Method for operating a reciprocating-piston internal combustion engine

Claim 1

A method for operating a reciprocating-piston internal combustion engine having an injector nozzle for directly injecting fuel into a combustion chamber and having a piston including a piston crown and a piston recess, the engine operating in a light part-load range, a part-load range, and a full load range, the method comprising: during the light part-load range, injecting a first amount of the fuel centrally into the piston recess at a substantially flat first angle relative to a top surface of the piston crown at a time shortly before the piston reaches a top dead center position so as to produce a heterogeneous mixture; during the part-load range, injecting a second amount of the fuel into the piston recess at least partly at a second angle steeper than the first angle relative to top surface of the piston crown at a time when the crank angle is within a range between 180° and 20° before the top dead center position so as to produce a homogeneous mixture; and during the full load range, injecting a portion of a third amount of the fuel into the piston recess at a steep and flat angle relative to the top surface of the piston crown at a time when the crank angle is within a range between 180° and 20° before the top dead center position so as to produce a homogeneous mixture and a remainder of the third amount of the fuel into the piston recess at a substantially flat angle relative to the surface of the piston crown at a time when the piston is approximately at the top dead center position so as to produce a heterogeneous mixture.

Claim 2

A method for operating a reciprocating-piston internal combustion engine having an injector nozzle for directly injecting fuel into a combustion chamber and having a piston including a piston crown and a piston recess, the engine operating in a light part-load range, a part-load range, and a full load range, the method comprising: during the light part-load range, injecting a first amount of the fuel centrally into the piston recess at a substantially flat first angle relative to a top surface of the piston crown at a time shortly before the piston reaches a top dead center position so as to produce a heterogeneous mixture; during the part-load range, injecting a second amount of the fuel into the piston recess at least partly at a second angle steeper than the first angle relative to top surface of the piston crown at a time when the crank angle is within a range between 180° and 20° before the top dead center position so as to produce a homogeneous mixture; and during the full load range, injecting a portion of a third amount of the fuel into the piston recess at a steep and flat angle relative to the top surface of the piston crown at a time when the crank angle is within a range between 180° and 20° before the top dead center position so as to produce a homogeneous mixture and a remainder of the third amount of the fuel into the piston recess at a substantially flat angle relative to the surface of the piston crown at a time when the piston is approximately at the top dead center position so as to produce a heterogeneous mixture.

Claim 3

A method for operating a reciprocating-piston internal combustion engine having an injector nozzle for injecting fuel into the combustion chamber and having a piston including a piston crown and a piston recess, the engine operating in a light part-load range, a part-load range, a heavy part-load range and a full load range, the method comprising: during the light part-load range, injecting a first amount of the fuel centrally into the piston recess at a substantially flat first angle relative to a top surface of the piston crown at a time shortly before the piston reaches a top dead center position so as to produce a heterogeneous mixture; during the part-load range, injecting a second amount of the fuel into the piston recess at least partly at a second angle steeper than the first angle relative to the top surface of the piston crown at a time when the crank angle is within a range between 180° and 20° before the top dead center position so as to produce a homogeneous mixture; and during the heavy part-load and full load ranges, injecting a third amount of fuel centrally into the piston recesses at the substantially flat first angle relative to the top surface of the piston crown at a time shortly before the piston reaches a top dead center position so as to produce a heterogeneous mixture.

Claim 4

A method for operating a reciprocating-piston internal combustion engine having an injector nozzle for injecting fuel into the combustion chamber and having a piston including a piston crown and a piston recess, the engine operating in a light part-load range, a part-load range, a heavy part-load range and a full load range, the method comprising: during the light part-load range, injecting a first amount of the fuel centrally into the piston recess at a substantially flat first angle relative to a top surface of the piston crown at a time shortly before the piston reaches a top dead center position so as to produce a heterogeneous mixture; during the part-load range, injecting a second amount of the fuel into the piston recess at least partly at a second angle steeper than the first angle relative to the top surface of the piston crown at a time when the crank angle is within a range between 180° and 20° before the top dead center position so as to produce a homogeneous mixture; and during the heavy part-load and full load ranges, injecting a third amount of fuel centrally into the piston recesses at the substantially flat first angle relative to the top surface of the piston crown at a time shortly before the piston reaches a top dead center position so as to produce a heterogeneous mixture.

Claim 5

A method for operating a reciprocating-piston internal combustion engine having an injector nozzle operable by a single valve element and configured to directly inject a fuel into a combustion chamber and having a piston including a piston crown and a piston recess, the method comprising the steps of: injecting the fuel by the injector nozzle into the combustion chamber in the form of separated jets of the fuel having different inclinations relative to a top surface of the piston crown; and selectively setting the inclinations of the fuel jets depending on an engine load.

Claim 6

A method for operating a reciprocating-piston internal combustion engine having an injector nozzle operable by a single valve element and configured to directly inject a fuel into a combustion chamber and having a piston including a piston crown and a piston recess, the method comprising the steps of: injecting the fuel by the injector nozzle into the combustion chamber in the form of separated jets of the fuel having different inclinations relative to a top surface of the piston crown; and selectively setting the inclinations of the fuel jets depending on an engine load.

Claim 7

A method for operating a reciprocating-piston internal combustion engine having an injector nozzle operable by a single valve element and configured to directly inject fuel into a combustion chamber and having a piston including a piston crown and a piston recess, the method comprising the steps of: injecting the fuel by the injector nozzle into the combustion chamber in the form of separated fuel jets having different inclinations relative to a top surface of the piston crown; and selectively and adjustably setting the inclinations of the fuel jets depending on an engine load.

Claim 8

A method for operating a reciprocating-piston internal combustion engine having an injector nozzle operable by a single valve element and configured to directly inject fuel into a combustion chamber and having a piston including a piston crown and a piston recess, the method comprising the steps of: injecting the fuel by the injector nozzle into the combustion chamber in the form of separated fuel jets having different inclinations relative to a top surface of the piston crown; and selectively and adjustably setting the inclinations of the fuel jets depending on an engine load.