Benzinski motor
Benzinski motor (benzinski motor) je motor koji koristi benzin kao gorivo. Kako je benzin niske viskoznosti i brzo isparava, sustav za ubrizgavanje benzina može se koristiti za ubrizgavanje benzina u cilindar. Nakon što kompresija dosegne određenu temperaturu i tlak, pali se svjećicom kako bi se plin proširio i izvršio rad. Benzinski motori karakteriziraju velika brzina, jednostavna struktura, mala težina, niska cijena, stabilan rad te praktična uporaba i održavanje. Benzinski motori su naširoko koristili u automobilima, posebno malim automobilima, i nisu opali.
Prema različitim metodama opskrbe gorivom, benzinski motori se mogu podijeliti u dvije kategorije: tip rasplinjača i tip ubrizgavanja (ili elektroničko ubrizgavanje). Karburatori se obično nalaze na motorima starijih modela, a većina motora sada koristi dovod mlaznog goriva. U benzinskom motoru s ubrizgavanjem, benzin se može ubrizgati na usisni otvor ili izravno u cilindar tijekom usisnog takta; proces ubrizgavanja goriva može se kontrolirati računalnim programom, a gorivo se može ravnomjernije rasporediti na svaki cilindar; u isto vrijeme, jer nema potrebe. Cijev za grlo smanjuje otpor tvorničkog usisnog zraka itd., što može povećati prosječni efektivni tlak i toplinsku učinkovitost u cilindru; osim toga, također može oslabiti ili izbjeći kucanje izgaranja.
U usporedbi s dizelskim motorima, benzinski motori imaju nižu toplinsku učinkovitost od dizel motora i veću potrošnju goriva. Sustav paljenja je složeniji od dizel motora, a pouzdanost i praktičnost održavanja nisu tako dobri kao dizelski motori.
Motori automobila (koji se odnose na klipne motore s unutarnjim izgaranjem) podijeljeni su u sljedeće kategorije prema različitim karakteristikama:
● Classified by piston movement mode: Piston type internal combustion engines can be divided into reciprocating piston type and rotary piston type. The former piston makes a reciprocating linear movement in the cylinder, and the latter piston makes a rotary movement in the cylinder. (The latter applies to rotary engines)
● According to the classification of the intake system: internal combustion engines can be divided into naturally aspirated (non-supercharged) engines and forced intake (supercharged) engines according to whether the intake system adopts supercharging. If the intake is close to the atmosphere, it is a non-supercharged internal combustion engine or a naturally aspirated internal combustion engine; if the intake pressure is increased by a supercharger, and the intake density increases, it is a supercharged internal combustion engine. Supercharging can increase the power of the internal combustion engine.
● Classification according to cylinder arrangement: internal combustion engines can be divided into single row, double row and three row according to different cylinder arrangements. Each cylinder of a single-row engine is arranged in a row, which is generally arranged vertically. However, in order to reduce the height, the cylinders are sometimes arranged to be inclined or even horizontal. A dual-row engine arranges cylinders into two rows. The angle between the two rows is less than 180 degree (generally 90 degree ), which is called a V-type engine. If the angle between the two rows is 180 degree , it is called an opposed engine. The three-row type arranges the cylinders into three rows to become a W-type engine.
● Classification according to the number of cylinders: Internal combustion engines can be divided into single-cylinder engines and multi-cylinder engines according to the number of cylinders. An engine with only one cylinder is called a single-cylinder engine; an engine with more than two cylinders is called a multi-cylinder engine. For example, two-cylinder, three-cylinder, four-cylinder, five-cylinder, six-cylinder, eight-cylinder, twelve-cylinder, sixteen-cylinder, etc. are all multi-cylinder engines. Modern vehicle engines mostly use three-cylinder, four-cylinder, six-cylinder, and eight-cylinder engines.
● Classification by cooling method: Internal combustion engines can be divided into water-cooled engines and air-cooled engines according to different cooling methods. The water-cooled engine uses the coolant circulating in the cylinder block and cylinder head cooling water jacket as the cooling medium for cooling; while the air-cooled engine uses the air flowing between the cylinder block and the fins on the outer surface of the cylinder head as the cooling medium Cooled. The water-cooled engine has uniform cooling, reliable operation and good cooling effect, and is widely used in modern vehicle engines.
● Classification according to stroke: Internal combustion engines can be divided into four-stroke internal combustion engines and two-stroke internal combustion engines according to the number of strokes required to complete a working cycle. Turn the crankshaft two revolutions (720 degree ) and the piston reciprocates up and down in the cylinder for four strokes. The internal combustion engine that completes a working cycle is called a four-stroke internal combustion engine; while the crankshaft rotates one revolution (360 degree ), the piston reciprocates up and down in the cylinder An internal combustion engine that moves two strokes and completes a working cycle is called a two-stroke internal combustion engine. Four-stroke internal combustion engines are widely used in automobile engines.
● Classified by valve mechanism: side valve (SV) engine, side camshaft (OHV) engine, overhead camshaft (OHC) engine, variable gas (VTEC) engine and Desmo valve mechanism engine.
● Classified by fuel supply mode: carburetor engine, electronic injection engine, direct injection engine.
● Classification according to the fuel used: Internal combustion engines can be divided into gasoline engines and diesel engines according to the different fuels used. An internal combustion engine that uses gasoline as fuel is called a gasoline engine; an internal combustion engine that uses diesel as a fuel is called a diesel engine. Compared with diesel engines, gasoline engines have their own characteristics; gasoline engines have high speed, low quality, low noise, easy starting, and low manufacturing costs; diesel engines have large compression ratios, high thermal efficiency, economic performance and emission performance than gasoline engines. At present, it is the most widely used and the most numerous The engine is a water-cooled, four-stroke reciprocating piston internal combustion engine. Gasoline engines are used in cars, light buses and trucks, while the engines of buses, medium and heavy trucks are mostly diesel engines. A few cars and light passenger and truck engines also use diesel engines.
Dizelski motori
Dizelski motor je motor koji sagorijeva dizelsko ulje kako bi dobio energiju i oslobodio je. Izumio ga je njemački izumitelj Rudolf Diesel 1892. U spomen na ovog izumitelja, dizel je predstavljen njegovim prezimenom Diesel, a dizel motori se nazivaju i Diesel motori.
Prednosti dizel motora su velika snaga i dobre ekonomske performanse. Radni proces dizel motora je isti kao i kod benzinskog motora. Svaki radni ciklus također prolazi kroz četiri takta: usisni, kompresijski, radni i ispušni. Međutim, budući da je gorivo koje se koristi u dizel motorima dizel, njegov je viskozitet veći od benzina, te ga nije lako ispariti, a temperatura spontanog izgaranja niža je od benzina. Stoga se stvaranje i paljenje zapaljive smjese razlikuju od benzinskih motora. Glavna razlika je u tome što se smjesa u cilindru dizelskog motora kompresijski-zapaljuje, a ne pali. Kada dizel motor radi, zrak ulazi u cilindar. Kada se zrak u cilindru stisne do kraja, temperatura može doseći 500-700 stupnjeva, a tlak 40-50 atmosfera. Kada je klip blizu gornje mrtve točke, visokotlačna-pumpa na motoru ubrizgava dizel u cilindar pod visokim tlakom. Dizel stvara fine čestice ulja koje se miješaju sa zrakom pod visokim pritiskom i visokom temperaturom. U ovom trenutku temperatura može doseći 1900-2000 stupnjeva, tlak može doseći 60-100 atmosfera, a generirana snaga je vrlo velika, tako da se dizelski motori naširoko koriste u velikim dizelskim vozilima.
The advantages of diesel engines in terms of energy saving and carbon dioxide emissions cannot be replaced by all heat engines, including gasoline engines. Therefore, advanced small high-speed diesel engines, whose emissions have reached the European III standard, have become "green engines." , Has now become the power plant of many new cars in Europe and America.