Engineer World

 What is the objective? To achieve zero inventory in APTICS dictionary. JIT is defined as," A philosophy of manufacturing based on elimination of all waste and continuous improvement of productivity." APICS-         " American production of inventory control and society" JIT is also defined as an approach with objective of producing a right part in right time  at right place. JIT was developed by TOYOTA in 1950.(1950-1970). 1980 - GEC ( General electric company ) Country -USA OTHER NAMES OF JIT- Toyota production system Lean production Stockless production Elements of JIT- Stabilize and level the MPS with uniform plant loading (Heijunka). Reduce set up time(Ex- Nascar pit screw) Reduce lot size Preventive maintenance  Reduce lead time Flexible workplace-Respect for people Require supplier quality assurance and implement a zero defect quality program (JIDOKA) QAT - Quality at Source M.P.S. - Master Production System Advantage of JIT-  Less inventory Minimum was

  Contents of Exhaust gas: The largest part of most combustion gas is Nitrogen (N2 ),  Water vapor (H2O) and  Carbon-dioxide (CO2 ) these are not toxic A relatively small part of combustion gas is toxic substances , such as  Carbon Monoxide (CO) from incomplete combustion,  Hydrocarbon (HC) from un-burnt fuel,  Nitrogen Oxide (NOx ) from excessive combustion temperatures  Particulate matter (PM).  Treatment of Exhaust gas: The Exhaust gas has more pollutant so that it should be reduced to prevent the pollution form the exhaust gas There are some treatment carried out for Exhaust gases are below      Exhaust Gas Recirculation(EGR) Selective Catalytic Reduction(SCR) Exhaust gas Recirculation(EGR) :  The diesel engines to run more efficiently cause them to run at higher temperature this leads to the creation of Nitrogen Oxides (NOx). The Combination of Nitrogen and Oxygen in the air to form Nitrogen Oxide . In order to reduce NOx an engine should run at a lower temperat

 The commonly occurring troubles in the lubricating system are unduly low or excessively high oil pressures. Low oil pressure Low oil level, which may be checked by the dipstick. Fill till the correct level or to Crankcase. The oil may have been diluted with constant use, which has to be changed. High oil pressure The oil used may be of too high a viscosity, which may be drained out and the oil with correct viscosity filled in. The oil lines, galleries may be clogged, which may be cleaned. Oil pressure gauge may be defective which may be inspected and repaired. Grades of Engine oil: The Society of Automotive Engineers (SAE) developed a scale for both engine (motor oil grades) and transmission oils. Viscosity is notated using the common classification “XW-XX”. The number preceding the “W” (winter) rates the oil’s flow (viscosity) at zero degrees Fahrenheit (-17.8 degrees Celsius). The lower the number, the less the oil thickens in cold weather.  The numbers “XX” indica

The moving parts of an I.C engine are likely to wear off due to continuous rubbing action of one part with another. In order to avoid an early wearing of the engine parts, a proper lubrication arrangement is provided in I.C. engines. Lubrication is an art of admitting a lubricant (oil, grease, etc.) between two surfaces that are in contact and in relative motion The main parts of an automotive engine require lubrication are: Main crankshaft bearings Big end bearings Gudgeon pin bearings  Piston rings and cylinder walls Camshaft and camshaft bearings Timing Gears Valve mechanism  Purpose of Lubrication: It reduces wear and tear of the moving parts. It damps down the vibrations of the engine. It dissipates the heat generated from the moving parts due to friction. It cleans the moving parts. It makes the piston gas-tight. Properties of Lubricant: Suitable viscosity Should not react with lubricating surfaces No tendency to form deposits by reacting with air, water, fuel or the

 Reasons to provide cooling system in engine: The even expansion of piston in the cylinder may result in seizure of the piston. High temperatures reduce strength of piston and cylinder liner. Overheated cylinder may lead to pre-ignition of charge, in case of SI engine. Physical and chemical changes may occur in lubricating oil which may case sticking of piston rings and excessive wear of cylinder. If the cylinder head temperature is high the volumetric efficiency and power output of engine reduces. Over cooling : Starting of engine becomes difficult. Engine life is reduced due to corrosion. Some of the heat which could be used to expand the gases will be lost. The fuel will not vaporize properly and some of the gases produced by combustion will condense on the cylinder walls. Inadequate lubrication of the engine, due to oil not being warm enough to flow freely.  Methods of Cooling: There are mainly following two methods/System of Cooling  Air Cooling Water/Liquid Cooling

Check the coolant level in your vehicle if it is overheating . If there is insufficient coolant in the vehicle, overheating will occur while driving. Add the appropriate amount of coolant to the coolant reservoir. Inspect your vehicle's thermostat to determine if it is stuck. If your thermostat is stuck, your vehicle will overheat almost immediately after driving a short distance. Another way to check the thermostat is to start the car, open the hood and feel the radiator hose. If the lower part of the radiator hose is hot and the upper part is cool, the thermostat is stuck.  Look at your fan belt to determine if it is broken or loose . Tighten the connections for the fan belt or replace it if necessary. Determine if the cooling system is clogged. Drain and flush the coolant from the cooling system to unclog it. Check the water pump to see if it is faulty and replace it if necessary *******Thanks*******