A piston and methods for constructing a piston for use in an internal combustion engine are presented wherein the piston includes a cylindrical body extending from the crown. The cylindrical body defines a ring groove, and a portion of the cylindrical body defines a non-circular cross-section below the ring groove. The ring groove is configured to correspond with an associated sealing ring. The non-circular cross-section creates a gap between the cylindrical body and an associated cylinder wall enabling a quantity of oil to pass from an annular region between the cylindrical body and the associated cylinder wall.

A piston capable of withstanding high temperatures and extreme conditions of a combustion chamber of an internal combustion engine and manufactured with reduced costs is provided. The method of manufacturing the piston includes casting or forging the bulk of the piston as a single-piece with an open cooling gallery from an economical first material, such as steel, cast iron, or aluminum. The method further includes forming a portion of a combustion bowl surface, which is a small area of the piston directly exposed to the combustion chamber, from a second material by additive machining. The second material has a higher thermal conductivity and higher resistance to oxidation, erosion, and oil coking, compared to the first material. The additive machining process is efficient and creates little waste, which further reduces production costs.

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 diesel engine piston has a body and a crown engaged to the body with three inertially welded struts. The body includes a base extending downward opposite the crown with pin bosses having pin bores and a skirt extending downward from the base.

A piston for an internal combustion engine is provided. The piston includes an open inner cooling area in which the undercrown surface is exposed, and an annular outer cooling gallery. The piston also includes an oil outlet scoop for local cooling of the undercrown surface of the piston. The outer cooling gallery includes an oil outlet opening, and the oil outlet scoop is beneath and vertically aligned with the oil outlet opening. The oil outlet scoop includes a concave surface facing the oil outlet opening. During operation, oil exits the oil outlet opening, and the oil outlet scoop catches the exiting oil and directs the oil to the inner cooling area and the exposed undercrown surface.

Piston blank for a piston, comprising a piston lower part, which comprises a first joining surface running around a central axis of the piston blank, and a piston upper part, which comprises a second joining surface running around the central axis and an inner surface running around the central axis and adjoining the second joining surface as viewed along the central axis, wherein the piston upper part can be placed with its second joining surface on the first joining surface, and wherein a tangential plane which is assigned to the second joining surface is inclined relative to the central axis such that the tangential plane intersects the inner surface.

A method for producing a piston may include providing a blank of a piston base member with an outer peripheral joining face, an inner peripheral joining face which may be expanded in a direction of a base region of a combustion bowl, and a lower cooling channel portion which may extend between the outer and inner peripheral joining faces, wherein at least one of (i) at least one of the outer and inner peripheral joining faces and (ii) the lower cooling channel portion may be not subsequently processed. The method may then include providing a blank of a piston ring element with an outer annular joining face, an inner annular joining face, and an upper cooling channel portion which may extend between the outer and inner annular joining faces, wherein at least one of (i) at least one of the outer and inner annular joining faces and (ii) the upper cooling channel portion may be not subsequently processed. The method may then include joining the blanks via the outer and inner peripheral joining faces and the outer and inner annular joining faces to form a piston blank in such a manner that, at least in the base region of the combustion bowl, a part-region of the expanded inner peripheral joining face of the blank of the piston base member may remain free. The method may further include subsequently at least partially processing the piston blank to form the piston with the part-region of the expanded inner peripheral joining face being removed.

A method for producing a piston for an internal combustion engine may include producing a piston upper part including a piston top, at least parts of a ring section, and at least part of a cooling channel, producing a piston lower part and closing the part of the cooling channel arranged in the piston upper part via an additive method, and finish-machining the piston. Finish-machining the piston may include producing at least one annular groove in a ring support for receiving a piston ring.

A piston for use in an internal combustion engine having a two-piece construction including an upper and a lower part. The upper and the lower parts include one or more overlapping cutouts to reduce the weight of the piston. One or more of the cutouts or connecting walls include wall regions that transition to adjacent walls without sharp or abrupt areas. The piston upper and lower parts are permanently joined together. One or more tongue and groove structures are used to provide a locking connection between the piston upper and lower parts.

Improving an IC Engine’s thermal efficiency by heat preservation by providing: heat insulation layers to the cylinder, piston crown, combustion chamber and cylinder-head including internal gaps/cavities with or without vacuum; reduced carbonisation of fuel and oil; reduced the thermal shock by exhaust gas recirculation - EGR with control/intake valves, heating and storage tank; improved thermal shock resistance of insulation with flexible/porous thread/fibre and cloth materials bound together by binding with paste, stitching, weaving, braiding or pressed/clamped together; improved distortion resistance using sapphire or tungsten steel; an elongated piston cap or cone; segmented or annular sheet cylinder/liner construction; direct or indirect cooling of fuel injectors with fuel recirculation or spark plugs with high pressure gas jets in pits or slits.