Patent ID: 7789064

Claim:
A piston engine, in particular in a motor vehicle, comprising: (a) a plurality of cylinders; (b) a plurality of combustion chambers; (c) a fresh gas system; (d) a valve arrangement comprising a partial-load intake valve, a partial-load extra valve, a full-load intake valve, and a full-load extra valve; and (e) a control unit; wherein each cylinder of the plurality of cylinders has a combustion chamber of the plurality of combustion chambers; wherein each combustion chamber of each cylinder of the plurality of cylinders is connected to the fresh gas system; wherein the fresh gas system has a full-load path and a partial-load path for at least one cylinder of the plurality of cylinders; wherein said full-load path and said partial-load path can supply fresh gas to the at least one cylinder of the plurality of cylinders; wherein the valve arrangement is provided at an intake end of the piston engine, said valve arrangement being provided for controlling the fresh gas stream through the full-load path and the partial-load path into the at least one cylinder of the plurality of cylinders; wherein the control unit actuates the valve arrangement; wherein at a partial load the control unit closes the full-load path using the valve arrangement so that fresh gas from the fresh gas stream streams through the partial-load path; wherein at a full load the control unit controls the valve arrangement to cause fresh gas from the fresh gas stream to stream through the full-load path; and wherein the partial-load extra valve is designed so that shorter switching times can be implemented with the partial-load extra valve than with the full-load extra valve and/or the partial-load extra valve is designed so that shorter switching times can be implemented with the partial-load extra valve than with the partial-load intake valve or the full-load intake valve.