Abstract: A combustion engine wherein said engine includes a cylinder chamber, a cylindrical piston adapted to move up and down within a defined passageway provided for by said cylinder chamber. The piston is characterised in having at one end of the piston a segment of the circumferential edge of the piston end at a raised elevation with respect to a diametrically opposed circumferential edge segment of said piston end, such that the end face of the piston is configured as an ellipse. The cylinder chamber passageway has an ellipse end configuration of comparable dimension and inclination to the ellipse piston end face, such that when the ellipse piston face is moved up the cylinder passageway during a compression stroke and at the moment of combustion ah ignited mix of air and fuel injected into the cylinder has a contactable surface area of the ellipse face of the piston to power a return of the piston to its lower position inside the cylinder chamber passageway after the combustion event.

Abstract: Disclosed is a piston for an engine having a stable behavior of a piston ring. The piston for the engine includes: an upper ring, a middle ring, and an oil ring, provided in an outer circumferential portion; and a ring-shaped groove formed between the upper ring, and the middle ring, wherein the ring-shaped groove has a deep portion which has a concave shape, a straight-line shaped first gap is formed between a liner of a cylinder, and an area from the ring-shaped groove to the middle ring, and the first gap is larger than a gap between the liner of the cylinder, and an area from a portion provided with the upper ring to the ring-shaped groove. In the disclosed piston, a blow-by gas, which is a mixed gas flowed into a crank case from a combustion chamber by passing through a gap between the cylinder and the piston, formed below the ring-shaped groove, is stabilized, thereby stabilizing the behavior of the upper ring and the middle ring.

Abstract: This invention is a piston in cylinder engine using water injection into a relative vacuum heated to steam by expanding in the cylinder and by an electric arc or other heat source. The resulting steam explosion applies a work force on the piston. The piston has jet nozzles uncovered at the end of its work stroke to jet the piston to help propel it during the return stroke and to form a vacuum in place of the usual compression stroke. The piston has a cover plate with tapered pins depending into jet nozzles through the piston to block the jet nozzles during the main work stroke.

Abstract: A piston and method of construction are provided. The piston includes an upper crown having a combustion surface with an upper land depending therefrom and a lower crown having a pair of pin bosses that depend to a pair of laterally spaced, axially aligned pin bores. The upper crown is constructed as a monolithic piece of a first material having a thermal conductivity within a range of about 7 to 25 W/m-K. The lower crown is constructed from a low grade steel material having a thermal conductivity higher than the upper crown. The upper crown is joined directly to the lower crown, wherein the upper crown acts as a barrier to thermal conductivity and thus, the heat within a combustion chamber housing the piston for reciprocation therein is maintained and maximized.

Abstract: The present invention is directed to a piston with a unique bowl geometry for optimizing a two-stroke locomotive diesel engine having an exhaust gas recirculation (“EGR”) system. This piston achieves a reduced level of smoke and particulate matter; promotes the mixing process in the engine cylinder; and provides a lower compression ratio for reducing NOx emissions.

Abstract: A piston 10 for an engine has a number of elongate pockets 21, 22, 23, 24 each of which is arranged at an angle relative to a longitudinal axis HP2 of a contact zone 15 on the thrust and anti-thrust sides of the piston 10. The pockets 21, 22, 23, 24 are arranged in two columns C1, C2 one on each longitudinal side of a central portion 20 of the contact zone 15 to form partial barriers to reduce the loss of oil from the central portion 20 during use of the piston 10. The pockets 21, 22, 23, 24 are oriented differently above and below a transverse axis HP1 of the contact zone 15 so as to reduce the loss of oil irrespective of the direction of motion of the piston 10.

Abstract: A piston for an internal combustion engine, for example a diesel engine, including a body defined laterally by a skirt configured to interact with walls of a cylinder having a revolution axis C in which the piston can slide along axis C, the piston including a front face that includes a central lug, a peripheral crown, and a bowl having a revolution axis B extending from the central lug to the peripheral crown to which it is connected at a lip having a thickness Ep. The bowl includes substantially over the lip a torus, for example having a half-dome profile, with a maximum radius Rt and capable of guiding a fuel injected under the lip in a region of a re-entrance zone R towards the central lug, wherein the central lug has separate upper A1 and lower A2 slopes, the upper slope A1 being more gentle than the lower slope A2.

Abstract: An internal combustion engine is provided having a cylinder case with at least one cylinder bore wall defining at least one cylinder bore. At least one piston is reciprocally movable within the at least one cylinder bore. The at least one piston includes at least one skirt portion preferably having a barrel-shaped profile. The cylinder bore wall has an oleophobic characteristic, while the at least one skirt portion has an oleophilic characteristic. The oleophobic and oleophilic characteristic is produced by at least one of coating and machining the at least one cylinder bore wall and the at least one skirt portion, respectively.

Abstract: In some aspects, there is provided an apparatus. The apparatus may include a cylinder for a reciprocating steam engine, wherein the cylinder further comprises a cylinder ring. The cylinder ring may include a face and a heel, wherein the face makes contact with a piston of the reciprocating steam engine, wherein the heel inserts into a cavity formed on an inner surface of the cylinder, wherein the cavity is positioned in a region of the inner surface proximate to a top of the piston, when the piston is at a bottom dead center position. Related apparatus and methods are also described.

Abstract: Inventive embodiments are directed to components, subassemblies, systems, and/or methods for internal combustion engines and in particularly for diesel engines having prechamber combustion systems. In one embodiment, a combustion system can be provided with a pre-chamber adapted to cooperate with a piston in a manner that produces a highly efficient combustion process. In some embodiments, the pre-chamber has passages that have a variable cross-section and a variable angular orientation with respect to a centerline of the pre-chamber body. In one embodiment, the piston is provided with a number of surfaces that facilitate the flow of fuel and air within the combustion chamber. In some embodiments, the piston surfaces are generally aligned with angles of the combustion chamber such as the angle of the intake and exhaust valves. In other embodiments, the piston has surfaces that are adapted to cooperate with a tip of the prechamber.

Abstract: The invention relates to a multi-part piston (10, 110, 210) for an internal combustion engine, comprising a piston upper part (11) and a piston lower part (12). The piston upper part (11) comprises a piston head (13), a continuous fire land (15) and a continuous ring part (16). The piston upper part (11) and the piston lower part (12) are connected together by securing means and form a continuous cooling channel (21). According to the invention, the connecting means connecting the piston upper part (11) and the piston lower part (12) are embodied as cooling elements (28, 128, 228) that are arranged in the cooling channel (21) and that are made of heating-conducting material.

Abstract: A cylindrical piston for internal combustion engines, comprising a piston crown and a piston base, in the piston base a hollow space being provided, and in a piston base wall forming the hollow space pinholes being provided, characterized in that the outer circumferential surface in at least the piston base at least one oil guide is provided, the direction thereof having an axial component relative to the piston axis and the oil guide extending from the piston crown in the direction of a pinhole.

Abstract: The invention relates to a cast piston for an internal combustion engine having a piston base, a cylindrical piston head connected to the piston base, and pin bores provided in an at least partially hollow piston shaft, which is positioned on the side of the piston head opposite the piston base. The piston has one or more supporting ribs located at least partially in the piston shaft, and at least one supporting rib has a recess on the side facing the piston base.

Abstract: The invention relates to a two-piece piston (1) for an internal combustion engine, comprising a piston base body (2) and a ring element (3), which is soldered to the piston base body (2) by an upper solder connection (23) having the length b, which is disposed on the radial inside of a piston crown (4) formed at least partially by the ring element (3), and by a lower solder connection (24) having the length c, which is disposed radially outside on the top of a center part (9).

Abstract: The invention relates to a pin boss (17) for a piston (10) for an internal combustion engine, the pin boss (17) having an inner boss surface (17a) and an outer boss surface (17b) and a boss bore (18) for accommodating a piston pin. The boss bore (18), in the vertex of the boss, has a pocket (20) the depth of which gradually decreases along the boss contour towards the outer boss surface (17b).

Abstract: A method for producing a piston for an internal combustion engine, designed as a cooling duct piston for small compression heights. The piston includes a lower part and an upper part which are supported by one or more corresponding joining planes and are connected of a friction welding process. The piston encloses an inner, trough-shaped cooling duct and an outer cooling duct which is axially spaced apart from an annual area. The inner cooling duct is formed in the lower part of the piston by a mechanical machining process, such as a forging process. Transfer openings which are assigned to the cooling ducts are formed before the frictional welding of the joining planes.

Abstract: A method for surface treatment capable of easily improving a mechanical strength of an internal combustion piston at a reasonable cost is provided. A modified surface layer is formed by injecting injection powders containing a reinforcing element to be collided with an Al—Si alloy-based piston obtained by casting and forging by injecting under predetermined conditions, the reinforcing element being diffused and penetrated in the piston to improve the strength thereof. When a function, such as fuel modification, is imparted to the modified surface layer, an element exhibiting a photocatalytic function by oxidation, such as Ti, Sn, Zn, Zr, or W, is selected as the reinforcing element.

Abstract: A cooling channel piston for an internal combustion engine which includes a piston bottom and a piston shaft that are joined thereto of a friction welding process. The piston bottom and the piston shaft jointly form a cooling channel. An annular wall which radially delimits the cooling channel towards the outside is formed by the piston bottom and/or the piston shaft. The annular wall can be sealed by a welding process once the piston bottom and the piston shaft have been joined together.

Abstract: A piston has an upper crown portion with an upper combustion wall against which combustion forces act and a lower crown portion with a pair of pin bosses spaced for receipt of a small end of a connecting rod therebetween. The upper crown portion and the lower crown portion form an outer oil gallery and a central oil gallery in fluid communication with one another. The central oil gallery is formed in part by an annular flange extending radially inwardly from the outer oil gallery and upwardly toward the upper combustion wall to a free edge spaced from the upper combustion wall. The free edge forms an opening about a central axis of the piston and has a non-planar uppermost surface with depressions aligned diametrically opposite one another across the opening to improve the oil flow throughout the central oil gallery.

Abstract: A coolable piston includes an annular wall extending between a crown and a lower distal end. First and second shoulders are provided in the wall. The first shoulder extends between first and second inner diameters of the wall. The second shoulder extends between the second and a third inner diameter. A collar is provided on the lower distal end of the wall and flanged over to project radially inwardly. An annular rib depends from the crown, with an annular cavity provided between the rib and the wall. An annular channel is formed in the rib. A ring member at least partially closes the cavity. The ring member is supported against axial movement by an inner periphery of the ring member being received in the annular channel. A locking ring is disposed in the collar against the second shoulder and supports an outer periphery of the ring member against axial movement.

Abstract: A piston (10, 10?) includes a piston body (12, 12?) having an upper crown portion (16, 16?) with an upper combustion dome (18, 18?) against which combustion forces act. The underside of the upper combustion dome (18, 18?) comprises an under-crown region (60, 60?). The piston body (12, 12?) also includes a lower crown portion (26, 26?) with a pair of pin bosses (36, 38) spaced apart for pivotally adjoining a connecting rod. An outer oil gallery (31, 31?) is formed as an inclusion between the upper (16, 16?) and lower (26, 26?) crown portions. The outer oil gallery (31, 31?) has an oil inlet (50, 50?) and an oil outlet (52, 52?). A tubular cooling nozzle (54, 54?) is affixed in fluid communication with the oil outlet (52, 52?) and extends toward the under-crown region (60, 60?) where oil is discharged during reciprocation of the piston (16, 16?).

Abstract: An improved internal combustion engine is provided with at least one channel or groove on its compression face. The at least one channel or groove can be open and of uniform width. The channel or groove can direct flow of an air-fuel mixture to increase combustion efficiency.

Abstract: A piston-type internal combustion engine is formed of a high performance synthetic resin material. The cylinders and pistons have an octagonal profile. Two or three rows of pin roller bearings are positioned in transverse semi-cylindrical grooves formed on the cylinder walls, to afford smooth, low-friction rolling contact and to seal the compression from leaking around the piston. There are angle support pieces fitted within the annular channels at respective vertices or corners, and are adapted for rotationally supporting the ends of adjacent pin roller bearings.

Abstract: The present invention generally relates to a recess in the top of a piston. More particularly, the present invention relates to a crescent-shaped recess in the top of an expansion piston of a split-cycle engine.

Abstract: A method to control combustion in an HCCI engine, to mitigate effects of combustion chamber deposits is detailed. The method comprises applying a specific surface coating to a combustion chamber surface. The surface coating has thermal properties substantially similar to the combustion chamber deposits. The thermal properties preferably include a) thermal conductivity, b) heat capacity, and c) thermal diffusivity. Applying a surface coating results in a reduction of combustion variability due to variation in combustion chamber deposits, and an improvement on combustion stability at low loads due to reduced heat loss. A preferred thermally insulating surface coating includes thermal parameters of a heat capacity in a range of 0.03×106 J/m3-K to 2.0×106 J/m3-K; a thermal conductivity in a range of 0.25 W/m-K to 2.5 W/m-K; and, a thermal diffusivity in a range of 1×10?7 m2/s to 8×10?6 m2/s.

Abstract: A piston for an internal combustion engine includes a piston base material and a film of lubrication coating composition. The coating composition has an inner coating layer formed on a surface of the piston base material and an outer coating layer formed on a surface of the inner coating layer. Each of the inner coating layer and the outer coating layer contains at least one of a polyamide-imide resin, a polyimide resin and an epoxy resin as a binder. The inner coating layer contains 0 to 50 wt % of at least one of graphite and molybdenum disulfide as a solid lubricant, whereas the outer coating layer contains 50 to 95 wt % of at least one of graphite and molybdenum disulfide as a solid lubricant.

Abstract: The present invention relates to a method for producing a single part piston (20) for an internal combustion engine from a piston blank (10), with a cooling channel (15) that is open in the downward direction running circularly inside a piston head (11), and an annular recess (16) built between the piston head (11) and a piston shaft (13), wherein the piston head (11) and the piston shaft (13) are connected to each other by means of a piston hub (14), and wherein the annular recess (16) and the cooling channel (15) are machined into the piston blank (10) by means of a cutting operation. According to the invention, it is provided that, for the cutting operation of the cooling channel (15), a tool (17) is moved into the area of the cooling channel (15) in an arc-shaped pivoting movement (A) through the recess (16), and that the cooling channel (15) is cut.

Abstract: A piston/connecting rod arrangement for an internal combustion engine has a piston upper part with hub supports which lie opposite one another and have hubs and hub holes which delimit a recess, in which the small connecting-rod eye of a connecting rod is arranged. A piston pin is mounted in the small connecting-rod eye and the hub holes. There is at least one oil-guiding face to be provided on that face of the hub support which faces the recess. At least one oil-guiding face opens into at least one oil-collecting space which is arranged in the hub hole, in such a way that the oil-guiding face guides oil into the oil-collecting space.

Abstract: An internal combustion engine piston includes a piston crown, a thrust-side skirt, an anti-thrust-side skirt, a first apron, and a second apron. The first and second aprons are connected to the thrust-side and anti-thrust-side skirts through connecting sections. Each connecting section has a thickness that gradually increases as followed from a proximal longitudinal end to a distal longitudinal end, wherein the proximal longitudinal end is closer to the piston crown, and the distal longitudinal end is closer to a distal longitudinal end of a corresponding one of the thrust-side and anti-thrust-side skirts.

Abstract: A plurality of convex portions are radially fanned and spaced apart from each other by a constant angle in a planar view on a tapered surface of a land portion formed on a bottom surface of a cavity formed in a top portion of a piston. Each convex portion is positioned such that the extending direction of the convex portion aligns with an axis X of a corresponding fuel spray. Thereby, each fuel spray moves forward through a space (convex portion space) between the corresponding convex portion and an inner wall of a cylinder head portion along the extending direction of the corresponding convex portion. When a fuel injection is performed during the latter half of a compression stroke, a pressure in a convex portion space is increased, compared with a pressure in a space of the other portion by the decrease of a ratio of the volume of the convex portion space relative to the volume of the space of the other portion by the proceeding of the compression by the piston.

Abstract: A method for surface treatment capable of easily improving a mechanical strength of an internal combustion piston at a reasonable cost is provided. A modified surface layer is formed by injecting injection powders containing a reinforcing element to be collided with an Al—Si alloy-based piston obtained by casting and forging by injecting under predetermined conditions, the reinforcing element being diffused and penetrated in the piston to improve the strength thereof. When a function, such as fuel modification, is imparted to the modified surface layer, an element exhibiting a photocatalytic function by oxidation, such as Ti, Sn, Zn, Zr, or W, is selected as the reinforcing element.

Abstract: In a two-stroke, opposed-piston internal combustion engine with optimized cooling and no engine block, opposed pistons protrude from the bore during at least a portion of an operating cycle of the engine and are cooled by application of a liquid coolant to their interiors.

Abstract: In a direct fuel injection diesel engine equipped with a pentroof-shaped piston, when fuel is injected into a cavity (25) recessed in a central part of a piston (13), for which the height of a top face changes in the circumferential direction, from a fuel injection point (Oinj) of a fuel injector disposed on a piston central axis along a plurality of fuel injection axes (Li1,Li2), if a cross-section of the cavity (25) passing along the fuel injection axis (Li1,Li2) is defined as a fuel injection cross-section (Sn), a cross-sectional shape (see shaded portion) of the cavity (25) defined by first to third specific points (An, Bn, Cn) on the fuel injection cross-section (Sn) is set so as to be substantially equal for each fuel injection cross-section (Sn). By so doing, the conditions in which fuel and air are mixed in each fuel injection cross-section (Sn) can be made uniform, the engine output can be improved, and harmful exhaust substances can be reduced.

Abstract: A coolable piston for internal combustion engines is disclosed herein. The coolable piston includes a head portion with a crown and an annular wall. First and second shoulders are defined in annular wall adjacent to one another. A collar is formed on a distal end of the annular wall and flanged over to project radially inwardly from the distal end. An annular rib extends from the crown and within the annular wall to thereby define an annular cavity with the annular wall. The annular cavity extends along the longitudinal axis from a first end closed by the crown to a second end at the distal end of the annular wall. The coolable piston also includes first and second pin bosses disposed at a distal end of the annular rib. The coolable piston also includes an annular notch formed in the annular rib and substantially opposing the first shoulder. The coolable piston also includes a ring member closing the second end of the annular cavity.

Abstract: A method of operating an internal combustion engine for the purposes of producing significantly lower NOx emissions than currently achieved without exhaust aftertreatment is described. The engine is equipped with an intake system and combustion chamber that minimizes overall in-cylinder angular momentum of the air fuel charge. The engine is fueled with a gaseous fuel such as natural gas. The purpose of the intake system and combustion chamber is to create low combustion peak temperature while keeping the overall average temperature the same. Charge dilution which can be in the form of excess combustion air, recirculated exhaust gases, water injection, or combinations of all three will be used to assist in reducing NOx emissions.

Abstract: A combination of a piston and a chamber, wherein the chamber defines an elongate chamber having a longitudinal axis, the chamber having, at a first longitudinal position thereof, a first cross-sectional area thereof and, at a second longitudinal position thereof, a second cross-sectional area, the second cross-sectional area being 95% or less of the first cross-sectional area, the change in cross-section of the chamber being at least substantially continuous between the first and second longitudinal positions, the piston being adapted to adapt itself to the cross-section of the chamber when moving from the first to the second longitudinal position of the chamber. The piston may comprise an umbrella-like support structure or a fibre enforced deformable container comprising a foam or a fluid. The combination may be used in a pump, a linear actuator, a motor, or a shock absorber.

Abstract: Disclosed is a piston for a combustion engine, comprising a cooling duct with a single inlet port and at least two outlet ports, at least two of which are separated from each other regarding the discharged coolant. Also disclosed is a combustion engine comprising at least one such piston.

Abstract: The present invention relates to a piston (10) for an internal combustion engine, having a combustion depression (13) which is provided in the piston head (11) and has an encircling undercut (14), wherein the encircling depression edge (15) which connects the undercut (14) to the piston head (11) has alternately rounded (16, 17) and sharp-edged depression edge regions (18, 19). It is provided according to the invention that the encircling depression edge (15) merges along its entire periphery into a planar encircling face (20) which in turn merges along its entire periphery with a sharp edge into the undercut (14).

Abstract: A piston device for internal combustion engines includes a first compression ring and a second compression ring in an outer circumference of a piston, wherein the second compression ring includes a notch extending from the inner circumference to the outer circumference on a lower surface of at least one of a pair of ends of the ring, and a gap between the ring ends at the notch on the second compression ring is larger than a gap between the ring ends of the first compression ring, and a gap between the ring ends at the section other than the notch on the second compression ring is the same or smaller than the gap between the ring ends of the first compression ring, and the second compression ring contains an outer circumferential surface comprised of a tapered surface decreasing the ring radial thickness towards the upper side, and an axial parallel surface formed below the tapered surface.

Abstract: Disclosed is a multipart, cooled piston for a combustion engine, comprising, in a radially outward direction, an annular cooling duct located on the bottom side that faces away from the piston head. The cooling duct is closed by a cooling duct cover which is embodied as a ring. The cooling duct cover is provided with a tongue in the radially inner zone. The tongue engages into a recess that is molded into the bottom piston part, thus preventing the cooling duct cover from rotating relative to the piston during assembly as well as during operation.

Abstract: A piston includes a piston head, two skirt walls disposed opposite one another and at least one pin bearing disposed between the skirt walls and supported on the piston head. Each skirt wall extends over a partial region of the periphery of the piston or piston head. The two skirt walls are connected by at least one self-supporting support wall disposed at a distance from the piston head. A cylinder and piston assembly and a piston ring for a cylinder, are also provided.

Abstract: A piston of an internal combustion engine has a piston crown with annular grooves and a shaft part disposed on the piston crown. The shaft part has bearing shaft wall sections which are connected to one another via inclined connecting walls which are retracted with respect to the outer diameter of the piston. Piston-pin bosses for accommodating a piston pin are disposed in connecting walls. The connecting walls are retracted at such an angle that, in progressing from the lower edge over an intermediate region which lies further back than the lower edge, into an end region which lies further back than the intermediate region the connecting walls to over flush into a hub supporting region below the piston crown.

Abstract: A piston for an internal combustion engine has a piston crown and a cooling channel disposed close to the piston crown and radially on the outside. The cooling channel is delimited on the underside by ribs uniformly distributed over the circumference, with openings lying between them. The openings of the cooling channel are closed off with two metal cover sheets attached to its underside, in the shape of a half circle. There is at least one oil inflow opening and at least one oil outflow opening in or between the cover sheets.

Abstract: This device is designed for a piston which is designed to move in alternating linear movement parallel to the axis of a chamber divided by the piston into a high pressure volume and a low pressure volume, and is of the type comprising: a circular cylindrical sliding surface bounding the chamber, an annular groove provided in the piston which is coaxial with the sliding surface and open towards the sliding surface, and a closed resilient sealing ring housed in a leak tight manner in the groove and intended to make sealing contact with the sliding surface. According to one aspect of the invention the ring is designed to determine the size of a lubricating oil film between the ring and the sliding surface to a limit lubricating thickness preferably from 0.1 ?m to 1 ?m when it moves from the high pressure volume to the low pressure volume.

Abstract: An engine piston is manufactured by assembling an outer shell, comprising a crown and tubular side wall in which a ring groove region and skirt are defined, with a plate-like mounting member and bonding them together by brazing or welding. The mounting member is located within the tubular side wall displaced axially from the crown and is bonded near, but displaced radially from, its centre to the crown and at its periphery to the side wall at the end of the ring groove region. The mounting member carries gudgeon pin boss means facing away from the crown. The outer shell is formed by extrusion or the like that permits minimal wall thickness and the bonded structure is of light weight but great strength and stiffness, particularly in the ring groove region. A combustion bowl formed in the crown facilitates bonding to the mounting member and defines with the mounting member an annular cooling chamber adjacent the ring groove region and crown.

Abstract: A two-part, cooled piston for an internal combustion engine has an upper piston part and a lower piston part, in which the piston parts are screwed together by way of a threaded pin disposed on the upper piston part and a threaded bore worked into the lower piston part. The material of the threaded pin, in order to improve its strength, has a stretching limit that is higher in comparison with the rest of the piston material. The increase in the stretching limit is achieved by means of lasting stretching of the threaded pin by approximately 1% of its length, in the axial direction.

Abstract: An engine includes: a cylinder block; and a piston ring, in which the cylinder block has a cylinder liner portion formed of an aluminum-based composite reinforced by a ceramic containing at least either of a silicon carbide and an alumina, and in which the piston ring is coated with a nitride film (20) including a vanadium nitride layer (21) exposed on an outer circumferential sliding surface (17).

Abstract: A multi-part piston for an internal combustion engine has an upper piston part with a piston crown, and a lower piston part with pin boss supports and pin bosses connected with the pin boss supports. The upper piston part and the lower piston part each have an inner and an outer support element, which elements delimit an outer circumferential cooling channel. The inner support elements delimit a cavity that is open toward the pin bosses. The cavity is provided with a separate cooling oil collector that has at least one cooling oil opening.

Abstract: A method for producing a multi-part piston for an internal combustion engine and the piston itself, which has an upper piston part and a lower piston part, each having an inner and an outer support element, which elements delimit an outer circumferential cooling channel and an inner cooling chamber. The inner support element of the upper piston part and/or the inner support element of the lower piston part have at least one recess on their surface. The upper piston part and the lower piston part are connected with one another by pressure welding.

Abstract: A multi-part piston for an internal combustion engine has an upper piston part and a lower piston part. The upper piston part and the lower piston part each have an inner and an outer support element, which elements delimit an outer circumferential cooling channel and an inner cooling chamber, whose cooling chamber bottom has an opening.