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Future valve system in engine
1. FUTURE VALVE SYSTEMS IN
ENGINES
PRESENTED BY
AAKASH RAJEEVAN
S7 MECHANICAL
ROLL NO:1
2. 2
INTRODUCTION
CAM
â˘Control the valves of an IC engine
â˘Cams push open valves at proper time & guide
their closure
â˘High power consumption
â˘High sound & Vibration
â˘They are inflexible except VTEC & VVT
â˘Could not vary timing, lift & duration of valve
opening
3. VALVE MECHANISM IN
CONVENTIONAL ENGINE
⢠CAM SHAFT
⢠CAM FOLLOWER
⢠PUSH ROD
⢠ROCKER ARM
⢠VALVE SPRING
⢠VALVE GUIDE
⢠VALVE STEM
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4. WHAT IS CAMLESS ENGINE
⢠Which eliminates camshaft & mechanical linkage
⢠It uses electromagnetic or hydraulic to open the
valves.
⢠Actuator can be used to both open and close the
valve or an actuator opens while spring closes it.
⢠Ability to achieve truly variable valve timing in each
cycle.
⢠It can make engines clean, efficient & responsive
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5. OVERVIEW OF CAMLESS ENGINE
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ELECTRONIC
CONTROL UNIT
VALVE
ACTUATORS
SENSORS
ďąMAIN SENSORS
â˘ENGINE LOAD SENSOR
â˘ENGINE SPEED SENSOR
â˘EXHAUST GAS SENSOR
â˘VALVE POSITION SENSOR
â˘AUXILARY SENSORS
6. 6
ďąELECTRONIC CONTROL UNIT(ECU)
â˘ECU contains microprocessors with associated
software
â˘Sensors sense parameters & send signals to ECU
â˘This ECU controls the actuators to work according to
requirements
ďąVALVE ACTUATORS
2 Types of valve actuators are mainly used
â˘ELECTRO-MECHANICAL SYSTEM
â˘ELECTRO-HYDRAULIC SYSTEM
7. ELECRO MECHANICAL SYSTEM
⢠These actuators are use electro magnetic effect
⢠Components used into these systems are coil ,
armature , solenoidâŚ
There are 2 types of actuators
1. Double solenoid actuator
2. Moving coil actuator
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8. DOUBLE SOLENOID ACTUATOR
ELECTRONIC
CONTROL UNIT
ENGINE SPEED
SENSOR
EXHAUST GAS
SENSOR
ENGINE LOAD
SENSOR
VALVE POSITION
SENSOR
â˘Sensor sense the parameters and send it to the ECU
â˘ECU analyze the data and send an electric current to the solenoid
â˘In the case of opening send current to solenoid 2 &for closing to the
solenoid 1
â˘Send a feed back from solenoid to ECU
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9. DISADVANTAGE OF DOUBLE SOLENOID
ACTUATOR
â˘It require high current for its operation
â˘High energy consumption
â˘Non linear behavior
â˘High seating velocity
â˘Require proper seating of valves
â˘Wearing in valves
â˘system cannot vary the amount of valve lift.
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10. MOOVING COIL ACTUATOR
â˘Air gap b/w coil &magnet are remain constant
â˘A force produce on coil when it get energized
â˘Variable valve lifting & timing can be possible by
adjusting the current in coil
â˘Almost linear behavior
â˘Single coil & controlling is simple
â˘Magnetic force is depends only in current not in
position of coil
â˘High precision position control
â˘Seating of valve is an easy task
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12. ELECTRO HYDRAULIC SYSTEM
⢠Electro hydraulic system uses the elastic property of fluids
⢠A source of pressurized hydraulic fluid and a hydraulic
actuator coupled to the poppet valve.
⢠In one design, the provision is made for solenoid valve to
control the flow of the fluid to the actuator.
⢠Solenoid valves are controlled by ECU
⢠provides continuously variable control of engine valve timing,
lift, and velocity
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13. 13
Fig1: Layout of hydraulic system
Fig2: Cross section of cylinder head
14. WORKING OF HYDRAULIC VALVE
â˘Working based on hydraulic pendulum
â˘During acceleration of valve PE of fluid is
converted into KE of valve
â˘During the deceleration KE of valve is converted
into PE of fluid in both opening & closing
â˘Minimize energy consumption
â˘HP solenoid valve open the engine valve& LP
close
â˘Opening & closing of solenoid valve by ECU
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15. 15
â˘Offers continuously variable & independent control of valve motion -
lift, operation duration, event of opening
â˘ECV system can control valve velocity, valve acceleration and deceleration
â˘Better fuel economy- 7 to 10 % increase
â˘Higher torque & power- 10 to 15 % increase
â˘Lower exhaust emissions- reduces NO x emissions
â˘Reduction in size & weight
DISADVANTAGE
â˘System is more complex
â˘Maintenance is difficult
â˘Cost of the system is high
ADVANTAGE OF CAMLESS ENGINE OVER CAMSHAFT ENGINE
16. CONCLUSION
Even though some disadvantages are
present, we can expect electro-hydraulic &
electromechanical valves to replace the
conventional camshaft technology.
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17. REFERENCE
[1] Michael M.Schechter and Michael B.Levin âCamless Engineâ SAE paper 960581.
[2] P. Kreuter, P. Heuser, and IvI. Schebitz, âStrategies to Improve Sl-Engine
performance by Means of variable Intake Lift, Timing and Durationâ, SAE paper
g2044g.
[3] K.Hatano, k. Lida, H. Higashi, and S. Murata, "Development of a New Multi-Mode
Variable Valve Timing Engineâ,SAE paper 930878
[4] V. Pieron, Y. Postel, E. Nicot, and D. Durrieu, "Electro-Magnetic Valve
Actuation System: First Steps toward Mass Production," SAE 2008-011360.
[5] Y. Wang, T. Megli, M. Haghgooie, K. S. Peterson, and A. G.
Stefanopoulou, "Modeling and Control of Electromechanical Valve
Actuator," SAE 2002-01-1106.
[6] C. Sugimoto, H. Sakai, A. Umemoto, Y. Shimizu, and H. Ozawa, "Study
on Variable Valve Timing System Using Electromagnetic Mechanism,"
SAE 2004-01-1869.
[7] P. Eyabi and G. Washington, "Nonlinear Modeling of an Electromagnetic
Valve Actuator," SAE 2006-01-0043.
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