| Monday, 04.29.2024, 5:01 PM Welcome Guest | ||||||||||
My site |
 |
|||||||||
| Home | Sign Up | Log In | RSS | ||||||||||
|
ENGINE
General arrangement and working cycle of the engine the internal combustion engine. The order of work the cylinders of the engine On cars set the engines internal combustion, which uses a pressure increaser- Xia gases generated by the combustion of fuel direct- but in the cylinder. However, it should be noted that in fact burnt working mixture consisting of the combustible mixture and OS- other defects of the exhaust gases of the previous working cycle. The method of formation of the combustible mixture (fuel vapor and air) and type of fuel used, the engines are distinguished: • with an external carburetion (carburetor, work melting on gasoline, and gas mixing, working on fuel gas); • with internal mixture formation (petrol, work- existing diesel fuel). The ignition of the working mixture by using electrical discharge or high compression ratio (diesel different engines). As a result of combustion of the working mixture way- present gases pressure on the piston, giving it straight movement, which with the help of connecting rod and crankshaft is converted into a rotary motion of the flywheel. To to keep the engine running, you should periodically eyes- should the combustion chamber of the cylinder from exhaust gases and perform it with fresh charge of the combustible mixture, which is maintained by- is with the exhaust and intake valves. The piston moving in the cylinder, makes a return- but-translational motion. End position, in which the piston changes its direction of motion, respectively- are called upper and lower dead points (TDC and BDC). The distance traveled by the piston between TDC and BDC, is called a stroke. The process occurring in the cylinder- Dre at one stroke, called stroke. The space in the cylinder vacated by the piston in it moves from TDC to BDC is called displacement volume reception of the cylinder. The smallest space in the cylinder processing ized when the piston is at TDC and is called volume reception of the combustion chamber. Stroke volume the volume of the combustion chamber constitute the entire volume of the cylinder. Sum- mA all of the working volume of the cylinder is called the displacement of the engine and is expressed in cubic centimeters. The the decision of the full volume of the cylinder to the volume of the combustion chamber is called the degree of compression, which is important indicator of the engine. With increasing degree of compression in lishaetsya efficiency and engine power. To perform a basic cycle in which occurs the combustion of the working mixture and expansion of gases, non- necessary to perform preparatory cycles: inlet sorrow- whose mixture, compression, and final — edition exhaust gases. Thus, continuous operation of the engine DOS thetsa by a set of periodically recurring in qi the eration processes — cycles, combining in a work cycle. Since the duty cycle is performed in four stroke of the piston, automotive engines are called four-stroke. The sequence of alternation of cycles in the working CEC lah engines with external mixture formation is the same as and in a diesel engine. The only difference is in compression ratio and SPO- the mode of ignition of the working mixture. Intake — the piston moves from TDC to BDC. Open vpus- know valve. Due to the increased volume inside the cylinder is the DRA creates negative pressure and fills the cylinder- RA fresh charge of the combustible mixture. Compression — the piston moves from BDC to TDC. Intake and exhaust valves are closed. The volume above the piston is reduced- decreases. The fuel mixture is compressed, whereby improved by evaporation and mixing of fuel vapour with air, Working stroke (combustion and expansion) — is re- plamennie the working mixture from the electric discharge in DWI gateleg with external mixture formation or due to you- high compression ratio in diesel engines. Under the pressure of the expanding gases, the piston moves from TDC to BDC. The intake and exhaust valves are closed. You high pressure gases, their temperature reaches 9000°C. Release — the piston moves from BDC to TDC. Open exhaust valve. The displacement of the exhaust gases from the combustion chamber of the cylinder. To ensure the normal operation of the engine the internal it combustion has the following mechanisms and systems: • crank mechanism; • gas-distributing mechanism; • the cooling system; • lubrication system; • power supply system; • ignition system |
|||||||||