Camless Engine
ABSTRACT
Camless internal combustion engines offer major improvements over traditional engines in terms of efficiency, maximum torque and power, pollutant emissions. Electromechanical valve actuators are very promising in this context, but still present significant control problems. Low valve seating velocity, small transition time for valve opening and closing, unavailability of position sensor are the main objectives to be considered in the design of the valve control system. Actuator physical limitations strongly influence the feasible trajectory when low valve seating velocity is required, thus affecting valve transition time.
Traditionally four stroke engine valves have been operated with cams and rocker arms. The biggest problem with this is they are subjected to wear and tear and other effect like tapped noise and so on. The camless engine will be the solution for this problem. The valve actuation can be done by different ways like electro hydraulic actuation, electro mechanical actuation, hydraulic actuation and solenoid actuation. Our study is on the replacement of the entire cam and rocker arm mechanism with an electronically controlled solenoid operated valve system.
A solenoid- operated valve for use in an internal combustion engine has a valve body controlled electronically using a solenoid to actuate it which in turn is controlled by an electronic control unit. The electronic control unit perform the task of converting the timing signal from optocoupler sensor into a pulse in the required form to the solenoid to open and close the valves.
TABLE OF CONTENTS
CHAPTER NO. TITLE PAGE NO. ABSTRACT LIST OF FIGURES LIST OF TABLES 1. INTRODUCTION 5 2.1 FOUR STROKE ENGINE 5 1.1.1 WORKING OF 4 STROKE ENGINE 6 1.1.2 VALVE MECHANISM 6 2.2 EXISTING VALVE ACTUATION SYSTEM 7 2.3 PARTS OF VALVE ACTUATION SYSTEM
Camless internal combustion engines offer major improvements over traditional engines in terms of efficiency, maximum torque and power, pollutant emissions. Electromechanical valve actuators are very promising in this context, but still present significant control problems. Low valve seating velocity, small transition time for valve opening and closing, unavailability of position sensor are the main objectives to be considered in the design of the valve control system. Actuator physical limitations strongly influence the feasible trajectory when low valve seating velocity is required, thus affecting valve transition time.
Traditionally four stroke engine valves have been operated with cams and rocker arms. The biggest problem with this is they are subjected to wear and tear and other effect like tapped noise and so on. The camless engine will be the solution for this problem. The valve actuation can be done by different ways like electro hydraulic actuation, electro mechanical actuation, hydraulic actuation and solenoid actuation. Our study is on the replacement of the entire cam and rocker arm mechanism with an electronically controlled solenoid operated valve system.
A solenoid- operated valve for use in an internal combustion engine has a valve body controlled electronically using a solenoid to actuate it which in turn is controlled by an electronic control unit. The electronic control unit perform the task of converting the timing signal from optocoupler sensor into a pulse in the required form to the solenoid to open and close the valves.
TABLE OF CONTENTS
CHAPTER NO. TITLE PAGE NO. ABSTRACT LIST OF FIGURES LIST OF TABLES 1. INTRODUCTION 5 2.1 FOUR STROKE ENGINE 5 1.1.1 WORKING OF 4 STROKE ENGINE 6 1.1.2 VALVE MECHANISM 6 2.2 EXISTING VALVE ACTUATION SYSTEM 7 2.3 PARTS OF VALVE ACTUATION SYSTEM
References: 1. C.Gray “A Review of Variable Engine Valve Timing”, SAE paper, no. 880386, (1988) 2 3. W.Hoffmann & A.Stefanopoulou “Valve Position Tracking for Soft Land of Electromechanical Camless Valve train”, 3rd IFAC Conference Advances in Automotive Control, (2001) 4 5. Isao Matsumoto & Hideyuki Nishida “Internal Combustion Engine having Solenoid-Operated Valves & Control Method”, Patent No. US 6,332,446B1, (2001) 6