|Developed for the latest 1-liter downsized gasoline engines. Click to enlarge.|
Continental will be supplying Ford with turbochargers for the carmaker’s new three-cylinder direct injection gasoline engine platform. (Earlier post.) The first two engines will generate 74 and 88 kW from a displacement of just one liter. These EcoBoost engines are slated for installation initially in the 2012 Ford Focus and later, in the Ford C-Max and in the completely new Ford B-Max.
The successful collaboration with Ford resulted in a turbocharger design that meets the particular technical challenges posed by small, downsized engines. The thermodynamics of the turbocharger system have been optimized to achieve the best possible coordination and balance between the compressor and turbine stages. The geometry of the blades has been specifically developed to suit the engine requirements.
By minimizing rotating masses and thus reducing inertia, and by optimizing thermodynamics, we have invested our turbocharger with excellent response characteristics.—Udo Schwerdel, head of Continental’s turbocharger product line
The turbocharger’s 38-millimeter diameter turbine rotates at up to 240,000 revolutions per minute (4,000 revolutions per second) in the exhaust flow, which can reach 1,050 degrees.
In order to prevent pressure from rising too steeply at high engine output, a waste-gate valve conducts the exhaust gases past the turbine. On the compressor side, a compressor bypass valve prevents air, which has already been compressed, from forcing its way back into the compressor housing when the throttle closes. This safeguard prevents compressor surge, which could damage the turbocharger.
Continental began developing turbochargers for gasoline engines in 2006. Free from the constraints of legacy designs or existing production facilities, Continental was able to start from scratch and develop an improved product. All the main components are designed for fully automated assembly along the same axis, whereas conventional turbochargers have to be put together in several stages, partly by hand. Fully-automated assembly not only ensures top quality but also generates cost benefits—an important consideration in view of the high volume of three-cylinder engines that Ford plans to build.
The new Continental turbochargers will be manufactured by Schaeffler, Continental’s partner in this venture, at its production plant in Lahr, Germany. The site will have sufficient production capacity for up to two million turbochargers a year.
Prior to starting the project, market studies revealed future worldwide demand for small, downsized turbocharged gasoline engines in response to the quest to sustainably reduce fuel consumption. But since Continental’s turbocharger design is scalable and flexible, it can be adapted to larger gasoline or diesel engines as well.
To meet the growing demands of tighter emissions regulations, the Powertrain Division is concentrating on developing and manufacturing fuel efficient engine systems. Aside from turbochargers, one of the most promising technologies for reducing fuel consumption is the Piezo injector, which particularly benefits diesel engines. Continental has managed to squeeze out a 10% improvement in diesel mileage over engines without these elements, simply by employing its high-end injection system in conjunction with downsizing and heat management. Continental’s after-treatment system can add another 4% to this figure.
Another innovation is the newly devised fuel-quality sensor. It improves injection by determining the quality of the fuel, thus helping to protect both the engine and the environment.