An additive manufactured piston having a crown portion and a skirt portion form of an aluminum-cerium-silicon alloy. The piston includes a least one recess pocket in an unstressed region located at an interface between an inner surface of the crown portion and an outer surface of the skirt portion. The skirt portion includes an outer panel surface defining an external rib adjacent a peripheral end surface, at least one stiffening rib extending from a pin boss to a skirt end, and a wall thickness of between 0.2 mm and 1.0 mm in a region between the external rib and the at least one stiffening rib. The skirt portion further includes an internal first rib having a width W1 on a thrust side portion and an internal second rib having a width W2 located on an anti-thrust side portion, in which W1 is greater than W2.

A cast piston for an internal combustion engine is made of an iron-based material and has windows in at least one side wall carrying a piston pin boss. The windows are asymmetric relative to one another on the side of the skirt walls.

A method of manufacturing an engine piston may include performing upper-body formation for forming an upper body as an upper portion of a piston body by pressing a powder-type sintered material, performing lower-body formation for forming a lower body as a lower portion of the piston body by pressing a powder-type sintered material, performing bonding for forming the piston body by providing a brazing material between the upper body and the lower body and brazing the upper body and the lower body to each other while sintering a sintered material, performing machining for removing pores from the surface of the piston body by machining the surface, and performing heat treatment for forming a passive film by performing at least one of nitriding heat treatment or oxidation heat treatment on the surface of the piston body.

A steel piston (1) for a combustion engine, having an upper part in which a ring section (7) with at least one ring groove (8) is arranged, wherein the upper part is adjoined by a lower part that has two opposing skirt wall sections (2), wherein the two skirt wall sections (2) are connected via two mutually opposite case walls (3), wherein a pin bore (4) surrounded by a piston boss (6) is provided in each case wall (3). In one example, there is at least one aperture (14) or at least one recess in the case wall (3) in the region between the piston boss (6) and the skirt wall section (2).

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 piston for an internal combustion engine includes a piston head portion, a pair of piston skirt portions, and a pair of side-wall portions. Each of the side-wall portions includes a pin boss portion having a piston pin hole, and is located between the pair of piston skirt portions. There are set a first axis corresponding to a center longitudinal axis of the piston, a second axis corresponding to an axis of the piston pin holes, and a reference plane corresponding to a plane that passes through the first axis and is orthogonal to the second axis. In a cross section of the side-wall portion being parallel to both of the first axis and the second axis, a distance between the reference plane and an outer peripheral surface of the side-wall portion in the second axis direction gradually increases from a side of the piston head portion toward an intermediate portion of the side-wall portion in the direction of the first axis and gradually decreases from the intermediate portion toward a side opposite to the piston head portion.

A galleryless steel 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 defines a combustion bowl. The piston further includes undercrown surface located directly opposite the combustion bowl with an exposed 2-dimensional surface area allowing for contact of cooling oil. The exposed 2-dimensional surface area ranges from 25 to 60 percent of a cross-sectional area defined by a maximum outer diameter of the piston body. To further enhance cooling, a portion of the undercrown surface is concave or convex, such that oil is channeled during reciprocation of the piston from one side to the opposite side of the piston.

A vehicle internal combustion piston and method of construction thereof are provided. The piston includes piston body extending along a central longitudinal axis, having an upper combustion wall forming an upper combustion surface and an undercrown surface opposite the upper combustion surface. An annular ring belt region depends from the upper combustion surface, a pair of skirt panels depend from the ring belt region, and a pair of pin bosses depend from the undercrown surface to provide laterally spaced pin bores aligned along a pin bore axis for receipt of a wrist pin. The undercrown surface forms a central undercrown region, and a portion of either an open outer cooling gallery, a sealed outer cooling gallery, or an outer galleryless region, wherein an insulating coating including a thermoset resin, such as a phenolic or epoxy resin, with additives is applied to at least one of the portions of the undercrown surface.

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.

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.