Abstract:
The invention relates to a method for producing a piston (10, 110) for an internal combustion engine, having a main piston body (11, 111) and a piston ring element (12, 112), wherein the main piston member (11, 111) comprises at least one piston skirt (15, 115) and at least one bottom region (27, 127) of a combustion recess (21, 121). The piston ring element (12, 112) comprises a piston crown (19, 119), at least one wall region (28, 28) of the combustion recess (21, 121), a circumferential fire land (22, 122) and at least one part of a circumferential ring part (23, 123) provided with annular grooves. The main piston body (11, 111) and the piston ring element (12, 112) form a circumferential closed cooling duct (24, 124). The method is characterised by the following method steps: (a) providing a blank (11', 111', 211') of the main piston body (11, 111), in which an outer circumferential joining surface (29, 129, 229) and an inner circumferential joining surface (31, 131, 231), which is widened in the direction of the bottom region (27, 127) of the combustion recess (24, 124), as well as a circumferential lower cooling duct part (24a, 124a, 224a) between the two joining surfaces (29, 31; 129, 131; 229, 231) are rough-machined, (b) providing a blank (12', 112', 212') of the piston ring element (12, 112) in which an outer annular joining surface (32, 132, 232) and an inner annular joining surface (33, 133, 233) as well as a circumferential upper cooling duct part (24b, 124b, 224b) between the two joining surfaces (32, 33; 132, 133; 232, 233) are rough-machined, (c) joining the blank (11', 111', 211') to the blank (12', 112', 212') via the joining surfaces (29, 129, 229; 31, 131, 231; 32, 132, 232; 33, 133, 232) thereof in order to form a piston blank (10', 110') in such a manner that at least in the bottom region (27, 127) of the combustion recess (24, 124) a sub-region (34, 134, 234) of the widened joining surface (31, 131, 231) of the blank (11', 111', 211') remains blank, (d) post-machining and/or finishing the piston blank (10', 110') to form a piston (10, 110) whilst removing the sub-region (34, 134, 234) of the widened joining surface (31, 131, 231).
Abstract:
The invention relates to a piston (10) for an internal combustion engine, comprising a piston head (10a), a piston skirt (15), and a circumferential recess (25) formed between the piston head (10a) and the piston skirt (15). The invention is characterized in that: - the piston (10) has a basic piston body (11) and a piston ring element (12); - the basic piston body (11) includes at least one bottom zone (19a) of a combustion recess (19) as well as the piston skirt (15); - the piston ring element (12) includes at least one piston crown (21), a wall region (19b) of the combustion recess (19), a circumferential top land (22), and a circumferential ring part (23) provided with annular grooves; - the piston ring element (12) has a circumferential cooling duct (27) between the wall region (19b) of the combustion recess (19) and the ring part (23), said cooling duct (27) being sealed by a sealing element (26); - in the area of the combustion recess (19), the basic piston body (11) and the piston ring element (12) each have a circumferential seam (28), by means of which the two are permanently joined together. The invention further relates to a method for producing such a piston.
Abstract:
A method of providing a machine readable marking on a substrate (20) being a part of an actuator (15) is described, in which the marking includes at least first and second marks and the method including repeatedly firing a laser device so that at each of a plurality of row positions of a first area of the substrate (20), substrate material (20) is heated and displaced thus to provide a depression (d) in the surface of the substrate (20) at least martial surrounded by displaced material, the method including providing a plurality of rows of such depressions in the first area to form the first mark, repeatedly firing a laser device so that at each of a plurality of row positions of a second area of the substrate (20), substrate material (20) is heated and displaced thus to provide a depression in the surface of the substrate (20) at least partially surrounded by displaced material, the method including providing a plurality of rows of such depressions in the second area to form the second mark, and wherein each depression of the rows of depressions of the first and second marks has a depth determined from the general surface of the substrate (20) less than 4µm, and the height of the displaced material determined from the general surface of the substrate (20) is not greater than 4µm.
Abstract:
Die Erfindung betrifft ein Verfahren zum Lötverbinden eines ersten Metallteils (1) mit einem zweiten Metallteil (2) zu einem gelöteten Metallbauteil, wobei eine zu verlötende Verbindungsfläche (3) des ersten Metallteils (1) mit einer zu verlötenden Verbindungsfläche (3') des zweiten Metallteils (2) zueinander ausgerichtet angeordnet werden, sodaß sie eine Berührungsfläche ausbilden und Lotmaterial im Bereich der Verbindungsfläche angeordnet ist; das erste und zweite Metallteil (1,2) unter Ausbilden einer mechanischen Verbindung gegeneinander gedrückt werden; die so verbundenen Metallteile in einen Ofen bei Löttemperatur überführt und dort bis zum Erhalt einer Lötverbindung zwischen den Metallteilen unter Ausbildung eines gelöteten Metallbauteils belassen werden; sowie ein danach hergestelltes gelötetes Metallbauteil, bei dem die Verbindungsfläche (3) des ersten verlöteten Metallteils (1) und die Verbindungsfläche (3') des zweiten verlöteten Metallteil (2) zur mechanischen Verbindung mit dem jeweils anderen Metallteil (2,1) entsprechend geformt ist, mit diesem in mechanischer Verbindung steht und im Bereich der aufeinander- liegenden Verbindungsflächen verlötet ist.
Abstract:
A piston (120) and method for making a piston (120) for a fuel-injected diesel engine adapted to withstand the damaging effects of fuel injection plume-induced oxidation in the regions of the piston bowl (134) and rim (130). The surfaces of the piston crown (126) targeted by the fuel injection plume (138) are first coated with a corrosion-resistant and oxidation-resistant composition applied as a slurry or by a thermal spraying technique, such as HVOF or plasma spraying. Thereafter, a high energy industrial laser beam irradiates the as-sprayed coating to increase its density, while simultaneously reforming its microstructure so as to fuse, alloy, and materially bond the coating material with the underlying steel substrate, thereby resulting in a durable protective surface for the steel piston crown (126).
Abstract:
The invention relates to a method for producing a piston (1), for an internal combustion engine, designed as a cooling duct piston for small compression heights. The piston (1) comprises a lower part (2) and an upper part (3) which are supported by means of one or more corresponding joining planes (10, 11, 12) and are connected by means of a friction welding process. The piston (1) encloses an inner, trough-shaped cooling duct (8) and an outer cooling duct (9) which is spaced apart axially from an annular area (4). The inner cooling duct (8) is formed in the lower part (2) of the piston (1) by a mechanical machining process, in particular a forging process. Transfer openings (22, 23) which are assigned to the cooling ducts (8, 9) are formed before the frictional welding of the joining planes (10, 11, 12).
Abstract:
The invention relates to a method for providing a component of a large machine, especially a piston head or an outlet valve head of a large two-stroke diesel engine, with a protective coating (4) which is applied to the corresponding surface (2 or 14) by means of surfacing. According to the ivnention, the method can be carried out in an economical and careful manner due to the fact that the large machine component provided with the protective coating (4) is cooled during the surfacing process.