January 12, 2015
Pierburg
Electric wastegate actuator ready for volume production
Downsizing is all the rage nowadays: in the effort to reduce CO2 emissions, among other things work is continuing on the technology of exhaust-gas turbocharging. For regulating the functions of the turbocharger, more and more OEMs are using electrically operated wastegates. Only last year, Pierburg succeeded in translating into a B-version a type of electric wastegate actuator. On the basis of experience gained from extensive verifications and in-vehicle tests, Pierburg has now fine-tuned the design ready for series production. Throughout these efforts, Pierburg has been in close contact with both OEMs and turbocharger manufacturers.
In terms of engineering design, during the lead-up to series production focus was directed at a number of additional requirements such as reduced actuation times, higher application temperatures, and enhanced ingress protection. Another development direction was to improve actuator robustness when working in light- and medium-duty truck environments. For these applications, integration with CAN BUS-compatible onboard position controlling electronics is being developed.
Improved to avoid inaccuracies
Besides the linear actuator, which is preferred on gasoline engines, the product range includes a rotary version primarily employed on VNT / VTG (“Variable Nozzle” or “Variable Turbine Geometry”) for diesel engines.
The linear version has a new technique that allows both improved position control (including a force plateau for the last millimeters of stroke intensity) plus integration with the vehicle’s onboard diagnosis system. The sensor system allows measuring the linear movement of the output linkage with the aid of a linear sensor, not indirectly but directly at the actuating linkage. This avoids any falsification of the position determined for the output element.
It has been shown that the diversity of market requirements cannot be met with a single linear actuator of universal design and so, as hitherto, a modular strategy is maintained with a view to reducing verification work and in order to be able to offer cost-competitive solutions.
Background information: In automotive engineering, the “waste gate” refers to the turbine wheel bypass on a turbocharger. Its job is to limit turbine speed on reaching the desired charge pressure by directly routing the exhaust gases into the exhaust system. Recent experience has indicated, however, that with ever rising demands on vehicle engine efficiency, the setup adopted until now of using a pressure can, will no longer suffice. In order to regulate quickly and independently of the charge-pressure, Pierburg has therefore come up with an electric actuator that permits extremely fine settings.
Contact:
Folke Heyer
Head of Communications
KSPG AG
Karl-Schmidt-Straße, 74172 Neckarsulm, Germany
P: +49 7132 33-3140, F: +49 7132 33-3150
Paul Klapproth
Senior Manager Communications USA
KSPG AG
975 S. Opdyke Road, Suite 100, Auburn Hills, MI 48326
P: 248 836 2904, F: 248 836 0249, C: 248 760 0596