C-20-A-302.1.ppt
- 1. 1 Department of Technical Education Andhra Pradesh Branch : Automobile Engineering Institute : Govt. Polytechnic, Atmakur Year/Semester : III Semester Subject : Automobile Power Plants Subject Code : A302 Topic : Engine Construction Duration : 50 Minutes Sub Topic : Classification, Functions & Materials of Engine Components Teaching Aids : Images, Animations & Text 20A302.1
- 2. 20A302.1 2
- 3. 3 Objectives On completion of this session, you would be able to know: • Functions of Cylinder Block, Cylinder and liners • Materials used for above components • Construction details of above components 20A302.1
- 4. 4 • Have you ever traveled by a bus ? • What the driver first do to move the bus ? • If your answer is starting the engine ? • What the engine consists of ? Introduction 20A302.1
- 5. 20A302.1 5 The actual meaning of prime mover is a primary source of power. It means all the machinery that provide power for performing different mechanical work. Prime Mover: an initial source of motive power (such as a windmill, waterwheel, turbine, or internal combustion engine) designed to receive and modify force and motion as supplied by some natural source and apply them to drive machinery.
- 6. Types of engines: Mainly engines are of two types. External Combustion Engines: The External Combustion Engines are those in which the combustion takes place outside the engine cylinder. E.g.: Steam Engine. Internal Combustion Engines: In the Internal Combustion Engines the combustion of fuel takes place inside the engine cylinder. E.g.: All Automobile Engines. Functions of I.C. Engine: Engine is that kind of prime mover which converts chemical energy of fuel into mechanical energy. The fuel on burning changes to gas which impinges upon the piston and pushes it to change into reciprocating motion. The reciprocating motion of piston is then converted to rotary motion of crank shaft with the help of slider mechanism involving connecting rod and crank shaft. Dr V Venkateswarlu 6
- 7. Classifications of I.C. Engines The I.C. Engine can be classified on the basis of 1.Working cycle: a. Otto cycle Engine or Spark Ignition Engine (S.I. Engine) b. Diesel Cycle Engine or Compression Ignition engine (C.I. Engine) 2. Number of strokes: a. Two Stroke engine, b. Four Stroke engine. 3. Fuel used: a.Liquefied petrol engines, b. Diesel engines, c. Gasoline or petrol, b.d. Compressed Natural gas engines, e. Methane or ethanol engines. 4. Fuel supply system: a. Fuel supply through carburetor, b. Fuel injected by Fuel injecting pump. Dr V Venkateswarlu 7
- 8. 5. Method of ignition: a. battery or coil ignition, b. Magneto ignition, c. Electronic ignition 6. Method of cooling: i) Air cooled, ii) Water cooled 7. Cylinder Arrangement: i) in line type, ii)V type, iii) Opposed cylinder type, iv)Radial type 8. Valve operating system: i) Overhead, ii) Side valve type Dr V Venkateswarlu 8
- 9. Materials used, function and Constructional details of Petrol Engine Components Engine consists of the following parts. 1.Cylinder block 2.Cylinder head 3.Crankcase 4.Piston 5.Piston Rings 6.Piston Pin 7.Connecting Rod 8. Crankshaft 9. Flywheel 10. Valves and valve mechanism 11. Rocker Arm 12. Camshaft besides the these components engine contain so many accessories like air cleaner, oil filter, automatic chokes, automatic heat controls, spark plug, ignition devices, carburetors, manifolds, vibration damper etc. 9
- 10. Dr V Venkateswarlu 10
- 11. 11 • The engine consists of several parts, • To understand the construction of the engine we have to know the function and constructional details of at least the main parts. • The main parts of an engine are – Cylinder or Cylinder block – Cylinder liner – Piston – Connecting rod – Crank shaft – Piston pin – Main bearings – Valves …etc., Engine Constructional Details 20A302.1
- 12. 12 Working of an I.C. Engine Model (Petrol) Fig:1 • What is this ? • An engine • What is the function of engine? • An engine is a energy converting device. • Used to convert the heat energy produced by the combustion of fuel into mechanical energy. • This mechanical energy is utilised for moving an automobile. 20A302.1
- 13. 13 I.C. Engine Model (Petrol) Figure 2 20A302.1
- 14. 14 CB CB Cylinder Block P Piston R Connecting Rod C Crank Shaft W Water jacket V Valves I Inlet Valve E Exhaust Valve S Spark Plug PP Piston pin PP Main Parts of an Internal Combustion Engine 20A302.1
- 15. 15 In-line Engine Cylinder Block (4-Cylinders) Fig:4 20A302.1
- 16. 16 Cylinder Block • Cylinder block forms the very base of the engine with cylinders formed in it • Cylinder block consists of three parts: • The Cylinders in which pistons move up and down • The ports or openings for the valves • The passages for the flow of cooling water 20A302.1
- 17. 17 Cylinder Block • In modern engines Cylinder block and Crank case form a single casting. • This gives advantages like increased rigidity and reduced cost. • Sheet metal core plugs made of steel, copper or brass are used to close the holes in the casting. 20A302.1
- 18. 18 A Typical Engine Cylinder Block Fig:3 20A302.1
- 19. 19 In-line Engine Cylinder Block (4 Cylinders) Fig:5 Cylinders in a line 20A302.1
- 20. 20 Cylinder Liners • The cylinder block is usually made of grey cast iron • Grey cast iron has good castability and machining quality but do not have a good wear resistance • Cylinders are subjected to high temperatures requiring wear resistant properties a elevated temperatures • In order to fulfill such a condition Cylinder Liners are used. 20A302.1
- 21. 21 Cylinder Liners • Cylinder liners are made of special alloy cast iron. • Cylinder liners are of two types: • Dry Liners • Wet Liners 20A302.1
- 22. 22 Dry Liners • Dry liner is made in the shape of a barrel having a flange at the top which keeps it into position in the cylinder block 20A302.1
- 23. 23 Dry Liners • Dry liner is made in the shape of a barrel having a flange at the top which keeps it into position in the cylinder block • The entire outer surface of the dry liner bears against the cylinder block casting • Thus it is not in direct contact with the cooling water, hence it is called as dry liner. 20A302.1
- 24. 24 Dry Liners • Therefore a dry liner has to be machined accurately on outer surface also • Dry liners thickness usually ranges from 1.5 to 3 mm • These liners are replaced when worn out. Dry Liners 20A302.1
- 25. 25 Cylinder Liners Dry Liners Fig:7 Wet Liner 20A302.1
- 26. 26 Wet Liners • The outer surface of these liners have direct contact with the cooling water • Therefore they are called as Wet Liners 20A302.1
- 27. 27 Wet Liners • A wet liner is provided with a flange at the top which fits into the groove in the cylinder block. • At the bottom either a block or the liner is provided with grooves, generally three in numbers 20A302.1
- 28. 28 Wet Liners • Packing rings made of rubber are inserted into the bottom grooves • The outer surface of a wet liner does not require accurate machining • Wet liners are thicker than dry liners. • Thickness usually ranges from 1.5 to 6mm 20A302.1
- 29. 29 Materials used for Engine Components Component Engine Component Material Cylinder Block Grey Cast Iron Aluminum Alloy Cylinder Liner Cast Iron 20A302.1
- 30. 30 Component Functions Cylinder Block • Forms base of the engine • Serves as a support and enclosure for moving parts • Should have water jackets for cooling system Cylinder Liners • Forms Cylinder walls • Should retain a film of lubricant • Should conduct heat quickly to coolant Functions of Engine Components 20A302.1
- 31. 31 Cylinder Block, Cylinder Head and Sump 20A302.1
- 32. 32 Summary In this session we have learnt about • Construction of a Cylinder Block and Cylinder Liners • Wet Liners • Dry liners 20A302.1
- 33. 33 Quiz 1. Cylinder Block is made of a) Alloy steel b) Brass c) Grey Cast Iron d) Aluminum 20A302.1
- 34. 34 Quiz 2. Cylinder Liners are made of a) Alloy steel b) Brass c) Grey Cast Iron d) Aluminum alloy 20A302.1
- 35. 35 Assignment 1. Explain the functions of wet liners and dry liners. 2. Explain cylinder block functions and materials. 20A302.1