A piston for use in an internal combustion engine having a pressure side and counterpressure side. The piston includes a piston skirt having skirt wall sections and box walls connecting the skirt wall sections. A spacing between the box walls on the pressure side is 35%-51% of the piston diameter and on the counterpressure side is 26%-39% of the piston diameter. Reduced angles of the extraction angle slopes on the pressure and counterpressure sides as well as larger free spaces are achieved which provides for lower piston mass and greater distribution of stresses in the box region of the piston.

A galleryless piston for an internal combustion engine is provided. The piston has a monolithic piston body including an upper wall forming an upper combustion surface with first and second portions. The first portion extends annularly along an outer periphery of the upper wall and the second portion includes a combustion bowl. The first portion can also include valve pockets formed therein to reduce weight. The upper wall has an undercrown surface directly opposite the second portion of the upper combustion surface. To enhance cooling, a center portion of the undercrown surface is concave, such that oil is channeled during reciprocation of the piston from one side to the opposite side of the piston.

A steel piston designed to improve thermal efficiency, fuel consumption, and performance of an engine is provided. The piston includes a steel body portion and a thermal barrier layer applied to an upper combustion surface and/or a ring belt to reduce the amount of heat transferred from a combustion chamber to the body portion. The thermal barrier layer has a thermal conductivity which is lower than a thermal conductivity of the steel body portion. The thermal barrier layer typically includes a ceramic material, for example ceria, ceria stabilized zirconia, and/or a mixture of ceria stabilized zirconia and yttria stabilized zirconia in an amount of 90 to 100 wt. %, based on the total weight of the ceramic material. The thermal barrier layer can also have a gradient structure which gradually transitions from 100 wt. % of a metal bond material to 100 wt. % of the ceramic material.

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.

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.

The present invention relates to an eco-mold apparatus for manufacturing a piston, a mold apparatus for manufacturing a piston, and a piston manufacturing method, which mold each part of a piston while decreasing the weight of the piston, and the apparatus may comprise: a first eco-mold part which may move forward or backward in a first direction to shape a portion of an eco-part of a piston; a second eco-mold part which may shape-match with the first eco-mold part to mold another portion of the eco-part of the piston; and a piston pickup part which picks up the piston over the second eco-mold part, so that the piston pickup part can separate the piston from the second eco-mold part.

A monobloc piston body for an internal combustion engine is provided. The piston body includes a first piece which includes a pair of skirt portions and a pair of pin bosses and a second piece which includes a crown portion with an upper combustion surface and an at least partially enclosed oil gallery. The first and second pieces are joined together at a joint that is located on a side of the oil gallery opposite of the upper combustion surface. The first piece is made through casting or forging, and the second piece is made through an additive manufacturing process, such as direct metal laser sintering.

A steel piston for coupling to a connecting rod and wrist pin is provided. The piston includes a body with an upper crown presenting a combustion surface for exposure to a combustion chamber. The upper crown presents an undercrown surface which is openly exposed as viewed from an underside of the piston and not bounded by a cooling gallery. The body includes a ring belt and pin bosses depending from the ring belt and presenting a pin bore for receiving the wrist pin. The body also includes ribs disposed along the undercrown surface. The body includes a ratio of compression height to outer diameter (CH/D) ranging from 34.8% to 42.0%. The piston also includes a low heat transfer coating on the combustion surface, and the low heat transfer coating has a thermal conductivity of about 0.20 to 0.80 W/m.Math.K.

A piston and method of construction thereof are provided. The piston includes an upper crown having an upper combustion surface and a lower crown depending therefrom. The lower crown includes a pair of laterally spaced, axially aligned pin bores configured for receipt of a wrist pin. A substantially closed, annular outer cooling gallery is formed between the upper and lower crowns, wherein a bottom surface of the cooling gallery is formed by a floor of the lower crown. An oil inlet and an oil outlet extend through the floor. The oil inlet includes an upstanding toroid-shaped protrusion that extends upwardly from the floor into the cooling gallery, wherein the protrusion is formed as a monolithic extrusion from the material of the lower crown floor.

A piston capable of reducing undesirable knock, reducing hydrocarbon emissions, and providing more complete combustion, is provided. The piston includes a multilayer coating having a thickness of 500 microns or less disposed on an upper combustion surface. The coating includes a bond layer including nickel disposed on the upper combustion surface. A thermal barrier layer including a ceramic composition is disposed on the bond layer. A sealant layer formed of metal is disposed on the thermal barrier layer. A catalytic layer including at least one of platinum, ruthenium, rhodium, palladium, osmium, and iridium is disposed on the sealant layer. The catalytic layer can be disposed on select regions or the entire upper combustion surface to promote combustion through a catalyzed reaction.