Cooled combustion engine piston with walled piston ring grooves

摘要

The annular wall (3) and annular rib (4) facing this are both threaded (8,9) to accept the sheet metal ring part of the ring-containing wall. The cooled and slotted ring fits into grooves designed into the annular wall and the opposing rib, the slotted part of the ring being eased in with the aid of an entry ramp piece. Both the threads and the specified groove come in rectangular profile and the ring is held in place by a clamping effect, notably provided by punched tongue. Otherwise the ring itself is corrugated or undulated to the same effect. The height and depth of the rectangular profile of the respective threads lies between 0.5 and 2 mm, with a thread pitch of between 1 and 2 mm. The cooled and slotted ring has openings for the coolant, to be engaged by conventional hand tools. The ring is twisted into the threads so the sheet and points meet to close off the cavity (6) from below. The proposed grooves cancel out the slight axial play produced by the thread pitch, although an absolute seal is optional.