Siemens VDO Automotive

Piezo Common Rail Diesel Direct Injection System

With Siemens’ Piezo Common Rail Diesel Direct Injection System, the company brings an innovative first to the automotive industry. The advent of common rail direct injection had already put the industry on the path to vastly improved diesel performance. This innovation has enabled the further development of cleaner, quieter, smoother, more fuel-efficient, more powerful diesel engines, better able to meet increasingly stringent exhaust emission regulations, both in Europe and in the United States. Indeed, these are some of the issues that have kept diesel engines from being popular choices in passenger cars and most light trucks in North America today.

Siemens’ successful development of piezoelectric actuators to control injection events in fuel injector valves has enabled diesel engine manufacturers to achieve further improvements in diesel engine exhaust emissions, increased fuel economy, and significantly reduced noise levels that Americans (now wrongly) assume are unavoidable in diesel technology.

“Electronic Ceramics versus Diesel Mechanics.” These innovative actuators are small switching elements that utilize ceramic crystals that expand and contract very rapidly in response to changes in electric current. Competitive common rail systems all use electro-mechanical solenoid driven injector actuators, which are as much as four times slower acting. Additionally, it is easier to profile or shape multiple fuel charges or injection events with piezo technology. Injector control is the most important parameter in a diesel engine combustion process, and is what distinguishes the Siemens’ common rail fuel system from all other common rail fuel systems in production today. In an industry where PACE award winners are constantly changing the rules of the game, all of Siemens’ competitors have announced plans to begin to develop “comparable systems” quickly.

Diesel engines inherently offer drivers improved torque, fuel economy, and other desirable performance characteristics, while requiring less maintenance and offering greater longevity over gasoline engines. As global automotive markets are increasingly demanding “greener” vehicles with improved fuel economy and performance, Siemens’ achievement in piezoelectric injection makes a significant contribution to meeting future regulatory and consumer demands.