The principle of operation of the petrol power unit is as follows: the small volume of fuel mix comes to the combustion chamber, there is its ignition and explosion as a result of which a certain energy is released. In the internal combustion engine of such explosions occurs several hundred in a minute.
The gas extending in the combustion chamber presses on the piston (M) which by means of the connecting rod (N) rotates the crankshaft (P).
The cycle of operation of the petrol engine consists of the following stages:
• Inlet clock period. At this moment the movement of the piston begins down, there is an opening of the inlet valve. Fuel-air mix comes to a cylinder.
• Compression. The piston begins to move up, thereby compresses mix in cylinders that is necessary for selection of bigger energy at the subsequent explosion.
• Working clock period. When the piston rises to upper dead point in a cylinder, the spark plug gets into gear and sets fire to fuel mix. After explosion the piston moves already down.
• Final clock period. After achievement opening of the final valve via which combustion products also leave the camera happens the piston of an extreme lower point.
After an exit of combustion products the new cycle of work of internal combustion engine begins.
Result of operation of the power unit – receiving rotational motion which optimum is suitable for a pro-collar of wheels of the machine. It is reached due to use of a bent shaft which will transform linear energy to rotation.
Device and main details of petrol internal combustion engine
Cylinder – the most important part of the petrol motor in which there is a movement of the piston caused by explosion of fuel mix. In the example described above it is about one cylinder. Such device can have the engine of the motor boat or mowing machines. In motors of cars of cylinders it is more – three, four, five, six, eight, twelve and more.
The arrangement of cylinders in internal combustion engine can be the following:
- opposite (cylinders horizontally are located the friend opposite to the friend):
Each arrangement of cylinders has the pluses and minuses of which there are characteristics of these or those engines and costs of their production.
Bucket (M). This detail is executed in the form of metal cylinder, moves in cylinder already of the engine up-down.
Valves. Can be inlet (A) and final (J). They open in various timing periods of operation of the engine. Through inlet the fuel-air mixture moves, through final there are exhaust gases. At the moments of compression and combustion of fuel all valves are closed.
Spark plugs (K). With their help the spark which is necessary for fuel ignition moves. The correct operation of the engine means the exact moment of giving of spark (advanced or delayed ignition – failures). At least one candle is the share of each cylinder of the engine.
Piston rings (M). Are sliding seal between the bucket and wall of cylinder.
With their help the following functions are performed:
• the fuel-air mixture does not get from combustion chamber into crankcase in operating time of internal combustion engine;
• interfere with penetration of engine oil from crankcase in combustion chambers.
In the cars suffering from the increased oil consumption, its waste in 90% of cases happens because of wear of piston rings. To understand that rings are worn-out it is possible замеряв engine compression on HUNDRED. But, it is worth understanding that in case of zakoksovka of oil-control rings compression rings can be as it should be, so – and the compression will be normal though it is already time to change rings.
Bent shaft (P). With its help progress of buckets will be transformed to rotary motion. To the crankshaft the flywheel which is necessary for starting engine operation fastens – бендикс the starter the teeths rotates his wreath. To flywheel also the clutch basket fastens. On other end of bent shaft there is pulley. The pulley rotates GRM drive gear by means of the belt or chain drive. Some designs of engines have additional pulleys which are used for rotation of the hinged equipment.
Crankcase (G). In it there is crankshaft and quantity of engine oil.
Connecting rod (N). Serves for joint among themselves of the crankshaft and the bucket.
Cam shaft (I). Its task consists in timely opening and closing of outlet and inlet valves.
Hydraulic compensator bars (on the scheme are not designated). Are applied not on all motors, serve for automatic adjustment of spacing between cam shaft and valves. In case of their absence, the spacing is regulated by means of special hollow disks, and it is necessary to carry out this procedure on HUNDRED on certain run of the engine.
Cylinder block (F). The most most part of the engine, its basis. Can be both pig-iron, and aluminum. The top part of the block contains head (D) and valve cap (B). Working bores of the block it are also engine cylinders.
On the above-stated scheme it is not designated, but it is worth describing it slightly in more detail. All hinged equipment consists of separate independent devices or elements of various systems. It, first of all:
Generator. Serves for transformation of mechanical energy into electric, necessary for food of onboard network of the car and charging of joint stock bank. The started car feeds the electronics from the generator.
Starter. Start-up the car is carried out with its help.
Injector or carburetor. These devices serve for preparation of fuel-air mixture. The carburetor is not used on rather new cars any more. Now producers use fuel stage with spray jets and injector.
TNVD. The fuel pump of high pressure is used also on some gasoline engines. Its task – to force certain fuel quantity under pressure and to regulate the moment and the number of its giving.
Turbocompressor (turbine). Carries out compulsory air supply in cylinders, than increases its power.
Water pump (pomp) of the cooling system. Is responsible for circulation of antifreeze on system. It should be noted also the thermostatically controlled chamber of the cooling system which starts up antifreeze on small or big circle (depending on extent of heating of OZh).
Air conditioner compressor. Is responsible for circulation of coolant in air conditioning system.
Pump GUR (steering booster). Moves GUR liquid on the system of steering.
Various sensors, adjusters and devices. Oil pressure sensors, mass flow of air (DMRV), AIR (adjuster of idle running), provisions of throttle valve, throttle valve, DPKV (crankshaft position sensor), DPRV (camshaft position sensor), etc. The above-stated devices control operation of the power unit, adjust air supply, transfer information to various EBU and meter panel.
Classification of petrol internal combustion engine
Except the above-stated classification of gasoline automobile engines by arrangement of cylinders they can differ also on:
• To smeseobrazovaniye mode (injector and carburetor).
• By quantity of cylinders (four, eight, etc.).
• On compression ratio (high or low degree).
• With turbo-supercharging and without forced aspiration.
• Rotor engines. Have not gained distribution, are used on single models of car (for example, the RX series Mazda cars).
About kinds of configurations of engines it is possible to learn HERE.
Life cycle and major repair of petrol motors
Most often these ask question the motorists buying the car in the secondary market. Nobody wants “to get” on fast overhaul or at all on replacement of the motor in the near future. So what resource of modern petrol internal combustion engine?
Still very famous many motorists information on old superreliable import engines (“million plus cities”) which can easily depart before major repair of 300-500 thousand km, and after it – as much again.
Now the situation in root has exchanged. Modern producers (especially budgetary cars) do not set as the purpose of the maximum increase in resource of the engine of the produced models. And the price of cars with such power units would leave “budgetary” category.
Besides, many inexpensive internal combustion engine have no repair spare parts, so capital of repair with boring of cylinders, etc. it is not possible to carry out by grinding work of the head.
The resource of modern gasoline engines is 150-300 thousand then some of them can be “kapitalit”, and some should at all – be changed.
Not the last influence renders quality of maintenance operation and style of driving of this or that driver on period of operation of internal combustion engine (someone likes to twist the cold motor to cut-off, someone long heats the engine on single turns that also harmfully, etc.).
The current trend of increase in engine power without change of its volume has led to use of turbo-supercharging. The small easy engine with turbocharger works constantly with the raised loading that promotes its fast wear. It is worth understanding that other things being equal the resource of atmospheric internal combustion engine is higher, than at same, but with the turbine. Rotor engines serve only 80-120 thousand km at all. One can be told precisely – the less “horses” are removed from cubic cm of the motor, the more its resource.