Piezo fuel injection systems have become firmly established as the state of the art in passenger vehicles, in particular in diesel and increasingly in gasoline powered cars. Since their market debut in the year 2000 more than ten million cars worldwide have been equipped with fuel injection systems that are based on multilayer piezo actuators. As the world market leader in piezo actuators for fuel injection systems, Epcos has now introduced a new generation of actuators based on an innovative ceramic technology with copper inner electrodes that offer unrivalled performance and durability. Epcos is the only manufacturer able to mass produce piezo actuators with copper inner electrodes.
Piezo-based systems offer clear advantages over other fuel injection technologies such as the conventional electromagnetic (solenoid) injectors. Although solenoids are still somewhat less expensive, piezo-based injectors offer faster response and a much more precise control of fuel injection volumes, which in turn results in greater fuel efficiency and reduced emissions as well as increased engine power. Moreover, for fuel injection valves, the specific displacement and force properties of piezo actuators enable system architectures with a substantially reduced number of mechanical elements.
Billions of cycles without failure
Piezo actuators consist of up to hundreds of stacked layers of piezo-ceramic material " lead zirconate titanate or PZT " each approximately 80 m thick, which are then sintered in a complex process at temperatures of between 900 and 1100°C. Epcos' portfolio of customer-specific actuators includes components ranging in length from 5 to 80 mm and featuring from 100 to 1000 layers. Depending on their length, these actuators can achieve displacements of between 5 and 130 m. These high-performance devices are designed to operate billions of cycles without failure.
Piezo actuator designs can range from 5 to 80 mm in height and supply up to 10 kN force and 130 m displacement
Because of their technological superiority piezo injectors have become a standard feature in many upper mid-range and premium cars. In order to make piezo fuel injection systems viable for a much broader range of commercial vehicles and lower priced cars, Epcos has developed a new generation of actuators. They reduce material costs and free users from fluctuating noble metal costs without sacrificing performance. Moreover, the durability of the actuators was increased substantially.
