An active intake manifold system with integrated charge air cooling and eBOOSTER is an innovative concept that simultaneously combines several technical highlights. These highlights include an intake manifold with a tumble flap system and a fully integrated, indirect charge air cooler, an “eBOOSTER”, a self-regulating bypass valve, and the sophisticated compensating joint, the “Agile Joint”. The integrative concept elicits additional power reserves from the engine, whilst simultaneously optimizing component weight.
Fully integrated intake charge air cooling
The first component feature to attract attention is the fully integrated charge air cooler. The design enables intelligent allocation of installation space and enables a shorter charge air duct and smaller charge air volume. The engine response characteristics benefit directly from these factors. Indirect charge air cooling contributes to a more constant cooling performance than direct charge air cooling, especially in dynamic operation. As a result, combustion across the entire engine speed and load characteristic of the engine can be optimized and fuel savings of up to three percent are possible.
Development partner BorgWarner contributed an electrically driven additional compressor to the integration concept, the so-called eBOOSTER. The intelligent control of the eBOOSTER and the turbocharger by the bypass valve increases the low-end torque, i.e. the torque in the lower engine speed range builds up faster. The eBOOSTER achieves a compression ratio of up to 1.45 and is characterized by a rapid response and high efficiency. In addition to enhanced engine dynamics, the compact component also reduces fuel consumption, which results in lower emissions thanks to demand-driven supercharging.
Self-regulating bypass valve
The mechanically self-regulating bypass valve controls the air flows from the turbocharger and eBOOSTER. If the boost pressure of the exhaust gas turbocharger is too low, the bypass valve flap is closed with a return spring to the exhaust gas turbocharger. In this state the boost pressure is then provided by the eBOOSTER. As soon as the boost pressure of the exhaust gas turbocharger exceeds that of the eBOOSTER, the bypass valve flap closes the charge air duct of the eBOOSTER and the eBOOSTER is switched off.
Turbulence in the cylinder
An additional highlight is the tumble flap system, which has already been successfully put into series production in this version by MANN+HUMMEL. This system regulates the turbulence in the cylinder independently of the charging status and engine speed and provides for optimized cylinder filling. It also helps to reduce fuel consumption and CO2 emissions. The charge motion system is fitted with a continuous stainless steel shaft with injection molded plastic valves. This is driven by a vacuum actuator with integrated, contactless position detection, thereby fulfilling the requirements of the OBD2 standard of the CARB (California Air Resources Board) standard.
Hot gas welding
To connect the plastic shells of the intake manifold, MANN+HUMMEL uses hot gas welding. This technique fulfills the cleanliness requirements. This completely prevents any abrasion and weld-related particles larger than 0.6 millimeters. Further positive features of this procedure are weight savings, improved weld seam strength and installation space advantages in design terms as a result of the reduced width of the surrounding weld seam.
The technical highlight is completed by the Agile Joint compensating joint in the charge air lines of the intake manifold system. This is an innovative joint solution using compensating bearings to compensate for the relative movements and component expansions in all directions.