Abstract: The invention relates to a process of manufacturing a composite comprising a layer of a polyimide and a substrate, comprising at least these steps: i. Providing a first composition comprising an acid compound; and a second composition comprising a diamine compound; ii. Forming a first layer on the substrate, and iii. Forming a second layer on the first layer, wherein if the first layer is formed by applying the first composition, the second layer is formed by applying the second composition, and vice versa; wherein the first and the second layer overlap at least in part thereby forming a pattern on the substrate; iv. Conducting a thermal treatment on the pattern wherein the polyimide layer is formed. The invention further relates to such a composite, a kit comprising a first composition comprising an acid compound and a second composition comprising a diamine compound as well as a use of the kit.

Abstract: A multi-part piston for an internal combustion engine has a piston upper part and a piston lower part. The piston upper part comprises a piston head, a continuous fire land and a continuous ring part. The piston upper part and the piston lower part are connected together by securing means and form a continuous cooling channel. According to the invention, the connecting means connecting the piston upper part and the piston lower part are embodied as cooling elements that are arranged in the cooling channel and that are made of heating-conducting material.

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: 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: 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 cooled piston (1) consisting of two parts, r an internal combustion engine, comprising a piston upper part (2) containing piston ring grooves and piston pin hubs and a piston shaft (3) exclusively connected in an articulated manner to said upper part by means of a piston pin (4). According to the invention, the piston upper part (2) is provided with a cooling oil annular channel (6), which is open towards the piston shaft (3), radially inside the piston annular groove area (5). On the end (7) of the piston shaft (3) which is arranged opposite the piston upper part (2), collecting pockets (8) at least partially cover the cooling oil annular channel (6). In order to prevent the development of starting blue smoke, a recess (12) for receiving the cooling oil is formed on the inside (11) of the piston shaft (3) in a lower region thereof.

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: A piston for an internal combustion engine, comprising a piston head (2) and at least one cooling chamber (4) that can be supplied with oil and is arranged underneath the head (2) of the piston, whereby the lower limit of the cooling chamber is formed by a sheet of metal that can be elastically deformed and is fixed to the piston. The objective of the invention is to enable the metal sheet (6) to be fixed in a simple manner. This is achieved by using components that are subjected to pressure, pressing the elastically deformable sheet of metal (6) against projections that are located at a height corresponding to approximately half way up the hub supports in the direction of the piston head (2).