Abstract: A piston for a direct injection engine is provided, the piston having a bowl at an upper end, the bowl forming a portion of a combustion chamber. The bowl includes an inner surface that defines a volume configured to receive a fuel-air mixture, the inner surface of the bowl including a generally concave portion including a flat bottom surrounding a central protruding dome. The relatively flat bottom portion is bounded by two radial concave surface portions which are disposed below two convex separation features for the injected fuel spray. Such surface geometries may reduce soot and improve fuel-air mixing.

Abstract: An internal combustion engine component is composed of an aluminum alloy containing silicon, and includes a plurality of silicon crystal grains located on a slide surface. The slide surface has a ten point-average roughness RzJIS of about 0.54 ?m or more, and a load length ratio Rmr(30) at a cut level of about 30% of the slide surface is about 20% or more.

Abstract: A piston for a direct injection engine is provided, the piston having a bowl at an upper end, the bowl forming a portion of a combustion chamber. The bowl includes an inner surface and a dome that defines a volume configured to receive a fuel-air mixture, the inner surface of the bowl and the dome each including at least one surface feature as a target for the fuel spray. The surface feature may protrude from the inner surface of the bowl or may be recessed into the inner surface. Such surface features may reduce soot and improve fuel-air mixing.

Abstract: Proposed is a piston (1) for an internal combustion engine having a closed annular duct (4) which is arranged close to the piston head (5) and radially at the outside, which annular duct (4) has, at the piston head side, an annular opening (21) which, in section, has the shape of a trapezium with limbs which taper conically in the direction away from the piston head, and which is closed off by an annular closure element (3) which, in section, has the same trapezium shape as the opening (21), with the closure element (3) being fastened in the opening (21) by means of friction welding.

Abstract: A piston for a compression ignition internal combustion engine includes a piston body having a combustion face defining a combustion bowl, and the combustion face including a compound bowl surface and a compound rim surface. The combustion face is profiled to balance a combustion efficiency property of the piston with emissions properties of the piston, and includes a profile of rotation defining a convex curve segment bisected by the longitudinal axis, and a plurality of concave curve segments outboard of the convex curve segment. The profile of rotation further includes a compound rim profile defining a plurality of convex curve segments corresponding to an inner rim surface. The convex curve segment of the compound bowl profile defines a relatively small radius of curvature, and the plurality of convex curve segments corresponding to the inner rim surface define a relatively large radius of curvature.

Abstract: A two stroke engine of a particular configuration can have its power output increased by running bigger pistons and using ports in the piston skirt through which to conduct compressed air within the skirt through short passages in the cylinder housing that conduct the air from within the skirt to above the piston. As a result a larger piston can be used for the same spacing and opening size in the block to save the need to redesign the block and the crankshaft. A position adjuster for the piston moves it axially without rotation of the piston ports out of alignment with inlet ports in the housing. The piston rod is held in the crosshead using a flat to prevent rotation while an adjuster nut that is turned creates axial movement in the piston rod with a lock nut securing the final piston position.

Abstract: An internal combustion engine may include a cylinder block defining a cylinder and a crankshaft having a crankpin. The crankshaft is rotatably received by the cylinder block and rotates along a longitudinal axis, and the crankpin defines a longitudinal axis parallel to and offset by a distance with respect to the longitudinal axis along which the crankshaft rotates. The engine may further include a piston configured to reciprocate within the cylinder and a connecting rod operably coupled to the piston and the crankpin. At least one of the piston and the connecting rod is configured such that a distance between a cross-sectional center of the crankpin and an upper surface of the piston is variable via hydraulic operation.

Abstract: A two-piece piston for an internal combustion engine has an upper piece and a lower piece, the lower piece having an upper base part with an opening lying coaxial to the piston axis into which a pin on the upper piece is inserted. The upper piece is connected to the lower piece with a hexagonal nut screwed onto the pin. A resilient sleeve is arranged between the upper piece and the lower piece comprising an inwardly directed collar on the against which the upper face of the hexagonal nut lies and in the region facing away from the piston crown, a contact surface facing the piston crown lying on a surface on the inner side of the opening. An economically produced two-piece piston results with a resilient sleeve between both screwed piston pieces which exerts a pre-tensioning and thus provides security for the screw connection.

Abstract: A piston and internal combustion engine therewith constructed in accordance with the present invention has a piston body with an upper crown having a substantially cylindrical outer surface depending from a top surface along a central axis. At least one annular ring groove extends radially into the outer surface to provide a top land extending from the ring groove to the top surface. A plurality of waves are formed circumferentially about the top land. Each of the waves has a valley extending radially into the outer surface of the top land and extending from the top surface to the ring groove. The waves traverse from the top surface to the ring groove and are configured in substantially non-overlapping relation with one another and in a predetermined orientation relative to at least one of a fuel spray stream, a pin bore axis or a thrust axis of the piston.

Abstract: Piston pin for a connecting rod in a reciprocating internal combustion engine, wherein the piston pin carries at least in the area of the running surface a thermal sprayed slide layer of a metallic bearing material or slide bearing material, as well as reciprocating internal combustion engine with a connecting rod with small and with large connecting rod eye, wherein at least the running surface of one of the piston pins is formed of a thermal sprayed slide layer of a metallic bearing material, which exhibits a lower hardness than the running surface of the corresponding connecting rod eye and process for manufacturing a described piston pin with the steps of a extrusion molding or machining a piston pin preform, introduction of a recess in the area which will later become the running surface, roughening the outer surface in the area of the recess, application of a coating of a bearing material by a thermal spray process.

Abstract: The invention relates to a method for producing a piston for a combustion engine comprising a combustion recess, during which an annular fiber preform for reinforcing the edge of the combustion recess is firstly fastened inside the casting mold. Afterwards, a low-silicon aluminum/copper melt is introduced into the casting mold by which the fiber preform is infiltrated and molded into the recess edge within the scope of the casting process. The piston blank produced in this manner is then subsequently compacted by a high-temperature isostatic pressing before the piston is completed by means of a machining completion process. The flanks and the base areas of the second and third annular groove are coated by means of anodic oxidation, and the hub boreholes are smoothed and hardened by roller-burnishing. This results in a very high-quality and heavy-duty piston.

Abstract: A piston (1) includes a cavity (5) defined by a curved recessed portion (5a) formed on a crown surface in a manner such that a surface of the curved recessed portion extends along a tumble flow produced during an intake stroke, and a weakening portion (6) that is disposed in the cavity. The weakening portion, for example, is disposed on the crown surface of the piston (1) so as to occupy the portion of the crown surface that includes substantially a center portion of the piston (1). The weakening portion (6) reduces the strength of tumble flow produced by the gas flowing into a combustion chamber when the intake valves are opened.

Abstract: The invention relates to a process for producing a piston of an internal combustion engine, wherein a piston blank is cast from an alloy of aluminium and silicon with the addition of copper fractions and is then finished, wherein the invention provides that the maximum fraction of copper in the alloy, of aluminium and silicon is 5.5%, and that fractions of titanium (Ti), zirconium (Zr), chromium (Cr) or vanadium (V) are admixed with the alloy of aluminium and silicon.

Abstract: A power assembly for an internal combustion engine includes a piston housed within a cylinder, with the cylinder having a welded cylinder head, with the cylinder also including a one-piece piston scraper which is welded to the cylinder head, as well as to the cylinder, with a common weld bead.

Abstract: Disclosed is a piston for internal-combustion engines, which includes a low thermal-conductive member disposed at the top portion thereof, the low thermal-conductive member including an alloy containing Fe and Mn. The low thermal-conductive member includes a sintered body having 10˜60 mass % of Mn, 2 mass % or less of C, and the balance of Fe and inevitable impurities. Since the piston has the low thermal-conductive member having low thermal conductivity and thermal expansion properties similar to those of the aluminum alloy, which is the base metal of the piston, an increase in the temperature of a combustion chamber and vaporization of fuel are effectively promoted. Furthermore, thermal fatigue failure and separation of the low thermal-conductive member are prevented.

Abstract: A piston for an internal combustion engine has annular cooling passage arranged in the vicinity of the piston crown and radially on the outside, which, in those regions of the pin bosses which lie close to the boss holes, has boss cooling passages which are connected to the cooling passage and are intended for improved cooling of the pin bosses.

Abstract: An exemplary piston assembly and method of making the same are disclosed. A piston assembly may include a piston crown and piston skirt. The crown may include a ring belt portion defining at least in part a cooling gallery, as well as radially inner and outer crown mating surfaces. The skirt may be received in a central opening of the crown such that the crown and skirt cooperate to form an upper combustion bowl surface. The skirt also may include radially inner and outer skirt mating surfaces that are abutted with the inner and outer crown mating surfaces, respectively, such that the cooling gallery is generally enclosed by the skirt.

Abstract: A piston for an internal combustion engine including: a piston head located at an uppermost section of the piston; a land located on a circumference of the piston head; a skirt located below the land; and a pair of pin bosses located on the lower section of the piston head. The piston head has a first cavity on the bottom of the piston head. Each of the pair of pin bosses has a second cavity in an outer upper section of the pin boss. The pin boss has a through hole that communicably connects the first cavity with the second cavity.

Abstract: The most difference for one kind of the positive-displacement engine from capacity-invariable engine is, the CVE has double pistons interlinked mutually in every cylinder. Inner piston connects with the piston pin by the connecting rod. Outer piston with a ring sits on inner piston supported by the spring. The characteristic of this engine is: Every stroke volume changes diversity. In exhaust stroke, outer piston gets to the tiptop of the cylinder, waste gas almost discharges (exhaust ratio can be to 95%˜98% in theory), compression ratio is improved (?12); In intake stroke, outer piston continues moving by the inertia at the end of the intake stroke, the air intake volume increases. So it realizes the automatic supercharging and the fuel efficiency and emission have improved. Since outer piston has the effect of storing energy, the peak pressure and the speed of the pressure raising have been reduced.

Abstract: A piston for an internal combustion engine wherein the piston includes a piston body fabricated from a metal and a piston head fabricated from a ceramic or ceramic composite material, the ceramic or ceramic composite piston head is press fit to the piston body and secured by an internal circumferential locking ring.

Abstract: In a method for producing a piston for an internal combustion engine, at least the region of the upper annular groove is at least partially recessed, an adhesion promoter layer containing aluminium is then applied, a wear-resistant layer is thermally sprayed onto said adhesion promoter layer and at least the upper annular groove is at least partially formed in said layers. The invention also relates to a piston for an internal combustion engine that comprises a base material, an adhesion promoter layer that contains aluminium and is applied to at least some regions of said material and a wear-resistant layer that is thermally sprayed onto said adhesion promoter layer. At least the upper annular groove is at lest partially formed in said layers.

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: The invention relates to a piston for an internal combustion engine, having shaft wall sections on the pressure and counter-pressure side, and connecting walls between the shaft wall sections, characterised in that the connecting walls are arched on the counter-pressure side, and that the connecting walls are largely straight on the pressure side such that the counter-pressure side is more elastic than the pressure side.

Abstract: A combustion system for a direct-injection, spark-ignition engine is disclosed. A side-mounted fuel injector located outboard the intake valves directs multiple fuel jets into a shallow, spherical bowl formed in a domed piston. Both good mixing to facilitate good air utilization with early injection and an ignitable mixture at the spark plug with late injection to facilitate cold start are provided with such a combustion system. Because the bowl is smooth and shallow, the surface area of the combustion chamber is less than with a deeper bowl of complicated shape. Lowering surface area in the combustion chamber leads to improved fuel economy.

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 of a gasoline direct engine may include a protuberance portion protruding along a circular arc shape having a radius (R1) equal to the piston diameter to have a predetermined height (T) from the upper surface thereof, and the edge of the protuberance portion is rounded to be connected with the upper surface; a bowl (B) having a bottom surface (F1) having an asymmetrical ellipse shape from the center of the protuberance portion to the intake side direction thereof, wherein the bottom surface thereof becomes deeper in the exhaust side direction to have a predetermined slope angle (?1), and the inner wall portion thereof has a circular arc shape to form a predetermined rising angle (?2) at the upper part thereof; and trumpet portions (TR) of which edge ends (E) thereof are expanded in the intake side direction of the protuberance portion to be connected to the bowl (B).

Abstract: A piston/piston ring arrangement for an internal combustion engine has a piston that is provided with at least one piston ring accommodated in a ring groove, which ring has a ring gap. A spring element is disposed between the groove root of the ring groove and the piston ring, which element fills the ring gap of the piston ring. A modular unit is composed of such a piston/piston ring arrangement and a cylinder or a cylinder sleeve of an internal combustion engine.

Abstract: The present invention relates to an inlay part (10, 110) for a piston of an internal combustion engine, wherein the piston has a piston head (21, 121) which is provided with a piston crown (22) which has a combustion depression (23), with an encircling fire land (24) and with an encircling ring part and with an encircling cooling duct (12) which is arranged at the level of the ring part. It is provided according to the invention that the inlay part (10, 11) is formed as a single-piece component which has an encircling cooling duct (12), a ring carrier region (11) and a depression region (13, 113) for a depression edge reinforcement. The present invention also relates to a piston or piston head (21, 121) provided with such an inlay part (10, 110).

Abstract: A piston for a compression ignition internal combustion engine includes a crown portion, torroidal portion, and a reentrant portion. The piston further has a recess portion about a central axis of the piston designed to reduce temperatures near a tip portion of the fuel injector.

Abstract: To provide a piston for an internal combustion engine including a skirt which causes a relatively small frictional resistance and can maintain a favorable frictional property over an extended period of time. In a piston for an internal combustion engine having a skirt 4 on whose sliding surface a resin coating layer is deposited, the skirt 4 comprises a thin walled portion 51 located in a circumferentially middle part thereof and a pair of thick walled portions 52 provided on either lateral side of the thin walled portion 51. The resin coating layer 44 at least in the part thereof deposited on the thick walled portions 52 is formed with a plurality of dimples 45. The skirt may comprise a skirt main body 41 extending axially at a fixed distance from the central axial line of the piston in an axially middle part thereof, and a first reduced diameter portion 42 depending from the lower end of the skirt main body and having a progressively smaller diameter toward a lower end thereof.

Abstract: A two-piece piston for an internal combustion engine has an upper piece and a lower piece, the lower piece having an upper base part with an opening lying coaxial to the piston axis into which a pin on the upper piece is inserted. The upper piece is connected to the lower piece with a hexagonal nut screwed onto the pin. A resilient sleeve is arranged between the upper piece and the lower piece comprising an inwardly directed collar on the against which the upper face of the hexagonal nut lies and in the region facing away from the piston crown, a contact surface facing the piston crown lying on a surface on the inner side of the opening. An economically produced two-piece piston results with a resilient sleeve between both screwed piston pieces which exerts a pre-tensioning and thus provides security for the screw connection.

Abstract: A system for moving fluids includes a pump device having a housing and at least one piston movable in the housing to displace fluids thereby causing flow. An actuator device is connected to the at least one piston for moving the piston within the housing to displace fluids as the actuator device is moved. The actuator device includes a plurality of side portions connected to one another to form a vacuum therein and movable relative to one another as the actuator device moves reciprocally between first and second positions with one of the side portions being connected to at least one piston thereby moving the at least one piston within the housing.

Abstract: A single-piece piston body for an internal combustion engine includes a crown portion having a circumferential ring belt including an oil ring groove configured to accommodate an oil control ring and a skirt portion having a first skirt wall disposed on the major thrust side and a second skirt wall disposed on the minor thrust side of the piston, and two box walls that connect the skirt walls and which are set back with respect to the ring belt. A first plurality and a second plurality of axial drain passages extend from the oil ring groove to the bottom of the crown portion, the first and second pluralities of axial drain passages being substantially centered at opposite box sides of the piston and each plurality of axial drain passages spanning an arcuate portion of about 45-75 degrees.

Abstract: A piston and method of construction is provided. The piston includes a top part fixed to a bottom part. The top part has an uppermost surface with annular inner and outer upper joining surfaces depending therefrom. The bottom part has a pair of pin bosses with pin bores aligned with one another along a pin bore axis; a pair of upwardly extending annular inner and outer lower joining surfaces and a combustion bowl wall. Inner and outer weld joints fix the inner and outer upper and lower joining surfaces to one another. An annular cooling gallery is formed laterally between the upper and lower joining surfaces. The inner weld joint joining the top part to the bottom part is located within the combustion bowl wall and configured to minimized the compression height of the piston.

Abstract: This invention relates to an articulated two piece piston designed for reciprocable movement within a combustion chamber of an internal combustion engine. The piston has a crown of high-strength ferrous material that is precision cast net to finished dimensions on all inner and outer surfaces to provide a controlled thickness throughout to ensure mechanical and thermal consistency without any additional machining of the crown. The crown is attached to a separate skirt by the use of a wrist pin, wherein the skirt is made of ferrous or non-ferrous materials by casting or other means.

Abstract: A piston for an internal combustion engine includes a piston crown connected to and above a body portion of the piston. The body portion forms two pin bores and the piston crown defines an outer cylindrical wall. At least one piston ring seal groove is formed in the outer cylindrical wall and extends peripherally around the piston crown. A first oil collection groove is formed in the outer cylindrical wall below the piston ring seal groove. The first oil collection groove has a first width measured along a centerline of the piston. A second oil collection groove is formed in the outer cylindrical wall below the first oil collection groove, extends parallel to the first oil collection groove around the entire periphery of the piston, and has a width that is at least double the width of the first oil collection groove.

Abstract: An oil ring Ro for an internal combustion engine according to the present invention includes at least one selected from the group consisting of hard carbon, CrN and TiN that covers an outer periphery 1 of the oil ring. A radius of curvature R at an outermost portion T of the oil ring in a sliding direction is 0.3 mm or more.

Abstract: The invention proposes a liquid-cooled assembled piston (1) having an upper part (2) and a lower part (3), wherein the upper part (2) and the lower part (3) are connected to one another by means of a radially outer annular support (12) and by means of a radially inner annular support (11). An outer cooling duct (13) is arranged between the outer support (12) and the inner support (11), and an inner cooling duct (18) is arranged radially within the inner support (11). Here, the outer cooling duct (13) is connected to the inner cooling duct (18) by means of at least one overflow duct (22, 22?).

Abstract: A reciprocating engine 1 includes an annular top ring 5 serving as a first piston ring disposed adjacent to a top surface (head end surface) 4 of a piston 3 defining a combustion chamber 2; an annular second ring 6 serving as a second piston ring disposed with the top ring 5 interposed between the annular second ring 6 and the top surface 4; an annular gas chamber 7 defined by the top ring 5 and the second ring 6; and a plurality of communicating passages 8 for allowing the annular gas chamber 7 and the combustion chamber 2 to communicate with each other. The top ring 5 and the second ring 6 are respectively inclined with respect to an X direction in which the piston 3 reciprocates, so as to be located further away from each other on a thrust side 9 than on an anti-thrust side 10.

Abstract: A method for producing a piston for internal combustion engines includes the following steps: a first part is pre-fabricated by hot forging and a recess which has an undercut is formed in the first part during pre-fabrication by forming on the first part a projection, to which projection a lateral force is applied to form the undercut; a second part is pre-fabricated by hot forging and a projection is formed on this second part whose dimensions are matched to the dimensions of the recess; the two parts are joined together so that the projection on one part engages in the recess in the other part; and a compressive force is applied to the two parts which is sufficiently large and so aligned that the material of the projection on one part flows into the recess in the other part and completely fills it to connect the parts by positive fit.

Abstract: A piston, a cylinder barrel or another engine component adjacent to the combustion chamber of an internal combustion engine comprises a layer or a coating facing the combustion chamber, the layer or coating comprising an aerogel. The method of manufacture of an engine component involves designing such a layer or the application of such a coating.

Abstract: A piston for an internal combustion engine including a piston crown having an upper surface and a lower surface; a piston skirt; and a generally cup-shaped undercrown formed on the lower surface of the piston crown and integral with the top portions of opposing side walls of the piston skirt, at least a portion of the surface of the undercrown being rough, defining at least one region of increased surface area, wherein the distance between an uppermost and lowermost points of the surface of the undercrown in the at least one region of increased surface area is in the range of approximately 0.1 mm to 1.0 mm.

Abstract: An embodiment of the invention provides a combustion chamber for non-soot emitting fuel. The combustion chamber includes a piston bowl, and a fuel injector mounted through a cylinder wall of a cylinder with the piston bowl, wherein the fuel injector injects fuel against a wall of the piston bowl in at least a substantially tangential manner.

Abstract: The invention relates to a cylinder having a piston (14) moving in a cylinder housing (12), said piston being fastened to a cylinder rod (16) and rotatable about a cylinder longitudinal axis (L), and further having a position sensor (18), comprising a sensor magnet (20) and a sensor element (22), which interacts with the sensor magnet (20), and which is configured for detecting a cylinder rod position relative to the cylinder housing (12). The invention provides that the sensor magnet (20) is fastened on the cylinder rod rotatably with respect to the cylinder rod (16) and is guided non-rotatably with respect to the cylinder housing (12).

Abstract: There is provided a slide part used in an environment where there is a lubricant containing a molybdenum compound including a hard protective layer formed on an outermost surface of a substrate of the slide part; in which: the hard protective layer includes mainly carbon, nitrogen, and a metal element; the hard protective layer is composed of a complex of an amorphous carbon body containing nitrogen and a compound crystal of the metal element; the compound crystal is composed of at least one of a metal carbide, a metal nitride, and a metal carbonitride; and a surface hardness of the hard protective layer is 1800 or larger in Vickers hardness.

Abstract: A piston for an internal combustion engine has an upper crown portion with a pair of pin bosses depending therefrom, wherein the pin bosses have pin bores axially aligned along a central pin bore axis. A pair of laterally spaced skirt portions are fixedly attached to the pin bosses and depend to a lowermost free edge. At least one of the skirt portions has a recess extending upwardly from the lowermost free edge beyond the central axis of the pin bores.

Abstract: A piston for an internal combustion engine, for example a diesel engine, including a body delimited laterally by a skirt and configured to collaborate with walls of a cylinder of axis of revolution C in which the piston can slide along the axis C, the piston including a transverse face that includes a central pip, a peripheral ring, and a bowl of axis of revolution B that extends from the central pip towards the peripheral ring to which it connects at a lip of thickness Ep. The bowl includes, in substantial vertical alignment with the lip, a torus in profile, for example of a dome-shaped, of maximum radius Rt capable of guiding fuel injected under the lip in a region of a re-entrant zone R towards the central pip. The tip of the pip lying on the axis of revolution B of the bowl rises to a height that is a distance Dt of between 5.4 mm and 8 mm, or substantially equal to 7.2 mm, below the level of the peripheral ring.

Abstract: There is provided an engine in which sliding surfaces of a cylinder and a piston do not tend to seize and the ratio of a lubricating oil to a composite fuel can be reduced. There is also provided a piston that allows the lubricating oil to be intentionally supplied to the surface of the piston that slides along the cylinder or a cylinder liner. In an aspect of the present invention, an engine in which an air-fuel mixture containing a lubricating oil is supplied into a combustion chamber includes supply means for supplying the air-fuel mixture to the interface between an inner wall of a cylinder or a cylinder liner and a tubular portion of a piston (portion between piston rings and/or piston ring portion). The supply means is, for example, through holes passing through the tubular portion of the piston and groove portions.

Abstract: A two-stroke internal combustion engine has at least one cylinder having a bore diameter, a piston slip-fit in the cylinder, the piston having an upper portion and a lower portion and a central portion of significantly less than the bore diameter, providing an annular space between the central portion and the cylinder wall, and an air pump providing air to one or more intake ports, wherein for a significant portion of every stroke both one or more exhaust ports and the one or more intake ports are open to the annular space between the central piston portion and the cylinder wall, allowing the air pump to force air from the one or more intake ports around the central piston portion to the one or more exhaust ports.

Abstract: A piston for an internal combustion engine, for example a diesel engine, including a body delimited laterally by a skirt and configured to collaborate with walls of a cylinder of axis of revolution C in which the piston is configured to slide along the axis C. The piston includes a transverse face including a central pip, a peripheral ring, and a bowl of axis of revolution B extending from the central pip towards the peripheral ring to which it connects at a lip. The bowl includes, in substantial vertical alignment with the lip, a torus in profile, for example dome-shaped, of maximum radius capable of guiding fuel injected under the lip in a region of a re-entrant zone towards the central pip. The tip of the pip lying on the axis of revolution B of the bowl rises to a height that is a distance of between 4.8 mm and 5.5 mm, or equal to 5.4 mm, below the level of the peripheral ring.