GOVERNMENT COLLEGE OF ENGINEERING,
GOVERNMENT COLLEGE OF ENGINEERING,
Presentation within is a synopsis of the conceptual development of a piezoelectric controlled hydraulic actuator. This actuator was develop for use as a replacement for the camshaft in an internal combustion engine (ICE). Its development results in a new device; called, the camless engine (CLE). The objective of the project was to prove the concept of a CLE. More specifically, it is a electro/hydraulic device capable of producing engine valve displacement at typical automotive demands. The goals for maximum displacement and frequency are 10 mm and 50 Hz, respectively. In general, the unit must be capable of varying engine valve displacement and valve timing. The system utilize a customize piezoelectric stack and hydraulic spool valve combined with an in-house designed hydraulic amplifier. Control is facilitate by a function generator, and feedback is monitored with an oscilloscope. The resulting system is capable of displacing an engine valve to nearly 11 mm, and frequencies up to 500 Hz have been obtained. As the ability of piezoelectric control of hydraulics for use as an ICE valve actuator.
WORKING OF PUSH ROD ENGINE
AN OVERVIEW OF CAMLESS ENGINE
Camless valve train
COMPONENT OF CAMLESS ENGINE
ADVANTAGES AND DISADVANTAGES
The cam has been an integral part of the IC engine from its invention. The cam controls the “breathing channels” of the IC engines, that is, the valves through which the fuel air mixture (in SI engines) or air (in CI engines) is supplied and exhaust driven out. Besieged by demands for better fuel economy, more power, and less pollution, motor engineers around the world are pursuing a radical “Camless” design that promises to deliver the internal – combustion engine’s biggest efficiency improvement in years. The aim of all this effort is liberation from a constraint that has handcuffed performance since the birth of the internal-combustion engine more than a century ago. Camless engine technology is soon to be a reality for commercial vehicles. In the Camless valve train, the valve motion is controlled directly by a valve actuator – there’s no camshaft or connecting mechanisms .Precise electro hydraulic Camless valve train controls the valve operations, opening, closing etc. The seminar looks at the working of the electro hydraulic Camless engine, its general features and benefits over conventional engines. The engines powering today’s vehicles, whether they burn gasoline or diesel fuel, rely on a system of valves to admit fuel and air to the cylinders and let exhaust gases escape after combustion. Rotating steel camshafts with precision-machined egg-shaped lobes, or cams, are the hard-tooled “brains” of the system. They push open the valves at the proper time and guide their closure, typically through an arrangement of pushrods, rocker arms, and other hardware. Stiff springs return the valves to their closed position. In an overhead-camshaft engine, a chain or belt driven by the crankshaft turns one or two camshafts located atop the cylinder head.
WORKING OF CONVENTIONAL ENGINE:
Pushrod engines have been installed in cars since the dawn of the horseless carriage. A pushrod is exactly what its name implies. It is a rod that goes from the camshaft to the top of the cylinder head which push open the valves for the passage of fuel air mixture and exhaust gases. Each cylinder of a pushrod engine has one arm (rocker arm) that operates the valves to bring the fuel air mixture and another arm to control the valve that lets exhaust gas escape after the engine fires. There are several valve train...
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