TWO-PART PISTON FOR AN INTERNAL COMBUSTION ENGINE
First Claim
1. Two-part piston (1) for an internal combustion engine,consisting of an upper part (2), and a lower part (3) screwed onto it,having a piston crown (6) formed by the upper part (2), and a piston skirt (22) formed by the lower part (3), which skirt has two pin bores (23, 24) that lie opposite one another,having a circumferential cooling channel (8) disposed radially on the outside, close to the piston crown (6),which is formed partly into the upper part (2) and partly into the lower part (3),which is delimited, radially on the outside, by a ring wall (9) connected with the piston crown (6), and a circumferential collar (27) affixed to the upper side of the lower part (3),and which is delimited, radially on the inside, partly by a circumferential upper ring rib (10) formed onto the underside of the upper part (2), facing away from the piston crown, and partly by a circumferential lower ring rib (11), affixed to the upper side of the lower part (3), on the side facing the piston crown,whereby the upper part (2) and the lower part (3) stand in contact with one another, partly by way of inner supporting surfaces (25, 26) that delimit the underside of the upper ring rib (10) and the upper side of the lower ring rib (11), and partly by way of outer supporting surfaces (28, 29) that delimit the underside of the ring wall (9) and the upper side of the collar (27),wherein at least one of the supporting surfaces (25, 26, 28, 29) is covered with a chrome layer (30) that has a structured surface, having a plurality of elevations and depressions.
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Accused Products
Abstract
The invention relates to a two-part piston (1) for an internal combustion engine, consisting of an upper part (2) and a lower part (3) which is screwed to the upper part. The upper part (2) and the lower part (3) are in contact with each other, partially by means of inner bearing surfaces (25, 26) defining the lower side of an upper ring rib (10) and the upper side of a lower ring rib (11), and partially by means of outer bearing surfaces (28, 29) defining the lower side of the ring wall (9) and the upper side of a collar (27) applied to the lower part (29). In order to avoid frictional rubbing, frictional heat sealing and pressure-related material heat sealing, at least one of the bearing surfaces (25, 26, 28, 29) is easily and economically provided with a chrome layer (30) which has a structured surface comprising a plurality of raised parts and recesses.
30 Citations
7 Claims
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1. Two-part piston (1) for an internal combustion engine,
consisting of an upper part (2), and a lower part (3) screwed onto it, having a piston crown (6) formed by the upper part (2), and a piston skirt (22) formed by the lower part (3), which skirt has two pin bores (23, 24) that lie opposite one another, having a circumferential cooling channel (8) disposed radially on the outside, close to the piston crown (6), which is formed partly into the upper part (2) and partly into the lower part (3), which is delimited, radially on the outside, by a ring wall (9) connected with the piston crown (6), and a circumferential collar (27) affixed to the upper side of the lower part (3), and which is delimited, radially on the inside, partly by a circumferential upper ring rib (10) formed onto the underside of the upper part (2), facing away from the piston crown, and partly by a circumferential lower ring rib (11), affixed to the upper side of the lower part (3), on the side facing the piston crown, whereby the upper part (2) and the lower part (3) stand in contact with one another, partly by way of inner supporting surfaces (25, 26) that delimit the underside of the upper ring rib (10) and the upper side of the lower ring rib (11), and partly by way of outer supporting surfaces (28, 29) that delimit the underside of the ring wall (9) and the upper side of the collar (27), wherein at least one of the supporting surfaces (25, 26, 28, 29) is covered with a chrome layer (30) that has a structured surface, having a plurality of elevations and depressions.
Specification