What are the systems that make up an automobile's electrical equipment?

Automobiles are generally composed of four basic parts: engine, chassis, body and electrical equipment. \x0d\\\x0d\\Automobile engine: the engine is the power unit of the car. By the body, crank connecting rod mechanism, gas distribution mechanism, cooling system, lubrication system, fuel system and ignition system (diesel engines do not have ignition system) and other components. According to the fuel points engine has gasoline and diesel engine two kinds; According to the way of working two-stroke and four-stroke two kinds, the general engine for the four-stroke engine. \x0d\\\\x0d\\ four-stroke engine work process: four-stroke engine is a piston reciprocating four strokes to complete a work cycle, including intake, compression, work, exhaust four processes. Four-stroke diesel engine and gasoline engine through the same process of intake, compression, work, exhaust. However, the difference with gasoline engine is: gasoline engine is ignition, diesel engine is compression ignition. \x0d\\\\x0d\\cooling system: generally consists of a water tank, water pump, radiator, fan, thermostat, water temperature gauge and drain switch. Automobile engines use two types of cooling, namely air cooling and water cooling. Generally automobile engines are mostly water-cooled. \x0d\\\\\x0d\\\lubrication system: the engine lubrication system consists of an oil pump, a collector filter, an oil filter, an oil channel, a pressure limiting valve, an oil gauge, a pressure sensing plug and a dipstick. \x0d\\\\\x0d\\fuel system: the gasoline engine fuel system consists of a gasoline tank, gasoline gauge, gasoline pipe, gasoline filter, gasoline pump, carburetor, air filter, intake and exhaust manifolds. \x0d\\\\\x0d\\carburetor: a device that mixes gasoline and air in a certain ratio into an atomized gas, which is called a combustible mixture, and is supplied into the cylinder in time and in the proper amount. \x0d\\\\\x0d\ chassis of the automobile: \x0d\ drive train: mainly composed of clutch, transmission, universal joints, drive shafts and drive axles. \x0d\ clutch: its role is to make the engine power and transmission smoothly engaged or temporarily separated, so as to facilitate the driver to carry out the car's starting, stopping, shifting gears and other operations. \x0d\ Transmission: It consists of transmission case, transmission cover, first shaft, second shaft, intermediate shaft, reverse gear shaft, gears, bearings, maneuvering mechanism and other machine parts, which is used to change the speed of the automobile and change the output torque. \x0d\ Driving system: consists of frame, axle, suspension and wheels. Its basic function is to support the full mass of the car and to ensure that the car is traveling. \x0d\ steel plate springs and shock absorbers: the role of steel plate springs is to make the frame and body and wheels or axles to maintain an elastic link between. The function of shock absorbers is to soften the vibration when the car is hit by vibration. Shock absorbers are used in parallel with leaf springs. \x0d\\ Steering: consists of steering wheel, steering gear, steering knuckle, steering knuckle arm, transverse tie-rod, straight tie-rod, etc. It serves to steer. \x0d\\\\x0d\\ front wheel alignment: in order to make the car to maintain a stable straight line driving, steering light, to reduce the wear and tear of the tires and steering components of the car in driving, the front wheels, steering main pin, the front axle installed between the three have a certain relative position, which is called "front wheel alignment". This is called "front wheel alignment". It includes the main pin tilt, the production pin tilt, and the front beam of the front wheels. The value of front beam refers to the difference between the distance between the front edges of the two front wheels, which is less than the distance between the rear edges. Braking system: the braking performance of a motor vehicle is the effectiveness of the vehicle to force a stop in the shortest possible time.? \x0d\ hand brake function: the hand brake is a device that keeps the car from skidding when parked, and in special cases, cooperates with the foot brake. \x0d\hydraulic brake structure: hydraulic brake device by the brake pedal, brake master pump, sub-pump, drum (wheel) brake and oil pipe and other components. \x0d\ pneumatic braking device: by the brake pedal, air compressor, air pressure gauge, brake valve, brake air chamber, drum (wheel) brake and air hose and other machine parts. \x0d\ electrical equipment: \x0d\ automobile electrical equipment mainly consists of batteries, generators, regulators, starter motors, ignition system, instruments, lighting devices, audio devices, windshield wipers and other components. \x0d\ battery: the role of the battery is to supply the starter motor with electricity, in the engine starting or low-speed operation to the engine ignition system and other electrical equipment power supply. When the generator generates enough power when the engine is running at high speed, the battery can store the excess power. Each single cell on the battery has positive and negative poles. The identification method is as follows: the positive post is engraved with a "+" sign, which is dark brown; the negative post is engraved with a "-" sign, which is light gray. \x0d\ starter: its role is to convert electrical energy into mechanical energy, drive the crankshaft rotation, start the engine. When the starter motor is used, it should be noted that each starting time shall not exceed 5 seconds, each use interval is not less than 10-15 seconds, and continuous use shall not exceed 3 times. If the continuous starting time is too long, it will cause a large amount of battery discharge and overheating and smoking of the starter coil, which is very easy to damage the parts. \x0d\2. Maximum gross mass?kg: the total mass of the car when fully loaded. \x0d\3. Maximum loaded mass?kg?: the maximum loaded mass of the car when it is traveling on the road. \x0d\4. Maximum axle load mass (kg): the maximum total mass carried by a single axle of the car. Related to road passability. \x0d\5. Vehicle length (mm): the distance between the two extreme points in the length direction of the vehicle. \x0d\6. Vehicle width?mm?: the distance between the two extreme points in the direction of the width of the vehicle. \x0d\7. Vehicle height?mm?: the distance between the highest point of the vehicle and the ground. \x0d\8. Wheelbase?mm?: the distance from the center of the front axle to the center of the rear axle of the car. \x0d\9. Wheelbase?mm?: the distance between the center lines of the tread of the left and right tires on the same axle. \x0d\10. Front overhang?mm?: the distance from the foremost end of the car to the center of the front axle. \x0d\11. Rear overhang?mm?: the distance from the last end of the car to the center of the rear axle. \x0d\12. Minimum Ground Clearance?mm?: the distance from the lowest point of the car to the ground when the car is fully loaded. \x0d\\\\x0d\\basic construction of automobiles\x0d\summary:Automobiles are generally composed of four basic parts: the engine, the chassis, the body and electrical equipment. Automobile engine: the engine is the power unit of the automobile. By the body, crank connecting rod mechanism, gas distribution mechanism, cooling system, lubrication system, fuel system and ignition system (diesel engine no ignition system) and other components. According to the fuel points engine has gasoline and diesel engine two kinds; According to the way of working two-stroke and four-stroke two kinds, the general engine for the four-stroke engine. \x0d\\\x0d\ Keywords: work, seal, engine, cooling system, lubrication system, fuel system, ignition system, compression ratio. Clutch, transmission, carburetor. \x0d\\\\x0d\ engine is the heart of the car, want to understand the car, it is necessary to have a general understanding of the engine first. \x0d\\\\x0d\\ First of all, let's take a look at one of the most common engine parameters - engine displacement. Engine displacement is the sum of the working volume of each cylinder of the engine, generally expressed in liters (L). The cylinder working volume is the volume of gas swept by the piston from the upper stop to the lower stop, also known as the single-cylinder displacement, which depends on the cylinder bore and piston stroke. Engine displacement is a very important engine parameter, it is more representative of the size of the engine than the bore and the number of cylinders, many indicators of the engine are closely related to the exhaust volume. Generally speaking, the larger the displacement, the greater the engine output. \x0d\\\\x0d\ understand the displacement, we look at other common parameters of the engine. Many junior car enthusiasts have reflected often in the car information in the engine column to see "L4", "V6", "V8", "W12 "V6", "V8", "W12" and other words, trying to understand what it means. These indicate the arrangement of engine cylinders and the number of cylinders. The number of cylinders commonly used in automobile engines are 3, 4, 6, 8, 10, 12 and so on. \x0d\\\\x0d\\ Generally speaking, engines with a displacement of 1 liter or less are commonly used 3 cylinders, such as the 0.8-liter Alto and the Flair sedan. Displacement of 1 liter to 2.5 liters is generally 4-cylinder engines, common economy cars and mid-range sedan engines are basically 4 cylinders. 3 liters of the engine is generally 6 cylinders, such as displacement of 3.0 liters of the Grandview and the new Accord sedan. \x0d\\\\x0d\\bord0\shad0\alphaH3D}Engines with a displacement of about 4 liters are usually 8 cylinders, such as the JEEP4700 of Beijing Jeep with a displacement of 4.7 liters. engines with a displacement of more than 5.5 liters are usually 12-cylinder engines, such as the BMW 760Li with a displacement of 6 liters, which adopts a V12 engine. Under the same cylinder bore, usually the more cylinders the greater the displacement, the higher the power; while in the case of the same engine displacement, the more cylinders, the smaller the bore, the engine speed can be increased, thus obtaining a larger boost power. Generally, the cylinders of engines with less than 5 cylinders are arranged in an in-line manner, and most of the common low-end cars are L4 engines, i.e., in-line 4 cylinders. In addition, there are also a few 6-cylinder engines with in-line arrangement. \x0d\\\\x0d\\\ in-line engine cylinder block into a one-liner, cylinder block, cylinder head and crankshaft structure is simple, low manufacturing costs, low-speed torque characteristics are good, fuel consumption is low, compact size, the application is more widely used, the disadvantage of the power is lower. Generally, gasoline engines below 1 liter mostly use inline 3 cylinders, and gasoline engines between 1 and 2.5 liters mostly use inline 4 cylinders. Some 4x4 vehicles use inline 6 cylinders because of their small width, which allows them to arrange facilities such as superchargers next to each other, e.g., the Beijing Jeep's JEEP 4000 uses an inline 6-cylinder engine. \x0d\\\\x0d\Also, according to professionals, inline 6-cylinder engines have better dynamic balance and relatively less vibration, so they are also adopted by some medium and high-class sedans. 6 to 12-cylinder engines are generally arranged in a V-shape, with the V10 engine being mainly fitted in racing cars. the V-shape engine has small dimensions in terms of length and height, and is very easy to arrange. The V-shaped engine is generally considered to be a more advanced engine, thus becoming one of the hallmarks of the sedan class. \x0d\\\x0d\\V8 engine structure is very complex, manufacturing cost is very high, so the use of less, V12 engine is too big and too heavy, only a very few premium sedans used, such as the above mentioned BMW 760Li. and Volkswagen has also recently developed a new W-type engine, there are two kinds of W8 and W12, that is, the cylinders are divided into four rows of staggered angular arrangement, the shape of the body is compact, Volkswagen's top car Phaeton has a W12 engine with a displacement of 6.0 liters. \x0d\\\x0d\ body is the skeleton of the engine, is the engine institutions and systems of the installation of the foundation, its internal and external installation of all the main parts of the engine and accessories, to withstand a variety of loads. Therefore, the body must have sufficient strength and rigidity. The body set is mainly composed of cylinder block, crankcase, cylinder head and cylinder gasket and other parts. \x0d\\\x0d\ I. Cylinder block \x0d\\\x0d\\ water-cooled engine cylinder block and the upper crankcase are often cast into one piece, called the cylinder block - crankcase, can also be called the cylinder block. Cylinder block is generally cast in gray cast iron, the cylindrical cavity in the upper part of the cylinder block is known as the cylinder, the lower half of the crankcase supporting the crankshaft, the inner cavity for the crankshaft movement space. Inside the cylinder block there are many reinforcing bars, cooling water jacket and lubricating oil channels cast. \x0d\\\\x0d\\cylinder block should have sufficient strength and stiffness, according to the cylinder block and the oil sump mounting plane of the different positions, usually the cylinder block is divided into the following three forms. \x0d\\\x0d\(1) General type cylinder block which is characterized by the oil sump mounting plane and the crankshaft rotation center at the same height. The advantages of this type of cylinder block are small body height, light weight, compact structure, easy to process, and easy to disassemble the crankshaft; however, its disadvantage is poor stiffness and strength \x0d\\\x0d\(2) gantry type cylinder block is characterized by the oil pan mounting plane is lower than the center of rotation of the crankshaft. It has the advantage of good strength and stiffness, and can withstand large mechanical loads; however, its disadvantages are poor craftsmanship, bulky structure, and more difficult to process. \x0d\\\x0d\(3)Tunnel cylinder blockThis form of cylinder block crankshaft main bearing holes are integral, using rolling bearings, the main bearing holes are larger, and the crankshaft is loaded from the rear of the cylinder block. The advantages are compact structure, good stiffness and strength, but the disadvantages are high machining accuracy requirements, poor workmanship, crankshaft disassembly is not convenient. \x0d\\\x0d\\ In order to be able to make the inner surface of the cylinder work properly at high temperatures, the cylinder and cylinder head must be properly cooled. There are two methods of cooling, one is water cooling and the other is air cooling. Water-cooled engines have cooling water jackets machined around the cylinder and in the cylinder head, and the cylinder block and cylinder head cooling water jackets are connected, and the cooling water circulates continuously in the water jacket, taking away some of the heat and cooling the cylinder and cylinder head. \x0d\\\x0d\\ modern automobiles are basically water-cooled multi-cylinder engines, for multi-cylinder engines, the arrangement of cylinders determines the engine external dimensions and structural characteristics, also has an impact on the rigidity and strength of the engine body, and relates to the overall arrangement of the car. According to the different arrangement of the cylinder, the cylinder block can also be divided into single-row type, V-type and opposed type three. \x0d\(1)In-line \x0d\\\x0d\\ engine cylinders are arranged in a row, generally vertically. Single in-line cylinder block structure is simple, easy to process, but the length and height of the engine is larger. General six-cylinder engine below the single-row type. For example, the Jetta, Fukang car, Red Flag car used by the engine are used in this in-line cylinder block. Some cars tilt the engine at an angle in order to reduce the height of the engine. \x0d\\\x0d\(2)V-type \x0d\\x0d\ cylinders arranged in two rows, the right and left two rows of cylinder centerline angle γ <180 °, known as the V-type engine, V-type engine compared with the in-line engine, shorten the length and height of the body, increase the rigidity of the cylinder block, reduce the weight of the engine, but increased the width of the engine, and the shape is more complex, processing difficulties, generally Used for more than 8-cylinder engines, 6-cylinder engines also have adopted this form of cylinder block. \x0d\\\x0d\(3)Opposed \x0d\\x0d\ cylinders arranged in two rows, the left and right two rows of cylinders in the same horizontal plane, that is, the right and left two rows of cylinders the center line of the angle γ = 180 °, known as opposed. It is characterized by a small height, easy overall arrangement, and is conducive to air cooling. This type of cylinder is used less. \x0d\ cylinder directly bored on the cylinder body is called integral cylinder, integral cylinder strength and stiffness are good, can withstand large loads, this cylinder on the high material requirements, high cost. If the cylinder is manufactured into a separate cylindrical parts (i.e., cylinder liner), and then installed into the cylinder body. In this way, the cylinder liner is made of wear-resistant high-quality materials, and the cylinder body can be manufactured from less expensive general materials, thus reducing manufacturing costs. At the same time, the cylinder liner can be removed from the cylinder block, thus facilitating repair and replacement, and can greatly extend the service life of the cylinder block. There are two types of cylinder liner: dry cylinder liner and wet cylinder liner. \x0d\\\x0d\\ dry cylinder liner is characterized by the cylinder liner installed into the cylinder block, its outer wall is not in direct contact with the cooling water, and the cylinder block wall in direct contact with the wall thickness is thinner, generally 1 ~ 3mm. it has the advantages of the integral cylinder block, the strength and stiffness is better, but the processing is more complex, the inner and outer surfaces need to be finishing, disassembly and installation is not convenient, heat dissipation is poor. \x0d\\\x0d\\ wet cylinder liner is characterized by the cylinder liner is installed into the cylinder block, its outer wall is directly in contact with the cooling water, the cylinder liner is only in the upper and lower each have a circular zone and the cylinder block contact, the wall thickness is generally 5 ~ 9mm. it is good heat dissipation, cooling uniformity, easy to process, usually only need to finish machining of the inner surfaces, and water contact with the outer surface does not need to be processed, dismantling and assembling convenient, but the disadvantage is the strength, Rigidity are not as good as dry cylinder liner, and it is easy to produce water leakage. Some anti-leakage measures should be taken. \x0d\ The lower part of the cylinder block used to install the crankshaft is called the crankcase, the crankcase is divided into the upper crankcase and lower crankcase. Upper crankcase and cylinder block cast into one, the lower crankcase is used to store lubricating oil, and closed on the crankcase, so it is also known as the oil sump figure (Figure 2-6). The oil pan is subjected to a small force, generally made of thin sheet steel stamping, its shape depends on the overall arrangement of the engine and the capacity of the oil. The oil sump is equipped with an oil stabilizer plate to prevent the oil level from fluctuating too much when the car is moving. The bottom of the oil sump is also equipped with an oil drain screw plug, which is usually equipped with a permanent magnet to adsorb metal shavings in the lubricating oil and reduce engine wear. A liner is fitted between the upper and lower crankcase mating surfaces to prevent lubricant leakage. \x0d\3. Cylinder head\x0d\ The cylinder head is mounted on top of the cylinder block, sealing the cylinder from above and forming the combustion chamber. It is often in contact with high temperature and high pressure gas, and is therefore subjected to great thermal and mechanical loads. Water-cooled engines have a cooling water jacket inside the cylinder head, and the cooling water holes in the lower face of the head are connected to the cooling water holes in the cylinder block. Circulating water is utilized to cool high temperature parts such as the combustion chamber. \x0d\\\x0d\cylinder head is also equipped with intake and exhaust valve seats, valve guide holes for the installation of intake and exhaust valves, as well as intake channels and exhaust channels. The cylinder head of the gasoline engine is machined with holes for installing spark plugs, while the cylinder head of the diesel engine is machined with holes for installing injectors. The cylinder head of an overhead camshaft type engine also has camshaft bearing holes machined for mounting the camshaft. \x0d\\\\x0d\\\cylinder heads are generally made of grey cast iron or alloy cast iron. Aluminum alloys have good thermal conductivity, which is conducive to improving the compression ratio, so in recent years aluminum alloy cylinder heads have been adopted more and more. \x0d\\\x0d\\cylinder head is an integral part of the combustion chamber, the shape of the combustion chamber has a great impact on the work of the engine, due to the different combustion methods of gasoline and diesel engines, the part of their cylinder head that makes up the combustion chamber varies greatly. The combustion chamber of a gasoline engine is mainly in the cylinder head, while the combustion chamber of a diesel engine is mainly in the pit on top of the piston. Only the combustion chamber of the gasoline engine is introduced here, while the combustion chamber of the diesel engine is introduced in the diesel fuel supply system. \x0d\\ Three common forms of combustion chambers for gasoline engines. \x0d\(1) hemispherical combustion chamber \x0d\\\x0d\ hemispherical combustion chamber compact structure, spark plugs are arranged in the center of the combustion chamber, the flame stroke is short, so the combustion rate is high, less heat dissipation, high thermal efficiency. This combustion chamber structure also allows the valve double row arrangement, the diameter of the intake port is larger, so the filling efficiency is higher, although the gas distribution mechanism becomes more complex, but is conducive to exhaust purification, in the car engine is widely used. \x0d\\\x0d\(2)Wedge-shaped combustion chamber \x0d\\x0d\ wedge-shaped combustion chamber structure is simple, compact, small heat dissipation area, heat loss is also small, to ensure that the mixture in the compression stroke of the formation of a good vortex movement, is conducive to improve the mixing quality of the mixture, the intake resistance is small, and improves the efficiency of the filling. The valves are lined up in a row, making the gas distribution mechanism simple, but the spark plug is placed high in the wedge-shaped combustion chamber, the flame propagation distance is a little longer, the Cherokee sedan engine uses this form of combustion chamber. \x0d\\\x0d\(3) basin-shaped combustion chamber \x0d\\x0d\basin-shaped combustion chamber, cylinder head craftsmanship is good, low manufacturing costs, but because of the valve diameter is easy to limit the intake and exhaust effect than hemispherical combustion chamber is poor. Jetta sedan engine, Audi sedan engine with basin-shaped combustion chamber. \x0d\\\\x0d\ iv. Cylinder gasket\x0d\\\x0d\\cylinder gasket mounted between the cylinder head and cylinder block, its function is to ensure that the cylinder head and cylinder block contact surface sealing, to prevent leakage of air, water and oil. \x0d\\\x0d\\cylinder gasket material should have a certain degree of elasticity, can compensate for the unevenness of the bonding surface to ensure that the seal, at the same time, should have a good heat resistance and pressure resistance, in the high temperature and high pressure without burning, not deformed. Currently more widely used is the copper - cotton structure of the cylinder gasket, due to the copper - cotton cylinder gasket flap with three layers of copper, compression than the asbestos is not easy to deform. Some engines are also used in the asbestos center with woven wire mesh or perforated steel plate for the skeleton, both sides of the asbestos and rubber binder pressed into the cylinder gasket. \x0d\\\x0d\\ when installing the cylinder gasket, first check the quality and integrity of the cylinder gasket, all the holes in the cylinder gasket should be aligned with the holes in the cylinder block. Secondly, the cylinder head bolts should be put on in strict accordance with the requirements of the instructions. When tightening the cylinder head bolts, they must be extended from the center symmetrically to all sides in the order of 2 to 3 times, and the last one tightened to the specified torque. \x0d\ four-stroke engine work process: four-stroke engine is a piston reciprocating four strokes to complete a work cycle, including intake, compression, work, exhaust four processes. Four-stroke diesel engine and gasoline engine through the same intake, compression, work, exhaust process. However, the difference with gasoline engine is: gasoline engine is ignition, diesel engine is compression ignition. \x0d\\\\x0d\\cooling system: generally consists of a water tank, water pump, radiator, fan, thermostat, water temperature gauge and drain switch. Automobile engines use two types of cooling, namely air cooling and water cooling. Generally automobile engines are mostly water-cooled. \x0d\\\\\x0d\\\lubrication system: the engine lubrication system consists of an oil pump, a collector filter, an oil filter, an oil channel, a pressure limiting valve, an oil gauge, a pressure sensing plug and a dipstick. \x0d\\\\\x0d\\fuel system: the gasoline engine fuel system consists of a gasoline tank, gasoline gauge, gasoline pipe, gasoline filter, gasoline pump, carburetor, air filter, intake and exhaust manifolds. \x0d\\\\\x0d\\carburetor: It is a device that mixes gasoline and air in a certain proportion into an atomized gas, which is called a combustible mixture, and is supplied to the cylinder in time and in the right amount. \x0d\\\\x0d\ The chassis of the automobile: \x0d\\\x0d\ Transmission: it is mainly composed of clutch, transmission, universal joints, drive shafts and drive axles. \x0d\\\\x0d\\clutch: its role is to make the engine power and transmission smoothly engaged or temporarily separated, in order to facilitate the driver to carry out the car's start, stop, shift gears and other operations. \x0d\\\x0d\\transmission: It consists of transmission case, transmission cover, first shaft, second shaft, intermediate shaft, reverse shaft, gears, bearings, maneuvering mechanism and other machine parts, which is used to change the speed of the car and change the output torque. \x0d\\\\x0d\\ Driving system: consists of frame, axle, suspension and wheels. Its basic function is to support the mass of the whole vehicle and ensure the traveling of the car. \x0d\\\x0d\\\Steel plate springs and shock absorbers: the role of the steel plate springs is to keep the frame and body of the car and the wheels or axles elastically connected to each other. The function of shock absorbers is to soften the shock when the car is hit by vibration. Shock absorbers are used in parallel with leaf springs. \x0d\\\x0d\\\steering system: consists of steering wheel, steering gear, steering knuckle, steering knuckle arm, cross tie rod, straight tie rod, etc., and serves to steer. \x0d\\\x0d\\ front wheel alignment: in order to make the car to maintain a stable straight line driving, steering light, to reduce the wear and tear of the tires and steering components of the car in driving, the front wheels, steering pin, the front axle installed between the three have a certain relative position, which is called "front wheel alignment". This is called "front wheel alignment". It includes the main pin tilt, the production pin tilt, and the front beam of the front wheels. The value of front beam refers to the difference between the distance between the front edges of the two front wheels, which is less than the distance between the rear edges. Braking system: the braking performance of a motor vehicle is the effectiveness of the vehicle to force a stop in the shortest possible time.? \x0d\\ hand brake function: The hand brake is a device that keeps the car from skidding when parked and, in special cases, is used in conjunction with the foot brake. \x0d\\\x0d\\hydraulic Brake Construction: The hydraulic brake device consists of the brake pedal, brake master pump, sub-pump, drum (wheel) brake and oil pipe and other machine parts. \x0d\\\\x0d\\\ pneumatic braking device: by the brake pedal, air compressor, air pressure gauge, brake valve, brake air chamber, drum (wheel) brake and air hose and other machine parts. \x0d\\ electrical equipment: \x0d\ vehicle electrical equipment mainly consists of batteries, generators, regulators, starter motors, ignition systems, instruments, lighting devices, audio devices, windshield wipers and other components. \x0d\\\\x0d\\battery: the role of the battery is to supply the starter motor with electricity, in the engine starting or low-speed operation to the engine ignition system and other electrical equipment power supply. When the generator generates sufficient power when the engine is running at high speed, the battery can store the excess power. Each single cell on the battery has positive and negative poles. The identification method is as follows: the positive post is engraved with a "+" sign, which is dark brown; the negative post is engraved with a "-" sign, which is light gray. Starter motor: its role is to convert electrical energy into mechanical energy, drive the crankshaft rotation, start the engine. When the starter is used, it should be noted that each starting time should not exceed 5 seconds, the interval between each use should not be less than 10-15 seconds, and the continuous use should not exceed 3 times. If the continuous starting time is too long, it will cause a large amount of battery discharge and the starter coil overheating smoke, very easy to damage the parts. \x0d\ Talk about automotive engine seal maintenance \x0d\ in the automotive engine maintenance, "three leaks" (water, oil and gas leaks) phenomenon most maintenance personnel headache. The "three leaks" may seem ordinary, not worth mentioning, but it directly affects the normal use of the car and the appearance of the car engine cleanliness. The ability to strictly control the engine important parts of the "three leaks" is an important issue that maintenance personnel must consider. \x0d\1 type of engine seals and their selection \x0d\ engine seals and the correct choice of material, directly affects the engine sealing performance of good and bad. \x0d\1.1 Cork board sealing gasket \x0d\ cork board sealing gasket is made of granular cork pressed with the appropriate adhesive. It is commonly used in oil pan, water jacket side cover, water outlet, thermostat shell, water pump and valve cover. In use, due to the cork board easy to break, installation inconvenience, etc., modern cars are no longer preferred such gaskets, but can still be used as a substitute. \x0d\1.2 liner asbestos sheet gasket \x0d\ liner asbestos sheet is a sheet material made of asbestos fibers mixed with bonding materials, which is heat-resistant, pressure-resistant, oil-resistant, and non-deforming. Commonly used in carburetors, gasoline pumps, oil filters, timing gear shells and so on. \x0d\1.3 Oil Resistant Rubber Gasket\x0d\ oil resistant rubber gasket is made of nitrile rubber and natural rubber as the main, adding asbestos wire added materials. It is often used as a molded gasket for automotive engine sealing, mainly used for oil pan, valve cover, timing gear shell and air filter. \x0d\1.4 Specialized gaskets\x0d\a.Crankshaft front and rear oil seals are usually specialized standard parts. Most of them use skeleton type rubber oil seals. Attention should be paid to its orientation when installing, if there is no labeling instruction, the lip with smaller inner diameter of the oil seal should be installed facing inside the engine. \x0d\b.Cylinder liners are usually made of steel or copper sheets covered with asbestos. At present, the automobile engine cylinder liner using composite gasket more, that is, in the middle of the asbestos layer and another layer of metal inner layer, in order to improve its stiffness, at the same time, by the edge of the cylinder hole using 4-5 layers of steel embossed, thus improving the cylinder liner resistance to "washout" sex. Cylinder liner installation should pay attention to its directionality, there are assembly marking symbol "TOP", should be facing up; no assembly marking, generally cast iron cylinder block cylinder liner smooth surface should be directed towards the cylinder block, while the aluminum alloy cylinder block cylinder liner smooth surface should be directed towards the cylinder head. \x0d\c.The intake and exhaust manifold gaskets are made of steel or copper skin wrapped with asbestos. When installing them, care should be taken to keep the rolled side (i.e., non-smooth side) toward the cylinder block. \x0d\d.The crankshaft's last main bearing cap side seal is usually sealed with soft art or bamboo pieces. However, in the absence of this piece, lubricant-soaked asbestos rope can also be used instead, but the filling should be done by smashing the asbestos rope solidly with a special cannon to prevent oil leakage. \x0d\e.spark plugs and exhaust pipe interface pad, disassembled once should be replaced with a new pad; should not be to prevent air leakage and take the method of adding a double gasket, experience has proved that the sealing of the double cushion but worse. \x0d\1.5 sealant \x0d\ sealant is a new type of sealing material in modern automobile engine repair, its appearance and development, to improve sealing technology, to solve the engine "three leaks" provides a good condition. There are many kinds of sealant, it can be applied to different parts of the car. Automobile engines usually use non-bonding type (commonly known as liquid gasket) sealant. It is a polymer compound as the substrate of the viscous liquid material, coated in the parts of the joint surface to form a uniform, stable, continuous adhesion of a thin layer or peelable film, and can be fully filled to join the surface of the depression and the gap to go. Sealant can be used in the engine valve cover, oil pan, valve tappet chamber cover, etc. alone or jointly with their gaskets, can also be used alone in the crankshaft under the last bearing cover and the oil hole screw plugs, oil plugs and other places.