VALVE MECHANISM BY G.DINESHPIRAN

FOR THERMAL & AUTOMOBILE ENGINEERING FROM EXCEL

1. Excel polytechnic college DEPARTMENT OF MECHANICAL ENGINEERING

2. SEMINAR THERMAL & AUTOMOBILE

3. Title : VALVE MECHANISM Subject : THERMAL & AUTOMOBILE Section : C Department: Mechanical Submitted by KEERTHIVASAN

4. CONTENTS INTRODUCTON OPERATION TYPES VALVE MECHANISM IN CONVENTIONAL TYPE SOLIENOID OPERATED VALVES ADVANTAGES DISADVANTAGES

5. INTRODUCTION The valves are used to release the sucked fuels , compressed gas or fuels , produced power , exhaust the un burnt fuel and for many purposes this is the introduction about valves.

6. OPERATION Consists of a central cam shaft When cam shaft rotates the lobes push against the valves to open them The cam is driven by taking input from the crank shaft. A single cam shaft can be used to open both the (i.e. intake and exhaust ) valves (SOHC) or two cams can be used one for intake and one for exhaust (DOHC). How the valves are opened and closed?

7. OPERATION Depending on RPM and engine load the ECM would directly control all valve timings. There will be no cam ( Camless Valves) Valve timing would be infinitely controllable Valve timing will be controlled electrically by Electronic Control Module (ECM) It is a future technology and currently not in production . Solenoid Operated Valves

8. TYPES OF VALVES COMPRESSION VALVE POWER VALVE SUCTION VALVE EXHAUST VALVE FOR 2 STROKE ENGINES FOR 4 STROKE ENGINES

9. CAM SHAFT CAM FOLLOWER PUSH ROD ROCKER ARM VALVE SPRING VALVE GUIDE VALVE STEM VALVE MECHANISM IN CONVENTIONAL ENGINE

10. Advantages Better fuel efficiency High initial torque Lover emission Better performance

11. Disadvantages Higher cost of engine More complex mechanisms Lower overall engine life because of increased wear .

12. CONCLUSION Even though some disadvantages are present, we can expect electro-hydraulic & electromechanical valves to replace the conventional camshaft technology .

13. THANK YOU