ElectroMagnetic Valve Actuation System e-Valve: Convergence Point Between Requirements of Fuel Economy and Cost Reduction

摘要

The transportation industry, and in particular the automotive industry is undergoing the effects of two major events: in 2008 the soaring price of oil and in 2009 the global economic crisis. In addition to these events, new regulations are being signed into law in many countries around the world to reduce, or at least control, CO_2 emissions. In parallel, to respond to these challenges, automotive manufacturers and suppliers are developing the internal combustion engine along 3 major trends: - Downsizing with integration of turbocharger or supercharger, - Hybridization: from micro hybrid to full hybrid, and - Low-cost engine for the just required performance. These new powertrain systems call for a growing number of combustion modes and separate controls, dependent of the operating point, to satisfy all functional and legislative requirements. Likewise, they require new components which are more and more complex and controllable with greater accuracy. This controllability is necessary to address the different modes of combustion, and their accuracy is required in order to be able to manage efficiently (and transparently to the driver) the different transient modes. The electromagnetic valve actuation system (EMVAS) developed by Valeo, e-Valve, whose design has reached today the required maturity level for mass production, allows addressing all new requirements in term of flexibility to change profiles during different engine operating points, and also flexibility during the engine design phase. With the increasing pace of innovation, this added flexibility helps meet the increasingly demanding requirements of the market. This paper describes how camless technology, in addition to the benefits brought to the engine in terms of downsizing and hybridization, also allows for the convergence of developments for low consumption and low cost (engines). The electromagnetic valve actuation system provides with accuracy all degrees of freedom (required to optimize the operation of a gasoline combustion engine), during engine development (for the manufacturer), production (for the manufacturer) and during the engine use (for the customer) without any extra cost. Also, the effective cost of an electromagnetic valve actuation system is almost proportional to the number of actuated valves; it is therefore appropriate to low-cost engines for the just required performance.