Siemens Aktiengesellschaft

Siemens Aktiengesell Schaft

Wolfgang Lingl

Christian Hoffmann

Richard Pirkl

Hellmut Freudenberg

Walter Schrod

Dirk Baranowski

Lorand D'Ouvenou

The current guided to the piezo actuator and the voltage which is consequently established thereon is used for calculating with the help of a non-linear actuator model, the characteristics of the longitudinal variations (s) and the force (F) exerted by the actuator (F), and variables therefrom or the derived variables (dF/dt) therefrom determine the beginning of the opening (tA) of a servovalve and the duration of injection (D).

Method for controlling a piezo-actuated fuel-injection valve

A method and a device for charging a capacitive actuator are described. The capacitive actuator, in particular for a fuel injection valve of an internal combustion engine, is charged or discharged with different charging and discharging times. In order to shorten the charging time, the capacitance of the recharging capacitor which is dimensioned for a maximum charging time is reduced at a predefined time during the charging process. Two exemplary embodiments of a device for carrying out the method are explained in more detail.

Method and device for charging a capacitive actuator

A method and an apparatus for charging at least one capacitive control element, in particular a fuel injection valve of an internal combustion engine, charge the capacitive control element with different charging times. In order to shorten a charging time, a charging process is interrupted at a predetermined time, and a tuned circuit is connected to a freewheeling circuit which contains the control element and a ringing or charge reversal coil. If the freewheeling circuit contains a further capacitor, the charging process is further shortened, and a portion of a charge energy is fed back into a charge source while the control element is being discharged.

Method and apparatus for charging at least one capacitive control element

Growing community of inventors

Wuppertal, Germany

Wolfgang Lingl