Method for operating an air-compressing auto-igniting internal combustion engine and injection valve suitable therefor

An injection valve for high pressure injection of a liquid fuel having a flow direction into a working space of an internal combustion engine comprising:

• at least two valve needle means concentrically nested within one another;
• at least two spring means each adapted to press said valve needle means adjacent an associated valve seat means;
• at least two valve seat means each associated with a respective valve needle means;
• at least two hydraulically, in-series connected pressure space means, each of said pressure space means being located upstream of an associated valve seat means;
• wherein each of said valve needle means further comprises:
• a valve needle piston means constructed larger in diameter than an associated valve seat means and a pressure space means in operative connection with an effective side of said valve needle piston means, with said valve needle means being pressed against an associated valve seat means by the force of an associated spring means in a closing direction and being operable to be lifted off from said associated valve seat means;
• whereby a downstream pressure space means, dimensioned approximately the same size as the largest fuel quantity to be injected by said injection valve per working cycle, is operable to be closed off hydraulically by the valve needle means and is arranged exposed in heat-absorbing relationship to the working space of the internal combustion engine.