Abstract: A multipart oil wiping ring for pistons of internal combustion engines comprises two steel strip-type lamellae with parallel sides, the running surfaces of which are provided with a convexly asymmetric shape having a vertex line that extends across the circumference of the lamellae, and a bracing spring located between the lamellae. The bracing spring presses the lamellae in an axial direction against one respective side of an annular groove in the piston and in a radial direction against the cylinder wall.

Abstract: The invention relates to an oil control ring for pistons of internal combustion engines. The aim of the invention is to provide an improved shape-adaptation capacity in comparison to prior art, with a tangential force that enables the ring to guarantee low friction and also low oil consumption during the operation of the engine. To achieve this, the inventive oil control ring comprises a solid bearing surface that lies against the cylinder wall, in addition to parallel ring flanks, between which a radial recess that runs around the periphery is configured in the rear of the ring, said recess being designed to receive a coil spring. The peripheral region of the ring flanks is provided with undulating end faces that face towards the rear of the ring. Said undulating end faces of the upper and lower ring flanks are offset out of phase with one another.

Abstract: The invention relates to a piston for an internal combustion engine, which comprises two boss bores that have respective outer areas with an oval cross-section that points on one side in the direction of the piston head. The great axis of the ovality is parallel to the piston axis and the degree of ovality increases towards the outer end of the boss bores.

Abstract: The invention related to a piston-pin boss (18) of a piston (6) for an internal combustion engine, comprising a piston-pin bore (1) for receiving a piston pin. To improve the passage of oil and to form an oil reservoir, the interior surface (2) of the bore comprises a transversal groove (5) that lies parallel to the longitudinal axis (3) of the piston-bore (1) and opens towards the exterior of the piston and an oil circulation groove (4) that intersects the transversal groove (5) and encircles the longitudinal axis (3).

Abstract: The invention relates to an oil scraper ring for pistons of internal combustion engines, said oil scraper ring comprising a disc (1) provided with a bearing surface (h) having an asymmetrical crowned form with a vertex line (3) extending over the periphery of the disc. Said disk (1) is arranged in a ring groove (7) of the piston and respectively has a ring groove side (6) opposing the piston head and a parallel ring groove side (5) facing the piston head. The aim of the invention is to achieve an improved oil scraping action compared to that of prior art, while reducing the friction and the abrasion of the bearing surface.

Abstract: The invention relates to a piston for internal combustion engines comprising a lower part which forms the shaft area and also comprising a piston upper part which is connected thereto by means of expandable screws and which forms the bottom and a ring area wherein the expanding screws in the piston upper part (1) are disposed on pressure pieces engaging in the respective bores in the lower piston part (1) and wherein the respective disposition between the pressure piece and the lower piston part (1) occurs via inclined adjacent surfaces. The aim of the invention is to invent a piston which is easy to produce, which in relation to prior art enables improved introduction of forces for the connection of the piston part to the piston.

Abstract: The invention relates to a method for producing a piston (1) for an internal combustion engine. The inventive method comprises producing the base (4) from aluminum by a forging process, casting, by way of a composite casting process, a ring support (10) which is provided with a cooling channel (15) into an aluminum ring element (6), and then welding the ring element (6) with the base (4).

Abstract: The invention relates to a piston (1), which is comprised of an approximately circular cylindrical upper area (5) and of a lower area (6), having two hubs (7), which are set back toward the piston central axis (8) so that, in the upper area (5), recesses (12, 12?) can be made, which are open toward the lower area (6), in the vicinity of the hubs (7). In order to make relief cuts (13, 13?) in the area between the hubs (7) and the upper area (5), a salt mold part (15) is placed on the respective window insert (14). The salt mold part (15) serves to produce the recesses (12, 12?) as well as the relief cuts (13, 13?) when casting the piston (1) and is washed out after the piston (1) has been cast.

Abstract: The aim of the invention is to produce a rounding off on a diesel piston comprising a combustion recess and valve recesses that lie at a slant in relation to the piston floor. The rounding off should not significantly increase particle emissions. To this end, the edge of the recess is rounded off in the area of the valve recesses in a special machining phase, the cutting edges of the cutting tool being guided in one or more planes that are parallel to the inclined valve recess surface.

Abstract: A light metal cylinder liner with a surface which facilitates the connection with the surrounding cast material may be produced. The cylinder liner is produced by a lost-foam method with a form for production of the cast foam model having a structured surface with height variations of 0.8 to 5 mm. The structured surface is, for example, grooves or longitudinal elevations.

Abstract: The invention relates to a piston for an internal combustion engine comprising piston-pin bores, into which lubrication grooves that run around the nadir and equator zones of said bores are machined. The aim of the invention, is to simplify the production of the piston-pin bores provided with said lubrication grooves. To achieve this, each of the lubrication grooves has a central region, whose groove base has a depth of less than 100 ?m. Said central region is flanked by groove areas facing towards the interior and exterior of the piston. The bases of said grooves are inclined towards the longitudinal axis, each forming an acute angle with the longitudinal axis of the piston-pin bore.

Abstract: The invention relates to a cooled piston (1) for an internal combustion engine comprising a cooling duct (2). This cooling duct encircles in an annular manner inside the piston head at the height of the ring part and is closed at its end, which is open toward the piston skirt, by men of a spring part (8). Said spring part is correspondingly shaped, is radially divided at least once on the periphery thereof, and provided with a cooling oil inlet (5). The aim of the invention is to achieve an improved location-dependent removal of heat from the particularly hot portions of the piston (1). To this end, an encircling oil guiding ring (3) is placed inside the cooling duct (2) and, from the cooling oil inlet (5) to the cooling oil outlet (6), symmetrically divides the cooling duct (2) on the periphery thereof into sections (4) of different cooling duct volumes.

Abstract: A method for the production of pistons having depression edge armoring for internal combustion engines, in which a more heat-resistant armoring ring, in comparison with a forged piston blank having a combustion depression, is connected with the piston blank in the region of the depression edge. The method comprises the following steps: a first piston blank is set on a projection of the armoring ring in the region of the depression edge; the armoring ring is connected with the first piston blank by friction-welding; a second piston blank is set onto the projection of the armoring ring, in such a manner that the two piston blanks do not touch; the second piston blank is connected with the armoring ring by means of friction-welding; a the armoring ring is cut between the piston blanks, and the pistons are given their final shape by a cutting work method.

Abstract: A piston-pin bearing for an internal combustion engine wherein a cylindrical piston pin is mounted. The piston-pin bearing has a hub bore that significantly reduces mechanical stress in the piston, results in a longer service life for the piston, and avoids the formation of noise in the piston-pin bearing. Thus hub bore has a lateral surface with a highly oval shape along the axis of the hub in the equatorial-zenith-equatorial area, corresponding to the parameter representation of an oval that follows x=b/2×cos ?; y=a/2×sin ? for 0°???180°. The hub bore has a circular cylindrical shape in the equatorial-nadir-equatorial region of the hub, whereby a is a large oval diameter; b=D is a small oval diameter; D is a diameter of the cylindrical hub; and ? is the angle forming any particular unlimited line counter to the z axis.

Abstract: Cooled two-part piston for internal combustion engines having an upper piston part containing the piston ring grooves and piston pin bosses, and a piston skirt connected with the former exclusively by way of a piston pin. The upper piston part has a cooling oil annular channel that is open towards the piston skirt, into which channel the cooling oil is introduced, and discharged. There are collecting pockets attached at the upper end of the piston skirt, which faces the upper piston part. The pockets at least partially cover the cooling oil annular channel. When the engine and piston are arranged horizontally, a tub-shaped recess is provided in an interior bottom region of the piston skirt for accommodating cooling oil. The circumferential wall limitation of the recess is formed exclusively by a wall of the inside piston skirt.

Abstract: The invention relates to a cooled ring carrier that is cast into a piston for internal combustion engines. According to the invention, the zone of the ring carrier facing the cooling channel is coated, thereby preventing air from escaping from the cooling channel through the ring carrier material to the melt during alfination of the cooled ring carrier, and forming oxides.

Abstract: An oil inlet (2) for a piston (1) provided with a cooling duct (4) and installed in an internal combustion engine is designed in order to enable an improved concentration of a cooling oil stream when entering the oil inlet and an improved distribution when exiting into the cooling duct. To this end, the inner wall surface (3) of the oil inlet (2) is shaped according to a function of a one-sheeted rotating hyperboloid or of a surface-delimited torus, whereby the shape is determined according to a stream position of the cooling oil stream (7), which is produced by an oil spraying nozzle (6), relative to the cross sectional opening area (B, D) of the oil inlet.

Abstract: The invention relates to a method for producing a ring support (1) with a sheet metal cooling channel welded thereon (5), which is transfused later with an aluminium melt for producing a piston. The aim of the invention is to improve the production of openings (4) for supplying and removing oil. Said openings are produced even before the transfusion of the cooled ring support. When the alfin pretreament of the cooling ring supports occurs, said cooling channel is filled with melt and emptied again during removal front the alfin bath.

Abstract: The invention relates to a slot piston ring (1) for the pistons of internal combustion engines or compressors, having a peripheral recess (9) (a so-called scraper ring) that extends close to the slot (2) on the external periphery (3) of the piston facing away from the combustion chamber. The aim of the invention is to reduce oil consumption and the amount of leakage gas of such a piston. To this end, the recess is configured to extend from a zone (10) diametrically opposite the slot, starting with a maximum height (12) which gradually decreases to zero (13) in the direction of the slot or close to the slot.

Abstract: A one-piece piston for an internal combustion engine, having a ring-shaped cooling channel arranged in the outer region of the piston head, is proposed, which is closed off by a ring-shaped cooling channel cover structured towards the side of the pin bosses as a support element. This cooling channel cover comprises at least two arc-shaped cover elements the outer edge of which supports the pin-boss-side face of the ring wall.