Title:
AUSLASSVENTIL FÜR VERBRENNUNGSMOTOR
Kind Code:
C5


Abstract:

An exhaust valve for an internal combustion engine, particularly a two-stroke crosshead engine, comprising a movable spindle with a valve disc of a nickel-based alloy which also constitutes an annular seat area at the upper surface of the valve disc, which seat area abuts a corresponding seat area on a stationary valve member in the closed position of the valve, the seat area of the valve disc having been subjected at its manufacture to a thermo-mechanical deformation process at which the material is at least partially cold-worked, characterized in that the valve disc is made of a nickel-based alloy which can achieve a yield strength of at least 1100 MPa, and that the seat area at the upper surface of the valve disc has been given dent mark preventing properties in the form of a yield strength (Rp0,2) of at least 1100 MPa at a temperature of approximately 20°C by means of the thermo-mechanical deformation process and possibly a yield strength increasing heat treatment.




Inventors:
HOEG, Harro (Andreas, DK-3450 Alleroed, DK)
Application Number:
DE69703444A
Publication Date:
03/30/2017
Filing Date:
06/03/1997
Assignee:
MAN DIESEL & TURBO, Filial AF MAN DIESEL & TURBO SE, Tyskland (Copenhagen, DK)



Attorney, Agent or Firm:
Munk, Ludwig, Dipl.-Ing., 86150, Augsburg, DE
Claims:
1. An exhaust valve for an internal combustion engine, particularly a two-stroke crosshead engine, comprising a movable spindle with a valve disc of a nickel-based alloy which also constitutes an annular seat area at the upper surface of the valve disc, which seat area abuts a corresponding seat area on a stationary valve member in the closed position of the valve, the seat area of the valve disc having been subjected at its manufacture to a thermo-mechanical deformation process at which the material is at least partially cold-worked, characterized in that the valve disc is made of a nickel-based alloy which can achieve a yield strength of at least 1100 MPa, and that the seat area at the upper surface of the valve disc has been given dent mark preventing properties in the form of a yield strength (Rp0,2) of at least 1100 MPa at a temperature of approximately 20°C by means of the thermo-mechanical deformation process and possibly a yield strength increasing heat treatment.

2. An exhaust valve according to claim 1, characterized in that the seat area material has a yield strength of at least 1200 MPa.

3. An exhaust valve according to claim 2, characterized in that the seat material has a yield strength of at least 1300 MPa, preferably at least 1400 MPa.

4. An exhaust valve according to any one of claims 1 to 3, characterized in that the seat areas on the stationary member and the valve disc, respectively, have substantially the same yield strength at the operating temperatures of the seat areas.

5. An exhaust valve according to any one of claims 1 to 3, characterized in that the seat area on the stationary member has a substantially higher yield strength than the seat area on the valve disc at the operation temperatures of the seat areas.

6. An exhaust valve according to any one of the preceding claims, characterized in that the external diameter of the valve disc is in the interval from 130 mm to 500 mm.

7. Use of a nickel-based chromium-containing alloy with a yield strength of at least 1100 MPa at approximately 20°C as a dent mark limiting or preventive material in an annular seat area at the upper surface of a movable valve disc in an exhaust valve for an internal combustion engine, particularly a two-stroke crosshead engine, the seat area abutting a corresponding seat area on a stationary valve member when the valve is closed.

Description:

Der X. Zivilsenat des Bundesgerichtshofs hat auf die mündliche Verhandlung vom 25. Januar 2011 für Recht erkannt:
Auf die Berufung der Beklagten wird das am 17. April 2008 verkündete Urteil des 10. Senats (Juristischen Beschwerdesenats und Nichtigkeitssenats) des Bundespatentgerichts abgeändert.
Das europäische Patent 901 564 wird unter Abweisung der Klage im Übrigen für das Hoheitsgebiet der Bundesrepublik Deutschland für nichtig erklärt, soweit es über folgende Fassung seiner Patentansprüche hinausgeht: