Patent attributes
A method of operating an internal-combustion engine (1) which has at least one cylinder (10,20,30,40,50,60) with a combustion chamber (17,27,37,47,57,67) assigned to it, in the cylinder (10,20,30,40,50,60), a piston (11,21,31,41,51,61) carries out an oscillating movement between a lower dead center and an upper dead center. In the combustion chamber (17,27,37,47,57,67) a fuel-air mixture is ignited. Exhaust gas forming during the combustion of the fuel-air mixture in the combustion chamber (17,27,37,47,57,67) is fed to an exhaust pipe (5), and the exhaust gas is purified in an exhaust treatment device (6) arranged in the exhaust pipe (5). For the regeneration of the exhaust treatment device (6), the temperature in the exhaust pipe (5) is increased in that an outlet valve (16, 26, 36, 46, 56, 66) opening up the combustion chamber (17, 27, 37, 47, 57, 67) in the direction of the exhaust pipe (5) is opened in the range of the upper compression dead center of the piston (11, 21, 31, 41, 51, 61).