Variable Valve Actuating (VVA) systems have the potential to improve engine efficiency and vehicle drivability. Though many VVA systems have been proposed, few have been implemented in production. This is due to the size, cost, reliability, and performance limitations that reduce the practicality and value of many VVA concepts. This paper describes a compact VVA mechanism that offers performance benefits and production value. This mechanism uses cams, roler oscillating followers, and links to move conventional poppet valves. Angular positioning of a control shaft continuously varies valve lift, duration, and phase. The paper includes a technical description of the mechanism and its adaptation to a modern four-valve-per-cylinder engine. Mechanism features are presented. Engine benefits, predicted from single-cylinder research engine testing and from engine simulation analysis, are also presented.
The application and engine performance benefits of a mechanical variable valve actuation system
Anwendung und Leistungsvorteile eines mechanischen vollvariablen Ventilsystems
Aachener Kolloquium Fahrzeug- und Motorentechnik, 7 ; 2 ; 1029-1040
1998
12 Seiten, 9 Bilder, 1 Tabelle
Conference paper
English
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