Ring-belt piston with head/skirt area(s) locally separated in the ring grooves (ring groove areas) by the ring belts

摘要

A control piston is shown in which a steel body is fitted in the ring groove or the ring groove areas thereof in such a way that, preferably in the cutting of the oil groove, the external skirt/head separation can be accomplished in the casting process by local free casting of the control element,. In addition to separating the skirt from the head, partial casting around or partial exposure of the steel element has the effect, inter alia, that the steel part, for example, locally prevents the head area from expanding when heated, whilst allowing the skirt area adjacent to the steel part to enlarge unimpeded when heated. In practice this design according to the invention results in an improved control value. In addition the load bearing capacity of the piston is improved because the steel elements can be directly supported on the skirt and head part. One manufacturing step for a special slot milling of the skirt - head - as hitherto - outside the steel ring area is eliminated.