Avl List Gmbh

Iwis Motorsysteme Gmbh & Co. Kg

Bernhard Kometter

Malte Heller

Martin Bodensteiner

Kai Arens

Siegfried Lösch

Steffen Latz

Zoltán Riba

Helmut Melde-Tuczai

Robert St John

Wilhelm Greylinger

Gerhard Heimel

Stefanie Bezner

Martin Rath

Christian Gallob

Heinrich Fürhapter

Alois Fürhapter

Uwe Dieter Grebe

Siegfried LÖSCH

A longitudinally adjustable connecting rod with a hydraulic control device for effecting a change in the effective length of the connecting rod is provided. The hydraulic control device comprises a hydraulic control valve which comprises a hydraulically actuatable control slide that is preloaded by way of a control slide spring, and two outlet valves which can be actuated by the control slide by way of two control contours arranged at a distance from one another. The control slide comprises a low-pressure section with a low-pressure piston for hydraulically actuating the control slide. For optimizing the control slide for such a longitudinally adjustable connecting rod, the two control contours are arranged together in a high-pressure section of the control slide which is arranged on one side of the low-pressure section and separated therefrom by way of a sealing section disposed therebetween. The control contours each comprise a closure region with control cams and an opening region adjoining the control cams. The closure region has a smaller cross-section than the opening region. The mass of the section of the control slide disposed between the two closure regions corresponds at most to 0.95 times the envelope volume of this section multiplied by the density of steel (7.85 g/mm) due to the selection of material and/or the contouring narrowing in comparison with the opening regions. A respective control slide and a reciprocating piston engine are also provided.

Longitudinally adjustable connecting rod with mass-optimized control slide

A longitudinally adjustable connecting rod for a piston engine, where the connecting rod includes a first connecting rod end for receiving a piston pin and a second connecting rod end for receiving a crankshaft journal, where the distance between the piston pin and the crankshaft journal is adjustable in the longitudinal direction (A) of the connecting rod by way of a hydraulic control device with a hydraulic control valve. The hydraulic control valve comprises a control cylinder and a control slide which is guided in a slidable manner in the control cylinder and which can be pressurized, and at least one outlet valve which can be actuated by the control slide. The control slide comprises a control piston which is arranged on the end face, with a control pressure surface which can be subjected to the hydraulic control pressure and which defines a control pressure chamber in the control cylinder. The use of such a longitudinally adjustable connecting rod with a hydraulic control device in a piston engine as well as a corresponding piston engine is also provided.

Hydraulic control valve for a longitudinally adjustable connecting rod with an end-face control piston

A length-adjustable connecting rod for an internal combustion engine, where the connecting rod includes at least one switchable outlet valve for opening and closing a pressure chamber, where the outlet valve comprises a valve body and a closing body that is operatively connected to the valve body, and a closing mechanism is present acting upon the closing body for directly moving the closing body and indirectly moving the valve body from a closed to an open position or vice versa. Such an outlet valve is to be configured to be operable. For this purpose, this closing body has a mass which is smaller than the volume defined by the envelope contour of the closing body multiplied by the density of steel (7.85 g/mm). The use of such a closing body for a respective length-adjustable connecting rod is also provided.

Length-adjustable connecting rod with reduced-mass outlet valve

The invention relates to a method for operating a reciprocating piston machine, particularly an internal combustion engine, having at least one piston rod that is hydraulically adjustable in length for setting a compression ratio, wherein the piston rod comprises a piston and a hydraulic cylinder for adjusting its length, wherein the piston with the hydraulic cylinder delimits at least one working chamber, through the fill level of which at least two switching positions of the piston rod are possible, wherein independently from the setting of the compression ratio the working chamber is at least partially filled and emptied as a function of at least one first predetermined requirement to effect an at least partial exchange of a hydraulic medium in the at least one working chamber.

Method for operating a reciprocating piston machine having at least one piston rod that is hydraulically adjustable in length

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Judendorf, Austria

Bernhard Kometter