Sep 10, 2013 - serves to precisely control the recirculated mass of exhaust gases. An electric motor controls the valve setting, between shut and open...
Compact EGR valve enters series production Pierburg GmbH has in recent years launched various exhaust gas recirculation (EGR) modules. New this autumn is a new generation of even more compact, even lighter EGR valves to be installed in all the diesel engines of a major German OEM. In order to comply with the low Euro 6 diesel engine emission norms, additional measures are necessary for reducing emissions of nitrogen oxides (NO x). These latter arise, in particular, when diesel fuel is burnt. One such measure is cooled exhaust gas recirculation. Such a system consists of a compact Pierburg EGR valve (cEM EGR), an EGR cooler, a bypass with a flap operated by a vacuum actuator, an EGR intake pipe that is directly fastened to the exhaust manifold, and an EGR exhaust pipe. Regarding the installation location of the cEM EGR valve, this is a so-called “hot mount,” able to withstand exhaust gas temperatures of up to 800 °C. In order to survive such heat, the valve is water cooled by the cooling unit. The cEM EGR valve serves to precisely control the recirculated mass of exhaust gases. An electric motor controls the valve setting, between shut and open. The unit’s small footprint allows it to be mounted directly in the cooler module. In order to permit the passage of high mass flow rates, the EGR valve opens in the direction of the exhaust gases. A contactless sensor determines the position. Another advantage is direct position identification with the aid of a sensor magnet on the valve rod for more precise control of the recirculated exhaust gases. With a powerful actuator, this is also able to tightly seal off for brief periods exhaust gas pressures of up to 5 bar.
