Agricultural engineering


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final question collection for UiTM student

Agricultural engineering

  2. 2. Marzuqi Salleh, UiTM Perlis PREPARED BY: MARZUQI BIN MOHD SALLHBrief the function of the following components in the system given and explain their roles.Water cooling systemi) water pump -heart of the cooling system, circulates the coolant through the systemiii) thermostat -to provide automatic control of engine temperature at the correct level in order to get the best performance.v) radiator-reservoir and heat exchanger for coolantiv) by-pass -allow water to distribute in all partLubricating systemi) oil strainer-Store up dirty oil lubricating to remove to drain plugii) oil sump-Made of iron casting, Seals the crankcase at the bottom, Functions as a reservoir for the lubricating oilvi) oil pan - act as reservoir for engine oilv) galleries-the passage through which the oil pumpediv) pressure guage- to tell operator if engine is normalElectrical systemi) Alternator-charge the battery/produce chargingii) Regulator-regulate the charging of battery charge/control the voltageiii) Distributor-distribute high voltage current to various spark plug for fireTransmission system,a) Clutch- to connect and disconnect powerb) Differential- to equalize power for turningc) Gear-box- to select speed and directiond) Final drive- to reduce speed and increase torquee) Drive wheels- to propel the machineGive the function of each of the following parts:i) Muffler -to reduce the noise of combustion of an engine,AGRICULTURAL ENGINEERING CONFIDENTIAL
  3. 3. Marzuqi Salleh, UiTM Perlis -exhaust from the engine is passed through a muffler, -the muffler is designed so the gases expand slowly.ii) Governor -Maintain a selected speed -Limit the slow and fast speed (4 marks)Please state the roles of the following component in the engine system.a) Camshaft • Is turned by the engine crankshaft. • A lobe (cam) on the camshaft causes the cam follower and push the rod to push the valve open • The spring closes the valve when the cam allows the push rod and cam follower to return to low side of the cam • Cam movements are designed to open or close the valves at the right momentb) Clutch plate • A clutch plate made of friction material is pressed on to the flywheel by a pressure plate that is spring loaded either by a number of coil springs or a spring diaphragm. • Clutch plate fitted with torsion springs to retain its shape. • The clutch plate and the pressure plate rotate together with the flywheel and power is taken out to the gearbox through a gearbox input shaft. • The clutch is said to be engaged.Explain the terms below:a) Diesel injection pump- the fuel pump moves fuel from the tank and pushes it through the filterb) SAE number -stands for society of automobile engineers -it is a means of classification of lubricating oil according to the viscosity/thickness -gear and transmission oil are given this number SAE 50, 70, 90.AGRICULTURAL ENGINEERING CONFIDENTIAL
  4. 4. Marzuqi Salleh, UiTM Perlisc) Compression ratio - Compression ratio is a characteristic of an engine i.e. related to engine efficiency i.e. the ability of the engine to convert in the fuel to useful mechanical energyd) Valve timing- -Opening and closing of both inlet and exhaust valves when the piston is at the exact top (TDC) or bottom (BDC) of its stroke.e) Valve overlap- -Both valves are open at once at the same period. (10 marks)Briefly describe the construction and function of the following:a) Cylinder head -upper part of the engine -contain holes valve -made from cast iron at combustion chamberb) Cylinder block -largest part in the engine -have valve -piston move up and down in the cylinder block -make from cast ironc) Piston -made from cast iron -transfer and receive energy during combustion processd) Piston rings- - A component that fitted into the slot around the piston which seal the combustion chamber and help transfer heate) Cams - Integral part of camshaft design to open the valve at the correct timing and to keep them open for the necessary duration.f) Crankshaft- - Receive the force from the pistons and transmits it as rotary driving force - Rear end carries the flywheel incorporating starter ring gear - Front end carries crankshaft gear used to drive valve timing mechanism, oil pumpg) Intake and exhaust valves -The valves allow fuel-air in and exhaust gases out of each cylinder during combustion cycle by opening and closing the intake and exhaust parts of the cylinder.AGRICULTURAL ENGINEERING CONFIDENTIAL
  5. 5. Marzuqi Salleh, UiTM Perlish) Gudgeon pin- -Forms the link between the small end of the connecting rod and the piston.i) Connecting rod- -bring down the energy that produce from piston to crankshaftj) Flywheel- -rote to start the engine -located at the end of crankshaft (10 marks)Define the term below:i) Theoretical field capacity (TFC) • Is the maximum possible capacity obtainable at a given speed, assuming the machine is using its full width. • TFC uses two of the factors – speed and width.ii) Effective field capacity (EFC) • The best way to determine EFC of a machine is to make an accurate check of the number of acres (hectares) actually covered over a long period of time. • EFC brings in the factor of efficiency. This capacity determination represent the real life or actual capacity obtainable over a period of timeiii) Field Efficiency and the factors that influence the field efficiency of a machine. (9 marks) • Speed - average rate of travel in km/hr. • Width - distance in feet/meters across the processing portion of the machine. • Efficiency -ratio of effective capacity of a machine to its theoretical capacity. -an indicator of how much time is spent working versus turning, filling hoppers and other jobs.Explain why maintenance is important for an engine and describe the maintenance proceduresfor the following:a) Diesel system and diesel fuel system • Clean the fuel filter • Change whenever necessary • Make sure the fuel tank is always top-upb) Transmission system • Check transmission oil as recommended • Change oil filter as necessaryc) Power-Take-Off (PTO) system • Change the hydraulic oilAGRICULTURAL ENGINEERING CONFIDENTIAL
  6. 6. Marzuqi Salleh, UiTM Perlis • Change the filter when necessary • Change the hoses and join foe leakaged) Lubricating system • Check the lubricating oil using dipstick if low add lubricating oil • At the oil filter, dist is taken out of the oil to help it keep cleane) Cooling system • Check water in the radiator if low top up the water • Check the connecting hose may be it has cracks (10 marks)Lubricating system 1. Oil strainer • filter dirt and foreign material 2. Oil galleries • allow lubricating oil pass way for oil to move through to the components that are move it 3. Pressure gauge • it helps to measure the pressure of the lubricating oil 4. Oil pan/sump/crankcase • reservoir for lubricating oil/storage lubricating oil • cool the lubricating oil • located beneath the engine block 5. Regulating valve • Control oil pressure and by pass oil at filter & oil cooler 6. Oil pump • Located in the oil pan • Drive from either the camshaft or the crankshaft • Supplies oil under pressure to the various parts of the engine 7. Oil filter • Cleans the oil particles of foreign material 8. Oil cooler • Help dissipate heat 9. Oil heaters • Use in winter to make starting easierWrite short notes on the following1) Fuel injection pump • The function is to pump diesel go to injector nozzle.AGRICULTURAL ENGINEERING CONFIDENTIAL
  7. 7. Marzuqi Salleh, UiTM Perlis • Fuel from the filters enters into the fuel injection pump which works to pressurize it. It not only has to inject the fuel at the correct pressure but also at the correct time. Along with the governor, it is also controls the amount of diesel discharged per injection and hence the engine speed.In a carburetor, explain the role of:I) Choke system • Control the supply of fuel to the engine. When starting the engine in cold weather, it can be partly closed, forming a greater vacuum. This vacuum causes more fuel and less air to be drawn into the combustion chamber. The richer mixture burns easierii) Venture (lubang-lubang masuk udara) • The venture principle is used to create fuel flow from the float bowl to the main discharge nozzle in the venture.iii) Throttle valve • Control of the rate at which some fluid moves from a region of relatively high pressure into a region of relatively low pressure. An example would be in an automobile engine, where the throttle controls the rate at which air (at or above atmospheric pressure) enters the engines intake manifold (near vacuum when the throttle is closed.)iv) needle valve • Control the flow of liquid or gas so that the flow can be decreased gradually and ultimately shut off completely. Needle valves help protect fragile gauges that might otherwise be damaged by high amounts of a pressurized substances releaseDifferentiate between the two systems below:a) Force-feed lubrication system and Petroil lubrication system • Lubricating system is the lubricating system for big engine and very reliable • Its configuration of component will ensure the delivery of lubrication oil to every moving partsb) Liquid Cooling system and Air Cooling System Air cooling system Liquid cooling system • Used primarily on small engine or • Normally uses water as a coolant aircraft as it is difficult to route air to • The circulates in a jacket around the all the heat points of lager engine cylinders and cylinder heat • Metal baffles, ducts, and blower are • As heat radiates, it is absorbed by the used to aid in distributing air. water which then flows to the radiatorAGRICULTURAL ENGINEERING CONFIDENTIAL
  8. 8. Marzuqi Salleh, UiTM Perlisc) Fuel Injection Pump of Diesel Fuel System and Carburetor of Petrol Fuel System • To control the fuel discharge in terms of quantity, timing and correct order of cylindered through the nozzle sprayer before enter into the combustion chamber.d) Battery Ignition system and Capacitor Discharge Ignition system (8 marks) • Although they perform the same job but battery ignition system differs in terms of mechanical component which doesn’t exist in capacitor discharge ignition system, the BIS using mechanical broken points to break and close the circuit.Discuss four (4) major differences between diesel and petrol engines. (8 marks) DIESEL ENGINE PETROL ENGINE1. Fuel System 1. Fuel System • Use diesel • Use petrol • No carburetor • Have carburetor • Uses heat & compressed air for • Uses electric spark to ignite air-fuel ignition mixture2. Higher compression ratio 2.Lower compression ratio • 14 – 16 : 1 • 7 – 10 : 13. Operation 3.Operation • No pre-mixing of air and fuel • Fuel and air mixed outside the • Air taken into cylinder through intake cylinders in the carburetor and intake manifold and compressed manifold • Fuel is sprayed into cylinders and • Mixture is forced into cylinders by mixed with air as the piston nears the partial vacuum created by intake top of its compression stroke stroke of pistonName the different types of brake systems. • The main types of brakes are disc brakes, drum brakes, air brakes, and vacuum brakes. • A brake is an apparatus used to slow or stop a moving vehicle, or, once the vehicle is stopped, to keep it from moving again. • Wheel brakes are generally friction devices, using resistance and energy lost through heat to slow the vehicle. • The vacuum brake was originally devised for use on trains. • These types of brakes works by creating air pressure changes in a compartment called the brake cylinder. Inside the cylinder is a piston, which is a mechanism designed to use the force of incoming air to move a rod. The rod is attached to the brake shoes. WhenAGRICULTURAL ENGINEERING CONFIDENTIAL
  9. 9. Marzuqi Salleh, UiTM Perlis the brake pedal is held down, air is let into the cylinder, which causes the piston to transfer that force onto the brake rod. The brake rod moves and, in turn, the brake shoes are pressed to the side of the wheel to cause friction. (10 marks)a) What do you understand by agricultural mechanization? (2 marks) • Needed to ease the operations of crop production by the use of machines to replace animal and human labor.b) Name and describe any two objectives of mechanization. (4 marks) • Reduce human labour. • Increase farm productivity through higher yield per unit area. • Distribution of labour for other activities. • Efficiency of field operation and reduction of labour at peak hour activities.c) Although having a farm tractor is good for field activities it may also bring along somedisadvantages. List five disadvantages of owning a farm tractor. (5 marks) • Tractor are expensive to buy/high investment • High cost of maintenance • Need a high skills and handlings maintenance • Farm work may be stopped, disturbed, if tractor break down • The tractor is value depreciate over time/low resale value.Describe five (5) common obstacles to farm mechanization and provide a solution to eachproblem. (10 marks) 1. Direct increase in the yields: • Example of equipment purchased in order to increase yields directly are irrigation and spraying equipment 2. Indirect increase in the yields: • Any investment in cultivation equipment to improve the condition of the soil in seedbed preparation would come under this heading 3. Increased yield through improved timeliness: • The speeding up of operation by mean of a larger, faster machine will raise average yields in an uncertain climate because of better timeliness 4. Increased price through higher quality:AGRICULTURAL ENGINEERING CONFIDENTIAL
  10. 10. Marzuqi Salleh, UiTM Perlis • Extra return may be achieved by obtaining a higher price as well as through better yields 5. Increased price through storage: • A higher price may also be obtained through storing the crop until later in the seasonList ten safety procedures while working in the farm workshop. For, describe what may happenif it is not followed. (10 marks)Tools: 1. Extension cables should be as short as possible • If the cable on drum, it should be completely unreeled to stop the wire overheating 2. Do not wrap your fingers tightly round a spanner • There is much risk of loosing the skin from your knuckles 3. Power tools must be well maintained • Never use an electric tool unless it is earthed correctly or double insulated 4. Google must be worn for eye protection when grinding • Without this precaution the metal might pick up on the drill bit and turn with itElectric shock: 5. Avoid electric shock is never to work with life electrical equipment • Poster should be display in every farm workshop. If this happens to someone else while you are near, some rapid action is neededCompressed air: 6. Never direct compressed air at the body • Can cause serious injuryWelding: 7. Never look directly at the glare of electric welder • A painful eye condition known as ‘arc-eye’.Jacks: 8. Always apply the hand break and choke the wheels of tractor before it is jacked up • Never use bricks or concrete blocks because they may crumble or slipAGRICULTURAL ENGINEERING CONFIDENTIAL
  11. 11. Marzuqi Salleh, UiTM PerlisPersonal protection: 9. The best clothing for workshop use is a boiler suit • If not follow them may be happened accident such as falling object on the legFirst aid: 10. There must be a first aid on the farm workshop • If have not there is too difficult for accident treatmentThe old farm tractor in the garage has been left idle for three months because there was notmuch field work to be done. The driver was only instructed to ignite the engine twice or threetimes a week for a few minutes to warm it up. What do you need to do to the tractor beforeyou drive it out to resume normal field operations? List eight of them. (8 marks)Recommend service intervals:After 500 hour of operation • servicing the distributor • timing the ignition • maintaining the starter and generator (or alternator) • servicing diesel engine fuel filters • servicing front- wheel bearing • maintaining the cooling system • checking and servicing others parts of the tractorAfter 1000 hour of operation • cleaning the tractor • servicing the oil-bath air- cleaner assembly • servicing the drive mechanism • servicing the hydraulic systems • adjusting the engine governorBriefly discuss the planning of farm mechanization in plantation to ensure the entire task to bedone in a proper manner in order to maximize the profit and reduce cost and risk. (10 marks)Labor: • can be measured in terms of hour or cost but also in term of ‘quality’ • the operation is key factor in success in the fieldPlanting:AGRICULTURAL ENGINEERING CONFIDENTIAL
  12. 12. Marzuqi Salleh, UiTM Perlis • it is necessary to identify the type of machines required and specify their required performance levelSize and type of machine: • the types depend partly on the requirements of the job and limitations of the environment and partly on what is available in the machinery marketTotal planning: • the way the physical characteristics of a machine fit in with the rest of the plantation • the overall balance of power requirement being kept at a reasonable level throughout the yearSpecification of machines: • There is only one real way to select machines and that is to list everything it has to do and everywhere it has to goName three basic types of tractor, based on their design configurations (3 marks) • 2 wheel drive • 4 wheel drive • Crawler tractorName 4 different types of tractor (4 marks) • Standard tread • Row crop • High clearance • Low profitBriefly explain the two main reasons for carrying out maintenance work on tractors. List down 4main maintenance work commonly being carried out on tractors (10 marks)Main reason: • To keep the engine operation at maximum efficiency • To prevent wear of engine partMain maintenance: • Cleaning the engine • Cleaning carburetor air cleaners • Cleaning fuel filter • Cleaning fuel tank vent cap • Cleaning crankcase breather • Checking oil level • Changing oil in the four-cycle engineAGRICULTURAL ENGINEERING CONFIDENTIAL
  13. 13. Marzuqi Salleh, UiTM Perlis • Lubricating of two-cycle engineList 4 types of tractor tyre tread commonly used for field operations. (4marks) • General purpose tread • Industrial lug • Floation • Deep lug/rice treadThere is various kind of power in farm mechanization. List types of power basically can bedetermined in the tractor. (4 marks) • Brake • PTO • DrawbarWhy proper valve adjustment is important in engine process? Briefly discuss. (4 marks) • Engine will use fuel more efficiently. • Engine will start more easily. • Maximum power will be achieved. • Valves will give longer service. • Overheating of engine is less likely to occur.The diesel fuel-injection system must perform five (5) basic functions. List the five (5) functions. (5 marks) • Supply the correct quantity of fuel/diesel • Time the fuel delivery • Control the delivery rate • Break up or atomize the fuel • Distribute fuel evenly through the cylindersCompare and contrast the process of the compression stroke of a diesel 4-stroke engine andgasoline 4-stroke engine. (5 marks)compression stroke of diesel 4-stroke engine compression stroke of gasoline 4-stroke engine • It compresses the fuel air mixture • • During the this stroke, both the intake and exhaust valves are closeAGRICULTURAL ENGINEERING CONFIDENTIAL
  14. 14. Marzuqi Salleh, UiTM PerlisExplain what happens to the piston, valves, spark plug and fuel-air mixture during thecompression stroke and exhaust stroke of a four-stroke petrol engine. (10 marks) compression stroke exhaust stroke • The piston moves up while both the • The cylinder will be filled with waste intake and exhaust valve are close. gas at the end of the power • This will result in the compression of • In the exhaust stroke, the piston the trapped fuel-air mixture moves from BDC to TDC. • When the piston approaches TDC, the • At this time, the exhaust valve is spark plug produce a spark to ignite opened and the waste gas moves out the mixture through it and into the environment via the muffler.Explain the energy conversions in an internal combustion engine. (4 marks) • Form of heat engine because heat engine produced by the burning of fuel within the engine is changed into mechanical energy. • Is a structure that converts chemical energy (fuel) to mechanical energy • Usually made available on a rotating output shaft. • Normal engine that been used on road is known as Internal Combustion Engine (IC). • Is a reciprocating engines that have pistons that move back and forth in cylinders within the engineWhat are lean and rich mixtures, and how can one be changed to the other? (4 marks)Too rich mixture -Fuel consumption increased -Cause carbon deposits to accumulate in combustion chamberToo lean mixture -Reduces power -Valve burning from extra hot slow burning gasesWhat are the four (4) basic components of the intake system? • Air cleaner • Intake manifold • Combustion chamber • Carburetor • Intake valveGive three (4) functions of exhaust system. • Carry away burn gases from combustion chamber • Reduce muffling of engine noiseAGRICULTURAL ENGINEERING CONFIDENTIAL
  15. 15. Marzuqi Salleh, UiTM Perlis • Reduce heat at the engineList three (3) basic components of the exhaust system. (10 marks) • Muffler • Silencer • Exhaust valve • Exhaust manifoldName three (3) types of engine lubricating system in which they are commonly found and howfull face feed system work? (6 marks)Type of engine lubricating system • Circulating splash • Internal force feed and splash • Full internal force feedHow full face feed system work? • Oil pump pushes oil through the system. • A reserve of oil is stored in the crankcase for circulation through the system. • At the oil filter, dirt is taken out of the oil to help it keep clean.List 5 major parts involve in the lubricating system. (5 marks) • Oil pump • Crankcase • Oil cooler • Oil filter • Pressure regulating valve • Pressure gaugeGive three main functions of an engine lubrication system (3 marks) • Reduces friction between moving parts • Absorbs and dissipates heat • Seal the piston rings and cylinder walls • Cleans and flushes moving parts • Helps deaden the noise of the engineAGRICULTURAL ENGINEERING CONFIDENTIAL
  16. 16. Marzuqi Salleh, UiTM PerlisWrite short notes on the effects of overheating in the cooling system of an engine. (5 marks) • Burned valves and spark plugs • Scored pistons • Lubrication failure • Excessive engine wear • Engine knock, Detonation, Pre ignition • Cylinder head and block can warp • Rings and valves may seize or stick due to gums, lacquers, and varnishes forming from overheated oil and carbon formation. • Bearings may be damaged causing excessive wear.2 type of fans that are commonly used in the engine cooling system • Blower fan • Suction fanCooling systemi) Pressure cap/radiator cap -reduce temperature of water in cooling system-to allow atmosphere pressure to enter the cooling systemii) Connecting hoses-help to reduce from vibration of the radiator-allow water to pass from engine block to the radiator-the flexible connections between the engine and other parts of the cooling systemDescribe 3 problems that can happen to an engine if there is no cooling system (3 marks) • Overheating could burn up engine a short period • Lubricating failure • Excessive engine wearDiscuss three major function of the engine cooling system (3 marks) • To prevent overheating of the engine • To regulate temperature at optimum level • To prevent from overheatingDescribe three (3) functions of the carburetor. (6 marks) • Atomizes fuel for the engine • Provides proper fuel-air ratio • An air tube which operate by a change in air pressure.AGRICULTURAL ENGINEERING CONFIDENTIAL
  17. 17. Marzuqi Salleh, UiTM PerlisList ten (10) components of the electrical system and explain their functions. (10 marks) • Starter- Activate the flow of current in the starter circuit. • Ammeter-Indicate the amount of charging produce by alternator to charge battery • Alternator-Charge the battery/produce charging • Voltage regulator-Regulate the charging of battery charge, and control the voltage • Starter solenoid-Attach the starter motor, to assist the starting of the engine • Starter motor-Start the engine with rotate the flywheel • Distributor-Distribute high voltage current to various spark plug for fire • Coil-Increase the low voltage to the high voltage of battery • Battery-Supply energy to the circuit • Spark plug-Produce spark in the combustion chamberWhat is the main purpose of an electrical system on a tractor? List various other purposes ofsuch system. (5 marks) • Recharge the battery after its electrical power is used up to start the engine or other electrical devices e.g. lights, horn, etc. • Generates current during operation. Purposes such Regulator system • Closes the circuit when engine is running & open the circuit when the engine is stopped. • Prevents overcharging the batter. • Prevent high flow of current through the system that could damage other components.Give some examples of preventive maintenance for an electrical system on a tractor. (4 marks) • Servicing and maintenance of battery • Servicing of spark plugs • Servicing the distributor • Replacing breaker point • Servicing alternator and starting motorName two type of generator and kind of electrical current each one produces (3 marks) • High tension wiring • Distributor cap • Low voltageAGRICULTURAL ENGINEERING CONFIDENTIAL
  18. 18. Marzuqi Salleh, UiTM Perlis • High voltage • Primary currentWhat is the major function of battery charging circuit (2 marks) • Receives and stores electrical charge that enters into it and supplies the electrical charge to other electrical devices.List 4 component involve in the battery charging circuit. (4 marks) • Battery • Regulator • Dynamo • Ampere MeterExplain the operation of the cranking or starting circuit. You are to list down the four basic partsof starting circuit. (10 marks)Battery - supply energy to the circuit.Starter switch - activate the circuit.Motor switch - engages the motor drive with the engine flywheel.Starting motor - drives the flywheel to start the engine, As soon as the engine starts, the starting motor disengages. It is designed to handle heavy loadsfor short periods of time only.What device is used to make starting easier in a magneto ignition system? (2 marks)Starting motor • Drives the flywheel to start the engine. As soon as the engine starts, the starting motor disengages. It is designed to handle heavy loads for short periods of time only.What is the difference between a dynamo and alternator? Explain their principles of operation. (4 marks) Dynamo Alternator- driven by the engine by the transmission belt - charge the battery and produce charging.and it supplies direct current to the battery.List three basic function of a regulator in the charging circuit. (3 marks)AGRICULTURAL ENGINEERING CONFIDENTIAL
  19. 19. Marzuqi Salleh, UiTM Perlis • Closes the circuit when engine is running & open the circuit when the engine is stopped. • Prevents overcharging the batter. • Prevent high flow of current through the system that could damage other components.Stage three major function of ignition distributor in the engine ignition system (3 marks) • To have available, at the proper spark plug • Enough voltage to cause a spark to jump the spark-plug gap for ignition of the fuel-air mixture in the cylinder.Name five (5) agricultural implements that are powered by the tractors PTO system and nameanother five (5) secondary tillage implements that are not PTO driven. (10 marks) PTO system not PTO driven • Slasher • Harrow • Rotovator • Fine spring time • Auger • Ridger • Boom sprayer • Spring fine cultivator • Bailer • Mulcher • Shredder • LevelerWhat is the differential lock and how does it work? • To break the differential component in transmission system • Both wheels are in same speed to make a corner. • Used it to down moth and wheel are embed • For factor that in roodGive 4 major component of power transmission system in an agricultural tractor • Clutch • Gearbox system • Differential • Final drive • Drive wheelsBriefly discuss the basic construction and operation of the PTO in a tractor. (4 marks)AGRICULTURAL ENGINEERING CONFIDENTIAL
  20. 20. Marzuqi Salleh, UiTM Perlis• Is an attachment in the power train of a machine, it drives auxiliary equipment.• Normally gear driven from the transmission and send power through a shaft to the PTO outlet where the driven equipment is coupled.• Drive equipment at standard speed of 540 – 1000 rpm.• Operated by a clutch release, which is sometimes part of the main engine clutch.Name 3 types of PTO system and function in how the clutch system operation • PTO, normal type - PTO takes its rotation from the engine through the same clutch as the gearbox therefore engaging the clutch starts both the tractor and the PTO. • PTO, live type - Clutch of the dual plate type controlled progressively by a pedal. • PTO, fully independent - Tractor provided with 2 clutches, one for gearbox and the other for PTO.List the four function of transmission system for a farm tractor (2 marks) • To connect and disconnect power • Select speed ratios • Provide a means of reversing • Equalizes power to the drive wheels for turningIn the term tractor hydraulic system, write short note regarding function and operation of thefollowing components: • Tree-point linkage -used for hitching mounted and semi mounted implement. It consists of one top link. • Position control system -in the hydraulic control of an attached and allow the operation to pre select and to position the implement as determined by the position of hand control levels. • Automatic draft control system -will automatically raise or lower an implement as the draft or resistance of the attached implement increase/decrease. -the position of the hand control level, effect established the draft to mount.Name the two basic types of hydraulic system (2 marks) • Open-center system • Closes-center systemAGRICULTURAL ENGINEERING CONFIDENTIAL
  21. 21. Marzuqi Salleh, UiTM PerlisExplain the six (6) advantages and two (2) disadvantages of hydraulic system. (16 marks) advantages of hydraulic system disadvantages of hydraulic systemFlexibility: power can remove to any location Efficiency: mechanical system is better than hydraulic systemSimplest the system Need for cleanlinessCompactness Need more maintenanceSafetyEconomyDescribe how the basic hydraulic system operates in a tractor. (4 marks)The basic hydraulic system has two components, namely the pump which moves the oil and thecylinder which uses the moving oil to do workExplain the difference between broadcast and full width fertilizer distributors. Name four (4)types of broadcast distributor. (6 marks) broadcast full width fertilizer distributors • These have a hopper for the fertilizer • Other type of fertilizer distributor with a spreading mechanism • Unlike broadcasters, this type of • The drive is usually from the PTO but distributor is almost as wide as the some machines have hydraulic motor spreading width when it is in work drive • 2 types of full width distributor: 1 has • Most broadcasters are mounted but mechanical feed, the other is the largest capacity models are trailed pneumatic • Either a spinning disc or oscillating spout is used to distribute the fertilizerTypes of broadcast distributor: • Spinning disc • Mounted machines • Pendulum or oscillating spoutProper mounting procedures have to be followed if the plough is to work efficiently. List downthe steps in the mounting procedures (10 marks) • The support wheels and accompanying frame structure required on pull-type implement ere eliminated, and a single depth or height control system, which is part of the tractor, serves for all or most of the mounted and semi-mounted implement used with any one tractor.AGRICULTURAL ENGINEERING CONFIDENTIAL
  22. 22. Marzuqi Salleh, UiTM Perlis • Maneuverability, visibility, ease of transport, and the advantage gained by draft sensing and weight transfer through the tractor’s control system make mounted implements popular standardization of the three-point hitch and quick-attaching couplers, to permit interchangeable use of different makes of equipment, has made attaching and detaching of mounted and semi-mounted implements a simple and easy operation. • The physical size and weight of equipment that can be mounted on the rear of a tractor and fully supported by it are limited by the carrying capacity of the tractor chassis and by the transport stability limitations of the combination. • Semi-mounting, in which the tractor carries only part of the weight, overcome these limitations and stills the advantage of maneuverability, lower investment cost and the ability to utilize the tractor’s draft-sensing system. • Semi-mounting, in preference to full mounting, is particularly appropriate for moldboard plows having more than 4 or 5 bottoms, because their weight and great length would produce an excessive moment on the tractor, thus causing instability during transport.There are basically four (4) general types of field implements based upon their relation to thepower unit. Briefly discuss each of these types of field implements. (10 marks) 1. Pull-type or trailed implements • Is one that is pulled and guided from a single hitch point and is never completely supported by the tractor. 2. Mounted implements • Is one that is attached through a hitch linkage in such a manner that it is completely supported by the tractor when in raised it position. 3. Semi-mounted implements • Is attached to the tractor through a horizontal or nearly horizontal hinge axis and is partially supported by the tractor, at least during transport, but is never completely supported by the tractor. 4. Self-propelled machine • In comparison with pull-type units, self –propelled machines tend to provide more flexibility and better maneuverability, better visibility and control by the operator andAGRICULTURAL ENGINEERING CONFIDENTIAL
  23. 23. Marzuqi Salleh, UiTM Perlis improved with field harvesting equipment, field operating losses are minimized because the cutting or gathering unit is across the front of the machine rather than projecting to one side.Name six types of soil tillage implements (3 marks) • Mouldbord • Disc plough • Sub soilers • Rotovator • Harrow • RidgerList 4 different types of implements for crop planting or seeding operation (4 marks) • Disc plough • Chisel plough • Sub soilers • Rotary tillersName four different implement for dry mineral fertilizer applications (4 marks) • Spinning disc • Mounted machine • Pendulum or oscillating spout • Mechanical feed • pneumaticWith the aid of a diagram, list the eight (8) major components of the mold board plow andexplain the function of each component. (10 marks) • The crass shalf -a still shalf to which the beam DF individual plow are mounted • The beam -on which the pull of the tractor is exerted and to which is mounted the leg and courter • The frog -which is mounted the share mould board and the landslide • The courter -which is mounted on the beam ahead of the plow body. It makes a vertical cut into the soil as the plow is drawn through the soilAGRICULTURAL ENGINEERING CONFIDENTIAL
  24. 24. Marzuqi Salleh, UiTM Perlis • The leg -which is mounted the shared, mould board and the landslide • The share -which is mounted in front of the flog and which act to make a horizontal run into the soil • The mould board -which acts to rats, overturn and bleak up the furrow slice the has been cut • The landslide -a flat rectangular pieces of metal which act to make on the side thrust on the plow as it is drawn through the soilWhat is tillage? (2 marks) • The mechanical modification of soil structure to make it suitable for seed germination and growth.What is the purpose of tillage? (6 marks) • To get suitable medium for seed germination and rood growth by loosing up the soil structure • To improve soil aeration and water absorption • To destroy weed • Plant residue • To control insect pest & diseases • To control soil moisture levelsWhy is secondary tillage necessary for seedbed preparation and plant growth? Explain five (5)benefits that can be achieved from this operation. (5 marks)Why is Secondary tillage? • The large soil clods resulting from primary tillage are not suitable for seed germination and plant growth. • To improve the rood penetration • Give opportunity to seed emergenceBenefits: • High whc • Destroy pest and disease • Destroy weed and grass • Improve soil fertility • Break down the bigger part of soil into the small part • Prevent soil erosionAGRICULTURAL ENGINEERING CONFIDENTIAL
  25. 25. Marzuqi Salleh, UiTM PerlisCompare and contrast primary and secondary tillage. List three implements that are used forprimary and secondary tillage. (5 marks) Primary tillage Secondary tillage • more aggressive, deeper operation and • works the soil to shallow depth usually • levels and firm the soil leaves the surface rough cut and • closes air pockets shatters soil • kill weeds and helps conserve moisture Implements: Implements: 1. Mouldboard and disc plough 1. Disc, spring tooth and spike tooth harrow 2. Chisel plough 2. Spring and rigid tined cultivators 3. Sub soilers 3. Ridgers, bedders or listers 4. Rotary tillers or cultivators 4. Roller pockets and roller harrows 5. Weed control implementWhat are the constructional features required if you are to design a general purpose seed drill?List the components and explain the function of those components. Explain how the seedingrate of the above seed drill is calibrated. (10 marks) = 10,000/N x C x W = kg/haConstruction of major components of Seed Drill: • Full width seed box to hold seeds • Furrow opener- to cut open a shallow furrow into which seeds are to be placed. • A metering device or feeding mechanism- meter out the correct amount of seeds for each row. • A seed hopper- to deliver seeds from feeding mechanism and drop into the furrow of each row. • A pair of land wheels - support the planter and to drive the feeding mechanismAGRICULTURAL ENGINEERING CONFIDENTIAL
  26. 26. Marzuqi Salleh, UiTM PerlisName four kind of seed drills (4marks) • Row crop planter-trailing drill • Front tractor mounted • Rear tractor mounted • Broadcast cop plantersWhy do we need irrigation agriculture activities? (4 marks) • Increasing demands of water • Limited availability • Costing • To provide water for plant growth • To obtain optimum yieldWhat is irrigation? • Not much new land waiting to be opened up for agriculture. The main increase in food supplies has to come from making better use of land already farmed • More efficient crop production will help e.g. better varieties, more use of fertilizer, mechanization, etc. but rainfall is still a limiting factor for a very large proportion of the earth’s surface and so irrigation is important in increasing production • With irrigation, crop yields may be made more reliable, or two crop a year may be possible instead of oneList the advantages of irrigation system. (4 marks) • To supply moisture which allows plant growth where there was none before, or to get better growth, or to extend the growing season • An insurance against drought • To allow the movement of plant nutrients. The chemicals for plant growth are absorbed by the plant in solutions • To leach undesirable salts, that is to wash them out in solution • To control the environment for growing plants. E.g. prevent frosts, to keep plant cool or to keep them moistTypes of irrigation method: • Subirrigation • Surface irrigation • Sprinkler irrigation • MicroirrigationAGRICULTURAL ENGINEERING CONFIDENTIAL
  27. 27. Marzuqi Salleh, UiTM PerlisGive 2 basic types of spray liquid chemical applications (2 marks) • Reaction rotation sprinkler • Fixed head sprays • Perforated pipe • Slow rotation sprinkler or Rain gunExplain three (3) factors that can influence the application rate of ground crop sprayers. (6marks) • Tractor forward speed A low forward speed gives a high application rate. By changing gear to double the forward, the application rate will be halved. • Spraying pressure Higher application rate are obtained by adjusting the relief valve control to increase working pressure. High pressure reduces droplet size and increases the risk of the chemical being blown away by the wind (drift) • Nozzle size Nozzles with a large hole will give a high applicationIn an ideal cycle of four stroke petrol engine, the valves open and close exactly at Top DeadCenter (TDC) and Bottom Dead Center (BDC). But in actual working condition, the valves openand close before or after the piston reaches the TDC or BDC. Explain in detail the reason why:(i) The intake valve opens 15° of crankshaft rotation before TDC on the exhaust stroke, • To allow more FAM to enter into the combustion explanted(ii) The exhaust valve opens 50° before the piston reach BDC. (4 marks) • To allow for smoke from combustion to flow out early and thus make an empty space for the FAM to fill upIn order to ensure the maximum life of an engine, it must be maintained regularly. Answerfollowing questions regarding engine maintenance.AGRICULTURAL ENGINEERING CONFIDENTIAL
  28. 28. Marzuqi Salleh, UiTM Perlisa) What is the tool use to set the clearance between the valve tip and rocker arm duringmaintenance of the valves? • Feeler gauge or micrometer or hole pageb) What must be done if the petrol engine runs too fast at idling? • Adjust the timing by screwing up or down the choke valvec) What must be done if one of the cylinders does not produce spark during the power stroke? • Change the spark plug or check the electrical circuit systemd) What are some basic maintenance that should be carried out at every 50 working hours oftractor? • Change oil, oil and fuel filter, clean up the air filter and clean the engine from debris/dirte) What type of lubrication oil is used inside the engine body in our country? • SAE 30, SAE 30w or SAE 30-50f) Which piston ring must be replaced if the black smoke from exhaust pipe is too thick? • Middle ringg) What may possibly prevent the engine from starting although it can be cranked at normalspeed at starting? • Ignition system defectiveh) What may cause the engine to overheat faster than usual during normal engine operation? • Late ignition timingi) What may cause exhaust smoke to turn blue? • Excessive oil consumptionj) What may happen if the regulator is removed from the circuit leaving the alternator to bedirectly connected to the other electrical devices? (10 marks) • Electrical devices may damage because of high current flow intoFor engine to operate, a definite of events must occur in sequence. List the four events insequence (4 marks) • Fill cylinder with combustible mixture • Compress mixture into smaller space • Invite mixture- causing it to expand and produce powerAGRICULTURAL ENGINEERING CONFIDENTIAL
  29. 29. Marzuqi Salleh, UiTM Perlis • Remove burned gasses from the cylinderWhat does it mean to ‘bleed’ the fuel line and when must this be done? (3 marks) • Removed air tube • When the diesel tank is empty and the engine tractor stopTractor has been referred to be a central power station in order to provide power for manyoperations or activities during mobile or stationary operations. List five (5) major functions ofsome of the power outlets in a tractor and examples of the equipments that use each of thoseoutlets. (10 marks) • To provide easy and accurate control of the equipment from the tractor drive’s seat • To provide electric starting, light and light-signalling • Have rapidly become common place include such item as multi-speed gear-boxes, live power take-off, differential lock, power steering and various devices for transferring weightWhat are the factors that may affect the field efficiency? Or list five (5) factors that can affectthe field efficiency. (5 marks) • Not using the full capacity of the tractor • Refilling procedures • Transporting procedures • Repairing of machine in the field • Irregular resting hours • Cleanliness of implements • Rest of operation • Adjustment of implementWhat other alternatives that can be used to reduce the seeding rate? (2 marks) • Treatment the seeds • Apply good distance • The best practice for plantingWhat are the factors that will result in the increase of the horsepower required for the samesize machine? (3 marks) • Moving the tractor over the ground • Pulling the implement over the ground • Powering the implement for useful workAGRICULTURAL ENGINEERING CONFIDENTIAL