Camless Engine

KONGU ENGINEERING COLLEGE
PERUNDURAI , ERODE -638052 Tamil Nadu. (Approved by AICTE, New Delhi)

CAMLESS IC ENGINE WITH ELECTRO HYDRAULIC VALVETRAIN AND CRANKSHAFT POSITION FEEDBACK

V.PIRANESH, Second Year Mechanical Engineering, [e-mail] ph:9597848518

R.YOGESHWARAN Second Year Mechanical Engineering , [e-mail] ph :9894882579

ABSTRACT Presented within is a synopsis of the conceptual design, analysis and testing of a camless engine (CLE) with an electro hydraulic valve train. The system makes use of a piezoelectric controlled hydraulic actuator. This actuator serves as a replacement for the camshaft in an internal combustion engine (ICE). In essence, the actuator is an 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 for a typical engine speed of 6000 RPM. The system design utilizes a customized piezoelectric stack and hydraulic spool valve combined with an in-house designed hydraulic amplifier. Control is facilitated 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. The system makes use of a magnetic or Hall Effect crankshaft position sensor in place of the conventional chain and sprocket timing drive. Valve timing can be varied by varying the input voltage signal to the piezoelectric stacks and electronic control also facilitates cylinder shut down. The electro hydraulic valve train therefore effectively implements variable valve timing and variable cylinder management.

EXISTING TECHNOLOGY: CAMSHAFT

THE

Since the origination of the automobile, the internal combustion engine has evolved considerably. However, one constant has remained throughout the decades of ICE development. The camshaft has been the primary means of controlling the

References: • Development of a piezoelectric controlled hydraulic actuator for a camless engine by John Steven Brader, University of south carolina www.autospeed.com/camless engines www.carbibles.com Adaptive control of camless valvetrain United states patent 5419301 Spool valve control of an electrohydraulic camless valvetrainsUnited States Patent 5456222 This development has proven the concept of replacing an internal combustion engine’s camshaft with a piezoelectric controlled, hydraulic actuator. Valve stroke requirements have been achieved, and, at some input variations, have been exceeded. The actuator has also performed at frequencies well in excess of 50 Hz. Testing has shown some limitations related to the flow rate and input waveforms. However, it is these limitations have provided the inspiration for continued development and discovery. The two extremes of the waveforms have been already tested; namely the sine wave • • • •