during the cold press molding, a thickness of a bent corner portion 3f, which at least makes a sleeve portion 3c and a step-like formed portion (spring seating portion) 3d continuous to each other, is configured to be increased by 30% or more relative to a thickness of the blank material 32, and then a hardened surface layer 3B is configured to be formed on both of the entire front and back sides of the plunger member by performing a soft nitriding treatment.