Abstract: A piezoelectric actuator for media flowing around it having a piezo stack which is arranged within a deformable isolating material so as to be in direct contact therewith at least over certain regions. The isolating material is for its part enclosed by a fluidically closed actuator housing, which is formed by a housing shell which is delimited at its one end by a dimensionally stable actuator top and at its other end by a dimensionally stable actuator bottom. The actuator top and bottom are arranged on the active main surfaces of the piezo stack. To increase the service life, the housing shell is produced from a limp and/or elastic material and is disposed at a distance from the piezo stack. The length of the housing shell, measured along the surface line, corresponds at least to the maximum extent of the piezo stack and/or the housing shell can be stretched accordingly.

Abstract: A piezoelectric actuator for media flowing around it having a piezo stack which is arranged within a deformable isolating material so as to be in direct contact therewith at least over certain regions. The isolating material is for its part enclosed by a fluidically closed actuator housing, which is formed by a housing shell which is delimited at its one end by a dimensionally stable actuator top and at its other end by a dimensionally stable actuator bottom. The actuator top and bottom are arranged on the active main surfaces of the piezo stack. To increase the service life, the housing shell is produced from a limp and/or elastic material and is disposed at a distance from the piezo stack. The length of the housing shell, measured along the surface line, corresponds at least to the maximum extent of the piezo stack and/or the housing shell can be stretched. accordingly.

Abstract: In a method of operating a diesel internal combustion engine, wherein a homogeneous mixture is formed in the combustion space before a spontaneous ignition by means of fuel injected directly into separately supplied combustion air, which combustion air is admitted to the combustion space in a swirling flow about the longitudinal axis of the cylinder that can be adjusted as regards its swirl intensity by a control element. A control unit adjusts the swirl intensity in a manner coordinated with the injection parameters to provide a homogeneous mixture igniting at a predetermined point for highly effective engine operation with low emissions.

Abstract: In a method for the injection of Diesel fuel into a combustion chamber of a Diesel engine by way of a fuel injection valve with a plurality of pilot and main fuel injection ports, the fuel is injected during partial load operation only by way of the pilot injection ports such that a homogeneous mixture is formed and, under full load operation, fuel is additionally injected—after a pause—through the main fuel injection ports in such a way that a fuel jet bundle is formed in combination with the fuel jets formed by the pilot ports which is extends over the whole periphery of the combustion chamber. The fuel injection valve has the main fuel ports arranged in a piezo-actuated tappet in series in the direction of the opening movement of the tappet behind the associated pilot ports. With the piezo drive the opening stroke of the tappet can be controlled so as to provide fuel injection pauses between the pilot fuel injection and the main fuel injection.

Abstract: An injector for a fuel injection system is provided with an injector housing in which a piezoelectric stack is located and with a valve housing connected with the injector housing in which a valve closing device with a jet needle is displaceably located. The valve closing device can be actuated by the piezoelectric stack. The valve closing device can be reset by a return device. A hydraulic following amplifier is located between the piezoelectric stack and the jet needle of the valve closing device. The amplifier has a displacement piston actuated by the piezoelectric stack. A control piston located downstream from the displacement piston and increases the displacement travel. A working piston that actuates the jet needle and increases the actuating force.