The working processes of the automotive motor pass at high temperatures, therefore, to ensure its performance for a long time, it is necessary to remove unnecessary heat. This feature provides a cooling system (CO). In the cold season, heating the cabin is made at the expense of this heat.

In the car used turbocharged, the function of the cooling system includes a decrease in air temperature supplied to the combustion chamber. Additionally, one of the circles from the cooling system of some models of cars equipped with an automatic transmission (automatic transmission), the oil cooling in the automatic transmission is turned on.

There are two main types of CO: Water and Air. The principle of operation of the cooling system with water cooling is to heat the fluid from the power plant or other nodes and the returns of such heat into the atmosphere through the radiator. In the air system, air is used as a working cooler. In both options there are their advantages and disadvantages.

However, a cooling system with liquid circulation was larger than distribution.

Air So.

Aerial cooling

The main advantages of this layout include the simplicity of the design and maintenance of the system. Such with practically does not increase the mass of the power unit, as well as not capricious to changes in ambient temperature. The negative includes a significant selection of the motor with a fan drive, an increased noise level when working, poorly balanced heat removal from individual nodes, the impossibility of using the engine block system, the impossibility of accumulating the heat of heat for further use, for example, heating the interior.

Liquid SO

Cooling fluid

The system with the use of heat removal using a special fluid due to its design can effectively remove the excess heat from the mechanisms and individual parts of the structure. In contrast to air, the engine of the engine cooling system with liquid contributes to a faster set of operating temperature at startup. Also, the motors with antifreeze are significantly quieter and are subject to smaller detonation.

Cooling system elements

Consider in more detail how the engine cooling system works on modern cars. There are no significant differences between gasoline and diesel engines in this regard.

As a "shirt" for cooling the motor, the structural cavities of the cylinder block are performing. They are located around zones from which it is necessary to distinguish heat. For a faster removal, a radiator is installed consisting of curved copper or aluminum tubes. A large number of additional edges accelerate the heat exchange process. Such ribs increase the cooling plane.

Before the radiator, the fan fan is installed. The influx of cooler streams begins after the electromagnetic coupling is closed. It turns on when fixed temperature values \u200b\u200bis reached.

Work thermostat

The continuity of cooling fluid circulation is ensured by the operation of the centrifugal pump. The belt or gear gear for it receives rotation from the power plant.

The thermostat is engaged in adjusting the flow directions.

If the coolant temperature is not high, the circulation passes through a small circle, without inclusion in it with the radiator. If the permissible thermal mode is exceeded, the thermostat is powered by a large circle with the participation of the radiator.

For closed hydraulic systems, the use of expansion tanks is typical. Such a tank is provided in from the car.

Circulation of coolant

Salon Warming is performed using a heater radiator. Warm air in this case does not go into the atmosphere, but it starts inside the car, creating comfort to the driver and passengers in the cold season. For greater efficiency, such an element is installed almost at the outlet of the liquid from the cylinder block.

The driver receives information about the state of the cooling system using the temperature sensor. Signals also go to the control unit. It can independently connect or turn off the actuators to comply with the balance in the system.

System work

Antifreeze with multiple additives, including anti-corrosion, are used as cooling fluids. They help increase the durability of the nodes and parts used in CO. Such a liquid is forcibly pumped through the centrifugal pump system. Begins to move from the cylinder block, the hottest point.

Initially, there is a movement at a small circle with a closed thermostat without entering the radiator, because even the working temperature for the motor has not yet been gained. After entering the operating mode, the circulation occurs in a large circle, where the radiator can be cooled by the oncoming stream or using the fan connected. After that, the fluid returns to the "shirt" around the cylinder block.

There are cars using two cooling circuits.

The first lowers the temperature of the motor, and the second take care of the influxing air, cooling it to form the fuel mixture.

Briefly on how the car engine cooling system works.

Answer the question which part of the car is more important:, or the engine cooling system? If you chose one or two of the proposed positions in the list, you answered incorrectly. In fact, all the above positions are vital for any machine. A failure in each of them will lead to serious consequences to correct which will not be easy.

Take, for example, the engine cooling system. If it is faulty or engine mode exceeds the work indicators laid when it is design, there is a possibility that you can see a rare phenomenon, which will later come to you in nightmarish dreams, from under the hood will begin to pour thick hot steam from under the hood, and the engine temperature sensor arrow will strengthen Red zone marking the critical overheating of the motor. The engine after such a steam bath and limit temperatures may well go to the car service for overhaul or straight to the landfill. This is the result of the improper operation of the cooling system.

And so, the first useful information for beginners. The purpose of the cooling system is to create the perfect thermal working conditions for the engine that will exclude its overheating. Exothermic reactions occur in the engine (i.e. it produces a large amount of heat) and if the cooling system is unable to pick up excessive heat from the cylinder block, the engine will begin to deform (maybe the head of the cylinder block), the oil will not be able to provide sufficient protection (It will deteriorate its protective properties), the engine will begin to wear quickly and ultimately swaps it.

The most important part of the engine cooling system is definitely a water pump. It causes a cooling fluid based on ethylene glycol to circulate along the hottest parts of the engine, as well as through the thermostat case, radiator, heater radiator, and other tubes and hoses included in the cooling system.

All internal combustion engines are cooled by convective heat exchange (heat transfer in unevenly heated liquid, gaseous and other fluid environments, read more detail here: yandex.ru) and in almost all modern cars, a liquid based on ethylene glycol is used as a liquid antifreeze. She has several advantages over other technical fluids, such as high heat capacity, very high boiling point and low freezing temperature. It is her that pumps it through the water pump engine driven by the drive belt drive of the auxiliary aggregates drive.

How does the thermostat work?

Thermostat uses wax. The wax flooded into a brass or aluminum capsule when heated pushes a small piston from the thermostat body, squeezing the spring. The thermostat opens. After cooling the spring system, the thermostat in the closed position is returned (the thermostat operation is shown at 5.37 minutes of video. By the way! This version can be used as an inspection of the thermostat from your car if you doubt it properly functioning)

On a cold engine, the coolant goes along the so-called small circle through the cylinder block, the head of the cylinder block, called the "head" and (for this reason you immediately get warm air in the cabin after starting the engine).

Once the motor reaches about 95 degrees, the wax in the thermostat is expanding and opens the valve directing the cooling fluid from the engine to the cooling radiator.

How is the cooling radiator?

The heated coolant passes through the radiator tubes, giving heat from the coolant (liquid) tubes, then transmitting it to the ribs of the radiator (the ribs are made of corrugated metal). The ribs, with their large surface area, contribute to high heat transfer met with a cooled air flux (to increase the cooling effect or in cases where the car is in a stationary state, a large fan is installed in front of the radiator, which additionally drives the air through the cooling edges). Thus, the coolant fluid is cooled through the radiator grille and falls into the opposite tank on the radiator. The cycle is repeated, the cooled fluid returns to the water pump and cools the engine, the circle closed.

The radiator slice shows us two rows of tubes through which the cooling fluid passes, which carries the heat from the engine to the ribs of the radiator grid.

In the photo Scheme of the engine cooling system Nissan Almera G15

The cooling system of standard-type engines cools its heated parts. In modern car systems, it performs other functions:

• cools the oil of the lubrication system;
• cools the air circulating in the turbocharging system;
• cools the spent gases in the system of recycling;
• cools the working fluid of the automatic transmission;
• heats air circulating in ventilation, heating and air conditioning systems.

There are several ways to cool the engine, from the use of the type of cooling system used. There are liquid, air and combined systems. Liquid - removes heat from the engine with a fluid flow, and air flow of air. In the combined system, both of these methods are combined.

More often than others in cars using a liquid cooling system. It evenly and quite effectively cools the engine parts and works with less noise than air. Based on the popularity of the liquid system, it is on its example and will be considered the principle of operation of the car cooling systems in general.

Engine cooling system circuit

In the photo of the engine cooling system of the VAZ 2110 engine cooling system with a carburetor and VAZ 2111 with an injector (fuel injection equipment).

For gasoline and diesel engines, similar designs of cooling systems are used. Their standard set of elements is as follows:

1. normal, oil radiator and coolant radiator;
2. radiator fan;
3. centrifugal pump;
4. thermostat;
5. heat exchanger heater;
6. expansion tank;
7. engine cooling shirt;
8. control system.

Consider each of these elements separately:

1. Radiators.

1. In the usual radiator, the heated liquid is cooled by the oncoming air flow. To increase its efficiency, a special tubular type is used in the design.
2. Oil radiator is designed to reduce the oil temperature of the lubrication system.
3. To cool the exhaust gases, the system of their recirculation use the third type of radiators. It allows you to cool the fuel and air mixture when it is combustion, thereby less nitrogen oxides are formed. An additional radiator is equipped with a separate pump, which is also included in the cooling system.

2. . To improve the efficiency of the radiator, it uses a fan that can have a different drive mechanism:

• hydraulic;
• mechanical (connected on a permanent basis with the crankshaft of the car motor);
• electric (running from the current of the battery).

The most common electric type of fans, which is carried out in fairly wide limits.

3. Centrifugal pump. Using the pump in the cooling system, the circulation of its liquid is ensured. The centrifugal pump can be equipped with a different type of drive, for example, belt or gear. In addition to the main engine, an additional centrifugal pump can be used in engines with a turbocharged pump for more efficient cooling of the turbocharger and superval. To control the operation of pumps, the engine control unit is used.

4. Thermostat. With the help of a thermostat, the amount of fluid falling into the radiator is adjusted. The thermostat is installed in the nozzle leading to the radiator from the motor cooling shirt. Thanks to the thermostat, you can control the temperature mode of the cooling system.

In cars with a powerful engine, a slightly different type can be used - with electric heating. It is able to regulate the temperature fluid temperature regimen in a two-step range at three operating positions.

In the open state, such a thermostat is located during the maximum engine operation. In this case, the temperature of the coolant passing through the radiator is dropped to 90 ° C, which reduces the likelihood of engine detonation. In the remaining two working positions of the thermostat (open and semi-open), the fluid temperature will be maintained at 105 ° C.

5. Heater heat exchanger. Air entering the heat exchanger heats up for subsequent use in the car's heating system. To increase the efficiency of the heat exchanger, it is placed directly at the outlet of the coolant, which passed through the engine and having a high temperature.

6. Expansion tank. Due to the change in the temperature of the coolant, its volume changes. To compensate it, an expansion tank is embedded in the cooling system that supports the volume of fluid in the system at one level.

7. Engine cooling shirt. In the design, such a shirt is a liquid channels passing through the engine of the engine block and the cylinder block.

8. Management system. The following devices can be presented as elements of controlling the engine cooling system:

1. Temperature sensor circulating fluid. The temperature sensor converts the temperature value into the corresponding electrical signal, which is fed to the control unit. In cases where the cooling system is used to cool the exhaust gases or in other tasks, another temperature sensor mounted on the outlet of the radiator can be installed.
2. Control unit on an electronic basis. Having obtained electrical signals from the temperature sensor, the control unit automatically reacts and performs the appropriate impact on other actuators of the system. Usually, the control unit has a software that performs all the functions for automating the processing of signals and setting up the cooling system.
3. Also, in the control system, the following devices and elements can be involved in the system: the engine cooling relay after stopping it, the relay of the auxiliary pump, the thermostable heater, controlling the radiator fan.

Principle of operation of the engine cooling system in action

The well-established cooling is due to the presence of a control system. In cars with modern engines, its operations are based on a mathematical model in which various parameter parameters are taken into account:

• lubricating oil temperature;
• the temperature of the liquid used to cool the engine;
• the temperature of the outer environment;
• other important indicators affecting the system work.

The control system, evaluating the various parameters and their effect on the operation of the system, compensates for their effect by regulating the working conditions of the managed elements.

Using the centrifugal pump, a coal circulation of coolant in the system is carried out. Passing through the cooling shirt, the liquid heats up, and hitting the radiator cooled. Heating liquid, engine parts themselves cooled. In the cooling shirt, the liquid can circulate both in the longitudinal (along the cylinder line) and in the transverse direction (from one collector to another).

The circle of its circulation depends on the coolant temperature. During the engine launch, it itself is cold, and to accelerate its heating, the liquid is sent to a small circle circulation, bypassing the radiator. In the future, when the engine is heated, the thermostat is heated and changes its working position to the semi-open. As a result, the coolant begins to flow through the radiator.

If the oncoming radiator air flow is not enough to reduce the temperature of the fluid to the desired value, the fan is turned on, forming an additional air flow. The cooled fluid gets into the cooling shirt and the cycle is repeated.

If the car uses turbocharging, it can be equipped with a two-circuit cooling system. Its first circuit cools the engine itself, and the second is an abandoned flow of air.

See the cognitive video about the principle of operation of the engine cooling system:

The figure shows the liquid cooling system of the carburetor V-engine. Each block of block has a separate water shirt. The injected water with water pump 5 is divided into two streams - in distribution channels and further into the water shirt of their row of block, and from them in the shirts of the cylinder heads.

Fig. Engine cooling system ZMZ-53: A - device; b - core; in - blinds; 1 - radiator; 2 - fluid overheating signaling sensor; 3 - radiator cork; 4 - casing; 5 - water pump; 6 - bypass hose; 7 and 12 - respectively removing and linguing hoses; 8 - thermostat; 9 - fluid temperature sensor; 10 - focus of a drain crane; 11 - cooling shirt; 13 - fan belt; 14 - drain crane; 15 - fan; 16 - blinds; 17 - heater fan; 18 - cabin heater; 19 - Blind Plate; 20 - cable

When the cooling system is running, a significant amount of fluid is supplied to the most heated places - pipes of exhaust valves and spark spark spark slots. In carburetor engines, water from the cylinder head shirts pre-passes through the water shirt of the intake pipe, wash the walls and heats the mixture coming from the carburetor through the inner channels of the pipe. At the same time, the evaporation of gasoline is improved.

The radiator is used to cool the water coming from the water shirt of the engine. The radiator consists of upper and lower tanks, cores and fastening parts. Tanks and cores for better conductivity warmth are made of brass.

A number of thin plates are placed in the core, through which many vertical tubes soldered to them. Water coming through the core of the radiator is branched to a large number of small pips. With such a structure of the core, the water is cooled intensively due to the increase in the area of \u200b\u200bcontact of water with the walls of the tubes.

The upper and lower tanks with hoses 7 and 12 are connected to the engine cooling shirt. In the lower tank there is a crane 14 for draining water from the radiator. For its descent from a water shirt at the bottom of the cylinder block, there are also craners (on both sides).

In the cooling system, water is poured through the neck of the top tank, closed by plug 3.

The heater of the cab 18 hot water comes from the water shirt of the block head and is given to the pipe to the water pump. The amount of water coming to the heater (or temperature in the driver's cabin) is regulated by a crane.

In the liquid cooling system, double control of the thermal mode of the engine is provided - with the help of blinds 16 and thermostat 8. The blinds consist of a set of plates 19, which are crucially fixed in the bar. In turn, the Planck is a traction and leverage system associated with the shutter control handle. The handle is placed in the cabin. Folds can be vertically or horizontally.

The water pump and the fan are combined in one case, which is attached through the sealing gasket to the site on the front wall of the block crankcase. In the case 7 of the pump on ball bearings, a roller is installed 4. At its front end, the pulley is fixed in its front end with the hub. 2. The cross is brought to its end, to which the impeller 1 of the fan is arrogant. When the engine is running, the pulley gets rotation from the crankshaft through the belt. The blades of the impeller 1, located at an angle to the rotation plane, take the air from the radiator, creating a vacuum inside the fan casing. Due to this, the cold air passes through the core of the radiator, taking warmth.

At the back end of the roller 4 rigidly planted the impeller of 5 centrifugal water pump, which is a disk with evenly located on it curvilinear blades. When the impeller rotates, the fluid from the supply pipe 8 goes to its center, is captured by the blades and under the action of the centrifugal force is discarded to the walls of the housing 7 and through the tide is supplied to the engine's water jacket.

Fig. Water pump and engine fan ZIL-508: 1 - fan impeller; 2 - pulley; 3 - Bearing; 4 - roller; 5 - Pump impeller; 6 - gasket; 7 - pump housing; 8 - sublinking nozzle; 9 - Bearing hull; 10 - cuff; 11 - sealing washer; 12 - Keeping Salp Seal

At the rear end of the roller 4 also provides a gland seal, which does not let the water from the water shirt. The seal is mounted in the cylindrical hub of the impeller and stroke in it with a spring ring. It consists of a textolite sealing washer 11, a rubber cuff 10 and a spring that presses the washer to the end of the bearing housing. His protractions, the washer enters into the grooves of the impeller 5 and is fixed by the rope 12.

On the engine of the car KAMAZ, the fan is located separately from the water pump and drives through the hydraulic coupling. Hydromefta (Fig. A) includes a sealing casing in a liquid filled. Two (with transverse blades) of spherical vessels D and r are placed in the casing, which is rigidly connected to the leading and slave B shafts, respectively.

The principle of operation of hydromefet is based on the action of centrifugal fluid power. If you quickly rotate the spherical vessel d (pump), filled with the working fluid, then under the action of centrifugal force, the liquid slides along the curvilinear surface of this vessel and falls into the second vessel of r (turbine), forcing it to rotate. Having lost energy when hitting, the liquid falls into the first vessel, accelerates in it, and the process is repeated. Thus, rotation from the drive shaft A, connected to one vessel D, on the slave shaft b, connected rigidly with another vessel of G. This principle of hydrodynamic transmission is used in the technique when designing various mechanisms.

Fig. Hydromefta: A - principle of operation; b - device; 1 - the cover of the cylinder block; 2 - body; 3 - casing; 4 - drive roller: 5 - pulley; 6 - Stupia fan; A - Most Val; B - slave shaft; In - casing; G, d - vessels; T - turbine wheel; N - pumping wheel

The hydromefta is placed in the cavity formed by the front cover 1 of the cylinder block and the body 2 connected by screws. The hydromefta consists of a casing of 3, pumping n and turbine r wheels leading and the slave of the shafts. The casing is connected through the drive shaft and with a crankshaft using a drive roller 4. On the other hand, the casing 3 is connected to the pumping wheel and the pulley 5 of the drive of the generator and the water pump. The slave shaft B relies on two ball bearing and is connected by one end with a turbine wheel, and another with a 6 fan hub.

The engine fan is located coaxially with a crankshaft, the front end of which is connected by a slotted shaft with the drive of the hydromeflip drive 4. A turn of the Hydrone switch lever can be specified one of the required fan operation modes: "P" - the fan is turned on constantly, "A" - the fan turns on automatically, "O" - the fan is turned off (the working fluid is released from the casing). On the "P" mode, only short-term work is allowed.

The automatic switching on the fan occurs when the coolant temperature is enhanced by a thermosyl sensor. At the cooling fluid temperature of 85 ° C, the sensor valve opens the oil channel in the housing of the switch and the working fluid - the engine oil - enters the hydromeflip of the engine oil from the main line of the engine lubricant system.

The thermostat is used to accelerate the warm-up engine and automatically regulate its thermal mode as specified limits. It is a valve that regulates the number of circulating fluid through the radiator.

On the engines studied, single-valve thermostats with solid filler - ceresin (oil wax) are used. The thermostat consists of a housing 2, inside which the copper cylinder 9 is placed, filled with an active weight of 8, consisting of a copper powder mixed with ceresin. The mass in the cylinder is tightly closed with a rubber membrane 7, on which the guide sleeve 6 is installed with a hole for rubber buffer 12. The last mounted rod 5 bound to the lever 4 with the valve. In the initial position (on a cold engine), the valve is tightly pressed to the saddle (Fig. B) The housing 2 of the spiral spring 1. The thermostat is mounted between nozzles 10 and 11, reducing heated fluid into the upper radiator tank and water pump.

Fig. Thermostat with rotary (A-B) and simple (d) valves: A - thermostat device with a swivel valve (Kilburetor engine ZIL-508); b - the valve is closed; B - the valve is open; g - thermostat device with a simple valve (carburetor engine 3m3-53); 1 - spiral spring; 2 - body; 3 - valve (valve); 4 - lever; 5 - rod; 6 - guide sleeve; 7 - membrane; 8 - active mass; 9 - cylinder; 10 and 11 - liquid removal nozzles in the radiator and water pump; 12 - rubber buffer; 13 - valve; 14 - Spring; 15 - hull seat; A - valve stroke

At a coolant temperature above 75 ° C, the active mass is melted and expanded, affecting the membrane, buffer and rod 5 to lever 4, which, overcoming the power of the spring 1, begins to open the valve 3 (Fig. B). Fully valve will open at a cooling fluid temperature of 90 ° C. In the temperature range of 75 ... 90 ° C, the thermostat valve, changing its position, adjusts the amount of coolant passing through the radiator, and thereby maintains the normal temperature mode of the engine.

In Figure G, the thermostat with a simple valve 13 is shown in the position when it is opened completely for the passage of fluid into the radiator, i.e. When his move is equal to the distance A. at a temperature of 90 ° C, when the active mass of the cylinder is melted, the valve along with the cylinder sits down, overcoming the springs resistance 14. As the mass is cooled in the cylinder and the spring lifts the valve up. At a temperature of 75 ° C, the valve 13 is pressed to the hull seat 15, closing the fluid yield into the radiator.

Fig. Steam valve: A - A steam valve is open; B - the air valve is open; 1 and 6 - respectively steam and air valves; 2 and 5 - springs of steam and air valves; 3 - a steam tube; 4 - plug (lid) of the bulk neck of the radiator

The steam valve is necessary for the communication of the inner cavity of the radiator with the atmosphere. It is mounted in a plug of 4 bulk neck radiator. The valve consists of a steam valve 1 and an air valve placed inside it 6. The steam valve under the action of the spring 2 tightly closes the neck of the radiator. If the temperature of the water in the radiator rises to the limit value (for this engine), then under the pressure of the steam valve opens and its excess comes out.

When, when cooling water and condensation, steam in the radiator creates a vacuum, the air valve opens and atmospheric air enters the radiator. The air valve is closed under the action of spring 5, when the air pressure inside the radiator is balancing with atmospheric. Through an air valve, water merges from the cooling system with a closed throat lid. At the same time, the radiator tubes are protected from destruction under the influence of atmospheric pressure during engine cooling.

To control the coolant temperature, a warning lamp and a remote thermometer are used. The lamp and the thermometer pointer are placed on the instrument panel, and their sensors can be in the cylinder head, in the drainage pipe, inlet pipe or in the top tank of the radiator.

The car is intended to protect the worker unit from overheating and thereby controls the performance of the entire engine unit. Cooling is an essential function in the operation of the internal combustion engine.

The consequences of the cooling malfunction in the engine can become fatal for the aggregate itself, up to the complete failure of the cylinder block. Damaged nodes may not be subject to restorative work, their maintainability will be zero. It should be with all attentiveness and responsibility to use and conduct a periodic flushing of the engine cooling system.

Controlling the cooling system, the car owner will directly take care of the "Heart Health" of its Iron "Horse".

Purpose of cooling system

The temperature in the cylinder block when the unit runs can rise to 1900. From this volume of heat only part is useful and used in the necessary modes of operation. The rest is displayed by the cooling system beyond the motor compartment. Increasing the temperature regime above the norm is fraught with negative consequences, which lead to the extension of lubricants, disruption of technical gaps between certain parts, especially in the piston group, which will lead to a decrease in their service life. Overheating of the motor, as a result of the engine cooling system, is one of the causes of the detonation of a combustible mixture supplied to the combustion chamber.

Engine supercooling is also undesirable. In the "cold" unit, the loss of power appears, the oil density increases, which increases the friction of non-shown nodes. The working combustible mixture is partially condensed, thereby damping the walls of the cylinder of lubricant. At the same time, the surface of the cylinder wall is subject to the process of corrosion due to the formation of sulfur sediments.

The engine cooling system is designed to stabilize the thermal mode necessary for the normal operation of the vehicle motor.

Types of cooling system

The engine cooling system is classified according to the method of heat removal:

• cooling with liquids in a closed type;
• air cooling in an open type;
• combined (hybrid) heat removal system.

Currently, air cooling in cars is extremely rare. Liquid can be an open type. In such systems, heat removal occurs through a steam-cutting tube into the environment. The closed system is isolated from an external atmosphere. Therefore, this type is much higher. At high pressure, the threshold of boiling the cooling element increases. The refrigerant temperature in the closed system can reach 120.

Air cooling

Natural supply cooling with air masses is the simplest way to remove heat. The engines with this cooling type are discharged to the environment using radiator ribs located on the surface of the aggregate. Such a system has a huge drawback in the functionality. The fact is that this method directly depends on the small specific heat capacity of the air. In addition, there are problems with the uniformity of heat removal from the motor.

Such nuances impede the installation of both efficient and compact installation. In the engine cooling system, the air comes unevenly to all parts, and then you have to avoid the possibility of local overheating. Following constructive features, the ribs for cooling are mounted in those places of the engine, where the air masses are least active, due to aerodynamic properties. Those parts of the motor that are most susceptible to heat, have towards air masses, while more "cold" sites are placed from behind.

Forced air cooling

Engines with such a type of excess heat removal are equipped with a fan and cooling edges. Such a set of structural assemblies allows artificially togeting air into the engine cooling system for blowing cooling edges. A protective cover is installed above the fan and ribs, which is involved in the direction of the air masses for cooling and prevents heat from the outside.

Positive moments in this type of cooling is made simplicity of structural features, low weight, lack of indoor components and refrigerant circulation. The disadvantages are considered a high noise level of system functioning and cumbersome device. Also in forced air cooled, the problem with the local overheating of the unit and the cutting of blowing, despite the installed covers, is not solved.

This type of engine overheating prevention was actively used up to the 70s. The operation of the engine cooling system with the forced air type was popular for small vehicles.

Cooling with liquids

The liquid cooling system today is the most popular and common. The process of heat removal occurs with the help of a liquid refrigerant circulating in the main elements of the engine using special closed highways. The hybrid system combines air cooling elements simultaneously with liquid. The liquid is cooled in the radiator having ribs and a fan with a casing. Also, such a radiator is cooled by the supply air masses when the vehicle is moved.

The liquid engine cooling system gives a minimum noise level during operation. This type is universally collecting heat and removes it from high efficiency engine.

According to the method of movement of the liquid refrigerant system, the system is classified:

Engine cooling system

The design of the liquid cooling has the same structure and items, both for a gasoline engine and for diesel. The system consists of:

• radiator block;
• oil radiator;
• fan, with a housing installed;
• pump (pump with centrifugal force);
• tank for expanding heated fluid and level control;
• circulation thermostat of refrigerant.

When washing the engine cooling system, all these nodes (except for the fan) are affected for more efficient operation.

The cooling fluid circulates through the mains inside the block. The combination of such aisles is called a "cooling shirt." It covers the most suspended areas of the engine. The refrigerant, moving along it, absorbs heat and carries it to the radiator unit. Cooling, it repeats the circle.

System functioning

One of the main elements in the engine cooling system is considered a radiator. His task is to cool the refrigerant. It consists of a radiator crate, inside of which tubes for the fluid movement are laid. The coolant enters the radiator through the bottom nozzle and goes through the top, which is mounted in the upper tank. Top of the tank has a neck closed with a lid with a special valve. When the pressure in the engine cooling system increases, the valve is turned off and the fluid enters the expansion tank attached separately in the engine compartment.

Also on the radiator is a temperature sensor that signals the driver about the limiting heating of the fluid by means of the device installed in the cabin on the information panel. In most cases, the fan is attached to the radiator (two) with a casing. The fan is activated automatically when the critical temperature of the coolant is reached or works forced from the drive with the pump.

POMP provides constant circulation of coolant throughout the system. The power of rotation pump receives by belt transmission from the pulley of the crankshaft.

The thermostat controls the large and small circle of refrigerant circulation. When the engine is first started, the thermostat is powered by a small circle liquid so that the motor unit is quickly warmed up to the operating temperature. After that, the thermostat opens a large circle of engine cooling system.

Antifreeze or water

Water or antifreeze is used as a coolant. Modern car owners began to apply more and more. Water freezes at minus temperatures and is a catalyst in corrosion processes, which negatively affects the system. The only advantage is its high heat transfer and also, perhaps, availability.

Antifreeze does not freeze when cold, prevents corrosion, prevents sulfur sediments in the engine cooling system. But it has a lower heat transfer that negatively affects the hot season.

Fault

The consequences of cooling faults are overheating or engine supercooling. Overheating can be caused by a fluid deficiency in the system, unstable operation of the pump or fan. Also incorrect operation of the thermostat when he must open a large cooling circle.

It may be caused by the strong contamination of the radiator, the lining of highways, poor operation of the radiator cover, expansion tank or poor-quality antifreeze.