نتایج جستجو برای: variable intake valve actuation

تعداد نتایج: 474871  

Journal: :IEEE Trans. Contr. Sys. Techn. 2003
Wolfgang Hoffmann Katherine S. Peterson Anna G. Stefanopoulou

Variable valve timing allows improvements of internal combustion engines and can be achieved by camless actuation technology. In this paper we consider an electromechanical valve (EMV) actuator. One of the main problems in the EMV actuator is the noise and wear associated with high contact velocities during the closing and opening of the valve. The contact velocity of the actuator parts can be ...

2014
A. Haas

In the paper the weak points of today's reciprocating compressors arc described. Referring to latest internal combustion engine technologies and improvements, some possible application on reciprocating compressors will be described and discussed as: • Application of advanced Electromechanical Valves (EMV) with fully variable valve actuation in order to increase compressor speed ("downsizing") a...

2010
Yihui Qiu David J. Perreault John G. Kassakian Thomas A. Keim

Research has shown that variable valve timing (VVT) can improve significantly the performance of internal combustion (IC) engines, including higher fuel efficiencies, lower emissions, and larger torque outputs at each point of the engine map. To achieve independent and continuous VVT for each valve, an electromechanical valve drive (EMV) system with a custom-designed limited-angle actuator was ...

2007
Massimo Capobianco Silvia Marelli

Turbocharging is becoming a key technology for both Spark Ignition (SI) and diesel automotive engines. As regards gasoline engines, turbocharging can help to reduce CO2 emissions when used in conjunction with other technologies, such as engine downsizing, direct injection and variable valve actuation, all managed on the basis of appropriate control strategies. However, the successful applicatio...

2005
Ashok Joshi

The study investigates the effects of servo valve nonlinearity, actuation compliance and friction related nonlinearity on the dynamics of a flight control surface, during its deployment through an electro-hydraulic actuation system. Starting from the pilot command, a realistic model of the electro-hydraulic actuation system is evolved, which includes the command lags, servo valve nonlinearity, ...

2002
W. S. Chang T. A. Parlikar M. D. Seeman D. J. Perreault T. A. Keim

In conventional internal combustion (IC) engines, engine valve displacements are fixed relative to crankshaft position. If these valves are actuated as a variable function of crankshaft angle, significant improvements in fuel economy can be achieved. Existing electromagnetically actuated variable-valve-timing (VVT) systems characteristically use springs to provide the large inertial power to mo...

2010
Marcin Marek Okarmus

The advantages of Variable Valve Actuation (VVA) in the aspects of improved engine performance, fuel economy and reduced emissions are well known in the industry. However, the design and optimization of such systems is complex and costly. The design process of VVA mechanisms can be greatly accelerated through the use of sophisticated simulation tools. Predictive numerical analysis of systems to...

2007
Jason Meyer James Schmiedeler

In the modern world, one of the largest concerns is the ever depleting supply of oil. The automotive industry is especially impacted. In recent years the price of gasoline has fluctuated substantially and the price of crude oil has reached record highs. The high price of gasoline coupled with the uncertainty of its availability and future price have put a high priority on fuel economy of an eng...

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