First serial car Ford was released at the beginning of the 20th century. He wore a proud prefix "T" and was another milestone in the development of mankind. Before that, cars were a lot of handful of enthusiasts who organized the surfacing, and from time to time we went to afternoon promenade.

Henry Ford arranged a real revolution. He put cars on the conveyor, and soon his cars filled themselves all the roads of America. Moreover, the factories were opened in the Soviet Union.

The main paradigm of Henry Ford was extremely simple: "The car can have any color if he is black." Such an approach has given the opportunity to have his own car. Optimization of costs and an increase in production scale allowed to make the price of a truly affordable.

Since then, a lot of time has passed. Cars indiscriminately evolved. Most changes and additions accounted for the engine. The cooling system was played a special role in this process. She was improved year after year, allowing you to extend the motor resource and avoid overheating.

The history of the engine cooling system

It is worth recognizing that the engine cooling system has always been in cars, however, its design has changed radically over the years. If you look exclusively today, the liquid type is installed in most cars. Its main advantages can be classified compactness and high performance.But it was not always.

The first cooling systems of the engines were extremely unreliable. Perhaps, if you tense memory, then remember movies in which events occur at the end of the XIX and at the beginning of the 20th century. At that time, the car on the side of the smoking engine was the usual phenomenon.

Attention! Initially, the main reason for overheating the engine H was the use of water as a coolant.

You as a motorist should know that in modern cars Antifreeze is used as a resource for the cooling system. His analogue was even in the Soviet Union, he was only called Tosol.

In principle, this is the same substance. It is based on alcohol, but due to additional additives, the effectiveness of antifreeze is radically higher. For example, Tosol in the engine cooling system covers the protective film absolutely everything that it extremely negatively affects the heat transfer. Because of this, the motor resource is reduced.

Antifreeze acts completely differently.It covers protective film only problem places. Also among differences, additional additives that are in antifreeze, a different booster temperature, and so on can be remembered. In any case, the most significant will be comparison with water.

Water boils at a temperature of 100 degrees. The boiling point of the antifreeze is about 110-115 degrees.Naturally, due to this, the boiling of the engine has practically disappeared.

It is worth a recognition that the designers conducted many experiments aimed at modernizing the engine cooling system. It is enough to remember exclusively air cooling. Such systems were quite actively used in the 50-70 years of the last century. But due to low efficiency and cumbersiness, they quickly come out of use.

As successful examples of cars with air cooling air systems, you can recall:

• Fiat 500
• Citroën 2CV,
• Volkswagen Beetle.

In the Soviet Union, there were also cars working using the engine cooling air system. Perhaps, every motorist born in the USSR, remembers the legendary "Cossacks", in which the engine was installed from behind.

How the engine cooling liquid cooling system works

The diagram of the liquid cooling system does not constitute anything superposter. Moreover, all the designs, regardless of which companies engaged in their production, are similar to each other.

Device

Before moving to the consideration of the principle of operation of the engine cooling system, it is necessary to study the basic elements of the design. This will allow you to imagine exactly how everything happens inside the device. Here are the main details of the node:

• Cooling shirt. These are small cavities filled with antifreeze. They are located in those places where cooling is most needed.
• The radiator dissipates heat into the atmosphere. Usually its cells are made from the combination of alloys to achieve the greatest efficiency. The design not only should effectively reduce the temperature of the fluid, but also to be durable. After all, even a small pebble can cause holes. The system itself consists of a combination of tubes and ribers.
• The fan is attached from behind the radiator so as not to interfere with the counterflow of the air. It works with the help of an electromagnetic or hydraulic coupling.
• The thermal sensor fixes the current state of antifreeze in the engine cooling system and, if necessary, let it in a large circle. This device is installed between the nozzle and the cooling jacket. In fact, this design element is a valve, which can be both bimetallic and electronic.
• Pomp is a centrifugal pump. Its main task to ensure uninterrupted circulation of the substance in the system. The device works with a belt or gear. Some models of motors can have two pumps at once.
• Radiator heating system. According to its size, a bit inferior to a similar device for the entire cooling system. In addition, it is inside the cabin. His main task is to transfer heat into the car.

Of course, these are not all elements of the engine cooling system there are still nozzles, tubes and many small details. But for the overall understanding of the work of the entire system of such a list, it is quite enough.

Principle of operation

IN engine cooling system There is an internal and external circle. In the first coolant circulates, the temperature of the antifreeze does not reach a certain feature. It is usually 80 or 90 degrees. Each manufacturer exposes its limitations.

As soon as the threshold of the limiting temperature is overcome - the liquid begins to circulate according to the second circle. In this case, it passes through special bimetallic cells in which cools. Simply put, antifreeze falls into the radiator, where it quickly cools with the help of an oncoming air flow.

This engine cooling system is quite effective, as it allows you to work with a car even at limit speeds. In addition, the oncoming air flow plays a major role in cooling.

Attention! The engine cooling system is responsible for the operation of the stove.

To better explain the principle of work modern Systems engine cooling deeper a little in construction features schemes. As you know, the main element of the engine is cylinders. In them, the pistons are constantly moving during the trip.

If you take a gasoline engine as an example, then during compression, the candle launches a spark. It flammifies the mixture, which leads to a small explosion. Naturally, the temperature at this time reaches several thousand degrees.

So that there is no overheating and there is a liquid shirt around the cylinders. She takes part of the heat and subsequently gives her. Antifreeze in the engine cooling system is constantly circulating.

How to use different cooling fluids affects the cooling system

As mentioned above, previously used in cooling systems ordinary water. But such a solution could not be called extremely successful. In addition, the engines constantly boiled, there was another side effect, namely, scale. In large quantities, she paralyzed the operation of the device.

The reason for the formation of scale lies in the chemical structure of water. The fact is that water in practice cannot have one hundred percent purity. The only way To achieve the complete exception of all extraneous elements is distillation.

Antifreeze, circulating inside the engine cooling system, do not create scale. Unfortunately, the process of permanent operation does not pass for them without a trace. Under the action of high temperatures, substances are decomposed. Result this process is the formation of decay products in the form of corrosion and organic matter.

Quite often to coolant circulating inside the system, extraneous substances fall. As a result, the efficiency of the entire system deteriorates significantly.

Attention! The greatest harm causes a sealant. Particles of this substance during the sealing the blades fall inside, mixing with the coolant.

The result of all these processes is that a variety of taxes are formed within the engine cooling system. They worsen thermal conductivity. In the worst case, blocks are formed in the pipes. This, in turn, leads to overheating.

Frequent problems of the system

Of course, liquid cooling systems have many advantages, in comparison with its nearest analogues. But even they sometimes fail. Most often in the design form is formed, which leads to a leakage of fluid and deterioration of the engine.

To flow in the engine cooling system may occur for such reasons:

1. Due to severe frosts, the liquid inside frozen, and the design was damaged.
2. Frequent cause Tech formations are leakage of hoses connections with nozzles.
3. High heaviness can also cause leakage.
4. Loss of elasticity as a result of high temperatures.
5. Mechanical damage.

It is the last reason that if you believe the statistics most often causes leaks in engine cooling systems. Most of all shots fall into the area of \u200b\u200bthe radiator. The stove is also quite often suffering.

Also in the engine cooling system often fails the thermostat. This is due to a constant contact with coolant. As a result, a corrosive layer is formed.

RESULTS

The engine cooling system may seem not particularly difficult. But for his creation, the years of experiments and thousands of unsuccessful attempts were needed. But now every car can work at the limit possible due to the high-quality heat removal from the motor.

Today from our permanent rubric " How it works»You will learn the device and the principle of work engine cooling systems, what do you need a thermostat and radiatorbut why not gained widespread aerial system cooling.

Cooling system Engine internal combustion carries out heat removal from engine parts and transfer it to environment. In addition to the main function, the system performs a number of secondary: oil cooling in the lubrication system; air heating in the heating and air conditioning system; Cooling of exhaust gases, etc.

When combustion of the working mixture, the temperature in the cylinder can reach 2500 ° C, while the operating temperature of the DVS is 80-90 ° C. It is for maintaining the optimal temperature mode that there is a cooling system that may be the following types, depending on the coolant: liquid, aerial and combined . It should be noted that liquid system in pure form is almost not usedsince it is not capable of supporting work for a long time modern engines in optimal thermal mode.

Combined engine cooling system:

In the combined cooling system as a coolant frequently used waterSince it has a high specific heat, availability and harmlessness for the body. However, water has a number of significant drawbacks: the formation of scale and freezing at negative temperatures. IN winter time The year in the cooling system it is necessary to pour low-chamber fluids - antifreeze (aqueous solutions of ethylene glycol, mixture of water with alcohol or with glycerin, with hydrocarbon additives, etc.).

The cooling system under consideration consists of: liquid pump, radiator, thermostat, expansion tank, Cylinder Cooling Shirts and Heads, Fan, Temperature Sensor and Sliding Hoses.

It is necessary that the engine cooling is forced, which means it is maintained overpressure (up to 100 kPa), as a result the boiling point of the coolant rises to 120 ° C.

When you start a cold engine, it is gradually heating. The first time coolant, under the action of a liquid pump, circulates in a small circle, That is, in the cavities between the walls of the cylinders and the engine walls (cooling shirt), without falling into the radiator. This restriction is necessary for the rapid administration of the engine into an efficient thermal mode. When the engine temperature exceeds the optimal values, the coolant begins to circulate through the radiator, where it is actively cooled (called large circulation circulation).

Device and principle of operation:

Liquid pump . Pump provides forced circulation Liquids in the engine cooling system. Most often apply paddle pumps of centrifugal type. The pump shaft 6 is mounted in the cover 4 using the bearing 5. At the end of the shaft, a cast iron impeller is pressed at the end of the shaft 1. When the pump shaft rotates, the cooling fluid through the nozzle 7 goes to the center of the impeller, captured by its blades, discarded to the pump body 2 under the action of centrifugal force and through The window 3 in the housing is sent to the engine cylinder cooling shirt.

RADIATOR Provides the heat of the cooling fluid heat into the environment. The radiator consists of upper and lower tanks and cores. It is fixed by car on rubber pillows with springs. The most common tubular and lamellar radiators. The first core is formed by several rows of brass tubes, passed through horizontal plates that increase the cooling surface and bringing rigidity to the radiator. The second core consists of one row of flat brass tubes, each of which is made of soldered among themselves along the edges of corrugated plates. The top tank has a bayful neck and a steam tube. The neck of the radiator is hermetically closed by a plug having two valves: steam to reduce pressure when the fluid is boiling, which opens with overpressure over 40 kPa (0.4 kgf / cm2), and air passing into the system with a decrease in pressure due to the cooling of the liquid and Protecting radiator tubes from flatness of atmospheric pressure. Used I. aluminum radiators: they are cheaperand easier but heat exchange properties and reliability below .

The cooling fluid "running" along the radiator tubes is cooled while moving by the oncoming air flow.

FAN strengthensair flow through the core of the radiator. The hub of the fan is fixed on the shaft of the liquid pump. They are brought together in rotation from pulley crankshaft belts. The fan is enclosed in the casing mounted on the radiator frame, which helps to increase the air flow rate passing through the radiator. Most often use four- and hexadener fans.

SENSOR The coolant temperatures refers to the control elements and is designed to establish the value of the controlled parameter and the material conversion to the electrical pulse. The electronic unit The control receives this pulse and sends certain signals to actuators. Using the coolant sensor, the computer determines the amount of fuel required for the normal operation of the DVS. Also, based on the readings of the coolant temperature sensor, the control unit generates a fan turning command.

Air cooling system:

In the air cooling system, the heat dissipation from the walls of the combustion chambers and the engine cylinders is carried out forced with a stream of air generated by a powerful fan. This cooling system is the simplestSince it does not require complex parts and control systems. Intensity air cooling The engines significantly depends on the organization of the direction of air flow and the location of the fan.

In row engines, the fans have a front, on the side or combine with the flywheel, and in V-shaped - usually in the collapse between the cylinders. Depending on the location of the fan, the cylinders are cooled with air, which is injected or amazed through the cooling system.

The optimal temperature mode of the air-cooled engine is considered to be such at which the oil temperature in the engine lubricant is 70 ... 110 ° C on all modes of engine operation. This is possible, provided that with the cooling air, it is dissipated into the environment to 35% of heat, which is released during the combustion of the fuel in the engine cylinders.

The air cooling system reduces the engine warming time, provides a stable heat removal from the walls of the combustion chambers and engine cylinders, is more reliable and easy to operate, easy to maintain, more technologically rear location engine, engine supercooling unlikely. However, the air cooling system increases dimensions Engine, creates increased noise When the engine is running, it is more complicated in production and requires the use of better fuel lubricants. Air heat capacity MalaThat does not allow evenly to divert a large amount of heat from the engine and, accordingly, create compact powerful power plants.

Cooling system

The cooling system is intendedto maintain normal thermal regime Engine.

When the engine is running, the temperature in the engine cylinders periodically rises above 2000 degrees, and the average temperature is 800-900 ° C!

If you do not distinguish heat from the engine, then after a few tens of seconds after the launch it will not be cold, but hopelessly hot. Next time you can run your cold Engine Only after it overhaul.

The cooling system is necessary for heat removal from the mechanisms and parts of the engine, but it is only half of its purpose, however, a large half.

To ensure a normal workflow, it is also important to accelerate the warm engine warming. And this is the second part of the cooling system.

As a rule, there is a liquid cooling system, a closed type, with forced fluid circulation and an expansion tank (Fig. 29).

The cooling system consists of:

shirts cooling block and head of the cylinder block,

centrifugal pump,

thermostat

radiator with an expansion tank,

fan,

connecting nozzles and hoses.

In fig. 29 You can easily distinguish two circle circulation of coolant.

Fig. 29. Engine cooling system scheme:1 - radiator; 2 - nozzle for circulating coolant; 3 - expansion tank; 4 - thermostat; 5 - water pump; 6 - shirt cooling block of cylinders; 7 - Block head cooling shirt; 8 - heater radiator with an electric fan; 9 - the heater radiator crane; 10 – cork for draining coolant from the block; 11 is a plug for draining coolant from the radiator; 12 - fan

The small circle of circulation (red arrows) is used for early warm-up warm engine. And when blue join the red arrows, the already heated liquid begins to circulate in a large circle, coolant in the radiator. Manages this process automatic device – thermostat.

To control the operation of the cooling system, on the instrument panel there is a coolant temperature pointer (see Fig. 67). The normal temperature of the coolant during engine operation should be within 80-90 ° C.

Engine cooling shirtit consists of a plurality of channels in the block and head of the cylinder block, which circulates the coolant.

Centrifugal type pumpmakes the liquid to move along the engine cooling shirt and the entire system. The pump is driven by the belt transmission from the pulley of the crankshaft of the engine. The belt tension is regulated by the deviation of the generator body (see Fig. 63 a) or tensioner roller Drive distribution Vala. Engine (see Fig. 11 b).

Thermostatdesigned to maintain a constant optimal thermal mode of the engine. When starting a cold engine, the thermostat is closed, and the entire liquid circulates only in a small circle (Fig. 29 A) for the early warm-up. When the temperature in the cooling system rises above 80-85 ° C, the thermostat automatically opens and part of the fluid enters the radiator for cooling. At high temperatures, the thermostat opens completely, and now the entire hot liquid is sent by a large circle for its active cooling.

Radiatorit serves to cool the fluid passing through it due to air flow, which is created when the vehicle is moving or using the fan. The radiator has many tubes and partitions that form a large surface area of \u200b\u200bthe cooling.

Expansion tankwe are necessary to compensate for changes in the volume and pressure of the coolant when it is heated and cooling.

Fanit is intended for a forced increase in air flow passing through a radiator of a moving car, as well as to create a stream of air in the case when the car costs without moving with the engine.

Two types of fans are used: permanently enabled, with a belt drive from a crankshaft pulley and an electric fan, which turns on automatically when the coolant temperature reaches approximately 100 ° C.

Pipes and hosesserve to connect cooling shirt with thermostat, pump, radiator and expansion tank.

The engine cooling system is also included salon heater.Hot cooling fluid passes through radiator heaterand heats the air supplied to the interior of the car.

Air temperature in the cabin is regulated by special cranewith which the driver increases or reduces the flow of fluid passing through the heater radiator.

Basic cooling system malfunctions

Bending coolantit may appear as a result of damage to the radiator, hoses, sealing gaskets and seals.

To eliminate the fault, you must tighten the hose mounting clamps and tubes, and damaged details Replace new ones. In case of damage to the radiator tubes, you can try to patch down holes and cracks, but, as a rule, everything ends with the replacement of the radiator.

Engine overheatingit occurs because of the insufficient level of coolant, weak tension of the fan belt, clogging of the radiator tubes, as well as when thermostat malfunction.

To eliminate the engine overheating, restore the fluid level in the cooling system, adjust the fan belt tension, rinse the radiator, replace the thermostat.

Often, the engine overheating also occurs with the serviceable elements of the cooling system, when the machine moves at low speed and large loads on the engine. This happens when driving in heavy road conditions, such as country roads and all boring city "traffic jams". In these cases, it is worth thinking about the engine of your car, and about yourself too, arranging periodic, at least short-term "respite."

Be careful behind the wheel and do not allow the emergency mode of operation of the engine! Remember that even one-time overheating of the engine disrupts the structure of the metal, while the life expectancy of the "heart" of the car is significantly reduced.

Operation of the cooling system

When operating a car, it should be periodically peeled under the hood. A timely noted malfunction in the cooling system will allow you to avoid engine overhaul.

If a cooling fluid level in the expansion tankit has dropped or the liquid is absent at all, then it is necessary to add it to the beginning, and then it should be sorted out (independently or with a specialist), where it is done.

In the process of operation of the engine, the liquid is heated to a temperature close to the boiling point. This means that the water, which is part of the coolant, will gradually evaporate.

If half a year daily exploitation The car level in the tank dropped a bit, then this is normal. But if yesterday was a complete tank, and today it is only on the bottom, then you need to look for a place of leakage of coolant.

The leakage of fluid from the system can be easily determined on dark spots on asphalt or snow after more or less long-lasting parking. Opening the hood, you can easily find a leakage place, comparing wet traces on the asphalt with the location of the cooling system elements under the hood.

The fluid level in the tank must be monitored at least once a week. If the level has decreased noticeably, then it is necessary to determine and eliminate the reason for its decline. In other words, the cooling system must be put in order, otherwise the engine can seriously "get sick" and demand "hospitalization".

Almost all domestic cars A special low-gas fluid with the title is used as a coolant Tosol A-40.Numeral 40 shows a negative temperature at which the liquid begins to freeze (crystallize). Under the conditions of the Far North applied Tosol A-65 , and accordingly, it starts to freeze at a temperature of minus 65 ° C.

Tosol is a mixture of water with ethylene glycol and additives. Such a solution combines a lot of advantages. First, it begins to freeze it only after the driver itself (joke), and secondly, Tosol has anti-corrosion, antitrusive properties and practically does not give deposits in the form of ordinary scale, since its composition includes clean distilled water . therefore you can only add distilled water into the cooling system.

When operating a car you need control not only the tension, but also the state of the water pump drive belt,since his opening on the road is always unpleasant. It is recommended to have a spare strap in the road set. If you don't, then someone from good people will help you change it.

Cooling fluid can boil and lead to engine breakdown in the event that failed fan electric drive sensor.If the electric fan has not received the command to turn on, the liquid continues to heat up, approaching the boiling point, without having a comprehensive assistance.

But at the driver before his eyes there is a device with an arrow and a red sector! Moreover, almost always when the fan is turned on, it feels small additional noise. There would be a desire to control, and the ways will always be found.

If on the way (and more often in the "plug") you noticed that the temperature of the coolant approaches the critical, and the fan works, then in this case there is a way out. It is necessary to include an additional radiator in the operation of the cooling system - the radiator of the cabin heater. Fully open the driver's crane, all turns include the heater fan, lower the glass of the doors and "pull" to the house or to the nearest car service. But at the same time, continue to closely monitor the engine temperature pointer. If she still goes into the red zone, stop immediately, open the hood and "cool".

Over time, can deliver trouble thermostat,if it stops letting the liquid in a large circle of circulation. Determine whether the thermostat works is not difficult. The radiator should not be heated (determined by hand) until the coolant temperature pointer arrow does not reach the middle position (the thermostat is closed). Later, the hot liquid will start entering the radiator, quickly heating it, which indicates the timely opening of the thermostat valve. If the radiator continues to remain cold, then there are two ways. Touch the body of the thermostat, maybe it will still open, or immediately, morally and financially, prepare for its replacement.

Immediately "give up" mechanics if on oil probe You will see the droplets of the liquid that fell from the cooling system into the lubrication system. It means that damaged cylinder head gasketand the coolant is seeping into the engine crankcase pallet. If you continue the operation of the engine with oil, half consisting of toosol, then wear engine parts acquires catastrophic speed.

Water pump bearingit does not break "suddenly." At first there will be a specific whistling sound from under the hood, and if the driver "thinks about the future", then the bearing will be replaced in a timely manner. Otherwise, it will still have to change it, but already with the consequence of finding the airport or on a business meeting, because of the "suddenly" broken car.

Each drivers should know and remember that on the hot engine, the cooling system is in a state of high pressure!

If the engine of your car overheated and "boiled", then, of course, it is necessary to stop and open the car hood, but you can not open a radiator cork or an expansion tank. To accelerate the engine cooling process, this will not give anything practically, and it is possible to get strongest burns.

Everyone knows than it turns around for a smartly dressed guests ineptly open bottle of champagne. Everything is much more serious in the car. If you quickly and mindlessly open the cork of the hot radiator, then the fountain will fly out from there, but no longer wines, and boiling toosol! In this case, not only the driver can suffer, but also the pedestrians. Therefore, if you ever have to open a radiator cork or an expansion tank, then it is pre-taking precautions and do it slowly.

The cooling system is a set of devices that provide forced adjustable removal and heat transfer from the engine parts into the environment.

The cooling system is designed to maintain the optimal temperature mode, which ensures maximum power, high efficiency and long time Engine services.

When combustion of the working mixture, the temperature in the engine cylinders rises to 2500 ° C and on average when the engine is running 800 ... 900 ° C. Therefore, the parts of the engine are very hot, and if they are not cooling, the engine power will be reduced, its economy, increase the wear of parts and can occur versions of the engine.

With excessive cooling, the engine also loses power, its economy deteriorates and wear out.

For forced and adjustable removal of heat in the engines of cars, two types of cooling systems () are used. The cooling system type is determined by the coolant (working substance) used to cool the engine.

Picture 1 - Types of cooling systems

Application in engines of various cooling systems depends on the type and purpose of the engine, its power and class of the car.

Liquid cooling system

IN liquid cooling system Special cooling fluids are used - antifreeze different markshaving a thickening temperature - 40 ° C and below. Antifreeze contain anti-corrosion and anti-speaking additives, excluding scale formation. They are very poisonous and demand cautious. Compared to water, antifreeze has a smaller heat capacity and therefore remove heat from the walls of the engine cylinders is less intensively.

So, when cooling with antifreeze, the temperature of the walls of cylinders by 15 ... 20 ° C is higher than when cooling with water. It accelerates the engine heating and reduces the wear of the cylinders, but in the summer it can lead to engine overheating.

The optimal temperature mode of the engine with a liquid cooling system is considered to be such at which the temperature of the coolant in the engine is 80 ... 100 ° C on all modes of engine operation.

This is possible, provided that the coolant is carried out into the environment 25 ... 35% of the heat released during the combustion of the fuel in the engine cylinders. At the same time, in gasoline engines, the value of the heat removed is greater than in diesels.

Engine cooling system consists From the cooling shirt head and block of cylinders, radiator, pump, thermostat, fan, expansion tank, connecting pipelines and drain crants. In addition, the cooling system includes a car body salon.

System work

Figure 3. - Engine cooling system

1, 2, 3, 5, 15, 18 - hoses; 4 - nozzle; 6 - tank; 7, 9 - plugs; 8 - cooling shirt; 10 - radiator; 11 - casing; 12 - fan; 13, 14 - pulleys; 16 - belt; 17 - pump; 19 - Thermostat

For impact engine The main valve of the thermostat 19 () is closed, and the coolant does not pass through the radiator 10. In this case, the liquid is injected with a pump 17 in the cooling shirt 8 and the engine cylinder head. From the head of the cylinder block through the hose 3, the liquid enters the additional thermostat valve and gets again to the pump. Due to the circulation of this part of the fluid, the engine is quickly heated. At the same time, a smaller part of the fluid comes from the head of the cylinder block into the heater (shirt) of the engine inlet pipeline, and with an open crane - to the heater of the car body salon.

For heated engine An additional thermostat valve is closed, and the main valve is open. In this case, most of the liquid from the cylinder head falls into the radiator, cooled in it and through the open main valve of the thermostat enters the pump. A smaller part of the fluid, as well as an impenetrable engine, circulates through the engine inlet pipe and the heater of the body's cabin. In some temperature range, the main and additional thermostat valves are open at the same time, and the coolant circulates in this case by two directions ( circles circulation).

The number of circulating fluid in each circle depends on the degree of opening the thermostat valves, which automatically maintains the optimal temperature mode of the engine. The expansion tank 6 filled with coolant is reported to the atmosphere through the rubber valve installed in the 7 tank stopper. The tank is connected by a hose with a bulk neck of the radiator, which has a plug 9 with valves. The tank compensates for changes in the coolant volume, and the system maintains a constant volume of circulating fluid.

To drain the coolant from the cooling system there are two drain holes With threaded plugs, one of which is located in the lower tank of the radiator, and the other in the engine cylinder block. The fluid temperature in the system is controlled by a pointer, the sensor of which is installed in the engine of the engine cylinder block.

The liquid pump provides forced fluid circulation in the engine cooling system. On the engines of cars apply paddle pumps of centrifugal type ().

Figure 4. - Liquid pump (a) and fan (b) engine

1 - impeller; 2 - body; 3 - window; 4 - lid; 5 - Bearing; 6 - shaft; 7 - hub; 8 - screw; 9 - sealing device; 10 - nozzle; 11, 13,14 - pulleys; 12 - belt; 15 - fan; 16 - lining; 17 - Bolt.

The pump shaft 6 is mounted in an aluminum alloy with a lid 4 in a double-row unintellular bearing 5. The bearing is placed and fixed in the cover of the locking screw 8. At one end of the shaft, the cast iron impeller 1, and on the other end - the hub 7 and pullee 11 fan 15 is press. When the pump shaft rotates, the coolant through the nozzle 10 goes to the center of the impeller, is captured by its blades, discarded to the pump body 2 under the action of centrifugal force and through the window 3 in the housing is sent to the engine cylinder cooling shirt. The sealing device 9, consisting of a self-sufficient cuff and a graphota componence ring, mounted on the pump shaft, eliminates the injection of the fluid into the shaft bearing.

Drive and fan drive is carried out wedge belt 12 from pulley 13, which is installed at the front end of the crankshaft engine. Using this belt also rotates 14 generator pulley. Normal work The pump and fan ensures the correct belt tension.

The belt tension is adjusted by moving the generator away from the engine (shown on the arrow). The pump is housing 2, cast from the aluminum alloy, is attached to the flange of the cylinder block in the front of the engine.

Liquid pump drive from a toothed belt

Consider the pump device whose drive is carried out with a gear strap ().

Figure 5. - Liquid engine pump

1 - pulley; 2 - screw; 3 - Bearing; 4 - shaft; 5 - case; 6 - sealing device; 7 - hole; 8 - impeller

The pump shaft 4 is installed in the housing 5 of the aluminum alloy in an unintended double-row ball bearing 3. The bearing will stop in the housing of the screw 2 and is compacted by a special device 6, which includes a graphota component ring and cuff. At the front end of the shaft pressed toothed pulley 1 from the sintered material, and at the rear end - the impeller 8. Two are made in the impeller through holes 7, which connects the coolant cavities among themselves, located on both sides of the impeller. Thanks to these holes, the cooling fluid pressure on the impeller on both sides, which eliminates axial loads On the pump shaft when it works.

The pump shaft is driven by rotation through the pulley 1 with a gearbelt of the camshaft drive from the crankshaft. When the shaft rotates, the fluid enters the center of the impeller and under the action of centrifugal force is sent to the engine cooling shirt. The pump is attached to the housing to the engine cylinder block through the sealing gasket.

It helps to accelerate the engine warming up and adjusts under certain limits the amount of coolant passing through the radiator. The thermostat is an automatic valve. In engine engines, unsubscribed two-flaped thermostats with solid filler are used.

Figure 6.

1, 6, 11 - nozzles; 2, 8 - valves; 3, 7 - springs; 4 - cylinder; 5 - diaphragm; 9 - rod; 10 - filler

) It has two inlet nozzles 1 and 11, the outlet nozzle 6, two valves (main 8, optional 2) and a sensitive element. The thermostat is mounted before entering the coolant pump and is connected to it through the nozzle 6. Through the nozzle 1, the thermostat is connected to the head of the engine cylinder block, and through the nozzle 11 with the lower tank of the radiator.

The sensitive element of the thermostat consists of a cylinder 4, rubber diaphragm of 5 and stock 9. Inside the cylinder between its wall and rubber diaphragm there is a solid filler 10 (fine-crystalline wax) with a high volume extension coefficient.

The main valve 8 of the thermostat with spring 7 begins to open at a coolant temperature of more than 80 ° C. At a temperature of less than 80 ° C, the main valve closes the yield of the fluid from the radiator, and it comes from the engine to the pump, passing through the opening additional valve 2 of the thermostat with spring 3.

As an increase in the temperature of the coolant more than 80 ° C in the sensitive element, a solid filler melts, and its volume increases. As a result, the rod 9 comes out of the cylinder 4, and the balloon moves up. An additional valve 2 begins to close and at a temperature of more than 94 ° C overlaps the coolant pass from the engine to the pump. The main valve 8 in this case opens completely, and the coolant circulates through the radiator.

Expansion tank

Expansion tank It serves to compensate for changes in the volume of coolant during fluctuations of its temperature and to control the amount of fluid in the cooling system. It also contains some coolant reserve on its natural loss and possible losses.

Translucent plastic tanks with a filling neck closed with plastic plug are used on cars. Through the neck, the system is filled with the coolant, and through the valves placed in the plug, the internal cavity of the tank and the cooling system with the atmosphere. In the plug of expansion tanks, there is often one rubber valve, triggered at a pressure close to the atmospheric. When draining the coolant from the system, the plug is removed from the expansion tank. The expansion tank is placed in open space Engine separation, where attached to the car body.

Car radiators

Radiator Provides the heat of the cooling fluid heat into the environment. On the passenger cars Tubular plate radiators are used.

Figure 7. - Inspection radiator (a) and casing (b) engine fan

1 - cork; 2 - neck; 3, 4 - tanks; 5 - core; 6 - nozzle; 7, 8 - valves; 9 - casing; 10 - Seal

On some engines () an electric fan is applied. It consists of an electric motor 6 and a fan 5. The fan is four-bladed, attached to the motor shaft. The blades on the hub of the fan are located unevenly and at an angle to the plane of its rotation. This increases the flow of the fan and reduces the noise of its operation. For more efficient operation, the electric fan is placed in a casing 7, which is attached to the radiator. Electristant attached to the casing on three rubber bushings. The electric fan is turned on and off automatically sensor 3, depending on the coolant temperature.

In the car is designed to protect the worker unit from overheating and thereby controls the performance of everything motor block. Cooling is an essential function in the operation of the internal combustion engine.

Consequences of malfunction cooling in DVS May 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 piston groupWhat 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. Working fuel mixture It is partially condensed, thereby making the lubricant cylinder walls. 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 air cooling with air masses is the most the simplest way Heat removal. 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 constructive features, low weight, absence of refrigerant feed and circulation nodes. 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 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 elements as for gasoline engineAnd 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 to ensure that the motor unit is faster to warm up to operating temperature. After that, the thermostat opens big circle Engine cooling systems.

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 fluid deficiency in the system, unstable work Pump or fan. Also incorrect operation of the thermostat when he must open a large cooling circle.

May be caused by strong pollution of the radiator, lining the highways, bad work Radiator covers, expansion tank or poor quality antifreeze.